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Laufer MK, Mungwira RG, Divala TH. Malaria prevention: advancing clinical trials to policy. Lancet Infect Dis 2024; 24:439-440. [PMID: 38224707 PMCID: PMC11058061 DOI: 10.1016/s1473-3099(23)00808-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Accepted: 12/14/2023] [Indexed: 01/17/2024]
Affiliation(s)
- Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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Portillo S, Oshinsky J, Williams M, Yoder S, Liang Y, Campbell JD, Laufer MK, Neuzil KM, Edwards KM, Pasetti MF. Quantitative analysis of pertussis, tetanus, and diphtheria antibodies in sera and breast milk from Tdap vaccinated women using a qualified multiplex assay. mSphere 2024; 9:e0052723. [PMID: 38497618 PMCID: PMC11036809 DOI: 10.1128/msphere.00527-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 02/15/2024] [Indexed: 03/19/2024] Open
Abstract
Pertussis (whooping cough) is a reemergent, highly contagious respiratory infection of public health concern. Infants prior to initiation of their primary vaccination series are the most vulnerable to severe infection, and even death. Vaccination during pregnancy is an efficacious means of reducing infection in infants. This approach relies on boosting maternal immunity and passive transfer of antibodies to the infant via placenta and breast milk. Similarly, maternal vaccination post-partum can enhance maternal-infant immunity. To support the analysis of pertussis immunity in the context of maternal-infant immunization, we developed a high throughput multiplex assay for simultaneous quantification of serum IgG antibodies against pertussis vaccine antigens: pertussis toxin (PT), filamentous hemagglutinin (FHA), pertactin (PRN), and fimbriae (FIM2/3), and against tetanus (TT) and diphtheria toxoids (DT), using the Meso Scale Discovery (MSD) platform. The assay was qualified, and specificity, sensitivity, accuracy, precision, linearity, and robustness were demonstrated. The assay was subsequently adapted for quantification of IgG and IgA in breast milk. Applied to a serological survey of pregnant women living in the United States and sub-Saharan Africa, this method revealed differences in magnitude and breadth of antibody profile, consistent with history of vaccination. A longitudinal analysis of Tdap responses in women vaccinated post-partum demonstrated a rapid increase in serum IgG that remained elevated for up to 24 months. Likewise, high levels of vaccine-specific IgA and IgG antibodies were present in breast milk, although they exhibited faster decay. This multiplex MSD assay is a reliable and practical tool for quantification of pertussis, tetanus, and diphtheria antibodies in serum and breast milk in serosurveys or vaccine studies. IMPORTANCE Pertussis (whooping cough) has reemerged in recent years. Vaccination during pregnancy is an effective approach to prevent illness during the first months of life. We developed a multiplex assay for quantification of pertussis, tetanus, and diphtheria serum antibodies using the Meso Scale Discovery (MSD) platform; the method was qualified, and specificity, precision, accuracy, linearity, and limits of quantification were defined. It was also adapted for quantification of antibodies in breast milk. We successfully determined serostatus in women from different regions and with different vaccination histories, as well as responses to Tdap in blood and breast milk post-partum. This is the first description of a multiplex assay for the quantification of pertussis, tetanus, and diphtheria antibodies in breast milk.
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Affiliation(s)
- Susana Portillo
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Jennifer Oshinsky
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Margaret Williams
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Sandra Yoder
- Division of Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Yuanyuan Liang
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - James D. Campbell
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Miriam K. Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Kathleen M. Neuzil
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Kathryn M. Edwards
- Division of Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Marcela F. Pasetti
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Vareta J, Horstman NA, Adams M, Seydel KB, McCann RS, Cohee LM, Laufer MK, Takala-Harrison S. Genotyping Plasmodium falciparum gametocytes using amplicon deep sequencing. Malar J 2024; 23:96. [PMID: 38582837 PMCID: PMC10999092 DOI: 10.1186/s12936-024-04920-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 03/27/2024] [Indexed: 04/08/2024] Open
Abstract
BACKGROUND Understanding the dynamics of gametocyte production in polyclonal Plasmodium falciparum infections requires a genotyping method that detects distinct gametocyte clones and estimates their relative frequencies. Here, a marker was identified and evaluated to genotype P. falciparum mature gametocytes using amplicon deep sequencing. METHODS A data set of polymorphic regions of the P. falciparum genome was mined to identify a gametocyte genotyping marker. To assess marker resolution, the number of unique haplotypes in the marker region was estimated from 95 Malawian P. falciparum whole genome sequences. Specificity of the marker for detection of mature gametocytes was evaluated using reverse transcription-polymerase chain reaction of RNA extracted from NF54 mature gametocytes and rings from a non-gametocyte-producing strain of P. falciparum. Amplicon deep sequencing was performed on experimental mixtures of mature gametocytes from two distinct parasite clones, as well as gametocyte-positive P. falciparum field isolates to evaluate the quantitative ability and determine the limit of detection of the genotyping approach. RESULTS A 400 bp region of the pfs230 gene was identified as a gametocyte genotyping marker. A larger number of unique haplotypes was observed at the pfs230 marker (34) compared to the sera-2 (18) and ama-1 (14) markers in field isolates from Malawi. RNA and DNA genotyping accurately estimated gametocyte and total parasite clone frequencies when evaluating agreement between expected and observed haplotype frequencies in gametocyte mixtures, with concordance correlation coefficients of 0.97 [95% CI: 0.92-0.99] and 0.92 [95% CI: 0.83-0.97], respectively. The detection limit of the genotyping method for male gametocytes was 0.41 pfmget transcripts/µl [95% CI: 0.28-0.72] and for female gametocytes was 1.98 ccp4 transcripts/µl [95% CI: 1.35-3.68]. CONCLUSIONS A region of the pfs230 gene was identified as a marker to genotype P. falciparum gametocytes. Amplicon deep sequencing of this marker can be used to estimate the number and relative frequency of parasite clones among mature gametocytes within P. falciparum infections. This gametocyte genotyping marker will be an important tool for studies aimed at understanding dynamics of gametocyte production in polyclonal P. falciparum infections.
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Affiliation(s)
- Jimmy Vareta
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Natalie A Horstman
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Matthew Adams
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Karl B Seydel
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
- College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA
| | - Robert S McCann
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Lauren M Cohee
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Shannon Takala-Harrison
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.
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Littmann J, Achu D, Laufer MK, Karema C, Schellenberg D. Making the most of malaria chemoprevention. Malar J 2024; 23:51. [PMID: 38369497 PMCID: PMC10875741 DOI: 10.1186/s12936-024-04867-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 01/30/2024] [Indexed: 02/20/2024] Open
Abstract
Against a backdrop of stalled progress in malaria control, it is surprising that the various forms of malaria chemoprevention are not more widely used. The World Health Organization (WHO) has recommended several malaria chemoprevention strategies, some of them for over a decade, and each with documented efficacy and cost effectiveness. In 2022, the WHO updated and augmented its malaria chemoprevention guidelines to facilitate their wider use. This paper considers new insights into the empirical evidence that supports the broader application of chemoprevention and encourages its application as a default strategy for young children living in moderate to high transmission settings given their high risk of severe disease and death. Chemoprevention is an effective medium-term strategy with potential benefits far outweighing costs. There is a strong argument for urgently increasing malaria chemoprevention in endemic countries.
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Affiliation(s)
- Jasper Littmann
- Bergen Centre for Ethics and Priority Setting-BCEPS, Department of Global Public Health and Primary Care, Faculty of Medicine, University of Bergen, Bergen, Norway.
- Division for Infection Control, The Norwegian Institute for Public Health, Oslo, Norway.
| | - Dorothy Achu
- World Health Organization, Regional Office for Africa, Brazzaville, Republic of Congo
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | | | - David Schellenberg
- Faculty of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, London, UK
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Mkandawire FA, Buchwald A, Nampota-Nkomba N, Nyirenda OM, Zuze K, Kuria S, Cairo C, Laufer MK. Prevalence and risk factors of detectable HIV viral load among pregnant women with HIV infection seeking antenatal care in Southern Malawi. AIDS Care 2024:1-8. [PMID: 38184889 DOI: 10.1080/09540121.2023.2298792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 12/18/2023] [Indexed: 01/09/2024]
Abstract
We evaluated detectable viral load (VL) in pregnant women established on antiretroviral therapy (ART) for at least 6 months before conception and those self-reported as ART naïve at first antenatal care (ANC) at two government clinics in Southern Malawi. We used logistic regression to identify the predictors of detectable viral load (VL), defined as any measure greater than 400 copies/ml. Of 816 women, 67.9% were established on ART and 32.1% self-reported as ART naïve. Among women established on ART, 10.8% had detectable VL and 9.9% had VL >1000 copies/ml (WHO criteria for virological failure). In adjusted analysis, among women established on ART, virological failure was associated with younger age (p = .02), "being single/widowed" (p = 0.001) and no previous deliveries (p = .05). One fifth of women who reported to be ART-naive were found to have an undetectable VL at first ANC. None of the demographic factors could significantly differentiate those with high versus low VL in the ART-naïve sub-sample. In this cohort, approximately 90% of women who had initiated ART prior to conception had an undetectable VL at first ANC. This demonstrates good success of the ART program but identifies high risk populations that require additional support.
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Affiliation(s)
- Felix A Mkandawire
- Blantyre Malaria Project, Kamuzu University of Health Sciences, College of Medicine, Blantyre, Malawi
- Amref International University, Nairobi, Kenya
| | - Andrea Buchwald
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Nginache Nampota-Nkomba
- Blantyre Malaria Project, Kamuzu University of Health Sciences, College of Medicine, Blantyre, Malawi
| | - Osward M Nyirenda
- Blantyre Malaria Project, Kamuzu University of Health Sciences, College of Medicine, Blantyre, Malawi
| | - Kingsley Zuze
- Blantyre Malaria Project, Kamuzu University of Health Sciences, College of Medicine, Blantyre, Malawi
| | | | - Cristiana Cairo
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
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Hsu H, Zanettini C, Coker M, Boudova S, Rach D, Mvula G, Divala TH, Mungwira RG, Boldrin F, Degiacomi G, Mazzabò LC, Manganelli R, Laufer MK, Zhang Y, Marchionni L, Cairo C. Concomitant assessment of PD-1 and CD56 expression identifies subsets of resting cord blood Vδ2 T cells with disparate cytotoxic potential. Cell Immunol 2024; 395-396:104797. [PMID: 38157646 DOI: 10.1016/j.cellimm.2023.104797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/17/2023] [Accepted: 12/22/2023] [Indexed: 01/03/2024]
Abstract
Vγ9Vδ2 T lymphocytes are programmed for broad antimicrobial responses with rapid production of Th1 cytokines even before birth, and thus thought to play key roles against pathogens in infants. The process regulating Vδ2 cell acquisition of cytotoxic potential shortly after birth remains understudied. We observed that perforin production in cord blood Vδ2 cells correlates with phenotypes defined by the concomitant assessment of PD-1 and CD56. Bulk RNA sequencing of sorted Vδ2 cell fractions indicated that transcripts related to cytotoxic activity and NK function are enriched in the subset with the highest proportion of perforin+ cells. Among differentially expressed transcripts, IRF8, previously linked to CD8 T cell effector differentiation and NK maturation, has the potential to mediate Vδ2 cell differentiation towards cytotoxic effectors. Our current and past results support the hypothesis that distinct mechanisms regulate Vδ2 cell cytotoxic function before and after birth, possibly linked to different levels of microbial exposure.
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Affiliation(s)
- Haoting Hsu
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Claudio Zanettini
- Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY, United States
| | - Modupe Coker
- Department of Oral Biology, Rutgers School of Dental Medicine, Rutgers State University of New Jersey, Newark, NJ, United States
| | - Sarah Boudova
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - David Rach
- Molecular Microbiology and Immunology Graduate Program, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Godfrey Mvula
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Titus H Divala
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Randy G Mungwira
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Francesca Boldrin
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | - Giulia Degiacomi
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | | | | | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Yuji Zhang
- Division of Biostatistics and Bioinformatics, Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD, United States; University of Maryland Marlene and Stewart Greenbaum Comprehensive Cancer Center, Baltimore, MD, United States
| | - Luigi Marchionni
- Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY, United States
| | - Cristiana Cairo
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, United States.
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Andronescu LR, Buchwald AG, Sharma A, Bauleni A, Mawindo P, Liang Y, Gutman JR, Mathanga DP, Chinkhumba J, Laufer MK. Plasmodium falciparum infection and disease in infancy associated with increased risk of malaria and anaemia in childhood. Malar J 2023; 22:217. [PMID: 37496052 PMCID: PMC10369742 DOI: 10.1186/s12936-023-04646-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 07/11/2023] [Indexed: 07/28/2023] Open
Abstract
BACKGROUND Infants under 6 months of age are often excluded from malaria surveillance and observational studies. The impact of malaria during early infancy on health later in childhood remains unknown. METHODS Infants from two birth cohorts in Malawi were monitored at quarterly intervals and whenever they were ill from birth through 24 months for Plasmodium falciparum infections and clinical malaria. Poisson regression and linear mixed effects models measured the effect of exposure to malaria in infancy on subsequent malaria incidence, weight-for-age z-scores (WAZ), and haemoglobin concentrations after 6 months. RESULTS Infants with at least one P. falciparum infection during their first 6 months had increased incidence ratio (IRR) of P. falciparum infection (IRR = 1.27, 95% CI, 1.06-1.52) and clinical malaria (IRR = 2.37, 95% CI, 2.02-2.80) compared to infants without infection. Infants with clinical malaria had increased risk of P. falciparum infection incidence between 6 and 24 months (IRR = 1.64, 95% CI, 1.38-1.94) and clinical malaria (IRR = 1.85, 95% CI, 1.48-2.32). Exposure to malaria was associated with lower WAZ over time (p = 0.02) and lower haemoglobin levels than unexposed infants at every time interval (p = 0.02). CONCLUSIONS Infants experiencing malaria infection or clinical malaria are at increased risk of subsequent infection and disease, have poorer growth, and lower haemoglobin concentrations.
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Affiliation(s)
- Liana R Andronescu
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, 21201, USA
| | - Andrea G Buchwald
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, 21201, USA
| | - Ankur Sharma
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, 21201, USA
| | - Andy Bauleni
- Malaria Alert Center, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Patricia Mawindo
- Malaria Alert Center, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Yuanyuan Liang
- Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, 21201, USA
| | - Julie R Gutman
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, 30333, USA
| | - Don P Mathanga
- Malaria Alert Center, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Jobiba Chinkhumba
- Malaria Alert Center, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, 21201, USA.
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Mbewe RB, Keven JB, Mangani C, Wilson ML, Mzilahowa T, Mathanga DP, Valim C, Laufer MK, Walker ED, Cohee LM. Genotyping of Anopheles mosquito blood meals reveals nonrandom human host selection: implications for human-to-mosquito Plasmodium falciparum transmission. Malar J 2023; 22:115. [PMID: 37029433 PMCID: PMC10080529 DOI: 10.1186/s12936-023-04541-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 03/22/2023] [Indexed: 04/09/2023] Open
Abstract
BACKGROUND Control of malaria parasite transmission can be enhanced by understanding which human demographic groups serve as the infectious reservoirs. Because vector biting can be heterogeneous, some infected individuals may contribute more to human-to-mosquito transmission than others. Infection prevalence peaks in school-age children, but it is not known how often they are fed upon. Genotypic profiling of human blood permits identification of individual humans who were bitten. The present investigation used this method to estimate which human demographic groups were most responsible for transmitting malaria parasites to Anopheles mosquitoes. It was hypothesized that school-age children contribute more than other demographic groups to human-to-mosquito malaria transmission. METHODS In a region of moderate-to-high malaria incidence in southeastern Malawi, randomly selected households were surveyed to collect human demographic information and blood samples. Blood-fed, female Anopheles mosquitoes were sampled indoors from the same houses. Genomic DNA from human blood samples and mosquito blood meals of human origin was genotyped using 24 microsatellite loci. The resultant genotypes were matched to identify which individual humans were sources of blood meals. In addition, Plasmodium falciparum DNA in mosquito abdomens was detected with polymerase chain reaction. The combined results were used to identify which humans were most frequently bitten, and the P. falciparum infection prevalence in mosquitoes that resulted from these blood meals. RESULTS Anopheles females selected human hosts non-randomly and fed on more than one human in 9% of the blood meals. Few humans contributed most of the blood meals to the Anopheles vector population. Children ≤ 5 years old were under-represented in mosquito blood meals while older males (31-75 years old) were over-represented. However, the largest number of malaria-infected blood meals was from school age children (6-15 years old). CONCLUSIONS The results support the hypothesis that humans aged 6-15 years are the most important demographic group contributing to the transmission of P. falciparum to the Anopheles mosquito vectors. This conclusion suggests that malaria control and prevention programmes should enhance efforts targeting school-age children and males.
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Affiliation(s)
- Rex B Mbewe
- Department of Entomology, Michigan State University, East Lansing, MI, USA.
