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Juliano JJ, Giesbrecht DJ, Simkin A, Fola AA, Lyimo BM, Pereus D, Bakari C, Madebe RA, Seth MD, Mandara CI, Popkin-Hall ZR, Moshi R, Mbwambo RB, Niaré K, MacInnis B, Francis F, Mbwambo D, Garimo I, Chacky F, Aaron S, Lusasi A, Molteni F, Njau RJA, Lazaro S, Mohamed A, Bailey JA, Ishengoma DS. Country wide surveillance reveals prevalent artemisinin partial resistance mutations with evidence for multiple origins and expansion of high level sulfadoxine-pyrimethamine resistance mutations in northwest Tanzania. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.11.07.23298207. [PMID: 37986920 PMCID: PMC10659475 DOI: 10.1101/2023.11.07.23298207] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Background Emergence of artemisinin partial resistance (ART-R) in Plasmodium falciparum is a growing threat to the efficacy of artemisinin combination therapies (ACT) and the efforts for malaria elimination. The emergence of Plasmodium falciparum Kelch13 (K13) R561H in Rwanda raised concern about the impact in neighboring Tanzania. In addition, regional concern over resistance affecting sulfadoxine-pyrimethamine (SP), which is used for chemoprevention strategies, is high. Methods To enhance longitudinal monitoring, the Molecular Surveillance of Malaria in Tanzania (MSMT) project was launched in 2020 with the goal of assessing and mapping antimalarial resistance. Community and clinic samples were assessed for resistance polymorphisms using a molecular inversion probe platform. Findings Genotyping of 6,278 samples collected countrywide in 2021 revealed a focus of K13 561H mutants in northwestern Tanzania (Kagera) with prevalence of 7.7% (50/649). A small number of 561H mutants (about 1%) were found as far as 800 km away in Tabora, Manyara, and Njombe. Genomic analysis suggests some of these parasites are highly related to isolates collected in Rwanda in 2015, supporting regional spread of 561H. However, a novel haplotype was also observed, likely indicating a second origin in the region. Other validated resistance polymorphisms (622I and 675V) were also identified. A focus of high sulfadoxine-pyrimethamine drug resistance was also identified in Kagera with a prevalence of dihydrofolate reductase 164L of 15% (80/526). Interpretation These findings demonstrate the K13 561H mutation is entrenched in the region and that multiple origins of ART-R, similar as to what was seen in Southeast Asia, have occurred. Mutations associated with high levels of SP resistance are increasing. These results raise concerns about the long-term efficacy of artemisinin and chemoprevention antimalarials in the region. Funding This study was funded by the Bill and Melinda Gates Foundation and the National Institutes of Health.
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Affiliation(s)
| | | | | | | | - Beatus M. Lyimo
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Nelson Mandela African Institute of Science and Technology, Arusha, Tanzania
| | - Dativa Pereus
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Catherine Bakari
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Rashid A. Madebe
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Misago D. Seth
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | | | - Ramadhan Moshi
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | - Ruth B. Mbwambo
- National Institute for Medical Research, Dar es Salaam, Tanzania
| | | | - Bronwyn MacInnis
- Harvard T.H Chan School of Public Health, Boston, MA, USA
- Broad Institute, Boston, MA, USA
| | | | | | - Issa Garimo
- National Malaria Control Programme, Dodoma, Tanzania
| | - Frank Chacky
- National Malaria Control Programme, Dodoma, Tanzania
| | | | | | | | - Ritha J. A. Njau
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Samwel Lazaro
- National Malaria Control Programme, Dodoma, Tanzania
| | - Ally Mohamed
- National Malaria Control Programme, Dodoma, Tanzania
| | | | - Deus S. Ishengoma
- National Institute for Medical Research, Dar es Salaam, Tanzania
- Harvard T.H Chan School of Public Health, Boston, MA, USA
- Faculty of Pharmaceutical Sciences, Monash University, Melbourne, Australia
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Spatiotemporal spread of Plasmodium falciparum mutations for resistance to sulfadoxine-pyrimethamine across Africa, 1990–2020. PLoS Comput Biol 2022; 18:e1010317. [PMID: 35951528 PMCID: PMC9371298 DOI: 10.1371/journal.pcbi.1010317] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 06/19/2022] [Indexed: 11/26/2022] Open
Abstract
Background Sulfadoxine-pyrimethamine (SP) is recommended in Africa in several antimalarial preventive regimens including Intermittent Preventive Treatment in pregnant women (IPTp), Intermittent Preventive Treatment in infants (IPTi) and Seasonal Malaria Chemoprevention (SMC). The effectiveness of SP-based preventive treatments are threatened in areas where Plasmodium falciparum resistance to SP is high. The prevalence of mutations in the dihydropteroate synthase gene (pfdhps) can be used to monitor SP effectiveness. IPTi-SP is recommended only in areas where the prevalence of the pfdhps540E mutation is below 50%. It has also been suggested that IPTp-SP does not have a protective effect in areas where the pfdhps581G mutation, exceeds 10%. However, pfdhps mutation prevalence data in Africa are extremely heterogenous and scattered, with data completely missing from many areas. Methods and findings The WWARN SP Molecular Surveyor database was designed to summarize dihydrofolate reductase (pfdhfr) and pfdhps gene mutation prevalence data. In this paper, pfdhps mutation prevalence data was used to generate continuous spatiotemporal surface maps of the estimated prevalence of the SP resistance markers pfdhps437G, pfdhps540E, and pfdhps581G in Africa from 1990 to 2020 using a geostatistical model, with a Bayesian