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Mwesigwa A, Ocan M, Musinguzi B, Nante RW, Nankabirwa JI, Kiwuwa SM, Kinengyere AA, Castelnuovo B, Karamagi C, Obuku EA, Nsobya SL, Mbulaiteye SM, Byakika-Kibwika P. Plasmodium falciparum genetic diversity and multiplicity of infection based on msp-1, msp-2, glurp and microsatellite genetic markers in sub-Saharan Africa: a systematic review and meta-analysis. Malar J 2024; 23:97. [PMID: 38589874 PMCID: PMC11000358 DOI: 10.1186/s12936-024-04925-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 04/01/2024] [Indexed: 04/10/2024] Open
Abstract
BACKGROUND In sub-Saharan Africa (SSA), Plasmodium falciparum causes most of the malaria cases. Despite its crucial roles in disease severity and drug resistance, comprehensive data on Plasmodium falciparum genetic diversity and multiplicity of infection (MOI) are sparse in SSA. This study summarizes available information on genetic diversity and MOI, focusing on key markers (msp-1, msp-2, glurp, and microsatellites). The systematic review aimed to evaluate their influence on malaria transmission dynamics and offer insights for enhancing malaria control measures in SSA. METHODS The review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Two reviewers conducted article screening, assessed the risk of bias (RoB), and performed data abstraction. Meta-analysis was performed using the random-effects model in STATA version 17. RESULTS The review included 52 articles: 39 cross-sectional studies and 13 Randomized Controlled Trial (RCT)/cohort studies, involving 11,640 genotyped parasite isolates from 23 SSA countries. The overall pooled mean expected heterozygosity was 0.65 (95% CI: 0.51-0.78). Regionally, values varied: East (0.58), Central (0.84), Southern (0.74), and West Africa (0.69). Overall pooled allele frequencies of msp-1 alleles K1, MAD20, and RO33 were 61%, 44%, and 40%, respectively, while msp-2 I/C 3D7 and FC27 alleles were 61% and 55%. Central Africa reported higher frequencies (K1: 74%, MAD20: 51%, RO33: 48%) than East Africa (K1: 46%, MAD20: 42%, RO33: 31%). For msp-2, East Africa had 60% and 55% for I/C 3D7 and FC27 alleles, while West Africa had 62% and 50%, respectively. The pooled allele frequency for glurp was 66%. The overall pooled mean MOI was 2.09 (95% CI: 1.88-2.30), with regional variations: East (2.05), Central (2.37), Southern (2.16), and West Africa (1.96). The overall prevalence of polyclonal Plasmodium falciparum infections was 63% (95% CI: 56-70), with regional prevalences as follows: East (62%), West (61%), Central (65%), and South Africa (71%). CONCLUSION The study shows substantial regional variation in Plasmodium falciparum parasite genetic diversity and MOI in SSA. These findings suggest a need for malaria control strategies and surveillance efforts considering regional-specific factors underlying Plasmodium falciparum infection.
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Affiliation(s)
- Alex Mwesigwa
- Clinical Epidemiology Unit, School of Medicine, College of Health Sciences, Makerere University, P. O. Box 7072, Kampala, Uganda.
- Department of Microbiology and Immunology, School of Medicine, Kabale University, P. O Box 314, Kabale, Uganda.
| | - Moses Ocan
- Department of Pharmacology and Therapeutics, School of Biomedical Sciences, College of Health Sciences, Makerere University, P.O. Box 7072, Kampala, Uganda
- African Center for Systematic Reviews and Knowledge Translation, College of Health Sciences, Makerere University, P.O. Box 7072, Kampala, Uganda
| | - Benson Musinguzi
- Departent of Medical Laboratory Science, Faculty of Health Sciences, Muni University, P.O Box 725, Arua, Uganda
| | - Rachel Wangi Nante
- African Center for Systematic Reviews and Knowledge Translation, College of Health Sciences, Makerere University, P.O. Box 7072, Kampala, Uganda
| | - Joaniter I Nankabirwa
- Clinical Epidemiology Unit, School of Medicine, College of Health Sciences, Makerere University, P. O. Box 7072, Kampala, Uganda
- Infectious Diseases Research Collaboration, College of Health Sciences, Makerere University, P.O. Box 7072, Kampala, Uganda
| | - Steven M Kiwuwa
- Department of Biochemistry, School of Biomedical Sciences, College of Health Sciences, Makerere, University, P.O. Box 7072, Kampala, Uganda
| | - Alison Annet Kinengyere
- Albert Cook Library, College of Health Sciences, Makerere University, P.O. Box 7072, Kampala, Uganda
| | - Barbara Castelnuovo
- Infectious Diseases Institute, College of Health Sciences, Makerere University, P. O. Box 7072, Kampala, Uganda
| | - Charles Karamagi
- Clinical Epidemiology Unit, School of Medicine, College of Health Sciences, Makerere University, P. O. Box 7072, Kampala, Uganda
| | - Ekwaro A Obuku
- Infectious Diseases Institute, College of Health Sciences, Makerere University, P. O. Box 7072, Kampala, Uganda
- African Center for Systematic Reviews and Knowledge Translation, College of Health Sciences, Makerere University, P.O. Box 7072, Kampala, Uganda
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Samuel L Nsobya
- Infectious Diseases Research Collaboration, College of Health Sciences, Makerere University, P.O. Box 7072, Kampala, Uganda
| | - Sam M Mbulaiteye
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, 9609 Medical Center Dr, 6E-118, Bethesda, MD, 20892, USA
| | - Pauline Byakika-Kibwika
- Department of Medicine, School of Medicine, College of Health Sciences, Makerere University, P. O. Box 7072, Kampala, Uganda
- Infectious Diseases Institute, College of Health Sciences, Makerere University, P. O. Box 7072, Kampala, Uganda
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2
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Fola AA, He Q, Xie S, Thimmapuram J, Bhide KP, Dorman J, Ciubotariu II, Mwenda MC, Mambwe B, Mulube C, Hawela M, Norris DE, Moss WJ, Bridges DJ, Carpi G. Genomics reveals heterogeneous Plasmodium falciparum transmission and selection signals in Zambia. COMMUNICATIONS MEDICINE 2024; 4:67. [PMID: 38582941 PMCID: PMC10998850 DOI: 10.1038/s43856-024-00498-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 03/28/2024] [Indexed: 04/08/2024] Open
Abstract
BACKGROUND Genomic surveillance is crucial for monitoring malaria transmission and understanding parasite adaptation to interventions. Zambia lacks prior nationwide efforts in malaria genomic surveillance among African countries. METHODS We conducted genomic surveillance of Plasmodium falciparum parasites from the 2018 Malaria Indicator Survey in Zambia, a nationally representative household survey of children under five years of age. We whole-genome sequenced and analyzed 241 P. falciparum genomes from regions with varying levels of malaria transmission across Zambia and estimated genetic metrics that are informative about transmission intensity, genetic relatedness between parasites, and selection. RESULTS We provide genomic evidence of widespread within-host polygenomic infections, regardless of epidemiological characteristics, underscoring the extensive and ongoing endemic malaria transmission in Zambia. Our analysis reveals country-level clustering of parasites from Zambia and neighboring regions, with distinct separation in West Africa. Within Zambia, identity by descent (IBD) relatedness analysis uncovers local spatial clustering and rare cases of long-distance sharing of closely related parasite pairs. Genomic regions with large shared IBD segments and strong positive selection signatures implicate genes involved in sulfadoxine-pyrimethamine and artemisinin combination therapies drug resistance, but no signature related to chloroquine resistance. Furthermore, differences in selection signatures, including drug resistance loci, are observed between eastern and western Zambian parasite populations, suggesting variable transmission intensity and ongoing drug pressure. CONCLUSIONS Our findings enhance our understanding of nationwide P. falciparum transmission in Zambia, establishing a baseline for analyzing parasite genetic metrics as they vary over time and space. These insights highlight the urgency of strengthening malaria control programs and surveillance of antimalarial drug resistance.