- Department of Physics and Biochemical Sciences, Malawi University of Business and Applied Sciences, Blantyre, Malawi.
| | - John B Keven
- Department of Entomology, Michigan State University, East Lansing, MI, USA
- Department of Public Health, College of Health Sciences, University of California-Irvine, Irvine, CA, USA
| | - Charles Mangani
- Malaria Alert Center, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Mark L Wilson
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Themba Mzilahowa
- Malaria Alert Center, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Don P Mathanga
- Malaria Alert Center, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Clarissa Valim
- Department of Global Health, Boston University School of Public Health, Boston, MA, USA
| | - Miriam K Laufer
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Edward D Walker
- Department of Entomology, Michigan State University, East Lansing, MI, USA
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - Lauren M Cohee
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
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Nyangulu W, Mungwira RG, Divala TH, Nampota-Nkomba N, Nyirenda OM, Buchwald AG, Miller J, Earland DE, Adams M, Plowe CV, Taylor TE, Mallewa JE, van Oosterhout JJ, Parikh S, Laurens MB, Laufer MK. Artemether-lumefantrine efficacy among adults on antiretroviral therapy in Malawi. Malar J 2023; 22:32. [PMID: 36707795 PMCID: PMC9881508 DOI: 10.1186/s12936-023-04466-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 01/20/2023] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND When people with human immunodeficiency virus (HIV) infection (PWH) develop malaria, they are at risk of poor anti-malarial treatment efficacy resulting from impairment in the immune response and/or drug-drug interactions that alter anti-malarial metabolism. The therapeutic efficacy of artemether-lumefantrine was evaluated in a cohort of PWH on antiretroviral therapy (ART) and included measurement of day 7 lumefantrine levels in a subset to evaluate for associations between lumefantrine exposure and treatment response. METHODS Adults living with HIV (≥ 18 years), on ART for ≥ 6 months with undetectable HIV RNA viral load and CD4 count ≥ 250/mm3 were randomized to daily trimethoprim-sulfamethoxazole (TS), weekly chloroquine (CQ) or no prophylaxis. After diagnosis of uncomplicated Plasmodium falciparum malaria, a therapeutic efficacy monitoring was conducted with PCR-correction according to WHO guidelines. The plasma lumefantrine levels on day 7 in 100 episodes of uncomplicated malaria was measured. A frailty proportional hazards model with random effects models to account for clustering examined the relationship between participant characteristics and malaria treatment failure within 28 days. Pearson's Chi-squared test was used to compare lumefantrine concentrations among patients with treatment failure and adequate clinical and parasitological response (ACPR). RESULTS 411 malaria episodes were observed among 186 participants over 5 years. The unadjusted ACPR rate was 81% (95% CI 77-86). However, after PCR correction to exclude new infections, ACPR rate was 94% (95% CI 92-97). Increasing age and living in Ndirande were associated with decreased hazard of treatment failure. In this population of adults with HIV on ART, 54% (51/94) had levels below a previously defined optimal day 7 lumefantrine level of 200 ng/ml. This occurred more commonly among participants who were receiving an efavirenz-based ART compared to other ART regimens (OR 5.09 [95% CI 1.52-7.9]). Participants who experienced treatment failure had lower day 7 median lumefantrine levels (91 ng/ml [95% CI 48-231]) than participants who experienced ACPR (190 ng/ml [95% CI 101-378], p-value < 0.008). CONCLUSION Recurrent malaria infections are frequent in this population of PWH on ART. The PCR-adjusted efficacy of AL meets the WHO criteria for acceptable treatment efficacy. Nevertheless, lumefantrine levels tend to be low in this population, particularly in those on efavirenz-based regimens, with lower concentrations associated with more frequent malaria infections following treatment. These results highlight the importance of understanding drug-drug interactions when diseases commonly co-occur.
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Affiliation(s)
- Wongani Nyangulu
- Dignitas International, Zomba, Malawi
- Public Health and Nutrition Research Group, Kamuzu University of Health Sciences, Mangochi, Malawi
| | - Randy G Mungwira
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | | | | | - Osward M Nyirenda
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Andrea G Buchwald
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St., Baltimore, MD, 21201, USA
| | - Jernelle Miller
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St., Baltimore, MD, 21201, USA
| | - Dominique E Earland
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St., Baltimore, MD, 21201, USA
| | - Matthew Adams
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St., Baltimore, MD, 21201, USA
| | - Christopher V Plowe
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St., Baltimore, MD, 21201, USA
| | - Terrie E Taylor
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
- Michigan State University, East Lansing, USA
| | - Jane E Mallewa
- Department of Medicine, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Joep J van Oosterhout
- Dignitas International, Zomba, Malawi
- Partners in Hope, Lilongwe Malawi and David Geffen School of Medicine, University of California, Los Angeles, USA
| | | | - Matthew B Laurens
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St., Baltimore, MD, 21201, USA
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St., Baltimore, MD, 21201, USA.
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10
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Buchwald AG, Boudova S, Peterson I, Divala T, Mungwira R, Mawindo P, Gladstone M, Cairo C, Laufer MK. The Association among Malaria in Pregnancy, Neonatal inflammation, and Neurocognitive Development in a Cohort of Malawian Infants. Am J Trop Med Hyg 2022; 107:1036-1040. [PMID: 36252805 PMCID: PMC9709022 DOI: 10.4269/ajtmh.22-0409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 07/27/2022] [Indexed: 11/07/2022] Open
Abstract
Malaria in pregnancy (MIP) causes poor birth outcomes, but its impact on neurocognitive development has not been well characterized. Between 2012 and 2014, we enrolled 307 mother-infant pairs and monitored 286 infants for neurocognitive development using the Malawi Developmental Assessment Tool at 6, 12, and 24 months of age. MIP was diagnosed from peripheral blood and placental specimens. Cord blood cytokine levels were assessed for a subset of neonates. Predictors of neurodevelopment were examined using mixed-effect logistic regression for developmental delay. Among the participants, 78 mothers (25.4%) had MIP, and 45 infants (15.7%) experienced severe neurocognitive delay. MIP was not associated with differences in cord blood cytokine levels or neurocognitive development. Preterm birth, low birthweight, increasing maternal education level, and increasing interleukin 6 levels were associated significantly with delay. The results highlight the prevalence of severe delay and a need for broad access to early childhood support in this setting.
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Affiliation(s)
- Andrea G. Buchwald
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Sarah Boudova
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Ingrid Peterson
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Titus Divala
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Randy Mungwira
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Patricia Mawindo
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Melissa Gladstone
- Institute of Translational Research, University of Liverpool, Liverpool, United Kingdom
| | - Cristiana Cairo
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Miriam K. Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
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11
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Ndungo E, Holm JB, Gama S, Buchwald AG, Tennant SM, Laufer MK, Pasetti MF, Rasko DA. Dynamics of the Gut Microbiome in Shigella-Infected Children during the First Two Years of Life. mSystems 2022; 7:e0044222. [PMID: 36121169 PMCID: PMC9600951 DOI: 10.1128/msystems.00442-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 08/23/2022] [Indexed: 02/02/2023] Open
Abstract
Shigella continues to be a major contributor to diarrheal illness and dysentery in children younger than 5 years of age in low- and middle-income countries. Strategies for the prevention of shigellosis have focused on enhancing adaptive immunity. The interaction between Shigella and intrinsic host factors, such as the microbiome, remains unknown. We hypothesized that Shigella infection would impact the developing microbial community in infancy and, conversely, that changes in the gastrointestinal microbiome may predispose infections. To test this hypothesis, we characterized the gastrointestinal microbiota in a longitudinal birth cohort from Malawi that was monitored for Shigella infection using 16S rRNA amplicon sequencing. Children with at least one Shigella quantitative polymerase chain reaction (qPCR) positive sample during the first 2 years of life (cases) were compared to uninfected controls that were matched for sex and age. Overall, the microbial species diversity, as measured by the Shannon diversity index, increased over time, regardless of case status. At early time points, the microbial community was dominated by Bifidobacterium longum and Escherichia/Shigella. A greater abundance of Prevotella 9 and Bifidobacterium kashiwanohense was observed at 2 years of age. While no single species was associated with susceptibility to Shigella infection, significant increases in Lachnospiraceae NK4A136 and Fusicatenibacter saccharivorans were observed following Shigella infection. Both taxa are in the family Lachnospiraceae, which are known short-chain fatty acid producers that may improve gut health. Our findings identified temporal changes in the gastrointestinal microbiota associated with Shigella infection in Malawian children and highlight the need to further elucidate the microbial communities associated with disease susceptibility and resolution. IMPORTANCE Shigella causes more than 180 million cases of diarrhea globally, mostly in children living in poor regions. Infection can lead to severe health impairments that reduce quality of life. There is increasing evidence that disruptions in the gut microbiome early in life can influence susceptibility to illnesses. A delayed or impaired reconstitution of the microbiota following infection can further impact overall health. Aiming to improve our understanding of the interaction between Shigella and the developing infant microbiome, we investigated changes in the gut microbiome of Shigella-infected and uninfected children over the course of their first 2 years of life. We identified species that may be involved in recovery from Shigella infection and in driving the microbiota back to homeostasis. These findings support future studies into the elucidation of the interaction between the microbiota and enteric pathogens in young children and into the identification of potential targets for prevention or treatment.
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Affiliation(s)
- Esther Ndungo
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Johanna B. Holm
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Syze Gama
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Andrea G. Buchwald
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Sharon M. Tennant
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Miriam K. Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Marcela F. Pasetti
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - David A. Rasko
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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12
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Mtove G, Minja DTR, Abdul O, Gesase S, Maleta K, Divala TH, Patson N, Ashorn U, Laufer MK, Madanitsa M, Ashorn P, Mathanga D, Chinkhumba J, Gutman JR, Ter Kuile FO, Møller SL, Bygbjerg IC, Alifrangis M, Theander T, Lusingu JPA, Schmiegelow C. The choice of reference chart affects the strength of the association between malaria in pregnancy and small for gestational age: an individual participant data meta-analysis comparing the Intergrowth-21 with a Tanzanian birthweight chart. Malar J 2022; 21:292. [PMID: 36224585 PMCID: PMC9559842 DOI: 10.1186/s12936-022-04307-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 09/23/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The prevalence of small for gestational age (SGA) may vary depending on the chosen weight-for-gestational-age reference chart. An individual participant data meta-analysis was conducted to assess the implications of using a local reference (STOPPAM) instead of a universal reference (Intergrowth-21) on the association between malaria in pregnancy and SGA. METHODS Individual participant data of 6,236 newborns were pooled from seven conveniently identified studies conducted in Tanzania and Malawi from 2003-2018 with data on malaria in pregnancy, birthweight, and ultrasound estimated gestational age. Mixed-effects regression models were used to compare the association between malaria in pregnancy and SGA when using the STOPPAM and the Intergrowth-21 references, respectively. RESULTS The 10th percentile for birthweights-for-gestational age was lower for STOPPAM than for Intergrowth-21, leading to a prevalence of SGASTOPPAM of 14.2% and SGAIG21 of 18.0%, p < 0.001. The association between malaria in pregnancy and SGA was stronger for STOPPAM (adjusted odds ratio (aOR) 1.30 [1.09-1.56], p < 0.01) than for Intergrowth-21 (aOR 1.19 [1.00-1.40], p = 0.04), particularly among paucigravidae (SGASTOPPAM aOR 1.36 [1.09-1.71], p < 0.01 vs SGAIG21 aOR 1.21 [0.97-1.50], p = 0.08). CONCLUSIONS The prevalence of SGA may be overestimated and the impact of malaria in pregnancy underestimated when using Intergrowth-21. Comparing local reference charts to global references when assessing and interpreting the impact of malaria in pregnancy may be appropriate.
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Affiliation(s)
- George Mtove
- Tanga Medical Research Centre, National Institute for Medical Research, P. O. Box, 210, Tanga, Tanzania.
| | - Daniel T R Minja
- Tanga Medical Research Centre, National Institute for Medical Research, P. O. Box, 210, Tanga, Tanzania
| | - Omari Abdul
- Tanga Medical Research Centre, National Institute for Medical Research, P. O. Box, 210, Tanga, Tanzania
| | - Samwel Gesase
- Tanga Medical Research Centre, National Institute for Medical Research, P. O. Box, 210, Tanga, Tanzania
| | | | | | - Noel Patson
- Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Ulla Ashorn
- Tampere Center for Child, Adolescent and Maternal Health Research, Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
| | | | | | - Per Ashorn
- Faculty of Medicine and Health Technology, Center for Child, Adolescent, and Maternal Health Research, Tampere University, Tampere, Finland
- Department of Paediatrics, Tampere University Hospital, Tampere, Finland
| | - Don Mathanga
- Kamuzu University of Health Sciences, Blantyre, Malawi
| | | | - Julie R Gutman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, US Centers for Diseases Control and Prevention, Atlanta, GA, USA
| | - Feiko O Ter Kuile
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Sofie Lykke Møller
- Section of Global Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Ib C Bygbjerg
- Section of Global Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Michael Alifrangis
- Centre for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Thor Theander
- Centre for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - John P A Lusingu
- Tanga Medical Research Centre, National Institute for Medical Research, P. O. Box, 210, Tanga, Tanzania
- Centre for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Christentze Schmiegelow
- Centre for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
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13
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Cohee LM, Goupeyou-Youmsi J, Seydel KB, Mangani C, Ntenda P, Sixpence A, Mbewe RB, Matengeni A, Takala-Harrison S, Walker ED, Wilson ML, Mzilahowa T, Laufer MK, Valim C, Taylor TE, Mathanga DP. Understanding the Intransigence of Malaria in Malawi. Am J Trop Med Hyg 2022; 107:40-48. [PMID: 36228915 PMCID: PMC9662216 DOI: 10.4269/ajtmh.21-1263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 03/19/2022] [Indexed: 01/29/2023] Open
Abstract
Despite the scale-up of interventions against malaria over the past decade, this disease remains a leading threat to health in Malawi. To evaluate the epidemiology of both Plasmodium falciparum infection and malaria disease, the Malawi International Center of Excellence for Malaria Research (ICEMR) has developed and implemented diverse and robust surveillance and research projects. Descriptive studies in ICEMR Phase 1 increased our understanding of the declining effectiveness of long-lasting insecticidal nets (LLINs), the role of school-age children in malaria parasite transmission, and the complexity of host-parasite interactions leading to disease. These findings informed the design of ICEMR Phase 2 to test hypotheses about LLIN use and effectiveness, vector resistance to insecticides, demographic targets of malaria control, patterns and causes of asymptomatic to life-threatening disease, and the impacts of RTS,S vaccination plus piperonyl butoxide-treated LLINs on infection and disease in young children. These investigations are helping us to understand mosquito-to-human and human-to-mosquito transmission in the context of Malawi's intransigent malaria problem.
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Affiliation(s)
- Lauren M. Cohee
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | | | - Karl B. Seydel
- Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan
| | - Charles Mangani
- School of Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Peter Ntenda
- Malaria Alert Centre, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Alick Sixpence
- Malaria Alert Centre, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Rex B. Mbewe
- Department of Physics and Biochemical Sciences, Malawi University of Business and Applied Sciences, Blantyre, Malawi
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan
| | - Alfred Matengeni
- Malaria Alert Centre, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Shannon Takala-Harrison
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Edward D. Walker
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan
| | - Mark L. Wilson
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan
| | - Themba Mzilahowa
- Malaria Alert Centre, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Miriam K. Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Clarissa Valim
- Department of Global Health, Boston University School of Public Health, Boston, Massachusetts
| | - Terrie E. Taylor
- Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan
| | - Don P. Mathanga
- Malaria Alert Centre, Kamuzu University of Health Sciences, Blantyre, Malawi
- School of Public Health, Kamuzu University of Health Sciences, Blantyre, Malawi
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14
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Mungwira RG, Laurens MB, Nyangulu W, Divala TH, Nampota-Nkomba N, Buchwald AG, Nyirenda OM, Mwinjiwa E, Kanjala M, Galileya LT, Earland DE, Adams M, Plowe CV, Taylor TE, Mallewa J, van Oosterhout JJ, Laufer MK. High burden of malaria among Malawian adults on antiretroviral therapy after discontinuing prophylaxis. AIDS 2022; 36:1675-1682. [PMID: 35848575 PMCID: PMC9444947 DOI: 10.1097/qad.0000000000003317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Many individuals living with the human immunodeficiency virus (HIV) infection and receiving antiretroviral therapy (ART) reside in areas at high risk for malaria but how malaria affects clinical outcomes is not well described in this population. We evaluated the burden of malaria infection and clinical malaria, and impact on HIV viral load and CD4 + cell count among adults on ART. DESIGN We recruited Malawian adults on ART who had an undetectable viral load and ≥250 CD4 + cells/μl to participate in this randomized trial to continue daily trimethoprim-sulfamethoxazole (TS), discontinue daily co-trimoxazole, or switch to weekly chloroquine (CQ). METHODS We defined clinical malaria as symptoms consistent with malaria and positive blood smear, and malaria infection as Plasmodium falciparum DNA detected from dried blood spots (collected every 4-12 weeks). CD4 + cell count and viral load were measured every 24 weeks. We used Poisson regression and survival analysis to compare the incidence of malaria infection and clinical malaria. Clinicaltrials.gov NCT01650558. RESULTS Among 1499 participants enrolled, clinical malaria incidence was 21.4/100 person-years of observation (PYO), 2.4/100 PYO and 1.9/100 PYO in the no prophylaxis, TS, and CQ arms, respectively. We identified twelve cases of malaria that led to hospitalization and all individuals recovered. The preventive effect of staying on prophylaxis was approximately 90% compared to no prophylaxis (TS: incidence rate ratio [IRR] 0.11, 95% confidence interval [CI] 0.08, 0.15 and CQ: IRR 0.09, 95% CI 0.06, 0.13). P. falciparum infection prevalence among all visits was 187/1475 (12.7%), 48/1563 (3.1%), and 29/1561 (1.9%) in the no prophylaxis, TS, and CQ arms, respectively. Malaria infection and clinical malaria were not associated with changes in CD4 + cell count or viral load. CONCLUSION In clinically stable adults living with HIV on ART, clinical malaria was common after chemoprophylaxis stopped. However, neither malaria infection nor clinical illness appeared to affect HIV disease progression.
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Affiliation(s)
- Randy G Mungwira
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Matthew B Laurens
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Mrayland, USA
| | | | - Titus H Divala
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | | | - Andrea G Buchwald
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Mrayland, USA
| | - Osward M Nyirenda
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | | | - Maxwell Kanjala
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | | | - Dominique E Earland
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Mrayland, USA
| | - Matthew Adams
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Mrayland, USA
| | - Christopher V Plowe
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Mrayland, USA
| | | | - Jane Mallewa
- Department of Medicine, Kamuzu University of Health Sciences, Blantyre, Malawi
| | | | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Mrayland, USA
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15
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Tsirizani-Galileya L, Milanzi E, Mungwira R, Divala T, Mallewa J, Mategula D, Nampota N, Mwapasa V, Buchwald A, Laurens MB, Laufer MK, Van Oosterhout JJ. Isoniazid preventive therapy-related adverse events among Malawian adults on antiretroviral therapy: A cohort study. Medicine (Baltimore) 2022; 101:e30591. [PMID: 36181120 PMCID: PMC9524894 DOI: 10.1097/md.0000000000030591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Adverse events may be a cause of observed poor completion of isoniazid preventive therapy (IPT) among people living with HIV in high tuberculosis burden areas. Data on IPT-related adverse events (AE) from sub-Saharan Africa are scarce. We report IPT-related AEs, associated clinical characteristics, and IPT discontinuations in adults who were stable on antiretroviral therapy (ART) when they initiated IPT. Cohort study nested within a randomized, controlled, clinical trial of cotrimoxazole and chloroquine prophylaxis in Malawians aged ≥ 18 years and virologically suppressed on ART. Eight hundred sixty-nine patients were followed for a median of 6 months after IPT initiation. IPT relatedness of AEs was determined retrospectively with the World Health Organization case-causality tool. Frailty survival regression modeling identified factors associated with time to first probably IPT-related AE. The overall IPT-related AE incidence rate was 1.1/person year of observation. IPT relatedness was mostly uncertain and few AEs were severe. Most common were liver and hematological toxicities. Higher age increased risk of a probably IPT-related AE (aHR = 1.02; 95% CI 1.00-1.06; P = .06) and higher weight reduced this risk (aHR = 0.98; 95% CI 0.96-1.00; P = .03). Of 869 patients, 114 (13%) discontinued IPT and 94/114 (82%) discontinuations occurred at the time of a possibly or probably IPT-related AE. We observed a high incidence of mostly mild IPT-related AEs among individuals who were stable on ART. More than 1 in 8 persons discontinued IPT. These findings inform strategies to improve implementation of IPT in adults on ART, including close monitoring of groups at higher risk of IPT-related AEs.