inference framework to estimate uncertainty. The maps of estimated prevalence show an expansion of the pfdhps437G mutations across the entire continent over the last three decades. The pfdhps540E mutation emerged from limited foci in East Africa to currently exceeding 50% estimated prevalence in most of East and South East Africa. pfdhps540E distribution is expanding at low or moderate prevalence in central Africa and a predicted focus in West Africa. Although the pfdhps581G mutation spread from one focus in East Africa in 2000, to exceeding 10% estimated prevalence in several foci in 2010, the predicted distribution of the marker did not expand in 2020, however our analysis indicated high uncertainty in areas where pfdhps581G is present. Uncertainty was higher in spatial regions where the prevalence of a marker is intermediate or where prevalence is changing over time. Conclusions The WWARN SP Molecular Surveyor database and a set of continuous spatiotemporal surface maps were built to provide users with standardized, current information on resistance marker distribution and prevalence estimates. According to the maps, the high prevalence of pfdhps540E mutation was to date restricted to East and South East Africa, which is reassuring for continued use of IPTi and SMC in West Africa, but continuous monitoring is needed as the pfdhps540E distribution is expanding. Several foci where pfdhps581G prevalence exceeded 10% were identified. More data on the pfdhps581G distribution in these areas needs to be collected to guide IPTp-SP recommendations. Prevalence and uncertainty maps can be utilized together to strategically identify sites where increased surveillance can be most informative. This study combines a molecular marker database and predictive modelling to highlight areas of concern, which can be used to support decisions in public health, highlight knowledge gaps in certain regions, and guide future research. Despite great success in reducing death and illness from malaria over the last 20 years, the disease is still one of the main leading causes of death in low-income countries with estimated 229 million cases and 409,000 deaths annually. One of the main obstacles in malaria control is the development and spread of drug resistance. Several intermittent preventive treatments depend on the efficacy of the antimalarial drug sulfadoxine-pyrimethamine (SP); Intermittent Preventive Treatment in pregnant women (IPTp), Intermittent Preventive Treatment in infants (IPTi) and Seasonal Malaria Chemoprevention (SMC). Mutations in the dihydropteroate synthase gene (pfdhps) can cause resistance to SP treatment. In this paper, we use pfdhps mutation prevalence data to generate continuous spatiotemporal surface maps of the estimated prevalence of the SP resistance markers in Africa from 1990 to 2020 using a Bayesian geostatistical model. These predictive maps provide much needed insight about where SP can be used as part of preventive treatments. Spatial information on the spread of antimalarial resistance is critical for health organizations to prioritize surveillance measures, and plan control and elimination efforts.
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Tuedom AGB, Sarah-Matio EM, Moukoko CEE, Feufack-Donfack BL, Maffo CN, Bayibeki AN, Awono-Ambene HP, Ayong L, Berry A, Abate L, Morlais I, Nsango SE. Antimalarial drug resistance in the Central and Adamawa regions of Cameroon: Prevalence of mutations in P. falciparum crt, Pfmdr1, Pfdhfr and Pfdhps genes. PLoS One 2021; 16:e0256343. [PMID: 34411157 PMCID: PMC8376100 DOI: 10.1371/journal.pone.0256343] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 08/05/2021] [Indexed: 11/19/2022] Open
Abstract
The spread of Plasmodium falciparum resistant parasites remains one of the major challenges for malaria control and elimination in Sub Saharan Africa. Monitoring of molecular markers conferring resistance to different antimalarials is important to track the spread of resistant parasites and to optimize the therapeutic lifespan of current drugs. This study aimed to evaluate the prevalence of known mutations in the drug resistance genes Pfcrt, Pfmdr1, Pfdhfr and Pfdhps in two different epidemiological settings in Cameroon. Dried blood spots collected in 2018 and 2019 from asymptomatic individuals were used for DNA extraction and then the Plasmodium infection status was determined byPCR. Detection of SNPs was performed by nested PCR followed by allele-specific restriction analysis (ASRA). The prevalence of each genotype was compared between sites using the Chi square and Fisher’s exact tests. A high prevalence of the Pfcrt K76 wild type allele was found in both sites (88.5 and 62.29% respectively; P< 0,0001). The prevalence of Pfmdr1 mutations 86Y and 1246Y was respectively 55.83 and 1.45% in Mfou and 45.87 and 5.97% in Tibati, with significant difference between the studied areas (P<0.0001). Overall, the Pfdhfr triple-mutant genotype (51I/59R/108N) was highly prevalent (> 96%), however no SNP was detected at codon 164. In Pfdhps, the prevalence of the 437G mutation reached (90%) and was at higher frequency in Mfou (P< 0.0001). Overall, the Pfdhps mutations 540E and 581G were less common (0.33 and 3.26%, respectively). The quadruple resistant genotype (Pfdhfr 51I/59R/108N+Pfdhp437G) was found almost 90% of the samples. The wild-type genotype (Pfdhfr N51/C59/S108/164I+Pfdhps A437/K540/A581) was never identified and the sextuple mutant (Pfdhfr 51I/59R/108N+Pfdhp437G/540E/581G), kwon as super resistant appeared in two samples from Tibati. These findings demonstrate declining trends in the prevalence of mutations conferring resistance to 4-aminoquinolines, especially to chloroquine. However, a high level of mutations in P. falciparum genes related to SP resistance was detected and this raises concerns about the future efficacy of IPTp-SP and SMC in Cameroon.