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Affiliation(s)
- Abebe A Fola
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - Qixin He
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Shaojun Xie
- Bioinformatics Core, Purdue University, Purdue University, West Lafayette, IN, USA
| | - Jyothi Thimmapuram
- Bioinformatics Core, Purdue University, Purdue University, West Lafayette, IN, USA
| | - Ketaki P Bhide
- Bioinformatics Core, Purdue University, Purdue University, West Lafayette, IN, USA
| | - Jack Dorman
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Ilinca I Ciubotariu
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Mulenga C Mwenda
- PATH-MACEPA, National Malaria Elimination Centre, Lusaka, Zambia
| | - Brenda Mambwe
- PATH-MACEPA, National Malaria Elimination Centre, Lusaka, Zambia
| | - Conceptor Mulube
- PATH-MACEPA, National Malaria Elimination Centre, Lusaka, Zambia
| | - Moonga Hawela
- PATH-MACEPA, National Malaria Elimination Centre, Lusaka, Zambia
| | - Douglas E Norris
- The Johns Hopkins Malaria Research Institute, W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - William J Moss
- The Johns Hopkins Malaria Research Institute, W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | | | - Giovanna Carpi
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA.
- The Johns Hopkins Malaria Research Institute, W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
- Purdue Institute for Inflammation, Immunology, & Infectious Disease, Purdue University, West Lafayette, IN, USA.
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3
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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] [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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Brokhattingen N, Matambisso G, da Silva C, Neubauer Vickers E, Pujol A, Mbeve H, Cisteró P, Maculuve S, Cuna B, Melembe C, Ndimande N, Palmer B, García-Ulloa M, Munguambe H, Montaña-Lopez J, Nhamussua L, Simone W, Chidimatembue A, Galatas B, Guinovart C, Rovira-Vallbona E, Saúte F, Aide P, Aranda-Díaz A, Greenhouse B, Macete E, Mayor A. Genomic malaria surveillance of antenatal care users detects reduced transmission following elimination interventions in Mozambique. Nat Commun 2024; 15:2402. [PMID: 38493162 PMCID: PMC10944499 DOI: 10.1038/s41467-024-46535-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 02/29/2024] [Indexed: 03/18/2024] Open
Abstract
Routine sampling of pregnant women at first antenatal care (ANC) visits could make Plasmodium falciparum genomic surveillance more cost-efficient and convenient in sub-Saharan Africa. We compare the genetic structure of parasite populations sampled from 289 first ANC users and 93 children from the community in Mozambique between 2015 and 2019. Samples are amplicon sequenced targeting 165 microhaplotypes and 15 drug resistance genes. Metrics of genetic diversity and relatedness, as well as the prevalence of drug resistance markers, are consistent between the two populations. In an area targeted for elimination, intra-host genetic diversity declines in both populations (p = 0.002-0.007), while for the ANC population, population genetic diversity is also lower (p = 0.0004), and genetic relatedness between infections is higher (p = 0.002) than control areas, indicating a recent reduction in the parasite population size. These results highlight the added value of genomic surveillance at ANC clinics to inform about changes in transmission beyond epidemiological data.
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Affiliation(s)
| | - Glória Matambisso
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Clemente da Silva
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Eric Neubauer Vickers
- EPPIcenter Research Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California, San Francisco, California, USA
| | - Arnau Pujol
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Henriques Mbeve
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Pau Cisteró
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Sónia Maculuve
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Boaventura Cuna
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Cardoso Melembe
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Nelo Ndimande
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Brian Palmer
- EPPIcenter Research Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California, San Francisco, California, USA
| | | | | | | | - Lidia Nhamussua
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Wilson Simone
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | | | - Beatriz Galatas
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | | | | | - Francisco Saúte
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Pedro Aide
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
| | - Andrés Aranda-Díaz
- EPPIcenter Research Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California, San Francisco, California, USA
| | - Bryan Greenhouse
- EPPIcenter Research Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California, San Francisco, California, USA
| | - Eusébio Macete
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
- National Directorate for Public Health, Ministry of Health, Maputo, Mozambique
| | - Alfredo Mayor
- ISGlobal, Hospital Clínic - Universitat de Barcelona, Barcelona, Spain.
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique.
- Spanish Consortium for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain.
- Department of Physiological Sciences, Faculty of Medicine, Universidade Eduardo Mondlane, Maputo, Mozambique.
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5
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Greyling N, van der Watt M, Gwarinda H, van Heerden A, Greenhouse B, Leroy D, Niemand J, Birkholtz LM. Genetic complexity alters drug susceptibility of asexual and gametocyte stages of Plasmodium falciparum to antimalarial candidates. Antimicrob Agents Chemother 2024; 68:e0129123. [PMID: 38259087 PMCID: PMC10916389 DOI: 10.1128/aac.01291-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 12/06/2023] [Indexed: 01/24/2024] Open
Abstract
Malaria elimination requires interventions able to target both the asexual blood stage (ABS) parasites and transmissible gametocyte stages of Plasmodium falciparum. Lead antimalarial candidates are evaluated against clinical isolates to address key concerns regarding efficacy and to confirm that the current, circulating parasites from endemic regions lack resistance against these candidates. While this has largely been performed on ABS parasites, limited data are available on the transmission-blocking efficacy of compounds with multistage activity. Here, we evaluated the efficacy of lead antimalarial candidates against both ABS parasites and late-stage gametocytes side-by-side, against clinical P. falciparum isolates from southern Africa. We additionally correlated drug efficacy to the genetic diversity of the clinical isolates as determined with a panel of well-characterized, genome-spanning microsatellite markers. Our data indicate varying sensitivities of the isolates to key antimalarial candidates, both for ABS parasites and gametocyte stages. While ABS parasites were efficiently killed, irrespective of genetic complexity, antimalarial candidates lost some gametocytocidal efficacy when the gametocytes originated from genetically complex, multiple-clone infections. This suggests a fitness benefit to multiclone isolates to sustain transmission and reduce drug susceptibility. In conclusion, this is the first study to investigate the efficacy of antimalarial candidates on both ABS parasites and gametocytes from P. falciparum clinical isolates where the influence of parasite genetic complexity is highlighted, ultimately aiding the malaria elimination agenda.