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Affiliation(s)
| | - Elasma Milanzi
- Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | - Randy Mungwira
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Titus Divala
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Jane Mallewa
- Department of Medicine, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Donnie Mategula
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Nginache Nampota
- Blantyre Malaria Project, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Victor Mwapasa
- School of Public Health and Family Medicine, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Andrea Buchwald
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Matthew B. Laurens
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Miriam K. Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Joep J. Van Oosterhout
- Dignitas International, Zomba, Malawi
- Partners in Hope, Lilongwe, Malawi & Division of Infectious Diseases, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- *Correspondence: Joep J van Oosterhout, Partners in Hope, PO Box 302, Lilongwe, Malawi (e-mail: )
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16
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Cohee LM, Peterson I, Buchwald AG, Coalson JE, Valim C, Chilombe M, Ngwira A, Bauleni A, Schaffer-DeRoo S, Seydel KB, Wilson ML, Taylor TE, Mathanga DP, Laufer MK. School-Based Malaria Screening and Treatment Reduces Plasmodium falciparum Infection and Anemia Prevalence in Two Transmission Settings in Malawi. J Infect Dis 2022; 226:138-146. [PMID: 35290461 PMCID: PMC9373151 DOI: 10.1093/infdis/jiac097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 03/12/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND In areas highly endemic for malaria, Plasmodium falciparum infection prevalence peaks in school-age children, adversely affecting health and education. School-based intermittent preventive treatment reduces this burden but concerns about cost and widespread use of antimalarial drugs limit enthusiasm for this approach. School-based screening and treatment is an attractive alternative. In a prospective cohort study, we evaluated the impact of school-based screening and treatment on the prevalence of P. falciparum infection and anemia in 2 transmission settings. METHODS We screened 704 students in 4 Malawian primary schools for P. falciparum infection using rapid diagnostic tests (RDTs), and treated students who tested positive with artemether-lumefantrine. We determined P. falciparum infection by microscopy and quantitative polymerase chain reaction (qPCR), and hemoglobin concentrations over 6 weeks in all students. RESULTS Prevalence of infection by RDT screening was 37% (9%-64% among schools). An additional 9% of students had infections detected by qPCR. Following the intervention, significant reductions in infections were detected by microscopy (adjusted relative reduction [aRR], 48.8%; P < .0001) and qPCR (aRR, 24.5%; P < .0001), and in anemia prevalence (aRR, 30.8%; P = .003). Intervention impact was reduced by infections not detected by RDT and new infections following treatment. CONCLUSIONS School-based screening and treatment reduced P. falciparum infection and anemia. This approach could be enhanced by repeating screening, using more-sensitive screening tests, and providing longer-acting drugs. CLINICAL TRIALS REGISTRATION NCT04858087.
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Affiliation(s)
- Lauren M Cohee
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ingrid Peterson
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Andrea G Buchwald
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Jenna E Coalson
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan, USA
| | - Clarissa Valim
- Department of Global Health, Boston University School of Public Health, Boston, Massachusetts, USA
| | - Moses Chilombe
- Malaria Alert Centre, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Andrew Ngwira
- Malaria Alert Centre, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Andy Bauleni
- Malaria Alert Centre, Kamuzu University of Health Sciences, Blantyre, Malawi
| | | | - Karl B Seydel
- College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Mark L Wilson
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan, USA
| | - Terrie E Taylor
- College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Don P Mathanga
- Malaria Alert Centre, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
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17
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Stanley CC, Mukaka M, Kazembe LN, Buchwald AG, Mathanga DP, Laufer MK, Chirwa TF. Analysis of Recurrent Times-to-Clinical Malaria Episodes and Plasmodium falciparum Parasitemia: A Joint Modeling Approach Applied to a Cohort Data. Front Epidemiol 2022; 2:924783. [PMID: 38455327 PMCID: PMC10911024 DOI: 10.3389/fepid.2022.924783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 06/08/2022] [Indexed: 03/09/2024]
Abstract
Background Recurrent clinical malaria episodes due to Plasmodium falciparum parasite infection are common in endemic regions. With each infection, acquired immunity develops, making subsequent disease episodes less likely. To capture the effect of acquired immunity to malaria, it may be necessary to model recurrent clinical disease episodes jointly with P. falciparum parasitemia data. A joint model of longitudinal parasitemia and time-to-first clinical malaria episode (single-event joint model) may be inaccurate because acquired immunity is lost when subsequent episodes are excluded. This study's informativeness assessed whether joint modeling of recurrent clinical malaria episodes and parasitemia is more accurate than a single-event joint model where the subsequent episodes are ignored. Methods The single event joint model comprised Cox Proportional Hazards (PH) sub-model for time-to-first clinical malaria episode and Negative Binomial (NB) mixed-effects sub-model for the longitudinal parasitemia. The recurrent events joint model extends the survival sub-model to a Gamma shared frailty model to include all recurrent clinical episodes. The models were applied to cohort data from Malawi. Simulations were also conducted to assess the performance of the model under different conditions. Results The recurrent events joint model, which yielded higher hazard ratios of clinical malaria, was more precise and in most cases produced smaller standard errors than the single-event joint model; hazard ratio (HR) = 1.42, [95% confidence interval [CI]: 1.22, 2.03] vs. HR = 1.29, [95% CI:1.60, 2.45] among participants who reported not to use LLINs every night compared to those who used the nets every night; HR = 0.96, [ 95% CI: 0.94, 0.98] vs. HR = 0.81, [95% CI: 0.75, 0.88] for each 1-year increase in participants' age; and HR = 1.36, [95% CI: 1.05, 1.75] vs. HR = 1.10, [95% CI: 0.83, 4.11] for observations during the rainy season compared to the dry season. Conclusion The recurrent events joint model in this study provides a way of estimating the risk of recurrent clinical malaria in a cohort where the effect of immunity on malaria disease acquired due to P. falciparum parasitemia with aging is captured. The simulation study has shown that if correctly specified, the recurrent events joint model can give risk estimates with low bias.
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Affiliation(s)
- Christopher C. Stanley
- Faculty of Health Sciences, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
- Malaria Alert Center, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Mavuto Mukaka
- Oxford Centre for Tropical Medicine and Global Health, Oxford, United Kingdom
- Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, Thailand
| | | | - Andrea G. Buchwald
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Don P. Mathanga
- Malaria Alert Center, Kamuzu University of Health Sciences, Blantyre, Malawi
| | - Miriam K. Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Tobias F. Chirwa
- Faculty of Health Sciences, School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
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18
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Abstract
The first malaria vaccine has been recently approved for children living in malaria-endemic areas. While this is long-awaited and welcome news, the modest efficacy of the vaccine highlights several areas that require further attention. Here, we describe the likely impact of the vaccine and where clinical and basic discovery research will still be required.
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Affiliation(s)
| | - Cristiana Cairo
- Institute for Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.
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19
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Mbewe RB, Keven JB, Mzilahowa T, Mathanga D, Wilson M, Cohee L, Laufer MK, Walker ED. Blood-feeding patterns of Anopheles vectors of human malaria in Malawi: implications for malaria transmission and effectiveness of LLIN interventions. Malar J 2022; 21:67. [PMID: 35241083 PMCID: PMC8892392 DOI: 10.1186/s12936-022-04089-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 02/16/2022] [Indexed: 11/23/2022] Open
Abstract
Background Access to human hosts by Anopheles mosquitoes is a key determinant of vectorial capacity for malaria, but it can be limited by use of long-lasting insecticidal nets (LLINs). In Malawi, pyrethroid-treated LLINs with and without the synergist piperonyl butoxide (PBO) were distributed to control malaria. This study investigated the blood-feeding patterns of malaria vectors and whether LLINs containing pyrethroid and PBO led to a reduction of human blood feeding than those containing only pyrethroids. Methods Mosquitoes were sampled inside houses from May 2019 through April 2020 by aspiration, pyrethrum spray catch, and light trap methods in two sites. One site (Namanolo, Balaka district) had LLINs containing only pyrethroids whereas the other (Ntaja, Machinga district) had LLINs with both pyrethroids and PBO. Anopheles species, their blood-meal host, and infection with Plasmodium falciparum were determined using PCR methods. Results A total of 6585 female Anopheles were sampled in 203 houses. Of these, 633 (9.6%) were blood-fed mosquitoes comprising of 279 (44.1%) Anopheles arabiensis, 103 (16.3%) Anopheles gambiae 212 (33.5), Anopheles funestus, 2 (0.3%), Anopheles parensis and 37 (5.8%) were unidentified Anopheles spp. Blood meal hosts were successfully identified for 85.5% (n = 541) of the blood-fed mosquitoes, of which 436 (81.0%) were human blood meals, 28 (5.2%) were goats, 11 (2.0%) were dogs, 60 (11.1%) were mixed goat-human blood meals, 5 (0.9%) were dog–human, and 1 was a mixed dog-goat. Human blood index (fraction of blood meals that were humans) was significantly higher in Namanolo (0.96) than Ntaja (0.89). Even though human blood index was high, goats were over-selected than humans after accounting for relative abundance of both hosts. The number of infectious Anopheles bites per person-year was 44 in Namanolo and 22 in Ntaja. Conclusion Although LLINs with PBO PBO may have reduced human blood feeding, access to humans was extremely high despite high LLIN ownership and usage rates in both sites. This finding could explain persistently high rates of malaria infections in Malawi. However, this study had one village for each net type, thus the observed differences may have been a result of other factors present in each village. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04089-7.
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Affiliation(s)
- Rex B Mbewe
- Department of Physics and Biochemical Sciences, Polytechnic, University of Malawi, Blantyre, Malawi. .,Department of Entomology, Michigan State University, East Lansing, MI, 48824, USA.
| | - John B Keven
- Department of Entomology, Michigan State University, East Lansing, MI, 48824, USA.,Department of Public Health, University of California-Irvine, Irvine, CA, USA
| | - Themba Mzilahowa
- Malaria Alert Center, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Don Mathanga
- Malaria Alert Center, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Mark Wilson
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Lauren Cohee
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Edward D Walker
- Department of Entomology, Michigan State University, East Lansing, MI, 48824, USA.,Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
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20
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Bershteyn A, Dahl AM, Dong TQ, Deming ME, Celum CL, Chu HY, Kottkamp AC, Greninger AL, Hoffman RM, Jerome KR, Johnston CM, Kissinger PJ, Landovitz RJ, Laufer MK, Luk A, Neuzil KM, Paasche-Orlow MK, Pitts RA, Schwartz MD, Stankiewicz Karita HC, Thorpe LE, Wald A, Zheng CY, Wener MH, Barnabas RV, Brown ER. Self-Assessed Severity as a Determinant of Coronavirus Disease 2019 Symptom Specificity: A Longitudinal Cohort Study. Clin Infect Dis 2022; 75:e1180-e1183. [PMID: 35152299 PMCID: PMC8903379 DOI: 10.1093/cid/ciac129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Indexed: 01/19/2023] Open
Abstract
Coronavirus disease 2019 symptom definitions rarely include symptom severity. We collected daily nasal swab samples and symptom diaries from contacts of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) case patients. Requiring ≥1 moderate or severe symptom reduced sensitivity to predict SARS-CoV-2 shedding from 60.0% (95% confidence interval [CI], 52.9%-66.7%) to 31.5% (95% CI, 25.7%- 38.0%) but increased specificity from 77.5% (95% CI, 75.3%-79.5%) to 93.8% (95% CI, 92.7%-94.8%).
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Affiliation(s)
- Anna Bershteyn
- Correspondence: A. Bershteyn, Department of Population Health, New York University Grossman School of Medicine, 227 E 30th St, New York, NY 10016 ()
| | | | - Tracy Q Dong
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Meagan E Deming
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Connie L Celum
- International Clinical Research Center and Department of Global Health, University of Washington, Seattle, Washington, USA
| | - Helen Y Chu
- Department of Medicine and Department of Epidemiology, University of Washington, Seattle, Washington, USA
| | - Angelica C Kottkamp
- Department of Medicine, New York University Grossman School of Medicine, New York, New York, USA
| | - Alexander L Greninger
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA,Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Risa M Hoffman
- Department of Medicine and Division of Infectious Diseases, University of California, Los Angeles, California, USA
| | - Keith R Jerome
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA,Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Christine M Johnston
- Department of Medicine and Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Patricia J Kissinger
- Department of Epidemiology, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana, USA
| | - Raphael J Landovitz
- Center for Clinical AIDS Research & Education, University of California, Los Angeles, California, USA
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Alfred Luk
- John W. Deming Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - Kathleen M Neuzil
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Michael K Paasche-Orlow
- Department of Medicine and Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Robert A Pitts
- Department of Medicine and Division of Infectious Diseases, NYC Health & Hospitals/Bellevue, New York, New York, USA
| | - Mark D Schwartz
- Department of Population Health, New York University Grossman School of Medicine, New York, New York, USA
| | | | - Lorna E Thorpe
- Department of Population Health, New York University Grossman School of Medicine, New York, New York, USA
| | - Anna Wald
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA,Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA,Department of Medicine, Department of Epidemiology, Seattle, Washington, USA
| | - Crystal Y Zheng
- John W. Deming Department of Medicine, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - Mark H Wener
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, Washington, USA
| | - Ruanne V Barnabas
- Department of Global Health and Department of Medicine, University of Washington, Seattle, Washington, USA,Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USAand
| | - Elizabeth R Brown
- Department of Biostatistics, University of Washington, Seattle, Washington, USA,Vaccine and Infectious Disease Division and Public Health Sciences Division, Fred Hutchinson Cancer Research Center, USA
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21
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Patson N, Mukaka M, Kazembe L, Eijkemans MJC, Mathanga D, Laufer MK, Chirwa T. Comparison of statistical methods for the analysis of recurrent adverse events in the presence of non-proportional hazards and unobserved heterogeneity: a simulation study. BMC Med Res Methodol 2022; 22:24. [PMID: 35057743 PMCID: PMC8771190 DOI: 10.1186/s12874-021-01475-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 11/19/2021] [Indexed: 12/04/2022] Open
Abstract
Background In preventive drug trials such as intermittent preventive treatment for malaria prevention during pregnancy (IPTp), where there is repeated treatment administration, recurrence of adverse events (AEs) is expected. Challenges in modelling the risk of the AEs include accounting for time-to-AE and within-patient-correlation, beyond the conventional methods. The correlation comes from two sources; (a) individual patient unobserved heterogeneity (i.e. frailty) and (b) the dependence between AEs characterised by time-dependent treatment effects. Potential AE-dependence can be modelled via time-dependent treatment effects, event-specific baseline and event-specific random effect, while heterogeneity can be modelled via subject-specific random effect. Methods that can improve the estimation of both the unobserved heterogeneity and treatment effects can be useful in understanding the evolution of risk of AEs, especially in preventive trials where time-dependent treatment effect is expected. Methods Using both a simulation study and the Chloroquine for Malaria in Pregnancy (NCT01443130) trial data to demonstrate the application of the models, we investigated whether the lognormal shared frailty models with restricted cubic splines and non-proportional hazards (LSF-NPH) assumption can improve estimates for both frailty variance and treatment effect compared to the conventional inverse Gaussian shared frailty model with proportional hazard (ISF-PH), in the presence of time-dependent treatment effects and unobserved patient heterogeneity. We assessed the bias, precision gain and coverage probability of 95% confidence interval of the frailty variance estimates for the models under varying known unobserved heterogeneity, sample sizes and time-dependent effects. Results The ISF-PH model provided a better coverage probability of 95% confidence interval, less bias and less precise frailty variance estimates compared to the LSF-NPH models. The LSF-NPH models yielded unbiased hazard ratio estimates at the expense of imprecision and high mean square error compared to the ISF-PH model. Conclusion The choice of the shared frailty model for the recurrent AEs analysis should be driven by the study objective. Using the LSF-NPH models is appropriate if unbiased hazard ratio estimation is of primary interest in the presence of time-dependent treatment effects. However, ISF-PH model is appropriate if unbiased frailty variance estimation is of primary interest. Trial registration ClinicalTrials.gov; NCT01443130
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22
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Patson N, Mukaka M, Peterson I, Divala T, Kazembe L, Mathanga D, Laufer MK, Chirwa T. Effect of adverse events on non-adherence and study non-completion in malaria chemoprevention during pregnancy trial: A nested case control study. PLoS One 2022; 17:e0262797. [PMID: 35045119 PMCID: PMC8769307 DOI: 10.1371/journal.pone.0262797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 10/18/2021] [Indexed: 11/18/2022] Open
Abstract
Background
In drug trials, adverse events (AEs) burden can induce treatment non-adherence or discontinuation. The non-adherence and discontinuation induce selection bias, affecting drug safety interpretation. Nested case-control (NCC) study can efficiently quantify the impact of the AEs, although choice of sampling approach is challenging. We investigated whether NCC study with incidence density sampling is more efficient than NCC with path sampling under conditional logistic or weighted Cox models in assessing the effect of AEs on treatment non-adherence and participation in preventive antimalarial drug during pregnancy trial.