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Affiliation(s)
- Aline Gaelle Bouopda Tuedom
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroun
| | - Elangwe Milo Sarah-Matio
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroun
- UMR MIVEGEC, IRD, CNRS, Institut de Recherche pour le Développement, Université Montpellier, Montpellier Cedex, France
| | - Carole Else Eboumbou Moukoko
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroun
| | - Brice Lionel Feufack-Donfack
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroun
- CNRS UPR9022, INSERM U963, Strasbourg, France
| | - Christelle Ngou Maffo
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroun
- UMR MIVEGEC, IRD, CNRS, Institut de Recherche pour le Développement, Université Montpellier, Montpellier Cedex, France
| | - Albert Ngano Bayibeki
- Université Catholique d’Afrique Centrale, Yaoundé-Campus Messa Cameroun, Yaoundé, Cameroun
| | - Hermann Parfait Awono-Ambene
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Yaoundé, Cameroun
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroun
| | - Antoine Berry
- Service de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Toulouse et UMR152 UPS-IRD, Université de Toulouse, Toulouse, France
| | - Luc Abate
- UMR MIVEGEC, IRD, CNRS, Institut de Recherche pour le Développement, Université Montpellier, Montpellier Cedex, France
| | - Isabelle Morlais
- UMR MIVEGEC, IRD, CNRS, Institut de Recherche pour le Développement, Université Montpellier, Montpellier Cedex, France
| | - Sandrine Eveline Nsango
- Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
- Malaria Research Unit, Centre Pasteur du Cameroun, Yaoundé, Cameroun
- * E-mail: ,
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Deutsch-Feldman M, Aydemir O, Carrel M, Brazeau NF, Bhatt S, Bailey JA, Kashamuka M, Tshefu AK, Taylor SM, Juliano JJ, Meshnick SR, Verity R. The changing landscape of Plasmodium falciparum drug resistance in the Democratic Republic of Congo. BMC Infect Dis 2019; 19:872. [PMID: 31640574 PMCID: PMC6805465 DOI: 10.1186/s12879-019-4523-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 09/30/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Drug resistant malaria is a growing concern in the Democratic Republic of the Congo (DRC), where previous studies indicate that parasites resistant to sulfadoxine/pyrimethamine or chloroquine are spatially clustered. This study explores longitudinal changes in spatial patterns to understand how resistant malaria may be spreading within the DRC, using samples from nation-wide population-representative surveys. METHODS We selected 552 children with PCR-detectable Plasmodium falciparum infection and identified known variants in the pfdhps and pfcrt genes associated with resistance. We compared the proportion of mutant parasites in 2013 to those previously reported from adults in 2007, and identified risk factors for carrying a resistant allele using multivariate mixed-effects modeling. Finally, we fit a spatial-temporal model to the observed data, providing smooth allele frequency estimates over space and time. RESULTS The proportion of co-occurring pfdhps K540E/A581G mutations increased by 16% between 2007 and 2013. The spatial-temporal model suggests that the spatial range of the pfdhps double mutants expanded over time, while the prevalence and range of pfcrt mutations remained steady. CONCLUSIONS This study uses population-representative samples to describe the changing landscape of SP resistance within the DRC, and the persistence of chloroquine resistance. Vigilant molecular surveillance is critical for controlling the spread of resistance.
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Affiliation(s)
- Molly Deutsch-Feldman
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, USA.
| | - Ozkan Aydemir
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - Margaret Carrel
- Department of Geographical & Sustainability Sciences, University of Iowa, Iowa City, IA, USA
| | - Nicholas F Brazeau
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, USA
| | - Samir Bhatt
- Medical Research Council Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Jeffrey A Bailey
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - Melchior Kashamuka
- Ecole de Santé Publique, , Faculté de Médecine, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Antoinette K Tshefu
- Ecole de Santé Publique, , Faculté de Médecine, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Steve M Taylor
- Division of Infectious Diseases and Duke Global Health Institute, Duke University, Durham, NC, USA
| | - Jonathan J Juliano
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, USA.,Division of Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, USA.,Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, USA
| | - Steven R Meshnick
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, USA
| | - Robert Verity
- Medical Research Council Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
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5
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Verity R, Hathaway NJ, Waltmann A, Doctor SM, Watson OJ, Patel JC, Mwandagalirwa K, Tshefu AK, Bailey JA, Ghani AC, Juliano JJ, Meshnick SR. Plasmodium falciparum genetic variation of var2csa in the Democratic Republic of the Congo. Malar J 2018; 17:46. [PMID: 29361940 PMCID: PMC5782373 DOI: 10.1186/s12936-018-2193-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 01/17/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Democratic Republic of the Congo (DRC) bears a high burden of malaria, which is exacerbated in pregnant women. The VAR2CSA protein plays a crucial role in pregnancy-associated malaria (PAM), and hence quantifying diversity at the var2csa locus in the DRC is important in understanding the basic epidemiology of PAM, and in developing a robust vaccine against PAM. METHODS Samples were taken from the 2013-14 Demographic and Health Survey conducted in the DRC, focusing on children under 5 years of age. A short subregion of the var2csa gene was sequenced in 115 spatial clusters, giving country-wide estimates of sequence polymorphism and spatial population structure. RESULTS Results indicate that var2csa is highly polymorphic, and that diversity is being maintained through balancing selection, however, there is no clear signal of phylogenetic or geographic structure to this diversity. Linear modelling demonstrates that the number of var2csa variants in a cluster correlates directly with cluster prevalence, but not with other epidemiological factors such as urbanicity. CONCLUSIONS Results suggest that the DRC fits within the global pattern of high var2csa diversity and little genetic differentiation between regions. A broad multivalent VAR2CSA vaccine candidate could benefit from targeting stable regions and common variants to address the substantial genetic diversity.