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Affiliation(s)
- Nicola Greyling
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Mariëtte van der Watt
- Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Hazel Gwarinda
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Ashleigh van Heerden
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Bryan Greenhouse
- Department of Medicine, University of California-San Francisco, San Francisco, California, USA
| | - Didier Leroy
- Medicines for Malaria Venture, Geneva, Switzerland
| | - Jandeli Niemand
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Lyn-Marié Birkholtz
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
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6
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Connelly SV, Brazeau NF, Msellem M, Ngasala BE, Aydemir Ö, Goel V, Niaré K, Giesbrecht DJ, Popkin-Hall ZR, Hennelly CM, Park Z, Moormann AM, Ong'echa JM, Verity R, Mohammed S, Shija SJ, Mhamilawa LE, Morris U, Mårtensson A, Lin JT, Björkman A, Juliano JJ, Bailey JA. Strong isolation by distance and evidence of population microstructure reflect ongoing Plasmodium falciparum transmission in Zanzibar. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2023.02.15.23285960. [PMID: 36865135 PMCID: PMC9980253 DOI: 10.1101/2023.02.15.23285960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The Zanzibar archipelago of Tanzania has become a low-transmission area for Plasmodium falciparum. Despite being considered an area of pre-elimination for years, achieving elimination has been difficult, likely due to a combination of imported infections from mainland Tanzania, and continued local transmission. To shed light on these sources of transmission, we applied highly multiplexed genotyping utilizing molecular inversion probes to characterize the genetic relatedness of 282 P. falciparum isolates collected across Zanzibar and in Bagamoyo District on the coastal mainland from 2016-2018. Overall, parasite populations on the coastal mainland and Zanzibar archipelago remain highly related. However, parasite isolates from Zanzibar exhibit population microstructure due to rapid decay of parasite relatedness over very short distances. This, along with highly related pairs within shehias, suggests ongoing low level local transmission. We also identified highly related parasites across shehias that reflect human mobility on the main island of Unguja and identified a cluster of highly related parasites, suggestive of an outbreak, in the Micheweni district on Pemba island. Parasites in asymptomatic infections demonstrated higher complexity of infection than those in symptomatic infections, but have similar core genomes. Our data support importation as a main source of genetic diversity and contribution to the parasite population on Zanzibar, but they also show local outbreak clusters where targeted interventions are essential to block local transmission. These results highlight the need for preventive measures against imported malaria and enhanced control measures in areas that remain receptive for malaria reemergence due to susceptible hosts and competent vectors.
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Affiliation(s)
- Sean V Connelly
- MD-PhD Program, University of North Carolina, Chapel Hill, NC 27599
| | | | - Mwinyi Msellem
- Research Division, Ministry of Health, Zanzibar, Tanzania
| | - Billy E Ngasala
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
- Global Health and Migration Unit, Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
| | - Özkan Aydemir
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA
| | - Varun Goel
- Carolina Population Center, University of North Carolina, Chapel Hill, NC 27599
| | - Karamoko Niaré
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, 02912 USA
| | - David J Giesbrecht
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, 02912 USA
| | - Zachary R Popkin-Hall
- Institute for Global Health and Infectious Diseases, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599 USA
| | - Christopher M Hennelly
- Institute for Global Health and Infectious Diseases, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599 USA
| | - Zackary Park
- Division of Infectious Diseases, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599 USA
| | - Ann M Moormann
- Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA
| | | | - Robert Verity
- MRC Centre for Global Infectious Disease Analysis, Imperial College, London
| | - Safia Mohammed
- Zanzibar Malaria Elimination Program (ZAMEP), Zanzibar, Tanzania
| | - Shija J Shija
- Zanzibar Malaria Elimination Program (ZAMEP), Zanzibar, Tanzania
| | - Lwidiko E Mhamilawa
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
- Global Health and Migration Unit, Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
| | - Ulrika Morris
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Andreas Mårtensson
- Global Health and Migration Unit, Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
| | - Jessica T Lin
- Division of Infectious Diseases, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599 USA
| | - Anders Björkman
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 17177 Stockholm, Sweden
- Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden
| | - Jonathan J Juliano
- Division of Infectious Diseases, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599 USA
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, 27599 USA
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599 USA
| | - Jeffrey A Bailey
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, 02912 USA
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7
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Fola AA, He Q, Xie S, Thimmapuram J, Bhide KP, Dorman J, Ciubotariu II, Mwenda MC, Mambwe B, Mulube C, Hawela M, Norris DE, Moss WJ, Bridges DJ, Carpi G. Genomics reveals heterogeneous Plasmodium falciparum transmission and population differentiation in Zambia and bordering countries. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.02.09.24302570. [PMID: 38370674 PMCID: PMC10871455 DOI: 10.1101/2024.02.09.24302570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Genomic surveillance plays a critical role in monitoring malaria transmission and understanding how the parasite adapts in response to interventions. We conducted genomic surveillance of malaria by sequencing 241 Plasmodium falciparum genomes from regions with varying levels of malaria transmission across Zambia. We found genomic evidence of high levels of within-host polygenomic infections, regardless of epidemiological characteristics, underscoring the extensive and ongoing endemic malaria transmission in the country. We identified country-level clustering of parasites from Zambia and neighboring countries, and distinct clustering of parasites from West Africa. Within Zambia, our identity by descent (IBD) relatedness analysis uncovered spatial clustering of closely related parasite pairs at the local level and rare cases of long-distance sharing. Genomic regions with large shared IBD segments and strong positive selection signatures identified genes involved in sulfadoxine-pyrimethamine and artemisinin combination therapies drug resistance, but no signature related to chloroquine resistance. Together, our findings enhance our understanding of P. falciparum transmission nationwide in Zambia and highlight the urgency of strengthening malaria control programs and surveillance of antimalarial drug resistance.
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Affiliation(s)
- Abebe A. Fola
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Qixin He
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Shaojun Xie
- Bioinformatics Core, Purdue University, Purdue University, West Lafayette, IN, USA
| | - Jyothi Thimmapuram
- Bioinformatics Core, Purdue University, Purdue University, West Lafayette, IN, USA
| | - Ketaki P. Bhide
- Bioinformatics Core, Purdue University, Purdue University, West Lafayette, IN, USA
| | - Jack Dorman
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | | | | | - Brenda Mambwe
- PATH-MACEPA, National Malaria Elimination Centre, Lusaka, Zambia
| | - Conceptor Mulube
- PATH-MACEPA, National Malaria Elimination Centre, Lusaka, Zambia
| | - Moonga Hawela
- PATH-MACEPA, National Malaria Elimination Centre, Lusaka, Zambia
| | - Douglas E. Norris
- The Johns Hopkins Malaria Research Institute, W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - William J. Moss
- The Johns Hopkins Malaria Research Institute, W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | | | - Giovanna Carpi
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
- The Johns Hopkins Malaria Research Institute, W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
- Purdue Institute for Inflammation, Immunology, & Infectious Disease, Purdue University, West Lafayette, IN, USA
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8
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Reda AG, Huwe T, Koepfli C, Assefa A, Tessema SK, Messele A, Golassa L, Mamo H. Amplicon deep sequencing of five highly polymorphic markers of Plasmodium falciparum reveals high parasite genetic diversity and moderate population structure in Ethiopia. Malar J 2023; 22:376. [PMID: 38087335 PMCID: PMC10714478 DOI: 10.1186/s12936-023-04814-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 12/02/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND Plasmodium falciparum genetic diversity can add information on transmission intensity and can be used to track control and elimination interventions. METHODS Dried blood spots (DBS) were collected from patients who were recruited for a P. falciparum malaria therapeutic efficacy trial in three malaria endemic sites in Ethiopia from October to December 2015, and November to December 2019. qPCR-confirmed infections were subject to amplicon sequencing of polymorphic markers ama1-D3, csp, cpp, cpmp, msp7. Genetic diversity, the proportion of multiclonal infections, multiplicity of infection, and population structure were analysed. RESULTS Among 198 samples selected for sequencing, data was obtained for 181 samples. Mean MOI was 1.38 (95% CI 1.24-1.53) and 17% (31/181) of infections were polyclonal. Mean He across all markers was 0.730. Population structure was moderate; populations from Metema and Metehara 2015 were very similar to each other, but distinct from Wondogent 2015 and Metehara 2019. CONCLUSION The high level of parasite genetic diversity and moderate population structure in this study suggests frequent gene flow of parasites among sites. The results obtained can be used as a baseline for additional parasite genetic diversity and structure studies, aiding in the formulation of appropriate control strategies in Ethiopia.