Methods
Using data from a trial of medication to prevent malaria in pregnancy that randomized 600 women to receive chloroquine or sulfadoxine-pyrimethamine during pregnancy, we conducted a NCC study assessing the role of prospectively collected AEs, as exposure of interest, on treatment non-adherence and study non-completion. We compared estimates from NCC study with incidence density against those from NCC with path sampling under conditional logistic and weighted Cox models.
Results
Out of 599 women with the outcomes of interest, 474 (79%) experienced at least one AE before delivery. For conditional logistic model, the hazard ratio for the effect of AE occurrence on treatment non-adherence was 0.70 (95% CI: 0.42, 1.17; p = 0.175) under incidence density sampling and 0.68 (95% CI: 0.41, 1.13; p = 0.137) for path sampling. For study non-completion, the hazard ratio was 1.02 (95% CI: 0.56, 1.83; p = 0.955) under incidence density sampling and 0.85 (95% CI: 0.45, 1.60; p = 0.619) under path sampling. We obtained similar hazard ratios and standard errors under incidence density sampling and path sampling whether weighted Cox or conditional logistic models were used.
Conclusion
NCC with incidence density sampling and NCC with path sampling are practically similar in efficiency whether conditional logistic or weighted Cox analytical methods although path sampling uses more unique controls to achieve the similar estimates.
Trial registration
ClinicalTrials.gov: NCT01443130.
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Affiliation(s)
- Noel Patson
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
- * E-mail:
| | - Mavuto Mukaka
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Ingrid Peterson
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Titus Divala
- TB Centre, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Helse Nord Tuberculosis Initiative, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Lawrence Kazembe
- Department of Biostatistics, University of Namibia, Windhoek, Namibia
| | - Don Mathanga
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Miriam K. Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Tobias Chirwa
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
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23
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Friedman-Klabanoff DJ, Fitzpatrick MC, Deming ME, Agrawal V, Sitar S, Schaafsma T, Brown E, Neuzil KM, Barnabas RV, Laufer MK. OUP accepted manuscript. J Infect Dis 2022; 226:225-235. [PMID: 35134185 PMCID: PMC8903329 DOI: 10.1093/infdis/jiac029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 01/30/2022] [Indexed: 11/14/2022] Open
Affiliation(s)
- DeAnna J Friedman-Klabanoff
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Meagan C Fitzpatrick
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Meagan E Deming
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Vaidehi Agrawal
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Sandra Sitar
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Torin Schaafsma
- Department of Global Health, University of Washington, Seattle, Washington, USA
| | - Elizabeth Brown
- Department of Biostatistics, University of Washington, Seattle, Washington, USA
- Vaccine and Infectious Disease Division, University of Washington, Seattle, Washington, USA
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Kathleen M Neuzil
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ruanne V Barnabas
- Present affiliation: Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Miriam K Laufer
- Correspondence: Miriam K. Laufer, MD, MPH, University of Maryland School of Medicine, Center for Vaccine Development and Global Health, 685 W Baltimore St, Rm 480, Baltimore, MD 21201, USA ()
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24
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Ndungo E, Andronescu LR, Buchwald AG, Lemme-Dumit JM, Mawindo P, Kapoor N, Fairman J, Laufer MK, Pasetti MF. Repertoire of Naturally Acquired Maternal Antibodies Transferred to Infants for Protection Against Shigellosis. Front Immunol 2021; 12:725129. [PMID: 34721387 PMCID: PMC8554191 DOI: 10.3389/fimmu.2021.725129] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 09/27/2021] [Indexed: 11/13/2022] Open
Abstract
Shigella is the second leading cause of diarrheal diseases, accounting for >200,000 infections and >50,000 deaths in children under 5 years of age annually worldwide. The incidence of Shigella-induced diarrhea is relatively low during the first year of life and increases substantially, reaching its peak between 11 to 24 months of age. This epidemiological trend hints at an early protective immunity of maternal origin and an increase in disease incidence when maternally acquired immunity wanes. The magnitude, type, antigenic diversity, and antimicrobial activity of maternal antibodies transferred via placenta that can prevent shigellosis during early infancy are not known. To address this knowledge gap, Shigella-specific antibodies directed against the lipopolysaccharide (LPS) and virulence factors (IpaB, IpaC, IpaD, IpaH, and VirG), and antibody-mediated serum bactericidal (SBA) and opsonophagocytic killing antibody (OPKA) activity were measured in maternal and cord blood sera from a longitudinal cohort of mother-infant pairs living in rural Malawi. Protein-specific (very high levels) and Shigella LPS IgG were detected in maternal and cord blood sera; efficiency of placental transfer was 100% and 60%, respectively, and had preferential IgG subclass distribution (protein-specific IgG1 > LPS-specific IgG2). In contrast, SBA and OPKA activity in cord blood was substantially lower as compared to maternal serum and varied among Shigella serotypes. LPS was identified as the primary target of SBA and OPKA activity. Maternal sera had remarkably elevated Shigella flexneri 2a LPS IgM, indicative of recent exposure. Our study revealed a broad repertoire of maternally acquired antibodies in infants living in a Shigella-endemic region and highlights the abundance of protein-specific antibodies and their likely contribution to disease prevention during the first months of life. These results contribute new knowledge on maternal infant immunity and target antigens that can inform the development of vaccines or therapeutics that can extend protection after maternally transferred immunity wanes.
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Affiliation(s)
- Esther Ndungo
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Liana R Andronescu
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Andrea G Buchwald
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Jose M Lemme-Dumit
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Patricia Mawindo
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | | | | | - Miriam K Laufer
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Marcela F Pasetti
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
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25
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Laurens MB, Downs M, Laufer MK. Reply to Ramirez and Diaz-Quijano. Clin Infect Dis 2021; 73:1551-1552. [PMID: 33900389 PMCID: PMC8528388 DOI: 10.1093/cid/ciab364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Matthew B Laurens
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
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26
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Patson N, Mukaka M, D'Alessandro U, Chapotera G, Mwapasa V, Mathanga D, Kazembe L, Laufer MK, Chirwa T. Joint modelling of multivariate longitudinal clinical laboratory safety outcomes, concomitant medication and clinical adverse events: application to artemisinin-based treatment during pregnancy clinical trial. BMC Med Res Methodol 2021; 21:208. [PMID: 34627141 PMCID: PMC8501924 DOI: 10.1186/s12874-021-01412-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 09/17/2021] [Indexed: 11/25/2022] Open
Abstract
Background In drug trials, clinical adverse events (AEs), concomitant medication and laboratory safety outcomes are repeatedly collected to support drug safety evidence. Despite the potential correlation of these outcomes, they are typically analysed separately, potentially leading to misinformation and inefficient estimates due to partial assessment of safety data. Using joint modelling, we investigated whether clinical AEs vary by treatment and how laboratory outcomes (alanine amino-transferase, total bilirubin) and concomitant medication are associated with clinical AEs over time following artemisinin-based antimalarial therapy. Methods We used data from a trial of artemisinin-based treatments for malaria during pregnancy that randomized 870 women to receive artemether–lumefantrine (AL), amodiaquine–artesunate (ASAQ) and dihydroartemisinin–piperaquine (DHAPQ). We fitted a joint model containing four sub-models from four outcomes: longitudinal sub-model for alanine aminotransferase, longitudinal sub-model for total bilirubin, Poisson sub-model for concomitant medication and Poisson sub-model for clinical AEs. Since the clinical AEs was our primary outcome, the longitudinal sub-models and concomitant medication sub-model were linked to the clinical AEs sub-model via current value and random effects association structures respectively. We fitted a conventional Poisson model for clinical AEs to assess if the effect of treatment on clinical AEs (i.e. incidence rate ratio (IRR)) estimates differed between the conventional Poisson and the joint models, where AL was reference treatment. Results Out of the 870 women, 564 (65%) experienced at least one AE. Using joint model, AEs were associated with the concomitant medication (log IRR 1.7487; 95% CI: 1.5471, 1.9503; p < 0.001) but not the total bilirubin (log IRR: -0.0288; 95% CI: − 0.5045, 0.4469; p = 0.906) and alanine aminotransferase (log IRR: 0.1153; 95% CI: − 0.0889, 0.3194; p = 0.269). The Poisson model underestimated the effects of treatment on AE incidence such that log IRR for ASAQ was 0.2118 (95% CI: 0.0082, 0.4154; p = 0.041) for joint model compared to 0.1838 (95% CI: 0.0574, 0.3102; p = 0.004) for Poisson model. Conclusion We demonstrated that although the AEs did not vary across the treatments, the joint model yielded efficient AE incidence estimates compared to the Poisson model. The joint model showed a positive relationship between the AEs and concomitant medication but not with laboratory outcomes. Trial registration ClinicalTrials.gov: NCT00852423
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Affiliation(s)
- Noel Patson
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa. .,School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi.
| | - Mavuto Mukaka
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand.,Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Umberto D'Alessandro
- Medical Research Council Unit, The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, Gambia
| | - Gertrude Chapotera
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Victor Mwapasa
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Don Mathanga
- School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Lawrence Kazembe
- Department of Biostatistics, University of Namibia, Windhoek, Namibia
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland, School of Medicine, Baltimore, MD, USA
| | - Tobias Chirwa
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
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27
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Laurens MB, Mungwira RG, Nampota N, Nyirenda OM, Divala TH, Kanjala M, Mkandawire FA, Galileya LT, Nyangulu W, Mwinjiwa E, Downs M, Tillman A, Taylor TE, Mallewa J, Plowe CV, van Oosterhout JJ, Laufer MK. Revisiting Co-trimoxazole Prophylaxis for African Adults in the Era of Antiretroviral Therapy: A Randomized Controlled Clinical Trial. Clin Infect Dis 2021; 73:1058-1065. [PMID: 33744963 DOI: 10.1093/cid/ciab252] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 03/18/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Daily co-trimoxazole is recommended for African adults living with human immunodeficiency virus (HIV) irrespective of antiretroviral treatment, immune status, or disease stage. Benefits of continued prophylaxis and whether co-trimoxazole can be stopped following immune reconstitution are unknown. METHODS We conducted a randomized controlled trial at 2 sites in Malawi that enrolled adults with HIV with undetectable viral load and CD4 count of >250/mm3 and randomized them to continue daily co-trimoxazole, discontinue daily co-trimoxazole and begin weekly chloroquine, or discontinue daily co-trimoxazole. The primary endpoint was the preventive effect of co-trimoxazole prophylaxis against death or World Health Organization (WHO) HIV/AIDS stage 3-4 events, using Cox proportional hazards modeling, in an intention-to-treat population. RESULTS 1499 adults were enrolled. The preventive effect of co-trimoxazole on the primary endpoint was 22% (95% CI: -14%-47%; P = .20) versus no prophylaxis and 25% (-10%-48%; P = .14) versus chloroquine. When WHO HIV/AIDS stage 2 events were added to the primary endpoint, preventive effect increased to 31% (3-51%; P = .032) and 32% (4-51%; P = .026), respectively. Co-trimoxazole and chloroquine prophylaxis effectively prevented clinical malaria episodes (3.8 and 3.0, respectively, vs 28/100 person-years; P < .001). CONCLUSIONS Malawian adults with HIV who immune reconstituted on ART and continued co-trimoxazole prophylaxis experienced fewer deaths and WHO HIV/AIDS stage 3-4 events compared with prophylaxis discontinuation, although statistical significance was not achieved. Co-trimoxazole prevented a composite of death plus WHO HIV/AIDS stage 2-4 events. Given poor healthcare access and lack of routine viral load monitoring, co-trimoxazole prophylaxis should continue in adults on ART after immune reconstitution in sub-Saharan Africa. Clinical Trials Registration. NCT01650558.
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Affiliation(s)
- Matthew B Laurens
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Randy G Mungwira
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Nginache Nampota
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Osward M Nyirenda
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Titus H Divala
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Maxwell Kanjala
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Felix A Mkandawire
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | | | | | | | | | - Amy Tillman
- Statistics Collaborative, Washington, DC, USA
| | - Terrie E Taylor
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi.,College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Jane Mallewa
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Christopher V Plowe
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Joep J van Oosterhout
- Dignitas International and University of Malawi College of Medicine, Blantyre, Malawi
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
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28
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Andronescu LR, Sharma A, Peterson I, Kachingwe M, Kachepa W, Liang Y, Gutman JR, Mathanga DP, Chinkhumba J, Laufer MK. The effect of intermittent preventive treatment of malaria during pregnancy and placental malaria on infant risk of malaria. J Infect Dis 2021; 225:248-256. [PMID: 34216212 DOI: 10.1093/infdis/jiab351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 07/02/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Intermittent preventive treatment of malaria during pregnancy (IPTp) with dihydroartemisinin-piperaquine (DP) provides greater protection from placental malaria than sulfadoxine-pyrimethamine (SP). Some studies suggest placental malaria alters the risk of malaria infection in infants, but few studies have quantified the effect of IPTp on infant susceptibility to malaria. METHODS Infants born to pregnant women enrolled in a randomized clinical trial comparing IPTp-SP and IPTp-DP in Malawi were followed from birth to 24 months to assess effect of IPTp and placental malaria on time to first malaria episode and P. falciparum incidence. RESULTS In total, 192 infants born to mothers randomized to IPTp-SP and 195 to mothers randomized to IPTp-DP were enrolled. Infants in the IPTp exposure groups did not differ significantly regarding incidence of clinical malaria (IRR= 1.03; 95% CI: 0.58 - 1.86) or incidence of infection (IRR= 1.18; 95% CI: 0.92-1.55). Placental malaria exposure was not associated with incidence of clinical malaria (IRR= 1.03; 95% CI: 0.66-1.59) or incidence of infection (IRR:= 1.15; 95% CI: 0.88-1.50). Infant sex, season of birth, and maternal gravidity did not confound results. CONCLUSIONS We did not find evidence that IPTp regimen or placental malaria exposure influenced risk of malaria during infancy in this population.
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Affiliation(s)
- Liana R Andronescu
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Ankur Sharma
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Ingrid Peterson
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Martin Kachingwe
- Malaria Alert Center, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Witness Kachepa
- Malaria Alert Center, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Yuanyuan Liang
- Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Julie R Gutman
- Malaria Branch, Centers for Disease Control and Prevention, Atlanta, GA 30333 USA
| | - Don P Mathanga
- Malaria Alert Center, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Jobiba Chinkhumba
- Malaria Alert Center, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201 USA
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Shah Z, Naung MT, Moser KA, Adams M, Buchwald AG, Dwivedi A, Ouattara A, Seydel KB, Mathanga DP, Barry AE, Serre D, Laufer MK, Silva JC, Takala-Harrison S. Whole-genome analysis of Malawian Plasmodium falciparum isolates identifies possible targets of allele-specific immunity to clinical malaria. PLoS Genet 2021; 17:e1009576. [PMID: 34033654 PMCID: PMC8184011 DOI: 10.1371/journal.pgen.1009576] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 06/07/2021] [Accepted: 05/04/2021] [Indexed: 12/30/2022] Open
Abstract
Individuals acquire immunity to clinical malaria after repeated Plasmodium falciparum infections. Immunity to disease is thought to reflect the acquisition of a repertoire of responses to multiple alleles in diverse parasite antigens. In previous studies, we identified polymorphic sites within individual antigens that are associated with parasite immune evasion by examining antigen allele dynamics in individuals followed longitudinally. Here we expand this approach by analyzing genome-wide polymorphisms using whole genome sequence data from 140 parasite isolates representing malaria cases from a longitudinal study in Malawi and identify 25 genes that encode possible targets of naturally acquired immunity that should be validated immunologically and further characterized for their potential as vaccine candidates.
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Affiliation(s)
- Zalak Shah
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Myo T. Naung
- Population Health and Immunity Division, Walter Eliza Hall of Medical Institute for Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Carlton, Victoria, Australia
- School of Medicine, Deakin University, Geelong, Victoria, Australia
| | - Kara A. Moser
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Matthew Adams
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Andrea G. Buchwald
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Ankit Dwivedi
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Amed Ouattara
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Karl B. Seydel
- Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan, United States of America
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Don P. Mathanga
- University of Malawi College of Medicine, Malaria Alert Centre, Blantyre, Malawi
| | - Alyssa E. Barry
- Population Health and Immunity Division, Walter Eliza Hall of Medical Institute for Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Carlton, Victoria, Australia
- School of Medicine, Deakin University, Geelong, Victoria, Australia
- Disease Elimination and Maternal and Child Health, Burnet Institute, Melbourne, Victoria, Australia
| | - David Serre
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Miriam K. Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Joana C. Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Shannon Takala-Harrison
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
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30
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Cohee LM, Valim C, Coalson JE, Nyambalo A, Chilombe M, Ngwira A, Bauleni A, Seydel KB, Wilson ML, Taylor TE, Mathanga DP, Laufer MK. School-based screening and treatment may reduce P. falciparum transmission. Sci Rep 2021; 11:6905. [PMID: 33767384 PMCID: PMC7994823 DOI: 10.1038/s41598-021-86450-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 03/16/2021] [Indexed: 11/22/2022] Open
Abstract
In areas where malaria remains entrenched, novel transmission-reducing interventions are essential for malaria elimination. We report the impact screening-and-treatment of asymptomatic Malawian schoolchildren (n = 364 in the rainy season and 341 in the dry season) had on gametocyte-the parasite stage responsible for human-to-mosquito transmission-carriage. We used concomitant household-based surveys to predict the potential reduction in transmission in the surrounding community. Among 253 students with P. falciparum infections at screening, 179 (71%) had infections containing gametocytes detected by Pfs25 qRT-PCR. 84% of gametocyte-containing infections were detected by malaria rapid diagnostic test. While the gametocyte prevalence remained constant in untreated children, treatment with artemether-lumefantrine reduced the gametocyte prevalence (p < 0.0001) from 51.8 to 9.7% and geometric mean gametocyte density (p = 0.008) from 0.52 to 0.05 gametocytes/microliter. In community surveys, 46% of all gametocyte-containing infections were in school-age children, who comprised only 35% of the population. Based on these estimates six weeks after the intervention, the gametocyte burden in the community could be reduced by 25-55% depending on the season and the measure used to characterize gametocyte carriage. Thus, school-based interventions to treat asymptomatic infections may be a high-yield approach to not only improve the health of schoolchildren, but also decrease malaria transmission.