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Affiliation(s)
- Robert Verity
- Medical Research Council Centre for Outbreak Analysis & Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK.
| | - Nicholas J Hathaway
- Program in Bioinformatics and Integrative Biology, University of Massachusetts, Worcester, MA, USA
- Division of Transfusion Medicine, Department of Medicine, University of Massachusetts, Worcester, MA, USA
| | - Andreea Waltmann
- Institute for Global Health and Infectious Diseases, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, USA
| | - Stephanie M Doctor
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, USA
| | - Oliver J Watson
- Medical Research Council Centre for Outbreak Analysis & Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Jaymin C Patel
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, USA
| | - Kashamuka Mwandagalirwa
- Kinshasa School of Public Health, Hôpital General Provincial de Reference de Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Antoinette K Tshefu
- Community Health, Kinshasa School of Public Health, School of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Jeffrey A Bailey
- Program in Bioinformatics and Integrative Biology, University of Massachusetts, Worcester, MA, USA
- Division of Transfusion Medicine, Department of Medicine, University of Massachusetts, Worcester, MA, USA
| | - Azra C Ghani
- Medical Research Council Centre for Outbreak Analysis & Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Jonathan J Juliano
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, USA
- Division of Infectious Diseases, University of North Carolina at Chapel Hill, 130 Mason Farm Road, Chapel Hill, 27599, USA
- Curriculum in Genetics and Microbiology, University of North Carolina at Chapel Hill, 321 South Columbia Street, Chapel Hill, NC, 27516, USA
| | - Steven R Meshnick
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, USA
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Ruh E, Bateko JP, Imir T, Taylan-Ozkan A. Molecular identification of sulfadoxine-pyrimethamine resistance in malaria infected women who received intermittent preventive treatment in the Democratic Republic of Congo. Malar J 2018; 17:17. [PMID: 29316929 PMCID: PMC5761196 DOI: 10.1186/s12936-017-2160-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 12/23/2017] [Indexed: 11/30/2022] Open
Abstract
Background Point mutations in Plasmodium falciparum dihydrofolate reductase (Pfdhfr) and dihydropteroate synthase (Pfdhps) genes which confer resistance to sulfadoxine-pyrimethamine (SP) occur at increasing rates. The present study aimed to identify Pfdhfr and Pfdhps mutations in P. falciparum isolates recovered from women who received two doses of SP during pregnancy in Bandundu, the Democratic Republic of Congo (DRC). Methods A total of 48 women with confirmed P. falciparum infection were enrolled in the study. Finger-prick blood samples that were collected on filter paper at the time of delivery were used for DNA isolation. Pfdhfr and Pfdhps genes were amplified by a nested PCR protocol. DNA sequencing was performed on both strands, and the point mutations were analysed. Results All of the 48 (100.0%) P. falciparum isolates carried at least one polymorphism in both genes. The wild-type haplotypes of Pfdhfr (CNCSI [C50, N51, C59, S108, I164]) and Pfdhps (SAKAA [S436, A437, K540, A581, A613]) were not observed in the study. In Pfdhfr, N51I (85.4%), C59R (60.4%), and S108N (100.0%) polymorphisms were detected. Triple mutation (CIRNI) (mutant amino acids are underlined) was the most prevalent (47.9%) Pfdhfr haplotype. In the study, all P. falciparum isolates (100.0%) harboured the A437G allele in Pfdhps gene. Also, K540E and A581G polymorphisms were observed in one (2.1%) isolate. Single mutant haplotype (SGKAA) was detected in 97.9% of the isolates. Mutant Pfdhfr and Pfdhps allele combinations revealed quintuple (CICNI-SGEGA; 2.1%), quadruple (CIRNI-SGKAA; 47.9%), triple (CICNI-SGKAA; 35.4%, CNRNI-SGKAA; 12.5%), and double (CNCNI-SGKAA; 2.1%) haplotypes. Conclusions In the study, the rate of SGEGA haplotype was low (2.1%). Although K540E and A581G alleles are more common in Eastern Africa, a distinct lineage of SGEGA is also present in the DRC, which is located in Central Africa. This haplotype is associated with decreased efficacy of SP in pregnant women and infants, therefore, it should be carefully considered in the DRC and SP resistance should be routinely monitored.
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Affiliation(s)
- Emrah Ruh
- Department of Medical Microbiology and Clinical Microbiology, Near East University Faculty of Medicine, Near East Boulevard, 99138, Nicosia, Northern Cyprus.