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Affiliation(s)
- Abeba Gebretsadik Reda
- Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
- Malaria and Neglected Tropical Diseases Research Team, Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
| | - Tiffany Huwe
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, USA.
| | - Cristian Koepfli
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, USA
| | - Ashenafi Assefa
- Malaria and Neglected Tropical Diseases Research Team, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | - Alebachew Messele
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.
| | - Hassen Mamo
- Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
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9
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Mayor A, Brokhattingen N, Matambisso G, da Silva C, Vickers EN, Pujol A, Mbeve H, Cistero P, Maculuve S, Cuna B, Melembe C, Ndimande N, Palmer B, García M, Munguambe H, Lopez JM, Nhamussa L, Simone W, Chidimatembue A, Galatas B, Guinovart C, Rovira-Vallbona E, Saute F, Aide P, Aranda-Díaz A, Greenhouse B, Macete E. Genomic malaria surveillance of antenatal care users detects reduced transmission following elimination interventions in Mozambique. RESEARCH SQUARE 2023:rs.3.rs-3545903. [PMID: 38014035 PMCID: PMC10680916 DOI: 10.21203/rs.3.rs-3545903/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Routine sampling of pregnant women at first antenatal care (ANC) visits could make Plasmodium falciparum genomic surveillance more cost-efficient and convenient in sub-Saharan Africa. We compared the genetic structure of parasite populations sampled from 289 first ANC attendees and 93 children from the community in Mozambique between 2015 and 2019. Samples were amplicon sequenced targeting 165 microhaplotypes and 15 drug resistance genes. Metrics of genetic diversity and relatedness, as well as the prevalence of drug resistance markers, were consistent between the two populations. In an area targeted for elimination, intra-host genetic diversity declined in both populations (p=0.002-0.007), while for the ANC population, population genetic diversity was also lower (p=0.0004), and genetic relatedness between infections were higher (p=0.002) than control areas, indicating a recent reduction in the parasite population size. These results highlight the added value of genomic surveillance at ANC clinics to inform about changes in transmission beyond epidemiological data.
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Affiliation(s)
- Alfredo Mayor
- Barcelona Institute for Global Health / Manhiça Health Research Centre
| | | | | | | | | | - Arnau Pujol
- ISGlobal, Barcelona Center for International Health Research (CRESIB), Hospital Clínic - Universitat de Barcelona / Centro de Investigação em Saúde da Manhiça
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - Beatriz Galatas
- ISGlobal, Barcelona Center for International Health Research (CRESIB), Hospital Clínic - Universitat de Barcelona / Centro de Investigação em Saúde da Manhiça
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10
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Murphy M, Greenhouse B. MOIRE: A software package for the estimation of allele frequencies and effective multiplicity of infection from polyallelic data. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.03.560769. [PMID: 37873322 PMCID: PMC10592951 DOI: 10.1101/2023.10.03.560769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Malaria parasite genetic data can provide insight into parasite phenotypes, evolution, and transmission. However, estimating key parameters such as allele frequencies, multiplicity of infection (MOI), and within-host relatedness from genetic data has been challenging, particularly in the presence of multiple related coinfecting strains. Existing methods often rely on single nucleotide polymorphism (SNP) data and do not account for within-host relatedness. In this study, we introduce a Bayesian approach called MOIRE (Multiplicity Of Infection and allele frequency REcovery), designed to estimate allele frequencies, MOI, and within-host relatedness from genetic data subject to experimental error. Importantly, MOIRE is flexible in accommodating both polyallelic and SNP data, making it adaptable to diverse genotyping panels. We also introduce a novel metric, the effective MOI ( e M O I ) , which integrates MOI and within-host relatedness, providing a robust and interpretable measure of genetic diversity. Using extensive simulations and real-world data from a malaria study in Namibia, we demonstrate the superior performance of MOIRE over naive estimation methods, accurately estimating MOI up to 7 with moderate sized panels of diverse loci (e.g. microhaplotypes). MOIRE also revealed substantial heterogeneity in population mean MOI and mean relatedness across health districts in Namibia, suggesting detectable differences in transmission dynamics. Notably, e M O I emerges as a portable metric of within-host diversity, facilitating meaningful comparisons across settings, even when allele frequencies or genotyping panels are different. MOIRE represents an important addition to the analysis toolkit for malaria population dynamics. Compared to existing software, MOIRE enhances the accuracy of parameter estimation and enables more comprehensive insights into within-host diversity and population structure. Additionally, MOIRE's adaptability to diverse data sources and potential for future improvements make it a valuable asset for research on malaria and other organisms, such as other eukaryotic pathogens. MOIRE is available as an R package at https://eppicenter.github.io/moire/.
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Affiliation(s)
- Maxwell Murphy
- Department of Biostatistics, School of Public Health, University of California, Berkeley, CA, USA
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, CA, USA
| | - Bryan Greenhouse
- EPPIcenter program, Division of HIV, ID and Global Medicine, University of California, San Francisco, CA, USA
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11
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Nganyewo NN, Bojang F, Oriero EC, Drammeh NF, Ajibola O, Mbye H, Jawara AS, Corea S, Awandare GA, D'Alessandro U, Amenga-Etego LN, Amambua-Ngwa A. Recent increase in low complexity polygenomic infections and sialic acid-independent invasion pathways in Plasmodium falciparum from Western Gambia. Parasit Vectors 2023; 16:309. [PMID: 37653544 PMCID: PMC10472613 DOI: 10.1186/s13071-023-05929-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 08/14/2023] [Indexed: 09/02/2023] Open
Abstract
BACKGROUND The malaria parasite Plasmodium falciparum utilizes multiple alternative receptor-ligand interactions for the invasion of human erythrocytes. While some P. falciparum clones make use of sialic acid (SA) residues on the surface of the human glycophorin receptors to invade the erythrocyte, others use alternative receptors independent of sialic acid residues. We hypothesized that over the years, intensified malaria control interventions and declining prevalence in The Gambia have resulted in a selection of parasites with a dominant invasion pathways and ligand expression profiles. METHODS Blood samples were collected from 65 malaria-infected participants with uncomplicated malaria across 3 years (2015, 2016, and 2021). Genetic diversity was determined by genotyping the merozoite surface protein 2 (msp2) polymorphic gene of P. falciparum. Erythrocyte invasion phenotypes were determined using neuraminidase, trypsin, and chymotrypsin enzymes, known to cleave different receptors from the surface of the erythrocyte. Schizont-stage transcript levels were obtained for a panel of 6 P. falciparum invasion ligand genes (eba175, eba181, Rh2b, Rh4, Rh5, and clag2) using 48 successfully cultured isolates. RESULTS Though the allelic heterozygosity of msp2 repeat region decreased as expected with reduced transmission, there was an increase in infections with more than a single msp2 allelotype from 2015 to 2021. The invasion phenotypes of these isolates were mostly SA independent with a continuous increase from 2015 to 2021. Isolates from 2021 were highly inhibited by chymotrypsin treatment compared to isolates from 2015 and 2016. Higher invasion inhibition for 2021 isolates was further obtained following erythrocyte treatment with a combination of chymotrypsin and trypsin. The transcript levels of invasion ligand genes varied across years. However, levels of clag2, a rhoptry-associated protein, were higher in 2015 and 2016 isolates than in 2021 isolates, while Rh5 levels were higher in 2021 compared to other years. CONCLUSIONS Overall, these findings suggest increasing mixed infections with an increase in the use of sialic-acid independent invasion pathways by P. falciparum clinical isolates in the Western part of Gambia.