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Affiliation(s)
- Lauren M Cohee
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
| | - Clarissa Valim
- Department of Global Health, Boston University School of Public Health, Boston, MA, USA
| | - Jenna E Coalson
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA
- Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
| | - Andrew Nyambalo
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Moses Chilombe
- Malaria Alert Center, University of Malawi College of Medicine, Blantyre, Malawi
| | - Andrew Ngwira
- Malaria Alert Center, University of Malawi College of Medicine, Blantyre, Malawi
| | - Andy Bauleni
- Malaria Alert Center, University of Malawi College of Medicine, Blantyre, Malawi
| | - Karl B Seydel
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
- College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA
| | - Mark L Wilson
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Terrie E Taylor
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
- College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA
| | - Don P Mathanga
- Malaria Alert Center, University of Malawi College of Medicine, Blantyre, Malawi
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
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Barnabas RV, Brown ER, Bershteyn A, Stankiewicz Karita HC, Johnston C, Thorpe LE, Kottkamp A, Neuzil KM, Laufer MK, Deming M, Paasche-Orlow MK, Kissinger PJ, Luk A, Paolino K, Landovitz RJ, Hoffman R, Schaafsma TT, Krows ML, Thomas KK, Morrison S, Haugen HS, Kidoguchi L, Wener M, Greninger AL, Huang ML, Jerome KR, Wald A, Celum C, Chu HY, Baeten JM. Hydroxychloroquine as Postexposure Prophylaxis to Prevent Severe Acute Respiratory Syndrome Coronavirus 2 Infection : A Randomized Trial. Ann Intern Med 2021; 174:344-352. [PMID: 33284679 PMCID: PMC7732017 DOI: 10.7326/m20-6519] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Effective prevention against coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is currently limited to nonpharmaceutical strategies. Laboratory and observational data suggested that hydroxychloroquine had biological activity against SARS-CoV-2, potentially permitting its use for prevention. OBJECTIVE To test hydroxychloroquine as postexposure prophylaxis for SARS-CoV-2 infection. DESIGN Household-randomized, double-blind, controlled trial of hydroxychloroquine postexposure prophylaxis. (ClinicalTrials.gov: NCT04328961). SETTING National U.S. multicenter study. PARTICIPANTS Close contacts recently exposed (<96 hours) to persons with diagnosed SARS-CoV-2 infection. INTERVENTION Hydroxychloroquine (400 mg/d for 3 days followed by 200 mg/d for 11 days) or ascorbic acid (500 mg/d followed by 250 mg/d) as a placebo-equivalent control. MEASUREMENTS Participants self-collected mid-turbinate swabs daily (days 1 to 14) for SARS-CoV-2 polymerase chain reaction (PCR) testing. The primary outcome was PCR-confirmed incident SARS-CoV-2 infection among persons who were SARS-CoV-2 negative at enrollment. RESULTS Between March and August 2020, 671 households were randomly assigned: 337 (407 participants) to the hydroxychloroquine group and 334 (422 participants) to the control group. Retention at day 14 was 91%, and 10 724 of 11 606 (92%) expected swabs were tested. Among the 689 (89%) participants who were SARS-CoV-2 negative at baseline, there was no difference between the hydroxychloroquine and control groups in SARS-CoV-2 acquisition by day 14 (53 versus 45 events; adjusted hazard ratio, 1.10 [95% CI, 0.73 to 1.66]; P > 0.20). The frequency of participants experiencing adverse events was higher in the hydroxychloroquine group than the control group (66 [16.2%] versus 46 [10.9%], respectively; P = 0.026). LIMITATION The delay between exposure, and then baseline testing and the first dose of hydroxychloroquine or ascorbic acid, was a median of 2 days. CONCLUSION This rigorous randomized controlled trial among persons with recent exposure excluded a clinically meaningful effect of hydroxychloroquine as postexposure prophylaxis to prevent SARS-CoV-2 infection. PRIMARY FUNDING SOURCE Bill & Melinda Gates Foundation.
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Affiliation(s)
- Ruanne V Barnabas
- University of Washington and Fred Hutchinson Cancer Research Center, Seattle, Washington (R.V.B., E.R.B., C.J., A.L.G., K.R.J., A.W.)
| | - Elizabeth R Brown
- University of Washington and Fred Hutchinson Cancer Research Center, Seattle, Washington (R.V.B., E.R.B., C.J., A.L.G., K.R.J., A.W.)
| | - Anna Bershteyn
- New York University Grossman School of Medicine, New York, New York (A.B., L.E.T., A.K.)
| | - Helen C Stankiewicz Karita
- University of Washington, Seattle, Washington (H.C.S., T.T.S., M.L.K., K.K.T., S.M., H.S.H., L.K., M.W., C.C., H.Y.C., J.M.B.)
| | - Christine Johnston
- University of Washington and Fred Hutchinson Cancer Research Center, Seattle, Washington (R.V.B., E.R.B., C.J., A.L.G., K.R.J., A.W.)
| | - Lorna E Thorpe
- New York University Grossman School of Medicine, New York, New York (A.B., L.E.T., A.K.)
| | - Angelica Kottkamp
- New York University Grossman School of Medicine, New York, New York (A.B., L.E.T., A.K.)
| | - Kathleen M Neuzil
- University of Maryland School of Medicine, Baltimore, Maryland (K.M.N., M.K.L., M.D.)
| | - Miriam K Laufer
- University of Maryland School of Medicine, Baltimore, Maryland (K.M.N., M.K.L., M.D.)
| | - Meagan Deming
- University of Maryland School of Medicine, Baltimore, Maryland (K.M.N., M.K.L., M.D.)
| | - Michael K Paasche-Orlow
- Boston University School of Medicine and Boston Medical Center, Boston, Massachusetts (M.K.P.)
| | - Patricia J Kissinger
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana (P.J.K.)
| | - Alfred Luk
- School of Medicine, Tulane University, New Orleans, Louisiana (A.L.)
| | - Kristopher Paolino
- State University of New York Upstate Medical University, Syracuse, New York (K.P.)
| | | | - Risa Hoffman
- University of California, Los Angeles, California (R.J.L., R.H.)
| | - Torin T Schaafsma
- University of Washington, Seattle, Washington (H.C.S., T.T.S., M.L.K., K.K.T., S.M., H.S.H., L.K., M.W., C.C., H.Y.C., J.M.B.)
| | - Meighan L Krows
- University of Washington, Seattle, Washington (H.C.S., T.T.S., M.L.K., K.K.T., S.M., H.S.H., L.K., M.W., C.C., H.Y.C., J.M.B.)
| | - Katherine K Thomas
- University of Washington, Seattle, Washington (H.C.S., T.T.S., M.L.K., K.K.T., S.M., H.S.H., L.K., M.W., C.C., H.Y.C., J.M.B.)
| | - Susan Morrison
- University of Washington, Seattle, Washington (H.C.S., T.T.S., M.L.K., K.K.T., S.M., H.S.H., L.K., M.W., C.C., H.Y.C., J.M.B.)
| | - Harald S Haugen
- University of Washington, Seattle, Washington (H.C.S., T.T.S., M.L.K., K.K.T., S.M., H.S.H., L.K., M.W., C.C., H.Y.C., J.M.B.)
| | - Lara Kidoguchi
- University of Washington, Seattle, Washington (H.C.S., T.T.S., M.L.K., K.K.T., S.M., H.S.H., L.K., M.W., C.C., H.Y.C., J.M.B.)
| | - Mark Wener
- University of Washington, Seattle, Washington (H.C.S., T.T.S., M.L.K., K.K.T., S.M., H.S.H., L.K., M.W., C.C., H.Y.C., J.M.B.)
| | - Alexander L Greninger
- University of Washington and Fred Hutchinson Cancer Research Center, Seattle, Washington (R.V.B., E.R.B., C.J., A.L.G., K.R.J., A.W.)
| | - Meei-Li Huang
- Fred Hutchinson Cancer Research Center, Seattle, Washington (M.H.)
| | - Keith R Jerome
- University of Washington and Fred Hutchinson Cancer Research Center, Seattle, Washington (R.V.B., E.R.B., C.J., A.L.G., K.R.J., A.W.)
| | - Anna Wald
- University of Washington and Fred Hutchinson Cancer Research Center, Seattle, Washington (R.V.B., E.R.B., C.J., A.L.G., K.R.J., A.W.)
| | - Connie Celum
- University of Washington, Seattle, Washington (H.C.S., T.T.S., M.L.K., K.K.T., S.M., H.S.H., L.K., M.W., C.C., H.Y.C., J.M.B.)
| | - Helen Y Chu
- University of Washington, Seattle, Washington (H.C.S., T.T.S., M.L.K., K.K.T., S.M., H.S.H., L.K., M.W., C.C., H.Y.C., J.M.B.)
| | - Jared M Baeten
- University of Washington, Seattle, Washington (H.C.S., T.T.S., M.L.K., K.K.T., S.M., H.S.H., L.K., M.W., C.C., H.Y.C., J.M.B.)
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Yimgang DP, Buchwald AG, Coalson JE, Walldorf JA, Bauleni A, Kapito-Tembo A, Mathanga DP, Taylor TE, Laufer MK, Cohee LM. Population Attributable Fraction of Anemia Associated with P. falciparum Infection in Children in Southern Malawi. Am J Trop Med Hyg 2021; 104:1013-1017. [PMID: 33399043 DOI: 10.4269/ajtmh.20-1120] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/16/2020] [Indexed: 01/09/2023] Open
Abstract
Anemia is a leading cause of morbidity in sub-Saharan Africa. The etiologies of anemia are multifactorial, and it is unclear what proportion of anemia is attributable to malaria in children of different ages in Malawi. We evaluated the population attributable fraction (PAF) of anemia due to malaria using multiple cross-sectional surveys in southern Malawi. We found a high prevalence of anemia, with the greatest proportion attributable to malaria among school-age children (5-15 years) in the rainy season (PAF = 18.8% [95% CI: 16.3, 21.0], compared with PAF = 5.2% [95% CI: 4.0, 6.2] among young children pooled across season [< 5 years] and PAF = 9.7% [95% CI: 6.5, 12.4] among school-age children in the dry season). Malaria control interventions will likely lead to decreases in anemia, especially among school-age children.
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Affiliation(s)
- Doris P Yimgang
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Andrea G Buchwald
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Jenna E Coalson
- University of Michigan School of Public Health, Ann Arbor, Michigan
| | - Jenny A Walldorf
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Andy Bauleni
- Malaria Alert Center, University of Malawi College of Medicine, Blantyre, Malawi
| | - Atupele Kapito-Tembo
- Malaria Alert Center, University of Malawi College of Medicine, Blantyre, Malawi
| | - Don P Mathanga
- Malaria Alert Center, University of Malawi College of Medicine, Blantyre, Malawi
| | - Terrie E Taylor
- Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Lauren M Cohee
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
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33
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Brown ER, Bershteyn A, Karita HCS, Johnston C, Thorpe L, Kottkamp A, Neuzil K, Laufer MK, Deming M, Paasche-Orlow MK, Kissinger PJ, Luk A, Paolino KM, Paolino KM, Landovitz RJ, Hoffman R, Schaafsma T, Krows ML, Thomas K, Morrison S, Kidoguchi L, Wener MH, Greninger AL, Huang ML, Jerome K, Wald A, Wald A, Celum C, Chu HY, Baeten JM. LB-17. Efficacy of Hydroxychloroquine (HCQ) for Post-exposure Prophylaxis to Prevent Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection: A Blinded, Randomized, Controlled Trial. Open Forum Infect Dis 2020. [PMCID: PMC7776476 DOI: 10.1093/ofid/ofaa515.1914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Prevention interventions for coronavirus disease (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), are currently limited to non-pharmaceutical strategies. Observational and laboratory data suggested that hydroxychloroquine (HCQ) had biologic activity against SARS-CoV-2. A blinded trial of HCQ in persons with confirmed exposure and virologic and clinical endpoints is needed.
Methods
We conducted a national, householdrandomized, double-blind, controlled trial of HCQ post-exposure prophylaxis, with entirely remote study procedures. We enrolled close contacts exposed to persons with SARS-CoV-2 infection in the past 96 hours. Participants were randomized to either HCQ (400 mg daily for three days followed by 200 mg daily for eleven days) or ascorbic acid (500 mg followed by 250 mg daily), as a placebo-equivalent control. Participants self-collected mid-turbinate swabs daily (days 1–14) for SARS-CoV-2 PCR testing. The primary outcome was PCR-confirmed, incident SARS-CoV-2 infection among persons SARS-CoV-2 negative at enrollment. Symptoms were assessed using criteria from the US CDC.
Results
From March-August 2020, 623 households were randomized; 311 households (381 participants) to the HCQ group and 312 households (400 participants) to the control group. Ninety- one percent of participants were retained up to day 14 and 9,595 of 10,588 (91%) of swabs were tested. Among participants who were SARS-CoV-2 negative at baseline (n=626/781, 80%), the cumulative incidence of SARS-CoV-2 was 14.5% (95% CI: 11.6–17.4) and the cumulative incidence of COVID-19 symptoms was 11.6% (95% CI: 8.9–14.2) at day 14. By day 14, there was no difference between the HCQ group and control group in SARS-CoV-2 acquisition (46 vs. 43 events, aHR= 0.99, 95% CI 0.64–1.52, p=0.95) or symptomatic disease (40 vs. 32 events, aHR= 1.23, 95% CI: 0.76–1.99, p=0.40). The adverse event frequency was similar between groups (59 [15.5%] participants in the HCQ and 45 [11.3%] in the control group, p=0.092).
Cumulative incidence of RT-PCR-confirmed SARS-CoV-2 infection among close contacts of diagnosed cases, by study group
Conclusion
This randomized, double-blind, controlled trial among persons with recent exposure and high incidence of SAR-CoV2 provides strong evidence that HCQ post-exposure prophylaxis did not prevent SARS-CoV-2 infection or modify clinical disease.
Disclosures
Anna Bershteyn, PhD, Bill and Melinda Gates Foundation (Grant/Research Support)Gates Ventures (Consultant)National Institutes of Health (Grant/Research Support) Kristopher M. Paolino, MD, MTM&H, Nothing to disclose Raphael J. Landovitz, MD, MSc, Gilead (Advisor or Review Panel member)Merck (Advisor or Review Panel member)Roche (Other Financial or Material Support, Speaker Honoraria) Anna Wald, MD, MPH, Aicuris (Individual(s) Involved: Self): Consultant; Gilead (Individual(s) Involved: Self): Consultant; GlaxoSmithKline (Individual(s) Involved: Self): Scientific Research Study Investigator; Merck (Individual(s) Involved: Self): DSMB participation; provision of vaccine for a study, Other Financial or Material Support; Sanofi (Individual(s) Involved: Self): Scientific Research Study Investigator; X-Vax (Individual(s) Involved: Self): Consultant Helen Y. Chu, MD MPH, Cepheid (Grant/Research Support)Ellume (Grant/Research Support)Glaxo Smith Kline (Consultant)Merck (Consultant)Sanofi-Pasteur (Grant/Research Support)
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Affiliation(s)
| | - Anna Bershteyn
- New York University Grossman School of Medicine, New York, New York
| | | | | | - Lorna Thorpe
- New York University Grossman School of Medicine, New York, New York
| | | | - Kathleen Neuzil
- University of Maryland School of Medicine, Baltimore, Maryland
| | - Miriam K Laufer
- University of Maryland School of Medicine, Baltimore, Maryland
| | - Meagan Deming
- Center for Vaccine Development, University of Maryland Medical Center, Baltimore, Maryland
| | | | | | | | | | | | | | - Risa Hoffman
- University of California, Los Angeles, California
| | | | | | | | | | | | | | | | | | | | - Anna Wald
- University of Washington, Seattle, Washington
| | - Anna Wald
- University of Washington, Seattle, Washington
| | | | - Helen Y Chu
- University of Washington, Seattle, Washington
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Bershteyn A, Schwartz MD, Thorpe LE, Paasche-Orlow MK, Kissinger P, Stankiewicz Karita HC, Laufer MK, Hoffman RM, Landovitz RJ, Paolino K, Barnabas RV. Taking a stand against the politicization of medical research: how 'swinging the pendulum' poses a hazard to clinical trials, study participants, and the progress of science. Expert Rev Clin Immunol 2020; 17:101-103. [PMID: 33284056 DOI: 10.1080/1744666x.2020.1860758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Anna Bershteyn
- Department of Population Health, NYU Grossman School of Medicine, New York, USA
| | - Mark D Schwartz
- Department of Population Health, NYU Grossman School of Medicine, New York, USA.,VA New York Harbor Healthcare System, New York, USA
| | - Lorna E Thorpe
- Department of Population Health, NYU Grossman School of Medicine, New York, USA
| | - Michael K Paasche-Orlow
- Department of Medicine, Boston University School of Medicine and Boston Medical Center, Boston, Massachusetts
| | - Patricia Kissinger
- Department of Epidemiology, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | | | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Risa M Hoffman
- David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Raphael J Landovitz
- David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Kristopher Paolino
- Division of Infectious Disease, SUNY Upstate Medical University, Syracuse, New York
| | - Ruanne V Barnabas
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington.,Department of Global Health, University of Washington School of Medicine, Seattle, Washington
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Cohee LM, Opondo C, Clarke SE, Halliday KE, Cano J, Shipper AG, Barger-Kamate B, Djimde A, Diarra S, Dokras A, Kamya MR, Lutumba P, Ly AB, Nankabirwa JI, Njagi JK, Maiga H, Maiteki-Sebuguzi C, Matangila J, Okello G, Rohner F, Roschnik N, Rouhani S, Sissoko MS, Staedke SG, Thera MA, Turner EL, Van Geertruyden JP, Zimmerman MB, Jukes MCH, Brooker SJ, Allen E, Laufer MK, Chico RM. Preventive malaria treatment among school-aged children in sub-Saharan Africa: a systematic review and meta-analyses. Lancet Glob Health 2020; 8:e1499-e1511. [PMID: 33222799 PMCID: PMC7721819 DOI: 10.1016/s2214-109x(20)30325-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 05/09/2020] [Accepted: 07/02/2020] [Indexed: 01/19/2023]
Abstract
BACKGROUND The burden of malaria infection in sub-Saharan Africa among school-aged children aged 5-15 years is underappreciated and represents an important source of human-to-mosquito transmission of Plasmodium falciparum. Additional interventions are needed to control and eliminate malaria. We aimed to assess whether preventive treatment of malaria might be an effective means of reducing P falciparum infection and anaemia in school-aged children and lowering parasite transmission. METHODS In this systematic review and two meta-analyses, we searched the online databases PubMed, Embase, Cochrane CENTRAL, and Clinicaltrials.gov for intervention studies published between Jan 1, 1990, and Dec 14, 2018. We included randomised studies that assessed the effect of antimalarial treatment among asymptomatic school-aged children aged 5-15 years in sub-Saharan Africa on prevalence of P falciparum infection and anaemia, clinical malaria, and cognitive function. We first extracted data for a study-level meta-analysis, then contacted research groups to request data for an individual participant data meta-analysis. Outcomes of interest included prevalence of P falciparum infection detected by microscopy, anaemia (study defined values or haemoglobin less than age-adjusted and sex-adjusted values), clinical malaria (infection and symptoms on the basis of study-specific definitions) during follow-up, and code transmission test scores. We assessed effects by treatment type and duration of time protected, and explored effect modification by transmission setting. For study-level meta-analysis, we calculated risk ratios for binary outcomes and standardised mean differences for continuous outcomes and pooled outcomes using fixed-effect and random-effects models. We used a hierarchical generalised linear model for meta-analysis of individual participant data. This study is registered with PROSPERO, CRD42016030197. FINDINGS Of 628 studies identified, 13 were eligible for the study-level meta-analysis (n=16 309). Researchers from 11 studies contributed data on at least one outcome (n=15 658) for an individual participant data meta-analysis. Interventions and study designs were highly heterogeneous; overall risk of bias was low. In the study-level meta-analysis, treatment was associated with reductions in P falciparum prevalence (risk ratio [RR] 0·27, 95% CI 0·17-0·44), anaemia (0·77, 0·65-0·91), and clinical malaria (0·40, 0·28-0·56); results for cognitive outcomes are not presented because data were only available for three trials. In our individual participant data meta-analysis, we found treatment significantly decreased P falciparum prevalence (adjusted RR [ARR] 0·46, 95% CI 0·40-0·53; p<0·0001; 15 648 individuals; 11 studies), anaemia (ARR 0·85, 0·77-0·92; p<0·0001; 15 026 individuals; 11 studies), and subsequent clinical malaria (ARR 0·50, 0·39-0·60; p<0·0001; 1815 individuals; four studies) across transmission settings. We detected a marginal effect on cognitive function in children older than 10 years (adjusted mean difference in standardised test scores 0·36, 0·01-0·71; p=0·044; 3962 individuals; five studies) although we found no significant effect when combined across all ages. INTERPRETATION Preventive treatment of malaria among school-aged children significantly decreases P falciparum prevalence, anaemia, and risk of subsequent clinical malaria across transmission settings. Policy makers and programme managers should consider preventive treatment of malaria to protect this age group and advance the goal of malaria elimination, while weighing these benefits against potential risks of chemoprevention. FUNDING US National Institutes of Health and Burroughs Wellcome Fund/ASTMH Fellowship.