| | - Jean Paul Bateko
- Department of Medical Microbiology and Clinical Microbiology, Near East University Faculty of Medicine, Near East Boulevard, 99138, Nicosia, Northern Cyprus.,Department of Medical Biology, Higher Institute of Medical Technology, Bandundu, Democratic Republic of the Congo
| | - Turgut Imir
- Department of Medical Microbiology and Clinical Microbiology, Near East University Faculty of Medicine, Near East Boulevard, 99138, Nicosia, Northern Cyprus
| | - Aysegul Taylan-Ozkan
- Department of Medical Microbiology and Clinical Microbiology, Near East University Faculty of Medicine, Near East Boulevard, 99138, Nicosia, Northern Cyprus.,Department of Medical Microbiology, Hitit University Faculty of Medicine, Corum, Turkey
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Ngondi JM, Ishengoma DS, Doctor SM, Thwai KL, Keeler C, Mkude S, Munishi OM, Willilo RA, Lalji S, Kaspar N, Kitojo C, Paxton LA, Hathaway NJ, Bailey JA, Juliano JJ, Meshnick SR, Gutman J. Surveillance for sulfadoxine-pyrimethamine resistant malaria parasites in the Lake and Southern Zones, Tanzania, using pooling and next-generation sequencing. Malar J 2017; 16:236. [PMID: 28583119 PMCID: PMC5460401 DOI: 10.1186/s12936-017-1886-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 05/30/2017] [Indexed: 11/16/2022] Open
Abstract
Background Malaria in pregnancy (MiP) remains a major public health challenge in areas of high malaria transmission. Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) is recommended to prevent the adverse consequences of MiP. The effectiveness of SP for IPTp may be reduced in areas where the dhps581 mutation (a key marker of high level SP resistance) is found; this mutation was previously reported to be common in the Tanga Region of northern Tanzania, but there are limited data from other areas. The frequency of molecular markers of SP resistance was investigated in malaria parasites from febrile patients at health centres (HC) in seven regions comprising the Lake and Southern Zones of mainland Tanzania as part of the ongoing efforts to generate national-wide data of SP resistance. Methods A cross-sectional survey was conducted in the outpatient departments of 14 HCs in seven regions from April to June, 2015. 1750 dried blood spot (DBS) samples were collected (117 to 160 per facility) from consenting patients with positive rapid diagnostic tests for malaria, and no recent (within past 2 months) exposure to SP or related drugs. DNA was extracted from the DBS, pooled by HC, and underwent pooled targeted amplicon deep sequencing to yield estimates of mutated parasite allele frequency at each locus of interest. Results The dhps540 mutation was common across all 14 sites, ranging from 55 to 98.4% of sequences obtained. Frequency of the dhps581 mutation ranged from 0 to 2.4%, except at Kayanga HC (Kagera Region, Lake Zone) where 24.9% of sequences obtained were mutated. The dhfr164 mutation was detected only at Kanyanga HC (0.06%). Conclusion By pooling DNA extracts, the allele frequency of mutations in 14 sites could be directly determined on a single deep-sequencing run. The dhps540 mutant was very common at all locations. Surprisingly, the dhps581 was common at one health center, but rare in all the others, suggesting that there is geographic micro-heterogeneity in mutant distribution and that accurate surveillance requires inclusion of multiple sites. A better understanding of the effect of the dhps581 mutant on the efficacy of IPTp-SP is needed.
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Affiliation(s)
| | | | | | - Kyaw L Thwai
- UNC Gillings School of Global Public Health, Chapel Hill, NC, USA
| | - Corinna Keeler
- UNC Gillings School of Global Public Health, Chapel Hill, NC, USA
| | - Sigsbert Mkude
- National Malaria Control Programme, Dar es Salaam, Tanzania
| | | | | | | | - Naomi Kaspar
- US President's Malaria Initiative/United States Agency for International Development, Dar es Salaam, Tanzania
| | - Chonge Kitojo
- US President's Malaria Initiative/United States Agency for International Development, Dar es Salaam, Tanzania
| | - Lynn A Paxton
- US President's Malaria Initiative, Malaria Branch, Division of Parasitic Diseases and Malaria, US Centers for Disease Control and Prevention, Dar es Salaam, Tanzania
| | - Nicholas J Hathaway
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Jeffrey A Bailey
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | | | | | - Julie Gutman
- Malaria Branch, Division of Parasitic Diseases and Malaria, US Centers for Disease Control and Prevention, Atlanta, GA, USA.
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Baraka V, Delgado-Ratto C, Nag S, Ishengoma DS, Madebe RA, Mavoko HM, Nabasumba C, Lutumba P, Alifrangis M, Van Geertruyden JP. Different origin and dispersal of sulfadoxine-resistant Plasmodium falciparum haplotypes between Eastern Africa and Democratic Republic of Congo. Int J Antimicrob Agents 2017; 49:456-464. [PMID: 28237831 DOI: 10.1016/j.ijantimicag.2016.12.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Revised: 12/05/2016] [Accepted: 12/17/2016] [Indexed: 10/20/2022]
Abstract
Sulfadoxine/pyrimethamine (SP) is still used for malaria control in sub-Saharan Africa; however, widespread resistance is a major concern. This study aimed to determine the dispersal and origin of sulfadoxine resistance lineages in the Democratic Republic of the Congo compared with East African Plasmodium falciparum dihydropteroate synthetase (Pfdhps) haplotypes. The analysis involved 264 isolates collected from patients with uncomplicated malaria from Tanzania, Uganda and DR Congo. Isolates were genotyped for Pfdhps mutations at codons 436, 437, 540, 581 and 613. Three microsatellite loci (0.8, 4.3 and 7.7 kb) flanking the Pfdhps gene were assayed. Evolutionary analysis revealed a shared origin of Pfdhps haplotypes in East Africa, with a distinct population clustering in DR Congo. Furthermore, in Tanzania there was an independent distinct origin of Pfdhps SGEGA resistant haplotype. In Uganda and Tanzania, gene flow patterns contribute to the dispersal and shared origin of parasites carrying double- and triple-mutant Pfdhps haplotypes associated with poor outcomes of intermittent preventive treatment during pregnancy using SP (IPTp-SP). However, the origins of the Pfdhps haplotypes in DR Congo and Eastern Africa sites are different. The genetic structure demonstrated a divergent and distinct population cluster predominated by single-mutant Pfdhps haplotypes at the DR Congo site. This reflects the limited dispersal of double- and triple-mutant Pfdhps haplotypes in DR Congo. This study highlights the current genetic structure and dispersal of high-grade Pfdhps resistant haplotypes, which is important to guide implementation of SP in malaria chemoprevention strategies in the region.