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Affiliation(s)
- Nora Nghochuzie Nganyewo
- Medical Research Council Unit The Gambia at London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana
| | - Fatoumata Bojang
- Medical Research Council Unit The Gambia at London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Eniyou Cheryll Oriero
- Medical Research Council Unit The Gambia at London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Ndey Fatou Drammeh
- Medical Research Council Unit The Gambia at London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Olumide Ajibola
- Medical Research Council Unit The Gambia at London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Haddijatou Mbye
- Medical Research Council Unit The Gambia at London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Aminata Seedy Jawara
- Medical Research Council Unit The Gambia at London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Simon Corea
- Medical Research Council Unit The Gambia at London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Gordon Akanzuwine Awandare
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia at London, School of Hygiene and Tropical Medicine, Banjul, The Gambia
| | - Lucas N Amenga-Etego
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana
| | - Alfred Amambua-Ngwa
- Medical Research Council Unit The Gambia at London, School of Hygiene and Tropical Medicine, Banjul, The Gambia.
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12
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Gwarinda HB, Tessema SK, Raman J, Greenhouse B, Birkholtz LM. Population structure and genetic connectivity of Plasmodium falciparum in pre-elimination settings of Southern Africa. FRONTIERS IN EPIDEMIOLOGY 2023; 3:1227071. [PMID: 38455947 PMCID: PMC10910941 DOI: 10.3389/fepid.2023.1227071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 07/17/2023] [Indexed: 03/09/2024]
Abstract
To accelerate malaria elimination in the Southern African region by 2030, it is essential to prevent cross-border malaria transmission. However, countries within the region are highly interconnected due to human migration that aids in the movement of the parasite across geographical borders. It is therefore important to better understand Plasmodium falciparum transmission dynamics in the region, and identify major parasite source and sink populations, as well as cross-border blocks of high parasite connectivity. We performed a meta-analysis using collated parasite allelic data generated by microsatellite genotyping of malaria parasites from Namibia, Eswatini, South Africa, and Mozambique (N = 5,314). The overall number of unique alleles was significantly higher (P ≤ 0.01) in Namibia (mean A = 17.3 ± 1.46) compared to South Africa (mean A = 12.2 ± 1.22) and Eswatini (mean A = 13.3 ± 1.27, P ≤ 0.05), whilst the level of heterozygosity was not significantly different between countries. The proportion of polyclonal infections was highest for Namibia (77%), and lowest for Mozambique (64%). A was significant population structure was detected between parasites from the four countries, and patterns of gene flow showed that Mozambique was the major source area and Eswatini the major sink area of parasites between the countries. This study showed strong signals of parasite population structure and genetic connectivity between malaria parasite populations across national borders. This calls for strengthening the harmonization of malaria control and elimination efforts between countries in the southern African region. This data also proves its potential utility as an additional surveillance tool for malaria surveillance on both a national and regional level for the identification of imported cases and/or outbreaks, as well as monitoring for the potential spread of anti-malarial drug resistance as countries work towards malaria elimination.
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Affiliation(s)
- Hazel B. Gwarinda
- Malaria Parasite Molecular Laboratory, Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Sofonias K. Tessema
- EppiCenter, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California San Francisco, San Francisco, CA, United States
| | - Jaishree Raman
- Laboratory for Antimalarial Resistance Monitoring and Malaria Operational Research (ARMMOR), Centre for Emerging Zoonotic and Parasitic Diseases, A Division of the National Health Laboratory Service, National Institute for Communicable Diseases, Johannesburg, South Africa
- Faculty of Health Sciences, Wits Research Institute for Malaria, University of Witwatersrand, Johannesburg, South Africa
| | - Bryan Greenhouse
- EppiCenter, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California San Francisco, San Francisco, CA, United States
| | - Lyn-Marié Birkholtz
- Malaria Parasite Molecular Laboratory, Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
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13
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Fola AA, Moser KA, Aydemir O, Hennelly C, Kobayashi T, Shields T, Hamapumbu H, Musonda M, Katowa B, Matoba J, Stevenson JC, Norris DE, Thuma PE, Wesolowski A, Moss WJ, Bailey JA, Juliano JJ. Temporal and spatial analysis of Plasmodium falciparum genomics reveals patterns of parasite connectivity in a low-transmission district in Southern Province, Zambia. Malar J 2023; 22:208. [PMID: 37420265 PMCID: PMC10327325 DOI: 10.1186/s12936-023-04637-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 06/30/2023] [Indexed: 07/09/2023] Open
Abstract
BACKGROUND Understanding temporal and spatial dynamics of malaria transmission will help to inform effective interventions and strategies in regions approaching elimination. Parasite genomics are increasingly used to monitor epidemiologic trends, including assessing residual transmission across seasons and importation of malaria into these regions. METHODS In a low and seasonal transmission setting of southern Zambia, a total of 441 Plasmodium falciparum samples collected from 8 neighbouring health centres between 2012 and 2018 were genotyped using molecular inversion probes (MIPs n = 1793) targeting a total of 1832 neutral and geographically informative SNPs distributed across the parasite genome. After filtering for quality and missingness, 302 samples and 1410 SNPs were retained and used for downstream population genomic analyses. RESULTS The analyses revealed most (67%, n = 202) infections harboured one clone (monogenomic) with some variation at local level suggesting low, but heterogenous malaria transmission. Relatedness identity-by-descent (IBD) analysis revealed variable distribution of IBD segments across the genome and 6% of pairs were highly-related (IBD ≥ 0.25). Some of the highly-related parasite populations persisted across multiple seasons, suggesting that persistence of malaria in this low-transmission region is fueled by parasites "seeding" across the dry season. For recent years, clusters of clonal parasites were identified that were dissimilar to the general parasite population, suggesting parasite populations were increasingly fragmented at small spatial scales due to intensified control efforts. Clustering analysis using PCA and t-SNE showed a lack of substantial parasite population structure. CONCLUSION Leveraging both genomic and epidemiological data provided comprehensive picture of fluctuations in parasite populations in this pre-elimination setting of southern Zambia over 7 years.