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Affiliation(s)
- Lauren M Cohee
- Center for Vaccine Development and Global Health, University of Maryland, Baltimore, MA, USA
| | - Charles Opondo
- Department of Medical Statistics, Faculty of Epidemiology and Population Health, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Siân E Clarke
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Katherine E Halliday
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Jorge Cano
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Andrea G Shipper
- University of Maryland School of Medicine, and Health Sciences and Human Services Library, University of Maryland, Baltimore, MA, USA
| | | | - Abdoulaye Djimde
- Faculty of Medicine, Pharmacy, and Odnonto-Stomatology, Malaria Research and Training Center, University of Sciences, Techniques and Technologies of Bamako, Mali
| | | | - Aditi Dokras
- Department of Pediatrics, University of Maryland, Baltimore, MA, USA
| | - Moses R Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Pascal Lutumba
- Tropical Medicine Department, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | | | - Joaniter I Nankabirwa
- School of Medicine, Makerere University College of Health Sciences, Kampala, Uganda; Infectious Diseases Research Collaboration, Kampala, Uganda
| | - J Kiambo Njagi
- National Malaria Control Programme, Ministry of Health, Nairobi, Kenya
| | - Hamma Maiga
- Faculty of Medicine, Pharmacy, and Odnonto-Stomatology, Malaria Research and Training Center, University of Sciences, Techniques and Technologies of Bamako, Mali
| | | | - Junior Matangila
- Tropical Medicine Department, University of Kinshasa, Kinshasa, Democratic Republic of Congo; Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - George Okello
- Health Systems and Social Science Research Group, Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | | | - Saba Rouhani
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK; Save the Children, Bamako, Mali
| | - Mahamadou S Sissoko
- Faculty of Medicine, Pharmacy, and Odnonto-Stomatology, Malaria Research and Training Center, University of Sciences, Techniques and Technologies of Bamako, Mali
| | - Sarah G Staedke
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Mahamadou A Thera
- Faculty of Medicine, Pharmacy, and Odnonto-Stomatology, Malaria Research and Training Center, University of Sciences, Techniques and Technologies of Bamako, Mali
| | - Elizabeth L Turner
- Department of Biostatistics & Bioinformatics and Duke Global Health Institute, Duke University, Durham, NC, USA
| | | | - Michael B Zimmerman
- Institute of Food, Nutrition, and Health, Swiss Federal Institute of Technology, Zurich, Switzerland
| | | | | | - Elizabeth Allen
- Department of Medical Statistics, Faculty of Epidemiology and Population Health, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland, Baltimore, MA, USA
| | - R Matthew Chico
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
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Hsu H, Boudova S, Mvula G, Divala TH, Rach D, Mungwira RG, Boldrin F, Degiacomi G, Manganelli R, Laufer MK, Cairo C. Age-related changes in PD-1 expression coincide with increased cytotoxic potential in Vδ2 T cells during infancy. Cell Immunol 2020; 359:104244. [PMID: 33248366 DOI: 10.1016/j.cellimm.2020.104244] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 10/08/2020] [Accepted: 10/30/2020] [Indexed: 12/19/2022]
Abstract
Human Vγ9Vδ2 T cells respond to several diverse pathogens by sensing microbial cholesterol intermediates. Unlike CD4 T cells, they are poised for rapid Th1-like responses even before birth, which allows them to play a key role in the first line of defense against pathogens in early life. However, their regulation and functional maturation during infancy (in particular the acquisition of cytotoxic potential) remain understudied. We thus characterized their responses to cholesterol intermediates and Bacille Calmette-Guérin in a cohort of African neonates and 12-month-old infants. Infant Vδ2 lymphocytes exhibited intermediate or adult-like expression of markers associated with differentiation or function, intermediate proliferative responses, and adult-like cytotoxic potential. The enhancement of Vδ2 cell cytotoxic potential coincided with decreasing PD-1 and increasing NKG2A expression. Our results are consistent with the hypothesis that switching from a PD-1+ to a NKG2A+ phenotype during infancy indicates a shift in mechanisms regulating Vδ2 T cell function.
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Affiliation(s)
- Haoting Hsu
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Sarah Boudova
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Godfrey Mvula
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Titus H Divala
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - David Rach
- Molecular Microbiology and Immunology Graduate Program, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Randy G Mungwira
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Francesca Boldrin
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | - Giulia Degiacomi
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | | | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Cristiana Cairo
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, United States.
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McCann RS, Cohee LM, Goupeyou-Youmsi J, Laufer MK. Maximizing Impact: Can Interventions to Prevent Clinical Malaria Reduce Parasite Transmission? Trends Parasitol 2020; 36:906-913. [PMID: 32917511 PMCID: PMC7581555 DOI: 10.1016/j.pt.2020.07.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 06/19/2020] [Accepted: 07/20/2020] [Indexed: 10/23/2022]
Abstract
Malaria interventions may reduce the burden of clinical malaria disease, the transmission of malaria parasites, or both. As malaria interventions are developed and evaluated, including those interventions primarily targeted at reducing disease, they may also impact parasite transmission. Achieving global malaria eradication will require optimizing the transmission-reducing potential of all available interventions. Herein, we discuss the relationship between malaria parasite transmission and disease, including mechanisms by which disease-targeting interventions might also impact parasite transmission. We then focus on three malaria interventions with strong evidence for reducing the burden of clinical malaria disease and examine their potential for also reducing malaria parasite transmission.
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Affiliation(s)
- Robert S McCann
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Lauren M Cohee
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jessy Goupeyou-Youmsi
- MAC Communicable Diseases Action Centre, College of Medicine, University of Malawi, Blantyre, Malawi
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
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Saito M, Mansoor R, Kennon K, Anvikar AR, Ashley EA, Chandramohan D, Cohee LM, D'Alessandro U, Genton B, Gilder ME, Juma E, Kalilani-Phiri L, Kuepfer I, Laufer MK, Lwin KM, Meshnick SR, Mosha D, Mwapasa V, Mwebaza N, Nambozi M, Ndiaye JLA, Nosten F, Nyunt M, Ogutu B, Parikh S, Paw MK, Phyo AP, Pimanpanarak M, Piola P, Rijken MJ, Sriprawat K, Tagbor HK, Tarning J, Tinto H, Valéa I, Valecha N, White NJ, Wiladphaingern J, Stepniewska K, McGready R, Guérin PJ. Efficacy and tolerability of artemisinin-based and quinine-based treatments for uncomplicated falciparum malaria in pregnancy: a systematic review and individual patient data meta-analysis. Lancet Infect Dis 2020; 20:943-952. [PMID: 32530424 PMCID: PMC7391007 DOI: 10.1016/s1473-3099(20)30064-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/17/2020] [Accepted: 01/30/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Malaria in pregnancy affects both the mother and the fetus. However, evidence supporting treatment guidelines for uncomplicated (including asymptomatic) falciparum malaria in pregnant women is scarce and assessed in varied ways. We did a systematic literature review and individual patient data (IPD) meta-analysis to compare the efficacy and tolerability of different artemisinin-based or quinine-based treatments for malaria in pregnant women. METHODS We did a systematic review of interventional or observational cohort studies assessing the efficacy of artemisinin-based or quinine-based treatments in pregnancy. Seven databases (MEDLINE, Embase, Global Health, Cochrane Library, Scopus, Web of Science, and Literatura Latino Americana em Ciencias da Saude) and two clinical trial registries (International Clinical Trials Registry Platform and ClinicalTrials.gov) were searched. The final search was done on April 26, 2019. Studies that assessed PCR-corrected treatment efficacy in pregnancy with follow-up of 28 days or more were included. Investigators of identified studies were invited to share data from individual patients. The outcomes assessed included PCR-corrected efficacy, PCR-uncorrected efficacy, parasite clearance, fever clearance, gametocyte development, and acute adverse events. One-stage IPD meta-analysis using Cox and logistic regression with random-effects was done to estimate the risk factors associated with PCR-corrected treatment failure, using artemether-lumefantrine as the reference. This study is registered with PROSPERO, CRD42018104013. FINDINGS Of the 30 studies assessed, 19 were included, representing 92% of patients in the literature (4968 of 5360 episodes). Risk of PCR-corrected treatment failure was higher for the quinine monotherapy (n=244, adjusted hazard ratio [aHR] 6·11, 95% CI 2·57-14·54, p<0·0001) but lower for artesunate-amodiaquine (n=840, 0·27, 95% 0·14-0·52, p<0·0001), artesunate-mefloquine (n=1028, 0·56, 95% 0·34-0·94, p=0·03), and dihydroartemisinin-piperaquine (n=872, 0·35, 95% CI 0·18-0·68, p=0·002) than artemether-lumefantrine (n=1278) after adjustment for baseline asexual parasitaemia and parity. The risk of gametocyte carriage on day 7 was higher after quinine-based therapy than artemisinin-based treatment (adjusted odds ratio [OR] 7·38, 95% CI 2·29-23·82). INTERPRETATION Efficacy and tolerability of artemisinin-based combination therapies (ACTs) in pregnant women are better than quinine. The lower efficacy of artemether-lumefantrine compared with other ACTs might require dose optimisation. FUNDING The Bill & Melinda Gates Foundation, ExxonMobil Foundation, and the University of Oxford Clarendon Fund.
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Affiliation(s)
- Makoto Saito
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, UK,Infectious Diseases Data Observatory (IDDO), Oxford, UK,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK,Dr Makoto Saito, Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford OX3 7LG, UK
| | - Rashid Mansoor
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, UK,Infectious Diseases Data Observatory (IDDO), Oxford, UK,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Kalynn Kennon
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, UK,Infectious Diseases Data Observatory (IDDO), Oxford, UK,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Anupkumar R Anvikar
- Indian Council of Medical Research, National Institute of Malaria Research, New Delhi, India
| | - Elizabeth A Ashley
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK,Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Vientiane, Laos
| | - Daniel Chandramohan
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Lauren M Cohee
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Umberto D'Alessandro
- Medical Research Council Unit, The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Blaise Genton
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland,University Center of General Medicine and Public Health, Lausanne, Switzerland
| | - Mary Ellen Gilder
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - Linda Kalilani-Phiri
- Department of Medicine, University of Malawi College of Medicine, Blantyre, Malawi
| | - Irene Kuepfer
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Khin Maung Lwin
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Steven R Meshnick
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, NC, USA
| | | | - Victor Mwapasa
- Department of Medicine, University of Malawi College of Medicine, Blantyre, Malawi
| | - Norah Mwebaza
- Infectious Disease Research Collaboration, Makerere University, Kampala, Uganda
| | - Michael Nambozi
- Department of Clinical Sciences, Tropical Diseases Research Centre, Ndola, Zambia
| | | | - François Nosten
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK,Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Myaing Nyunt
- Duke Global Health Institute, Duke University, Durham, NC, USA
| | | | - Sunil Parikh
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | - Moo Kho Paw
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Aung Pyae Phyo
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand,Myanmar–Oxford Clinical Research Unit, Yangon, Myanmar
| | - Mupawjay Pimanpanarak
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Patrice Piola
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Marcus J Rijken
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand,Department of Obstetrics and Gynecology, Division of Woman and Baby, University Medical Center Utrecht, Utrecht, Netherlands
| | - Kanlaya Sriprawat
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Harry K Tagbor
- School of Medicine, University of Health and Allied Sciences, Ho, Ghana
| | - Joel Tarning
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, UK,Infectious Diseases Data Observatory (IDDO), Oxford, UK,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK,Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Halidou Tinto
- Clinical Research Unit of Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Innocent Valéa
- Clinical Research Unit of Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Neena Valecha
- Indian Council of Medical Research, National Institute of Malaria Research, New Delhi, India
| | - Nicholas J White
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK,Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jacher Wiladphaingern
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Kasia Stepniewska
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, UK,Infectious Diseases Data Observatory (IDDO), Oxford, UK,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Rose McGready
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK,Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Philippe J Guérin
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, UK,Infectious Diseases Data Observatory (IDDO), Oxford, UK,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK,Correspondence to: Prof Philippe J Guérin, Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford OX3 7LG, UK
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Ouattara A, Niangaly A, Adams M, Coulibaly D, Kone AK, Traore K, Laurens MB, Tolo Y, Kouriba B, Diallo DA, Doumbo OK, Plowe CV, Djimdé A, Thera MA, Laufer MK, Takala-Harrison S, Silva JC. Epitope-based sieve analysis of Plasmodium falciparum sequences from a FMP2.1/AS02 A vaccine trial is consistent with differential vaccine efficacy against immunologically relevant AMA1 variants. Vaccine 2020; 38:5700-5706. [PMID: 32571720 DOI: 10.1016/j.vaccine.2020.06.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 05/28/2020] [Accepted: 06/12/2020] [Indexed: 01/23/2023]
Abstract
To prevent premature dismissal of promising vaccine programs, it is critical to determine if lack of efficacy in the field is due to allele specific-efficacy, rather than to the lack of immunogenicity of the candidate antigen. Here we use samples collected during a field trial of the AMA1-based FMP2.1/AS02A malaria vaccine, which incorporates the AMA1 variant encoded by the reference Plasmodium falciparum 3D7 strain, to assess the usefulness of epitope-based sieve analysis for the detection of vaccine-induced allele-specific immune responses. The samples used are from volunteers who received the malaria vaccine FMP2.1/AS02A or a control (rabies vaccine), during a vaccine efficacy field trial, and who later developed malaria. In a previous study, P. falciparum DNA was extracted from all samples, and the ama1 locus amplified and sequenced. Here, a sieve analysis was used to measure T and B-cell escape, and difference in 3D7-like epitopes in the two treatment arms. Overall, no difference was observed in mean amino acid distance to the 3D7 AMA1 variant between sequences from vaccinees and controls in B-cell epitopes. However, we found a significantly greater proportion of 3D7-like T-cell epitopes that map to the AMA1 cluster one loop (c1L) region in the control vs. the vaccinee group (p = 0.02), consistent with allele-specific vaccine efficacy. Interestingly, AMA1 epitopes in infections from vaccinees had higher mean IC50, and consequently lower binding affinity, than epitopes generated from the control group (p = 0.01), suggesting that vaccine-induced selection impacted the immunological profile of the strains that pass through the sieve imposed by the vaccine-induced protection. These findings are consistent with a vaccine-derived sieve effect on the c1L region of AMA1 and suggest that sieve analyses of malaria vaccine trial samples targeted to epitopes identified in silico can help identify protective malaria antigens that may be efficacious if combined in a multivalent vaccine.