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Affiliation(s)
- Vito Baraka
- National Institute for Medical Research, Tanga Research Centre, P.O. Box 5004, Tanga, United Republic of Tanzania; Global Health Institute, University of Antwerp, Antwerp, Belgium.
| | | | - Sidsel Nag
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark; Department of Infectious Diseases, National University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Deus S Ishengoma
- National Institute for Medical Research, Tanga Research Centre, P.O. Box 5004, Tanga, United Republic of Tanzania
| | - Rashid A Madebe
- National Institute for Medical Research, Tanga Research Centre, P.O. Box 5004, Tanga, United Republic of Tanzania
| | - Hypolite Muhindo Mavoko
- Global Health Institute, University of Antwerp, Antwerp, Belgium; Département de Médecine Tropicale, Faculté de Médecine, Université de Kinshasa, B.P. 747 Kin XI, Kinshasa, The Democratic Republic of the Congo
| | - Carolyn Nabasumba
- Global Health Institute, University of Antwerp, Antwerp, Belgium; Epicentre Mbarara Research Base, P.O. Box 930, Mbarara, Uganda
| | - Pascal Lutumba
- Département de Médecine Tropicale, Faculté de Médecine, Université de Kinshasa, B.P. 747 Kin XI, Kinshasa, The Democratic Republic of the Congo
| | - Michael Alifrangis
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark; Department of Infectious Diseases, National University Hospital (Rigshospitalet), Copenhagen, Denmark
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9
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Desai M, Gutman J, Taylor SM, Wiegand RE, Khairallah C, Kayentao K, Ouma P, Coulibaly SO, Kalilani L, Mace KE, Arinaitwe E, Mathanga DP, Doumbo O, Otieno K, Edgar D, Chaluluka E, Kamuliwo M, Ades V, Skarbinski J, Shi YP, Magnussen P, Meshnick S, Ter Kuile FO. Impact of Sulfadoxine-Pyrimethamine Resistance on Effectiveness of Intermittent Preventive Therapy for Malaria in Pregnancy at Clearing Infections and Preventing Low Birth Weight. Clin Infect Dis 2015; 62:323-333. [PMID: 26486699 DOI: 10.1093/cid/civ881] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 10/03/2015] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Owing to increasing sulfadoxine-pyrimethamine (SP) resistance in sub-Saharan Africa, monitoring the effectiveness of intermittent preventive therapy in pregnancy (IPTp) with SP is crucial. METHODS Between 2009 and 2013, both the efficacy of IPTp-SP at clearing existing peripheral malaria infections and the effectiveness of IPTp-SP at reducing low birth weight (LBW) were assessed among human immunodeficiency virus-uninfected participants in 8 sites in 6 countries. Sites were classified as high, medium, or low resistance after measuring parasite mutations conferring SP resistance. An individual-level prospective pooled analysis was conducted. RESULTS Among 1222 parasitemic pregnant women, overall polymerase chain reaction-uncorrected and -corrected failure rates by day 42 were 21.3% and 10.0%, respectively (39.7% and 21.1% in high-resistance areas; 4.9% and 1.1% in low-resistance areas). Median time to recurrence decreased with increasing prevalence of Pfdhps-K540E. Among 6099 women at delivery, IPTp-SP was associated with a 22% reduction in the risk of LBW (prevalence ratio [PR], 0.78; 95% confidence interval [CI], .69-.88; P < .001). This association was not modified by insecticide-treated net use or gravidity, and remained significant in areas with high SP resistance (PR, 0.81; 95% CI, .67-.97; P = .02). CONCLUSIONS The efficacy of SP to clear peripheral parasites and prevent new infections during pregnancy is compromised in areas with >90% prevalence of Pfdhps-K540E. Nevertheless, in these high-resistance areas, IPTp-SP use remains associated with increases in birth weight and maternal hemoglobin. The effectiveness of IPTp in eastern and southern Africa is threatened by further increases in SP resistance and reinforces the need to evaluate alternative drugs and strategies for the control of malaria in pregnancy.
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Affiliation(s)
- Meghna Desai
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia.,Malaria Branch, Center for Global Health Research, Kenya Medical Research Institute, Kisumu
| | - Julie Gutman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Steve M Taylor
- Division of Infectious Diseases and International Health, Duke University Medical Center, Durham, North Carolina.,Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill
| | - Ryan E Wiegand
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Carole Khairallah
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, United Kingdom
| | - Kassoum Kayentao
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, United Kingdom.,Malaria Research and Training Center, University of Sciences, Technics and Technologies of Bamako, Mali
| | - Peter Ouma
- Malaria Branch, Center for Global Health Research, Kenya Medical Research Institute, Kisumu
| | | | | | - Kimberly E Mace
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | | | - Ogobara Doumbo
- Malaria Research and Training Center, University of Sciences, Technics and Technologies of Bamako, Mali
| | - Kephas Otieno
- Malaria Branch, Center for Global Health Research, Kenya Medical Research Institute, Kisumu
| | | | | | | | - Veronica Ades
- New York University Langone Medical Center, New York
| | - Jacek Skarbinski
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Ya Ping Shi
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Pascal Magnussen
- Centre for Medical Parasitology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Steve Meshnick
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill
| | - Feiko O Ter Kuile
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, United Kingdom
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10
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Gutman J, Taylor S, Meshnick SR, Ter Kuile FO. Reply to Harrington et al. J Infect Dis 2015; 213:497-8. [PMID: 26290609 DOI: 10.1093/infdis/jiv421] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 08/07/2015] [Indexed: 11/14/2022] Open
Affiliation(s)
- Julie Gutman
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Steve Taylor
- Duke University Medical Center, Durham University of North Carolina, Chapel Hill
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11