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Affiliation(s)
- Abebe A. Fola
- Department of Pathology and Laboratory Medicine, Brown University, 55 Claverick Street, Providence, RI 02906 USA
| | - Kara A. Moser
- University of North Carolina Institute for Global Health and Infectious Diseases, University of North Carolina Chapel Hill, Chapel Hill, NC 27599 USA
| | - Ozkan Aydemir
- Department of Pathology and Laboratory Medicine, Brown University, 55 Claverick Street, Providence, RI 02906 USA
| | - Chris Hennelly
- University of North Carolina Institute for Global Health and Infectious Diseases, University of North Carolina Chapel Hill, Chapel Hill, NC 27599 USA
| | - Tamaki Kobayashi
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 USA
| | - Timothy Shields
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 USA
| | | | | | - Ben Katowa
- Macha Research Trust, Choma District, Choma, Zambia
| | | | | | - Douglas E. Norris
- Department of Molecular Microbiology and Immunology, The Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 USA
| | | | - Amy Wesolowski
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 USA
| | - William J. Moss
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 USA
- Department of Molecular Microbiology and Immunology, The Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 USA
| | - Jeffrey A. Bailey
- Department of Pathology and Laboratory Medicine, Brown University, 55 Claverick Street, Providence, RI 02906 USA
| | - Jonathan J. Juliano
- University of North Carolina Institute for Global Health and Infectious Diseases, University of North Carolina Chapel Hill, Chapel Hill, NC 27599 USA
- Division of Infectious Diseases, School of Medicine, University of North Carolina Chapel Hill, Chapel Hill, NC 27599 USA
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina Chapel Hill, Chapel Hill, NC 27599 USA
- Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina Chapel Hill, Chapel Hill, NC 27599 USA
| | - the Southern, Central Africa International Center of Excellence for Malaria Research (ICEMR)
- Department of Pathology and Laboratory Medicine, Brown University, 55 Claverick Street, Providence, RI 02906 USA
- University of North Carolina Institute for Global Health and Infectious Diseases, University of North Carolina Chapel Hill, Chapel Hill, NC 27599 USA
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 USA
- Macha Research Trust, Choma District, Choma, Zambia
- Department of Molecular Microbiology and Immunology, The Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 USA
- Division of Infectious Diseases, School of Medicine, University of North Carolina Chapel Hill, Chapel Hill, NC 27599 USA
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina Chapel Hill, Chapel Hill, NC 27599 USA
- Curriculum in Genetics and Molecular Biology, School of Medicine, University of North Carolina Chapel Hill, Chapel Hill, NC 27599 USA
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14
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Holzschuh A, Lerch A, Gerlovina I, Fakih BS, Al-Mafazy AWH, Reaves EJ, Ali A, Abbas F, Ali MH, Ali MA, Hetzel MW, Yukich J, Koepfli C. Multiplexed ddPCR-amplicon sequencing reveals isolated Plasmodium falciparum populations amenable to local elimination in Zanzibar, Tanzania. Nat Commun 2023; 14:3699. [PMID: 37349311 PMCID: PMC10287761 DOI: 10.1038/s41467-023-39417-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 06/13/2023] [Indexed: 06/24/2023] Open
Abstract
Zanzibar has made significant progress toward malaria elimination, but recent stagnation requires novel approaches. We developed a highly multiplexed droplet digital PCR (ddPCR)-based amplicon sequencing method targeting 35 microhaplotypes and drug-resistance loci, and successfully sequenced 290 samples from five districts covering both main islands. Here, we elucidate fine-scale Plasmodium falciparum population structure and infer relatedness and connectivity of infections using an identity-by-descent (IBD) approach. Despite high genetic diversity, we observe pronounced fine-scale spatial and temporal parasite genetic structure. Clusters of near-clonal infections on Pemba indicate persistent local transmission with limited parasite importation, presenting an opportunity for local elimination efforts. Furthermore, we observe an admixed parasite population on Unguja and detect a substantial fraction (2.9%) of significantly related infection pairs between Zanzibar and the mainland, suggesting recent importation. Our study provides a high-resolution view of parasite genetic structure across the Zanzibar archipelago and provides actionable insights for prioritizing malaria elimination efforts.
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Affiliation(s)
- Aurel Holzschuh
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Indiana, IN, USA.
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland.
| | - Anita Lerch
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Indiana, IN, USA
| | - Inna Gerlovina
- EPPIcenter Research Program, Division of HIV, ID and Global Medicine, Department of Medicine, University of California, San Francisco, CA, USA
| | - Bakar S Fakih
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
- Ifakara Health Institute, Dar es Salaam, United Republic of Tanzania
| | | | - Erik J Reaves
- U.S. Centers for Disease Control and Prevention, President's Malaria Initiative, Dar es Salaam, United Republic of Tanzania
| | - Abdullah Ali
- Zanzibar Malaria Elimination Programme, Zanzibar, United Republic of Tanzania
| | - Faiza Abbas
- Zanzibar Malaria Elimination Programme, Zanzibar, United Republic of Tanzania
| | - Mohamed Haji Ali
- Zanzibar Malaria Elimination Programme, Zanzibar, United Republic of Tanzania
| | - Mohamed Ali Ali
- Zanzibar Malaria Elimination Programme, Zanzibar, United Republic of Tanzania
| | - Manuel W Hetzel
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Joshua Yukich
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA
| | - Cristian Koepfli
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Indiana, IN, USA.
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15
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Wasakul V, Disratthakit A, Mayxay M, Chindavongsa K, Sengsavath V, Thuy-Nhien N, Pearson RD, Phalivong S, Xayvanghang S, Maude RJ, Gonçalves S, Day NP, Newton PN, Ashley EA, Kwiatkowski DP, Dondorp AM, Miotto O. Malaria outbreak in Laos driven by a selective sweep for Plasmodium falciparum kelch13 R539T mutants: a genetic epidemiology analysis. THE LANCET. INFECTIOUS DISEASES 2023; 23:568-577. [PMID: 36462526 PMCID: PMC10914674 DOI: 10.1016/s1473-3099(22)00697-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 10/13/2022] [Accepted: 10/13/2022] [Indexed: 12/02/2022]
Abstract
BACKGROUND Malaria outbreaks are important public health concerns that can cause resurgence in endemic regions approaching elimination. We investigated a Plasmodium falciparum outbreak in Attapeu Province, Laos, during the 2020-21 malaria season, using genomic epidemiology methods to elucidate parasite population dynamics and identify its causes. METHODS In this genetic analysis, 2164 P falciparum dried blood spot samples were collected from southern Laos between Jan 1, 2017, and April 1, 2021, which included 249 collected during the Attapeu outbreak between April 1, 2020, and April 1, 2021, by routine surveillance. Genetic barcodes obtained from these samples were used to investigate epidemiological changes underpinning the outbreak, estimate population diversity, and analyse population structure. Whole-genome sequencing data from additional historical samples were used to reconstruct the ancestry of outbreak strains using identity-by-descent analyses. FINDINGS The outbreak parasite populations were characterised by unprecedented loss of genetic diversity, primarily caused by rapid clonal expansion of a multidrug-resistant strain (LAA1) carrying the kelch13 Arg539Thr (R539T) mutation. LAA1 replaced kelch13 Cys580Tyr (C580Y) mutants resistant to dihydroartemisinin-piperaquine (KEL1/PLA1) as the dominant strain. LAA1 inherited 58·8% of its genome from a strain circulating in Cambodia in 2008. A secondary outbreak strain (LAA2) carried the kelch13 C580Y allele, and a genome that is essentially identical to a Cambodian parasite from 2009. A third, low-frequency strain (LAA7) was a recombinant of KEL1/PLA1 with a kelch13 R539T mutant. INTERPRETATION These results strongly suggest that the outbreak was driven by a selective sweep, possibly associated with multidrug-resistant phenotypes of the outbreak strains. Established resistant populations can circulate at low frequencies for years before suddenly overwhelming dominant strains when the conditions for selection become favourable-eg, when front-line therapies change. Genetic surveillance can support elimination by characterising key properties of outbreaks such as population diversity, drug resistance marker prevalence, and the origins of outbreak strains. FUNDING Bill & Melinda Gates Foundation; The Global Fund to Fight AIDS, Tuberculosis and Malaria; Wellcome Trust. TRANSLATION For the Lao translation of the abstract see Supplementary Materials section.
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Affiliation(s)
- Varanya Wasakul
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Areeya Disratthakit
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Mayfong Mayxay
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos; Institute of Research and Education Development, University of Health Sciences, Ministry of Health, Vientiane, Laos; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford University, Oxford, UK
| | | | | | - Nguyen Thuy-Nhien
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam
| | | | - Sonexay Phalivong
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos
| | - Saiamphone Xayvanghang
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos
| | - Richard J Maude
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford University, Oxford, UK; Harvard TH Chan School of Public Health, Harvard University, Boston, MA, USA
| | | | - Nicholas P Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford University, Oxford, UK
| | - Paul N Newton
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford University, Oxford, UK
| | - Elizabeth A Ashley
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Laos; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford University, Oxford, UK
| | | | - Arjen M Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford University, Oxford, UK
| | - Olivo Miotto
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, Oxford University, Oxford, UK; Wellcome Sanger Institute, Hinxton, UK.