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Affiliation(s)
- Amed Ouattara
- Malaria Research Program, Center for Vaccine Development and Global Heath, University of Maryland School of Medicine, 685 West Baltimore Street HSF1-480 Baltimore, MD 21201, USA; Malaria Research and Training Center, University of Sciences, Techniques and Technology, BP 1805, Bamako, Mali.
| | - Amadou Niangaly
- Malaria Research and Training Center, University of Sciences, Techniques and Technology, BP 1805, Bamako, Mali.
| | - Matthew Adams
- Malaria Research Program, Center for Vaccine Development and Global Heath, University of Maryland School of Medicine, 685 West Baltimore Street HSF1-480 Baltimore, MD 21201, USA.
| | - Drissa Coulibaly
- Malaria Research and Training Center, University of Sciences, Techniques and Technology, BP 1805, Bamako, Mali.
| | - Abdoulaye K Kone
- Malaria Research and Training Center, University of Sciences, Techniques and Technology, BP 1805, Bamako, Mali.
| | - Karim Traore
- Malaria Research and Training Center, University of Sciences, Techniques and Technology, BP 1805, Bamako, Mali.
| | - Matthew B Laurens
- Malaria Research Program, Center for Vaccine Development and Global Heath, University of Maryland School of Medicine, 685 West Baltimore Street HSF1-480 Baltimore, MD 21201, USA.
| | - Youssouf Tolo
- Malaria Research and Training Center, University of Sciences, Techniques and Technology, BP 1805, Bamako, Mali.
| | - Bourema Kouriba
- Malaria Research and Training Center, University of Sciences, Techniques and Technology, BP 1805, Bamako, Mali.
| | - Dapa A Diallo
- Malaria Research and Training Center, University of Sciences, Techniques and Technology, BP 1805, Bamako, Mali.
| | - Ogobara K Doumbo
- Malaria Research and Training Center, University of Sciences, Techniques and Technology, BP 1805, Bamako, Mali.
| | | | - Abdoulaye Djimdé
- Malaria Research and Training Center, University of Sciences, Techniques and Technology, BP 1805, Bamako, Mali.
| | - Mahamadou A Thera
- Malaria Research and Training Center, University of Sciences, Techniques and Technology, BP 1805, Bamako, Mali.
| | - Miriam K Laufer
- Malaria Research Program, Center for Vaccine Development and Global Heath, University of Maryland School of Medicine, 685 West Baltimore Street HSF1-480 Baltimore, MD 21201, USA.
| | - Shannon Takala-Harrison
- Malaria Research Program, Center for Vaccine Development and Global Heath, University of Maryland School of Medicine, 685 West Baltimore Street HSF1-480 Baltimore, MD 21201, USA.
| | - Joana C Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, 670 West Baltimore St, Baltimore, MD 21201, USA; Department of Microbiology and Immunology, University of Maryland School of Medicine, 685 West Baltimore St, Baltimore, MD 21201, USA.
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Kapito-Tembo A, Mathanga D, Bauleni A, Nyirenda O, Pensulo P, Ali D, Valim C, Taylor TE, Laufer MK. Prevalence and Clinical Management of Non-malarial Febrile Illnesses among Outpatients in the Era of Universal Malaria Testing in Malawi. Am J Trop Med Hyg 2020; 103:887-893. [PMID: 32588795 DOI: 10.4269/ajtmh.18-0800] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Increasing access to rapid diagnostic tests for malaria (mRDTs) has raised awareness of the challenges healthcare workers face in managing non-malarial febrile illnesses (NMFIs). We examined NMFI prevalence, clinical diagnoses, and prescribing practices in outpatient clinics across different malaria transmission settings in Malawi. Standardized facility-based malaria surveillance was conducted at three facilities one of every 4 weeks over 2 years. Information on demographics, presenting symptoms, temperature, clinical diagnosis, and treatment were collected from outpatients presenting with malaria-like symptoms. Of the 25,486 patients with fever, 69% had NMFI. Non-malarial febrile illness prevalence was lower in 5- to 15-year-old patients (55%) than in children < 5 years (72%) and adults > 15 years of age (77%). The most common clinical diagnoses among febrile patients with negative mRDTs in all age-groups and settings were respiratory infections (46%), sepsis (29%), gastroenteritis (13%), musculoskeletal pain (9%), and malaria (5%). Antibiotic prescribing was high in all age-groups and settings. Trimethoprim-sulfamethoxazole (40%) and amoxicillin (29%) were the most commonly prescribed antibiotics and were used for nearly all clinical diagnoses. In these settings with minimal access to diagnostic tools, patients with fever and a negative mRDT received a limited number of clinical diagnoses. Many were likely to be inaccurate and were associated with the inappropriate use of the limited range of available antibiotics. Prescription and diagnostic practices for NMFIs in the facilities require research and policy input. Resource-limited malaria-endemic countries urgently need more point-of-care diagnostic tools and evidence-based diagnosis and treatment algorithms to provide effective and cost-efficient care.
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Affiliation(s)
- Atupele Kapito-Tembo
- Malaria Alert Center, University of Malawi College of Medicine, Blantyre, Malawi
| | - Don Mathanga
- Malaria Alert Center, University of Malawi College of Medicine, Blantyre, Malawi
| | - Andrew Bauleni
- Malaria Alert Center, University of Malawi College of Medicine, Blantyre, Malawi
| | - Osward Nyirenda
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Paul Pensulo
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Doreen Ali
- Malawi National Malaria Control Program, Lilongwe, Malawi
| | - Clarissa Valim
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts
| | - Terrie E Taylor
- College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan.,Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
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Saito M, Mansoor R, Kennon K, Anvikar AR, Ashley EA, Chandramohan D, Cohee LM, D'Alessandro U, Genton B, Gilder ME, Juma E, Kalilani-Phiri L, Kuepfer I, Laufer MK, Lwin KM, Meshnick SR, Mosha D, Muehlenbachs A, Mwapasa V, Mwebaza N, Nambozi M, Ndiaye JLA, Nosten F, Nyunt M, Ogutu B, Parikh S, Paw MK, Phyo AP, Pimanpanarak M, Piola P, Rijken MJ, Sriprawat K, Tagbor HK, Tarning J, Tinto H, Valéa I, Valecha N, White NJ, Wiladphaingern J, Stepniewska K, McGready R, Guérin PJ. Pregnancy outcomes and risk of placental malaria after artemisinin-based and quinine-based treatment for uncomplicated falciparum malaria in pregnancy: a WorldWide Antimalarial Resistance Network systematic review and individual patient data meta-analysis. BMC Med 2020; 18:138. [PMID: 32482173 PMCID: PMC7263905 DOI: 10.1186/s12916-020-01592-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 04/14/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Malaria in pregnancy, including asymptomatic infection, has a detrimental impact on foetal development. Individual patient data (IPD) meta-analysis was conducted to compare the association between antimalarial treatments and adverse pregnancy outcomes, including placental malaria, accompanied with the gestational age at diagnosis of uncomplicated falciparum malaria infection. METHODS A systematic review and one-stage IPD meta-analysis of studies assessing the efficacy of artemisinin-based and quinine-based treatments for patent microscopic uncomplicated falciparum malaria infection (hereinafter uncomplicated falciparum malaria) in pregnancy was conducted. The risks of stillbirth (pregnancy loss at ≥ 28.0 weeks of gestation), moderate to late preterm birth (PTB, live birth between 32.0 and < 37.0 weeks), small for gestational age (SGA, birthweight of < 10th percentile), and placental malaria (defined as deposition of malaria pigment in the placenta with or without parasites) after different treatments of uncomplicated falciparum malaria were assessed by mixed-effects logistic regression, using artemether-lumefantrine, the most used antimalarial, as the reference standard. Registration PROSPERO: CRD42018104013. RESULTS Of the 22 eligible studies (n = 5015), IPD from16 studies were shared, representing 95.0% (n = 4765) of the women enrolled in literature. Malaria treatment in this pooled analysis mostly occurred in the second (68.4%, 3064/4501) or third trimester (31.6%, 1421/4501), with gestational age confirmed by ultrasound in 91.5% (4120/4503). Quinine (n = 184) and five commonly used artemisinin-based combination therapies (ACTs) were included: artemether-lumefantrine (n = 1087), artesunate-amodiaquine (n = 775), artesunate-mefloquine (n = 965), and dihydroartemisinin-piperaquine (n = 837). The overall pooled proportion of stillbirth was 1.1% (84/4361), PTB 10.0% (619/4131), SGA 32.3% (1007/3707), and placental malaria 80.1% (2543/3035), and there were no significant differences of considered outcomes by ACT. Higher parasitaemia before treatment was associated with a higher risk of SGA (adjusted odds ratio [aOR] 1.14 per 10-fold increase, 95% confidence interval [CI] 1.03 to 1.26, p = 0.009) and deposition of malaria pigment in the placenta (aOR 1.67 per 10-fold increase, 95% CI 1.42 to 1.96, p < 0.001). CONCLUSIONS The risks of stillbirth, PTB, SGA, and placental malaria were not different between the commonly used ACTs. The risk of SGA was high among pregnant women infected with falciparum malaria despite treatment with highly effective drugs. Reduction of malaria-associated adverse birth outcomes requires effective prevention in pregnant women.
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Affiliation(s)
- Makoto Saito
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, UK.
- Infectious Diseases Data Observatory (IDDO), Oxford, UK.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - Rashid Mansoor
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, UK
- Infectious Diseases Data Observatory (IDDO), Oxford, UK
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Kalynn Kennon
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, UK
- Infectious Diseases Data Observatory (IDDO), Oxford, UK
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - Elizabeth A Ashley
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Vientiane, Lao PDR
| | | | - Lauren M Cohee
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Umberto D'Alessandro
- Medical Research Council Unit, The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Blaise Genton
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- University Center of General Medicine and Public Health, Lausanne, Switzerland
| | - Mary Ellen Gilder
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand
| | | | - Linda Kalilani-Phiri
- Department of Medicine, University of Malawi College of Medicine, Blantyre, Malawi
| | - Irene Kuepfer
- London School of Hygiene and Tropical Medicine, London, UK
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Khin Maung Lwin
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand
| | - Steven R Meshnick
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
| | | | | | - Victor Mwapasa
- Department of Medicine, University of Malawi College of Medicine, Blantyre, Malawi
| | - Norah Mwebaza
- Infectious Disease Research Collaboration, Makerere University, Kampala, Uganda
| | - Michael Nambozi
- Department of Clinical Sciences, Tropical Diseases Research Centre, Ndola, Zambia
| | | | - François Nosten
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand
| | - Myaing Nyunt
- Duke Global Health Institute, Duke University, Durham, NC, USA
| | | | - Sunil Parikh
- Yale School of Public Health, New Haven, CT, USA
| | - Moo Kho Paw
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand
| | - Aung Pyae Phyo
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand
- Myanmar-Oxford Clinical Research Unit, Yangon, Myanmar
| | - Mupawjay Pimanpanarak
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand
| | | | - Marcus J Rijken
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand
- Department of Obstetrics and Gynecology, Division of Woman and Baby, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Kanlaya Sriprawat
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand
| | - Harry K Tagbor
- School of Medicine, University of Health and Allied Sciences, Ho, Ghana
| | - Joel Tarning
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, UK
- Infectious Diseases Data Observatory (IDDO), Oxford, UK
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Halidou Tinto
- Clinical Research Unit of Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Innocent Valéa
- Clinical Research Unit of Nanoro, Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Neena Valecha
- ICMR-National Institute of Malaria Research, New Delhi, India
| | - Nicholas J White
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jacher Wiladphaingern
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand
| | - Kasia Stepniewska
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, UK
- Infectious Diseases Data Observatory (IDDO), Oxford, UK
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Rose McGready
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Tak, Thailand
| | - Philippe J Guérin
- WorldWide Antimalarial Resistance Network (WWARN), Oxford, UK.
- Infectious Diseases Data Observatory (IDDO), Oxford, UK.
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
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Shah Z, Adams M, Moser KA, Shrestha B, Stucke EM, Laufer MK, Serre D, Silva JC, Takala-Harrison S. Optimization of parasite DNA enrichment approaches to generate whole genome sequencing data for Plasmodium falciparum from low parasitaemia samples. Malar J 2020; 19:135. [PMID: 32228559 PMCID: PMC7106660 DOI: 10.1186/s12936-020-03195-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 03/20/2020] [Indexed: 12/30/2022] Open
Abstract
Background Owing to the large amount of host DNA in clinical samples, generation of high-quality Plasmodium falciparum whole genome sequencing (WGS) data requires enrichment for parasite DNA. Enrichment is often achieved by leukocyte depletion of infected blood prior to storage. However, leukocyte depletion is difficult in low-resource settings and limits analysis to prospectively-collected samples. As a result, approaches such as selective whole genome amplification (sWGA) are being used to enrich for parasite DNA. However, sWGA has had limited success in generating reliable sequencing data from low parasitaemia samples. In this study, enzymatic digestion with MspJI prior to sWGA and whole genome sequencing was evaluated to determine whether this approach improved genome coverage compared to sWGA alone. The potential of sWGA to cause amplification bias in polyclonal infections was also examined. Methods DNA extracted from laboratory-created dried blood spots was treated with a modification-dependent restriction endonuclease, MspJI, and filtered via vacuum filtration. Samples were then selectively amplified using a previously reported sWGA protocol and subjected to WGS. Genome coverage statistics were compared between the optimized sWGA approach and the previously reported sWGA approach performed in parallel. Differential amplification by sWGA was assessed by comparing WGS data generated from lab-created mixtures of parasite isolates, from the same geographical region, generated with or without sWGA. Results MspJI digestion did not enrich for parasite DNA. Samples that underwent vacuum filtration (without MspJI digestion) prior to sWGA had the highest parasite DNA concentration and displayed greater genome coverage compared to MspJI + sWGA and sWGA alone, particularly for low parasitaemia samples. The optimized sWGA (filtration + sWGA) approach was successfully used to generate WGS data from 218 non-leukocyte depleted field samples from Malawi. Sequences from lab-created mixtures of parasites did not show evidence of differential amplification of parasite strains compared to directly sequenced samples. Conclusion This optimized sWGA approach is a reliable method to obtain WGS data from non-leukocyte depleted, low parasitaemia samples. The absence of amplification bias in data generated from mixtures of isolates from the same geographic region suggests that this approach can be appropriately used for molecular epidemiological studies.
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Affiliation(s)
- Zalak Shah
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Matthew Adams
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kara A Moser
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Biraj Shrestha
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Emily M Stucke
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Miriam K Laufer
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - David Serre
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Joana C Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA.,Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Shannon Takala-Harrison
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.
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Patson N, Mukaka M, Otwombe KN, Kazembe L, Mathanga DP, Mwapasa V, Kabaghe AN, Eijkemans MJC, Laufer MK, Chirwa T. Systematic review of statistical methods for safety data in malaria chemoprevention in pregnancy trials. Malar J 2020; 19:119. [PMID: 32197619 PMCID: PMC7085184 DOI: 10.1186/s12936-020-03190-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Accepted: 03/12/2020] [Indexed: 12/28/2022] Open
Abstract
Background Drug safety assessments in clinical trials present unique analytical challenges. Some of these include adjusting for individual follow-up time, repeated measurements of multiple outcomes and missing data among others. Furthermore, pre-specifying appropriate analysis becomes difficult as some safety endpoints are unexpected. Although existing guidelines such as CONSORT encourage thorough reporting of adverse events (AEs) in clinical trials, they provide limited details for safety data analysis. The limited guidelines may influence suboptimal analysis by failing to account for some analysis challenges above. A typical example where such challenges exist are trials of anti-malarial drugs for malaria prevention during pregnancy. Lack of proper standardized evaluation of the safety of antimalarial drugs has limited the ability to draw conclusions about safety. Therefore, a systematic review was conducted to establish the current practice in statistical analysis for preventive antimalarial drug safety in pregnancy. Methods The search included five databases (PubMed, Embase, Scopus, Malaria in Pregnancy Library and Cochrane Central Register of Controlled Trials) to identify original English articles reporting Phase III randomized controlled trials (RCTs) on anti-malarial drugs for malaria prevention in pregnancy published from January 2010 to July 2019. Results Eighteen trials were included in this review that collected multiple longitudinal safety outcomes including AEs. Statistical analysis and reporting of the safety outcomes in all the trials used descriptive statistics; proportions/counts (n = 18, 100%) and mean/median (n = 2, 11.1%). Results presentation included tabular (n = 16, 88.9%) and text description (n = 2, 11.1%). Univariate inferential methods were reported in most trials (n = 16, 88.9%); including Chi square/Fisher’s exact test (n = 12, 66.7%), t test (n = 2, 11.1%) and Mann–Whitney/Wilcoxon test (n = 1, 5.6%). Multivariable methods, including Poisson and negative binomial were reported in few trials (n = 3, 16.7%). Assessment of a potential link between missing efficacy data and safety outcomes was not reported in any of the trials that reported efficacy missing data (n = 7, 38.9%). Conclusion The review demonstrated that statistical analysis of safety data in anti-malarial drugs for malarial chemoprevention in pregnancy RCTs is inadequate. The analyses insufficiently account for multiple safety outcomes potential dependence, follow-up time and informative missing data which can compromise anti-malarial drug safety evidence development, based on the available data.
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Affiliation(s)
- Noel Patson
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa.,University of Malawi, College of Medicine, Blantyre, Malawi
| | - Mavuto Mukaka
- Mahidol Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand.,Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Kennedy N Otwombe
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa.,Perinatal HIV Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Lawrence Kazembe
- Department of Biostatistics, University of Namibia, Windhoek, Namibia
| | - Don P Mathanga
- University of Malawi, College of Medicine, Blantyre, Malawi
| | - Victor Mwapasa
- University of Malawi, College of Medicine, Blantyre, Malawi
| | | | - Marinus J C Eijkemans
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland, School of Medicine, 685 W. Baltimore St., HSF-1 Room 480, Baltimore, MD, 21201, USA.
| | - Tobias Chirwa
- School of Public Health, University of the Witwatersrand, Johannesburg, South Africa
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Buchwald AG, Sixpence A, Chimenya M, Damson M, Sorkin JD, Wilson ML, Seydel K, Hochman S, Mathanga DP, Taylor TE, Laufer MK. Clinical Implications of Asymptomatic Plasmodium falciparum Infections in Malawi. Clin Infect Dis 2020; 68:106-112. [PMID: 29788054 DOI: 10.1093/cid/ciy427] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 05/15/2018] [Indexed: 11/14/2022] Open
Abstract
Background Asymptomatic Plasmodium falciparum infections are common in Malawi; however, the implications of these infections for the burden of malaria illness are unknown. Whether asymptomatic infections eventually progress to malaria illness, persist without causing symptoms, or clear spontaneously remains undetermined. We identified asymptomatic infections and evaluated the associations between persistent asymptomatic infections and malaria illness. Methods Children and adults (N = 120) who presented at a health facility with uncomplicated malaria were followed monthly for 2 years. During follow-up visits, participants with malaria symptoms were tested and, if positive, treated. Samples from all visits were tested for parasites using both microscopy and polymerase chain reaction, and all malaria infections underwent genotyping. Cox frailty models were used to estimate the temporal association between asymptomatic infections and malaria illness episodes. Mixed models were used to estimate the odds of clinical symptoms associated with new versus persistent infections. Results Participants had a median follow-up time of 720 days. Asymptomatic infections were detected during 23% of visits. Persistent asymptomatic infections were associated with decreased risk of malaria illness in all ages (hazard ratio 0.50, P < .001). When asymptomatic infections preceded malaria illness, newly-acquired infections were detected at 92% of subsequent clinical episodes, independent of presence of persistent infections. Malaria illness among children was more likely due to newly-acquired infections (odds ratio, 1.4; 95% confidence interval, 1.3-1.5) than to persistent infections. Conclusions Asymptomatic P. falciparum infections are associated with decreased incidence of malaria illness, but do not protect against disease when new infection occurs.