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Gutman J, Kalilani L, Taylor S, Zhou Z, Wiegand RE, Thwai KL, Mwandama D, Khairallah C, Madanitsa M, Chaluluka E, Dzinjalamala F, Ali D, Mathanga DP, Skarbinski J, Shi YP, Meshnick S, ter Kuile FO. The A581G Mutation in the Gene Encoding Plasmodium falciparum Dihydropteroate Synthetase Reduces the Effectiveness of Sulfadoxine-Pyrimethamine Preventive Therapy in Malawian Pregnant Women. J Infect Dis 2015; 211:1997-2005. [PMID: 25564249 PMCID: PMC4539907 DOI: 10.1093/infdis/jiu836] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 12/15/2014] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The A581 G: mutation in the gene encoding Plasmodium falciparum dihydropteroate synthase (dhps), in combination with the quintuple mutant involving mutations in both dhps and the gene encoding dihydrofolate reductase (dhfr), the so-called sextuple mutant, has been associated with increased placental inflammation and decreased infant birth weight among women receiving intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP) during pregnancy. METHODS Between 2009 and 2011, delivering women without human immunodeficiency virus infection were enrolled in an observational study of IPTp-SP effectiveness in Malawi. Parasites were detected by polymerase chain reaction (PCR); positive samples were sequenced to genotype the dhfr and dhps loci. The presence of K540 E: in dhps was used as a marker for the quintuple mutant. RESULTS Samples from 1809 women were analyzed by PCR; 220 (12%) were positive for P. falciparum. A total of 202 specimens were genotyped at codon 581 of dhps; 17 (8.4%) harbored the sextuple mutant. The sextuple mutant was associated with higher risks of patent infection in peripheral blood (adjusted prevalence ratio [aPR], 2.76; 95% confidence interval [CI], 1.82-4.18) and placental blood (aPR 3.28; 95% CI, 1.88-5.78) and higher parasite densities. Recent SP use was not associated with increased parasite densities or placental pathology overall and among women with parasites carrying dhps A581 G: . CONCLUSIONS IPTp-SP failed to inhibit parasite growth but did not exacerbate pathology among women infected with sextuple-mutant parasites. New interventions to prevent malaria during pregnancy are needed urgently.
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Affiliation(s)
- Julie Gutman
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Linda Kalilani
- College of Medicine, University of Malawi
- Department of Community Health, College of Medicine, Blantyre
| | - Steve Taylor
- Duke University Medical Center, Durham
- University of North Carolina, Chapel Hill
| | - Zhiyong Zhou
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Ryan E. Wiegand
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | - Dyson Mwandama
- Malaria Alert Centre, University of Malawi College of Medicine
| | | | - Mwayi Madanitsa
- College of Medicine, University of Malawi
- Department of Community Health, College of Medicine, Blantyre
| | - Ebbie Chaluluka
- College of Medicine, University of Malawi
- Department of Community Health, College of Medicine, Blantyre
| | - Fraction Dzinjalamala
- College of Medicine, University of Malawi
- Malaria Alert Centre, University of Malawi College of Medicine
| | - Doreen Ali
- National Malaria Control Program, Lilongwe, Malawi
| | - Don P. Mathanga
- Malaria Alert Centre, University of Malawi College of Medicine
- Department of Community Health, College of Medicine, Blantyre
| | - Jacek Skarbinski
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Ya Ping Shi
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
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12
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Chandrasiri UP, Fowkes FJI, Richards JS, Langer C, Fan YM, Taylor SM, Beeson JG, Dewey KG, Maleta K, Ashorn P, Rogerson SJ. The impact of lipid-based nutrient supplementation on anti-malarial antibodies in pregnant women in a randomized controlled trial. Malar J 2015; 14:193. [PMID: 25957793 PMCID: PMC4438573 DOI: 10.1186/s12936-015-0707-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 04/16/2015] [Indexed: 11/12/2022] Open
Abstract
Background Malaria and undernutrition frequently coexist, especially in pregnant women and young children. Nutrient supplementation of these vulnerable groups might reduce their susceptibility to malaria by improving immunity. Methods Antibody immunity to antigens expressed by a placental-binding parasite isolate, a non-placental binding parasite isolate, merozoites and schizonts at enrolment (before 20 gestation weeks) and at 36 gestation weeks were measured in 1,009 Malawian pregnant women receiving a daily lipid-based nutrient supplement, multiple micronutrients or iron and folic acid, who were participants in a randomized clinical trial assessing the effects of nutrient supplementation on pregnancy outcomes and child development(registration ID: NCT01239693). Results Antibodies to placental-binding isolates significantly increased while antibodies to most merozoite antigens declined over pregnancy. Overall, after adjustment for covariates, the type of supplementation did not influence antibody levels at 36 gestation weeks or the rate of change in antibody levels from enrolment to 36 weeks. A negative association between maternal body mass index and opsonizing antibodies to placental-binding antigens (coefficient (95% CI) -1.04 (−1.84, −0.24), was observed. Similarly, women with higher socioeconomic status had significantly lower IgG and opsonizing antibodies to placental-binding antigens. Neither of these associations was significantly influenced by the supplementation type. Conclusions In the current cohort nutrient supplementation did not affect anti-malarial antibody responses, but poor and undernourished mothers should be a priority group in future trials. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0707-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Upeksha P Chandrasiri
- Department of Medicine, Clinical Sciences Building, The University of Melbourne, Royal Parade, Parkville, VIC, 3052, Australia.
| | - Freya J I Fowkes
- Macfarlane Burnet Institute of Medical Research, 85 Commercial Road, Melbourne, Australia. .,Centre for Epidemiology and Biostatistics, Department of Epidemiology, The University of Melbourne, Melbourne, Australia. .,Preventive Medicine and Department of Infectious Diseases, Monash University, Melbourne, Australia.
| | - Jack S Richards
- Department of Medicine, Clinical Sciences Building, The University of Melbourne, Royal Parade, Parkville, VIC, 3052, Australia. .,Macfarlane Burnet Institute of Medical Research, 85 Commercial Road, Melbourne, Australia.
| | - Christine Langer
- Macfarlane Burnet Institute of Medical Research, 85 Commercial Road, Melbourne, Australia.