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16
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Measurably recombining malaria parasites. Trends Parasitol 2023; 39:17-25. [PMID: 36435688 PMCID: PMC9893849 DOI: 10.1016/j.pt.2022.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 11/02/2022] [Accepted: 11/02/2022] [Indexed: 11/24/2022]
Abstract
Genomic epidemiology has guided research and policy for various viral pathogens and there has been a parallel effort towards using genomic epidemiology to combat diseases that are caused by eukaryotic pathogens, such as the malaria parasite. However, the central concept of viral genomic epidemiology, namely that of measurably mutating pathogens, does not apply easily to sexually recombining parasites. Here we introduce the related but different concept of measurably recombining malaria parasites to promote convergence around a unifying theoretical framework for malaria genomic epidemiology. Akin to viral phylodynamics, we anticipate that an inferential framework developed around recombination will help guide practical research and thus realize the full public health potential of genomic epidemiology for malaria parasites and other sexually recombining pathogens.
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17
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Tadele G, Jaiteh FK, Oboh M, Oriero E, Dugassa S, Amambua-Ngwa A, Golassa L. Low genetic diversity of Plasmodium falciparum merozoite surface protein 1 and 2 and multiplicity of infections in western Ethiopia following effective malaria interventions. Malar J 2022; 21:383. [PMID: 36522733 PMCID: PMC9753253 DOI: 10.1186/s12936-022-04394-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 11/19/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Genetic diversity of malaria parasites can inform the intensity of transmission and poses a major threat to malaria control and elimination interventions. Characterization of the genetic diversity would provide essential information about the ongoing control efforts. This study aimed to explore allelic polymorphism of merozoite surface protein 1 (msp1) and merozoite surface protein 2 (msp2) to determine the genetic diversity and multiplicity of Plasmodium falciparum infections circulating in high and low transmission sites in western Ethiopia. METHODS Parasite genomic DNA was extracted from a total of 225 dried blood spots collected from confirmed uncomplicated P. falciparum malaria-infected patients in western Ethiopia. Of these, 72.4% (163/225) and 27.6% (62/225) of the samples were collected in high and low transmission areas, respectively. Polymorphic msp1 and msp2 genes were used to explore the genetic diversity and multiplicity of falciparum malaria infections. Genotyping of msp1 was successful in 86.5% (141/163) and 88.7% (55/62) samples collected from high and low transmission areas, respectively. Genotyping of msp2 was carried out among 85.3% (139/163) and 96.8% (60/62) of the samples collected in high and low transmission sites, respectively. Plasmodium falciparum msp1 and msp2 genes were amplified by nested PCR and the PCR products were analysed by QIAxcel ScreenGel Software. A P-value of less or equal to 0.05 was considered significant. RESULTS High prevalence of falciparum malaria was identified in children less than 15 years as compared with those ≥ 15 years old (AOR = 2.438, P = 0.005). The three allelic families of msp1 (K1, MAD20, and RO33) and the two allelic families of msp2 (FC27 and 3D7), were observed in samples collected in high and low transmission areas. However, MAD 20 and FC 27 alleles were the predominant allelic families in both settings. Plasmodium falciparum isolates circulating in western Ethiopia had low genetic diversity and mean MOI. No difference in mean MOI between high transmission sites (mean MOI 1.104) compared with low transmission area (mean MOI 1.08) (p > 0.05). The expected heterozygosity of msp1 was slightly higher in isolates collected from high transmission sites (He = 0.17) than in those isolates from low transmission (He = 0.12). However, the heterozygosity of msp2 was not different in both settings (Pfmsp2: 0.04 in high transmission; pfmsp2: 0.03 in low transmission). CONCLUSION Plasmodium falciparum from clinical malaria cases in western Ethiopia has low genetic diversity and multiplicity of infection irrespective of the intensity of transmission at the site of sampling. These may be signaling the effectiveness of malaria control strategies in Ethiopia; although further studies are required to determine how specific intervention strategies and other parameters that drive the pattern.
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Affiliation(s)
- Geletta Tadele
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.
| | - Fatou K Jaiteh
- Medical Research Council Unit the Gambia, London School of Hygiene and Tropical Medicine, Serrekunda, The Gambia
| | - Mary Oboh
- Medical Research Council Unit the Gambia, London School of Hygiene and Tropical Medicine, Serrekunda, The Gambia
| | - Eniyou Oriero
- Medical Research Council Unit the Gambia, London School of Hygiene and Tropical Medicine, Serrekunda, The Gambia
| | - Sisay Dugassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Alfred Amambua-Ngwa
- Medical Research Council Unit the Gambia, London School of Hygiene and Tropical Medicine, Serrekunda, The Gambia
| | - Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
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18
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Mensah BA, Akyea-Bobi NE, Ghansah A. Genomic approaches for monitoring transmission dynamics of malaria: A case for malaria molecular surveillance in Sub-Saharan Africa. FRONTIERS IN EPIDEMIOLOGY 2022; 2:939291. [PMID: 38455324 PMCID: PMC10911004 DOI: 10.3389/fepid.2022.939291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 10/10/2022] [Indexed: 03/09/2024]
Abstract
Transmission dynamics is an important indicator for malaria control and elimination. As we move closer to eliminating malaria in Sub-Saharan Africa (sSA), transmission indices with higher resolution (genomic approaches) will complement our current measurements of transmission. Most of the present programmatic knowledge of malaria transmission patterns are derived from assessments of epidemiologic and clinical data, such as case counts, parasitological estimates of parasite prevalence, and Entomological Inoculation Rates (EIR). However, to eliminate malaria from endemic areas, we need to track changes in the parasite population and how they will impact transmission. This is made possible through the evolving field of genomics and genetics, as well as the development of tools for more in-depth studies on the diversity of parasites and the complexity of infections, among other topics. If malaria elimination is to be achieved globally, country-specific elimination activities should be supported by parasite genomic data from regularly collected blood samples for diagnosis, surveillance and possibly from other programmatic interventions. This presents a unique opportunity to track the spread of malaria parasites and shed additional light on intervention efficacy. In this review, various genetic techniques are highlighted along with their significance for an enhanced understanding of transmission patterns in distinct topological settings throughout Sub-Saharan Africa. The importance of these methods and their limitations in malaria surveillance to guide control and elimination strategies, are explored.
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Affiliation(s)
- Benedicta A. Mensah
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Nukunu E. Akyea-Bobi
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Anita Ghansah
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
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19
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Atuh NI, Anong DN, Jerome FC, Oriero E, Mohammed NI, D’Alessandro U, Amambua-Ngwa A. High genetic complexity but low relatedness in Plasmodium falciparum infections from Western Savannah Highlands and coastal equatorial Lowlands of Cameroon. Pathog Glob Health 2022; 116:428-437. [PMID: 34308788 PMCID: PMC9518281 DOI: 10.1080/20477724.2021.1953686] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To determine the diversity and connectivity of infections in Northwestern and Southwestern Cameroon, 232 Plasmodium falciparum infections, collected in 2018 from the Ndop Health District (NHD) in the western savannah highlands in the Northwest and the Limbe Health District (LHD) in the coastal lowland forests in the Southwest of Cameroon were genotyped for nine neutral microsatellite markers. Overall infection complexity and genetic diversity was significantly (p < 0.05) lower in NHD than LHD, (Mean MOI = 2.45 vs. 2.97; Fws = 0.42 vs. 0.47; Mean He = 0.84 vs. 0.89, respectively). Multi-locus linkage disequilibrium was generally low but significantly higher in the NHD than LHD population (mean ISA= 0.376 vs 0.093). Consequently, highly related pairs of isolates were observed in NHD (mean IBS = 0.086) compared to those from the LHD (mean IBS = 0.059). Infections from the two regions were mostly unrelated (mean IBS = 0.059), though the overall genetic differentiation across the geographical range was low. Indices of differentiation between the populations were however significant (overall pairwise Fst = 0.048, Jost's D = 0.133, p < 0.01). Despite the high human migration across the 270km separating the study sites, these results suggest significant restrictions to gene flow against contiguous geospatial transmission of malaria in west Cameroon. Clonal infections in the highland sites could be driven by lower levels of malaria prevalence and seasonal transmission. How these differences in genetic diversity and complexity affect responses to interventions such as drugs will require further investigations from broader community sampling.