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Affiliation(s)
- Andrea G Buchwald
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore
| | - Alick Sixpence
- Malaria Alert Center, University of Malawi College of Medicine, Blantyre
| | - Mabvuto Chimenya
- Malaria Alert Center, University of Malawi College of Medicine, Blantyre
| | - Milius Damson
- Malaria Alert Center, University of Malawi College of Medicine, Blantyre
| | - John D Sorkin
- Department of Veterans Affairs, Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore
| | - Mark L Wilson
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor
| | - Karl Seydel
- College of Osteopathic Medicine, Michigan State University, East Lansing
| | - Sarah Hochman
- Department of Medicine, New York University School of Medicine
| | - Don P Mathanga
- Malaria Alert Center, University of Malawi College of Medicine, Blantyre
| | - Terrie E Taylor
- College of Osteopathic Medicine, Michigan State University, East Lansing
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore
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Moser KA, Drábek EF, Dwivedi A, Stucke EM, Crabtree J, Dara A, Shah Z, Adams M, Li T, Rodrigues PT, Koren S, Phillippy AM, Munro JB, Ouattara A, Sparklin BC, Dunning Hotopp JC, Lyke KE, Sadzewicz L, Tallon LJ, Spring MD, Jongsakul K, Lon C, Saunders DL, Ferreira MU, Nyunt MM, Laufer MK, Travassos MA, Sauerwein RW, Takala-Harrison S, Fraser CM, Sim BKL, Hoffman SL, Plowe CV, Silva JC. Strains used in whole organism Plasmodium falciparum vaccine trials differ in genome structure, sequence, and immunogenic potential. Genome Med 2020; 12:6. [PMID: 31915075 PMCID: PMC6950926 DOI: 10.1186/s13073-019-0708-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 12/19/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Plasmodium falciparum (Pf) whole-organism sporozoite vaccines have been shown to provide significant protection against controlled human malaria infection (CHMI) in clinical trials. Initial CHMI studies showed significantly higher durable protection against homologous than heterologous strains, suggesting the presence of strain-specific vaccine-induced protection. However, interpretation of these results and understanding of their relevance to vaccine efficacy have been hampered by the lack of knowledge on genetic differences between vaccine and CHMI strains, and how these strains are related to parasites in malaria endemic regions. METHODS Whole genome sequencing using long-read (Pacific Biosciences) and short-read (Illumina) sequencing platforms was conducted to generate de novo genome assemblies for the vaccine strain, NF54, and for strains used in heterologous CHMI (7G8 from Brazil, NF166.C8 from Guinea, and NF135.C10 from Cambodia). The assemblies were used to characterize sequences in each strain relative to the reference 3D7 (a clone of NF54) genome. Strains were compared to each other and to a collection of clinical isolates (sequenced as part of this study or from public repositories) from South America, sub-Saharan Africa, and Southeast Asia. RESULTS While few variants were detected between 3D7 and NF54, we identified tens of thousands of variants between NF54 and the three heterologous strains. These variants include SNPs, indels, and small structural variants that fall in regulatory and immunologically important regions, including transcription factors (such as PfAP2-L and PfAP2-G) and pre-erythrocytic antigens that may be key for sporozoite vaccine-induced protection. Additionally, these variants directly contributed to diversity in immunologically important regions of the genomes as detected through in silico CD8+ T cell epitope predictions. Of all heterologous strains, NF135.C10 had the highest number of unique predicted epitope sequences when compared to NF54. Comparison to global clinical isolates revealed that these four strains are representative of their geographic origin despite long-term culture adaptation; of note, NF135.C10 is from an admixed population, and not part of recently formed subpopulations resistant to artemisinin-based therapies present in the Greater Mekong Sub-region. CONCLUSIONS These results will assist in the interpretation of vaccine efficacy of whole-organism vaccines against homologous and heterologous CHMI.
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Affiliation(s)
- Kara A. Moser
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201 USA
- Present address: Institute for Global Health and Infectious Diseases, University of North Carolina Chapel Hill, Chapel Hill, USA
| | - Elliott F. Drábek
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Ankit Dwivedi
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Emily M. Stucke
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Jonathan Crabtree
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Antoine Dara
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Zalak Shah
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Matthew Adams
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Tao Li
- Sanaria, Inc., Rockville, MD 20850 USA
| | - Priscila T. Rodrigues
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Sergey Koren
- Genome Informatics Section, Computational and Statistical Genomics Branch, National Human Genome Research Institute, Bethesda, MD 20892 USA
| | - Adam M. Phillippy
- Genome Informatics Section, Computational and Statistical Genomics Branch, National Human Genome Research Institute, Bethesda, MD 20892 USA
| | - James B. Munro
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Amed Ouattara
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Benjamin C. Sparklin
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Julie C. Dunning Hotopp
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Kirsten E. Lyke
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Lisa Sadzewicz
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Luke J. Tallon
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Michele D. Spring
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Krisada Jongsakul
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Chanthap Lon
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - David L. Saunders
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
- Present address: Warfighter Expeditionary Medicine and Treatment, US Army Medical Material Development Activity, Frederick, USA
| | - Marcelo U. Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Myaing M. Nyunt
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201 USA
- Present address: Duke Global Health Institute, Duke University, Durham, NC 27708 USA
| | - Miriam K. Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Mark A. Travassos
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Robert W. Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Shannon Takala-Harrison
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | - Claire M. Fraser
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201 USA
| | | | | | - Christopher V. Plowe
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201 USA
- Present address: Duke Global Health Institute, Duke University, Durham, NC 27708 USA
| | - Joana C. Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201 USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201 USA
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46
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Coalson JE, Cohee LM, Walldorf JA, Bauleni A, Mathanga DP, Taylor TE, Wilson ML, Laufer MK. Challenges in Treatment for Fever among School-Age Children and Adults in Malawi. Am J Trop Med Hyg 2019; 100:287-295. [PMID: 30526747 DOI: 10.4269/ajtmh.18-0687] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Prompt and effective treatment is key to malaria control and prevention, as it reduces disease morbidity and mortality and minimizes the number of transmission reservoirs. Transmission reduction may be particularly important among school-age children (SAC, 5-15 years old), who have the highest prevalence of Plasmodium falciparum infection in southern Malawi. We hypothesized that one factor contributing to this difference in prevalence is that SAC are less likely to seek appropriate treatment for fever than children younger than 5 years. In this study, we assessed treatment-seeking behaviors of people of all ages between 2012 and 2014 in Malawi. During each of the five cross-sectional surveys, all members of ∼900 households reported on fever and treatment-seeking in the previous 2 weeks. Multilevel logistic regression was used to analyze predictors of whether febrile people sought treatment and whether they did so at formal (government/private clinics) or informal sources (primarily shops). Twenty-two percent of participants (3,579/16,621) reported fever, and 2,715 of those (75.9%) sought treatment. Seeking treatment exclusively from local shops remains a common practice, although use of recommended diagnostic testing and antimalarial drugs was infrequently reported there. Although SAC were not significantly less likely than children aged < 5 years to seek treatment, SAC and adults (age ≥ 16 years) were significantly less likely to use formal sources. Our results indicate that encouraging treatment at government/private clinics and increasing retail access to appropriate antimalarial testing and treatment, especially among SAC, could help remedy inadequate treatment of symptomatic disease and potentially reduce Plasmodium transmission in Malawi.
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Affiliation(s)
- Jenna E Coalson
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, Michigan
| | - Lauren M Cohee
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Jenny A Walldorf
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Andrew Bauleni
- Malaria Alert Center, University of Malawi College of Medicine, Blantyre, Malawi
| | - Don P Mathanga
- Malaria Alert Center, University of Malawi College of Medicine, Blantyre, Malawi
| | - Terrie E Taylor
- College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan
| | - Mark L Wilson
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, Michigan
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
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47
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Andronescu LR, Buchwald AG, Coalson JE, Cohee L, Bauleni A, Walldorf JA, Kandangwe C, Mzilahowa T, Taylor TE, Mathanga DP, Laufer MK. Net age, but not integrity, may be associated with decreased protection against Plasmodium falciparum infection in southern Malawi. Malar J 2019; 18:329. [PMID: 31551076 PMCID: PMC6760057 DOI: 10.1186/s12936-019-2930-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 08/22/2019] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Distribution campaigns for insecticide-treated nets (ITN) have increased the use of ITNs in Malawi, but malaria prevalence remains high even among those using the nets. Previous studies have addressed ITN ownership, insecticide resistance, and frequency of ITN use as possible contributing factors to the high prevalence of malaria infection despite high ITN coverage, but have rarely considered whether the condition of the ITN, or how many people use it, impacts efficacy. This study assessed how ITN integrity, ITN age, and the number of persons sharing a net might mitigate or reduce protective efficacy among self-identified ITN users in Malawi. METHODS From 2012 to 2014, six cross-sectional surveys were conducted in both the rainy and dry seasons in southern Malawi. Data were collected on ITN use, integrity (number and size of holes), and age. Blood samples for detecting Plasmodium falciparum infection were obtained from reported ITN users over 6 months of age. Generalized linear mixed models were used to account for clustering at the household and community level. The final model controlled for gender, household eaves, and community-level infection prevalence during the rainy season. RESULTS There were 9646 ITN users with blood samples across six surveys, 15% of whom tested positive for P. falciparum infection. Among children under 5 years old, there was a 50% increased odds of P. falciparum infection among those sleeping under an ITN older than two years, compared to those using an ITN less than 2 years old (OR = 1.50; 95% CI 1.07-2.08). ITN integrity and number of individuals sharing an ITN were not associated with P. falciparum infection. CONCLUSIONS Older ITNs were associated with higher rates of P. falciparum in young children, which may indicate that insecticide concentrations play a larger role in infection prevention than the physical barrier of an ITN. ITN use was self-reported and the integrity measures lacked the precision of newer methods, suggesting a need for objective measures of ITN use and more precise assessment of ITN integrity.
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Affiliation(s)
- Liana R. Andronescu
- 0000 0001 2175 4264grid.411024.2Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W, Baltimore Street, Baltimore, MD 21201 USA
| | - Andrea G. Buchwald
- 0000 0001 2175 4264grid.411024.2Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W, Baltimore Street, Baltimore, MD 21201 USA ,0000 0001 0703 675Xgrid.430503.1Present Address: University of Colorado School of Public Health, University of Colorado, 13001 E, 17th Place, Mail Stop B119, Aurora, CO 80045 USA
| | - Jenna E. Coalson
- 0000 0001 2168 186Xgrid.134563.6Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295N Martin Ave, Tucson, AZ 85724 USA
| | - Lauren Cohee
- 0000 0001 2175 4264grid.411024.2Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W, Baltimore Street, Baltimore, MD 21201 USA
| | - Andy Bauleni
- 0000 0001 2113 2211grid.10595.38Malaria Alert Centre, University of Malawi College of Medicine, Blantyre, Malawi
| | - Jenny A. Walldorf
- 0000 0001 2175 4264grid.411024.2Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W, Baltimore Street, Baltimore, MD 21201 USA ,0000 0001 2163 0069grid.416738.fPresent Address: Global Immunization Division, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Chifundo Kandangwe
- 0000 0001 2113 2211grid.10595.38Malaria Alert Centre, University of Malawi College of Medicine, Blantyre, Malawi
| | - Themba Mzilahowa
- 0000 0001 2113 2211grid.10595.38Malaria Alert Centre, University of Malawi College of Medicine, Blantyre, Malawi
| | - Terrie E. Taylor
- 0000 0001 2150 1785grid.17088.36Department of Osteopathic Medical Specialties, Michigan State University, 909 Fee Road, East Lansing, MI 48824 USA
| | - Don P. Mathanga
- 0000 0001 2113 2211grid.10595.38Malaria Alert Centre, University of Malawi College of Medicine, Blantyre, Malawi
| | - Miriam K. Laufer
- 0000 0001 2175 4264grid.411024.2Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W, Baltimore Street, Baltimore, MD 21201 USA
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48
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Cohee LM, Laufer MK. The unanticipated benefits of protecting young children from malaria. Lancet Infect Dis 2019; 19:918-919. [PMID: 31307884 PMCID: PMC10369479 DOI: 10.1016/s1473-3099(19)30285-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 05/24/2019] [Indexed: 06/10/2023]
Affiliation(s)
- Lauren M Cohee
- Center for Vaccine Development and Global Health, School of Medicine, University of Maryland, Baltimore, MD 21201, USA.
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, School of Medicine, University of Maryland, Baltimore, MD 21201, USA
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49
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Earland D, Buchwald AG, Sixpence A, Chimenya M, Damson M, Seydel KB, Mathanga DP, Taylor TE, Laufer MK. Impact of Multiplicity of Plasmodium falciparum Infection on Clinical Disease in Malawi. Am J Trop Med Hyg 2019; 101:412-415. [PMID: 31219007 PMCID: PMC6685583 DOI: 10.4269/ajtmh.19-0093] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/22/2019] [Indexed: 11/07/2022] Open
Abstract
Multiplicity of infection (MOI), the number of unique Plasmodium falciparum parasite genotypes found in one infected individual, may contribute to the development of clinical malaria disease. However, the independent contribution of MOI and parasite density to clinical disease has not been well characterized. We conducted a two-year longitudinal cohort study of adults and children in a high-transmission setting in Malawi to test the hypothesis that increased MOI was independently associated with clinical disease, after accounting for parasite density. Of 1,062 episodes of infection, 477 (44.9%) were associated with symptoms. After controlling for repeated measures within an individual, key demographic factors, and parasite density, there was no association between MOI and clinical disease (OR = 1.02, 95% CI: 0.70-1.51). Although the limited ability to discern MOI in low-density asymptomatic infections may have impacted our results, we conclude that MOI is not an independent risk factor for clinical disease.
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Affiliation(s)
- Dominique Earland
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Andrea G. Buchwald
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
| | - Alick Sixpence
- Malaria Alert Centre, Communicable Disease Action Centre, University of Malawi College of Medicine, Blantyre, Malawi
| | - Mabvuto Chimenya
- Malaria Alert Centre, Communicable Disease Action Centre, University of Malawi College of Medicine, Blantyre, Malawi
| | - Milius Damson
- Malaria Alert Centre, Communicable Disease Action Centre, University of Malawi College of Medicine, Blantyre, Malawi
| | - Karl B. Seydel
- College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan
| | - Don P. Mathanga
- Malaria Alert Centre, Communicable Disease Action Centre, University of Malawi College of Medicine, Blantyre, Malawi
| | - Terrie E. Taylor
- College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan
| | - Miriam K. Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland
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50
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Stanley CC, Kazembe LN, Mukaka M, Otwombe KN, Buchwald AG, Hudgens MG, Mathanga DP, Laufer MK, Chirwa TF. Systematic review of analytical methods applied to longitudinal studies of malaria. Malar J 2019; 18:254. [PMID: 31357990 PMCID: PMC6664716 DOI: 10.1186/s12936-019-2885-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 07/19/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Modelling risk of malaria in longitudinal studies is common, because individuals are at risk for repeated infections over time. Malaria infections result in acquired immunity to clinical malaria disease. Prospective cohorts are an ideal design to relate the historical exposure to infection and development of clinical malaria over time, and analysis methods should consider the longitudinal nature of the data. Models must take into account the acquisition of immunity to disease that increases with each infection and the heterogeneous exposure to bites from infected Anopheles mosquitoes. Methods that fail to capture these important factors in malaria risk will not accurately model risk of malaria infection or disease. METHODS Statistical methods applied to prospective cohort studies of clinical malaria or Plasmodium falciparum infection and disease were reviewed to assess trends in usage of the appropriate statistical methods. The study was designed to test the hypothesis that studies often fail to use appropriate statistical methods but that this would improve with the recent increase in accessibility to and expertise in longitudinal data analysis. RESULTS Of 197 articles reviewed, the most commonly reported methods included contingency tables which comprised Pearson Chi-square, Fisher exact and McNemar's tests (n = 102, 51.8%), Student's t-tests (n = 82, 41.6%), followed by Cox models (n = 62, 31.5%) and Kaplan-Meier estimators (n = 59, 30.0%). The longitudinal analysis methods generalized estimating equations and mixed-effects models were reported in 41 (20.8%) and 24 (12.2%) articles, respectively, and increased in use over time. A positive trend in choice of more appropriate analytical methods was identified over time. CONCLUSIONS Despite similar study designs across the reports, the statistical methods varied substantially and often represented overly simplistic models of risk. The results underscore the need for more effort to be channelled towards adopting standardized longitudinal methods to analyse prospective cohort studies of malaria infection and disease.
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Affiliation(s)
- Christopher C Stanley
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Malaria Alert Centre, University of Malawi College of Medicine, Blantyre, Malawi
| | | | - Mavuto Mukaka
- Oxford Centre for Tropical Medicine and Global Health, Oxford, UK.,Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, Thailand
| | - Kennedy N Otwombe
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Perinatal HIV Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Andrea G Buchwald
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St. HSF-1 Room 480, Baltimore, MD, 21201, USA
| | - Michael G Hudgens
- Department of Biostatistics, Center for AIDS Research, University of North Carolina Chapel Hill, Chapel Hill, NC, USA
| | - Don P Mathanga
- Malaria Alert Centre, University of Malawi College of Medicine, Blantyre, Malawi
| | - Miriam K Laufer
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 W. Baltimore St. HSF-1 Room 480, Baltimore, MD, 21201, USA.
| | - Tobias F Chirwa
- School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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