| | - Yue-Mei Fan
- Department for International Health, University of Tampere School of Medicine, Tampere, Finland. .,Department of Paediatrics, Tampere University Hospital, Tampere, Finland.
| | - Steve M Taylor
- Duke University Medical Center, Durham, North Carolina, USA. .,Gillings School of Global Public Health, University of North Carolina, Chapel Hill, USA.
| | - James G Beeson
- Department of Medicine, Clinical Sciences Building, The University of Melbourne, Royal Parade, Parkville, VIC, 3052, Australia. .,Macfarlane Burnet Institute of Medical Research, 85 Commercial Road, Melbourne, Australia.
| | - Kathryn G Dewey
- Department of Nutrition, University of California Davis, Davis, California, USA.
| | - Kenneth Maleta
- College of Medicine, University of Malawi, Blantyre, Malawi.
| | - Per Ashorn
- Department for International Health, University of Tampere School of Medicine, Tampere, Finland. .,Department of Paediatrics, Tampere University Hospital, Tampere, Finland.
| | - Stephen J Rogerson
- Department of Medicine, Clinical Sciences Building, The University of Melbourne, Royal Parade, Parkville, VIC, 3052, Australia.
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13
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Increasing prevalence of a novel triple-mutant dihydropteroate synthase genotype in Plasmodium falciparum in western Kenya. Antimicrob Agents Chemother 2015; 59:3995-4002. [PMID: 25896703 DOI: 10.1128/aac.04961-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 04/14/2015] [Indexed: 11/20/2022] Open
Abstract
The molecular basis of sulfadoxine-pyrimethamine (SP) resistance lies in a combination of single-nucleotide polymorphisms (SNPs) in two genes coding for Plasmodium falciparum dihydrofolate reductase (Pfdhfr) and P. falciparum dihydropteroate synthase (Pfdhps), targeted by pyrimethamine and sulfadoxine, respectively. The continued use of SP for intermittent preventive treatment in pregnant women in many African countries, despite SP's discontinuation as a first-line antimalarial treatment option due to high levels of drug resistance, may further increase the prevalence of SP-resistant parasites and/or lead to the selection of new mutations. An antimalarial drug resistance surveillance study was conducted in western Kenya between 2010 and 2013. A total of 203 clinical samples from children with uncomplicated malaria were genotyped for SNPs associated with SP resistance. The prevalence of the triple-mutant Pfdhfr C50 I51R59N108: I164 genotype and the double-mutant Pfdhps S436 G437E540: A581A613 genotype was high. Two triple-mutant Pfdhps genotypes, S436 G437E540G581: A613 and H436G437E540: A581A613, were found, with the latter thus far being uniquely found in western Kenya. The prevalence of the S436 G437E540G581: A613 genotype was low. However, a steady increase in the prevalence of the Pfdhps triple-mutant H436G437E540: A581A613 genotype has been observed since its appearance in early 2000. Isolates with these genotypes shared substantial microsatellite haplotypes with the most common double-mutant allele, suggesting that this triple-mutant allele may have evolved locally. Overall, these findings show that the prevalence of the H436G437E540: A581A613 triple mutant may be increasing in this population and could compromise the efficacy of SP for intermittent preventive treatment in pregnant women if it increases the resistance threshold further.
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14
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Artimovich E, Schneider K, Taylor TE, Kublin JG, Dzinjalamala FK, Escalante AA, Plowe CV, Laufer MK, Takala-Harrison S. Persistence of Sulfadoxine-Pyrimethamine Resistance Despite Reduction of Drug Pressure in Malawi. J Infect Dis 2015; 212:694-701. [PMID: 25672905 DOI: 10.1093/infdis/jiv078] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 01/15/2015] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND In 2007, Malawi replaced sulfadoxine-pyrimethamine (SP) with an artemisinin-based combination therapy as the first-line treatment for uncomplicated Plasmodium falciparum malaria in response to failing SP efficacy. Here we estimate the effect of reduced SP pressure on the prevalence of SP-resistant parasites and the characteristics of the associated selective sweeps flanking the resistance loci. METHODS Samples obtained from individuals with clinical malaria during a period of high SP use (1999-2001), a transitional period (2007-2008), and a period of low SP use (2012) were genotyped for resistance markers at pfdhfr-ts codons 51, 59, and 108 and pfdhps codons 437, 540, and 581. Expected heterozygosity was estimated to evaluate the genetic diversity flanking pfdhfr-ts and pfdhps. RESULTS An increase in the prevalence of the resistance haplotypes DHFR 51I/59R/108N and DHPS 437G/540E occurred under sustained drug pressure, with no change in haplotype prevalence 5 years after reduction in SP pressure. The DHPS 437G/540E/581G haplotype was observed in 2007 and increased in prevalence during a period of reduced SP pressure. Changes to the sweep characteristics flanking pfdhfr-ts and pfdhps were minimal. CONCLUSIONS In contrast to the rapid and complete return of chloroquine-susceptible falciparum malaria after chloroquine was withdrawn from Malawi, a reemergence of SP efficacy is unlikely in the near future.
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Affiliation(s)
- Elena Artimovich
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore
| | - Kristan Schneider
- Department of Fakultät Mathematik/Naturwissenschaften/Informatik, University of Applied Sciences Mittweida, Germany
| | | | - James G Kublin
- Fred Hutchinson Cancer Research Center, Seattle, Washington
| | | | | | - Christopher V Plowe
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore
| | - Miriam K Laufer
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore
| | - Shannon Takala-Harrison
- Howard Hughes Medical Institute/Center for Vaccine Development, University of Maryland School of Medicine, Baltimore
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