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Affiliation(s)
- Ngoh Ines Atuh
- Department of Biomedical Science, Faculty of Health Science, University of Buea, Buea, Cameroon
- Disease Control and Elimination, Medical Research Council Unit the Gambia at LSHTM. Banjul, The Gambia
| | - Damian Nota Anong
- Department of Microbiology & Parasitology, Faculty of Science, University of Buea, Molyko Buea, Cameroon
| | - Fru-Cho Jerome
- Department of Biomedical Science, Faculty of Health Science, University of Buea, Buea, Cameroon
| | - Eniyou Oriero
- Disease Control and Elimination, Medical Research Council Unit the Gambia at LSHTM. Banjul, The Gambia
| | - Nuredin Ibrahim Mohammed
- Disease Control and Elimination, Medical Research Council Unit the Gambia at LSHTM. Banjul, The Gambia
| | - Umberto D’Alessandro
- Department of Microbiology & Parasitology, Faculty of Science, University of Buea, Molyko Buea, Cameroon
| | - Alfred Amambua-Ngwa
- Disease Control and Elimination, Medical Research Council Unit the Gambia at LSHTM. Banjul, The Gambia
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20
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Wong W, Volkman S, Daniels R, Schaffner S, Sy M, Ndiaye YD, Badiane AS, Deme AB, Diallo MA, Gomis J, Sy N, Ndiaye D, Wirth DF, Hartl DL. R H: a genetic metric for measuring intrahost Plasmodium falciparum relatedness and distinguishing cotransmission from superinfection. PNAS NEXUS 2022; 1:pgac187. [PMID: 36246152 PMCID: PMC9552330 DOI: 10.1093/pnasnexus/pgac187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 09/08/2022] [Indexed: 01/29/2023]
Abstract
Multiple-strain (polygenomic) infections are a ubiquitous feature of Plasmodium falciparum parasite population genetics. Under simple assumptions of superinfection, polygenomic infections are hypothesized to be the result of multiple infectious bites. As a result, polygenomic infections have been used as evidence of repeat exposure and used to derive genetic metrics associated with high transmission intensity. However, not all polygenomic infections are the result of multiple infectious bites. Some result from the transmission of multiple, genetically related strains during a single infectious bite (cotransmission). Superinfection and cotransmission represent two distinct transmission processes, and distinguishing between the two could improve inferences regarding parasite transmission intensity. Here, we describe a new metric, R H, that utilizes the correlation in allelic state (heterozygosity) within polygenomic infections to estimate the likelihood that the observed complexity resulted from either superinfection or cotransmission. R H is flexible and can be applied to any type of genetic data. As a proof of concept, we used R H to quantify polygenomic relatedness and estimate cotransmission and superinfection rates from a set of 1,758 malaria infections genotyped with a 24 single nucleotide polymorphism (SNP) molecular barcode. Contrary to expectation, we found that cotransmission was responsible for a significant fraction of 43% to 53% of the polygenomic infections collected in three distinct epidemiological regions in Senegal. The prediction that polygenomic infections frequently result from cotransmission stresses the need to incorporate estimates of relatedness within polygenomic infections to ensure the accuracy of genomic epidemiology surveillance data for informing public health activities.
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Affiliation(s)
- Wesley Wong
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA
| | - Sarah Volkman
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, MA 02142, USA
- College of Natural, Behavioral, and Health Sciences, Simmons University, Boston, MA 02115, USA
| | - Rachel Daniels
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, MA 02142, USA
| | - Stephen Schaffner
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, MA 02142, USA
| | - Mouhamad Sy
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar 10200, Senegal
| | - Yaye Die Ndiaye
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar 10200, Senegal
| | - Aida S Badiane
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar 10200, Senegal
| | - Awa B Deme
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar 10200, Senegal
| | - Mamadou Alpha Diallo
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar 10200, Senegal
| | - Jules Gomis
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar 10200, Senegal
| | - Ngayo Sy
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar 10200, Senegal
| | - Daouda Ndiaye
- Laboratory of Parasitology and Mycology, Aristide le Dantec Hospital, Cheikh Anta Diop University, Dakar 10200, Senegal
| | - Dyann F Wirth
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, MA 02142, USA
| | - Daniel L Hartl
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
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21
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Gerlovina I, Gerlovin B, Rodríguez-Barraquer I, Greenhouse B. Dcifer: an IBD-based method to calculate genetic distance between polyclonal infections. Genetics 2022; 222:6674513. [PMID: 36000888 PMCID: PMC9526043 DOI: 10.1093/genetics/iyac126] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 08/04/2022] [Indexed: 11/23/2022] Open
Abstract
An essential step toward reconstructing pathogen transmission and answering epidemiologically relevant questions from genomic data is obtaining pairwise genetic distance between infections. For recombining organisms such as malaria parasites, relatedness measures quantifying recent shared ancestry would provide a meaningful distance, suggesting methods based on identity by descent (IBD). While the concept of relatedness and consequently an IBD approach is fairly straightforward for individual parasites, the distance between polyclonal infections, which are prevalent in malaria, presents specific challenges, and awaits a general solution that could be applied to infections of any clonality and accommodate multiallelic (e.g. microsatellite or microhaplotype) and biallelic [single nucleotide polymorphism (SNP)] data. Filling this methodological gap, we present Dcifer (Distance for complex infections: fast estimation of relatedness), a method for calculating genetic distance between polyclonal infections, which is designed for unphased data, explicitly accounts for population allele frequencies and complexity of infection, and provides reliable inference. Dcifer’s IBD-based framework allows us to define model parameters that represent interhost relatedness and to propose corresponding estimators with attractive statistical properties. By using combinatorics to account for unobserved phased haplotypes, Dcifer is able to quickly process large datasets and estimate pairwise relatedness along with measures of uncertainty. We show that Dcifer delivers accurate and interpretable results and detects related infections with statistical power that is 2–4 times greater than that of approaches based on identity by state. Applications to real data indicate that relatedness structure aligns with geographic locations. Dcifer is implemented in a comprehensive publicly available software package.
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Affiliation(s)
- Inna Gerlovina
- EPPIcenter research program, Division of HIV, ID and Global Medicine, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Boris Gerlovin
- EPPIcenter research program, Division of HIV, ID and Global Medicine, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Isabel Rodríguez-Barraquer
- EPPIcenter research program, Division of HIV, ID and Global Medicine, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Bryan Greenhouse
- EPPIcenter research program, Division of HIV, ID and Global Medicine, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
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22
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Huwe T, Kibria MG, Johora FT, Phru CS, Jahan N, Hossain MS, Khan WA, Price RN, Ley B, Alam MS, Koepfli C. Heterogeneity in prevalence of subclinical Plasmodium falciparum and Plasmodium vivax infections but no parasite genomic clustering in the Chittagong Hill Tracts, Bangladesh. Malar J 2022; 21:218. [PMID: 35836171 PMCID: PMC9281141 DOI: 10.1186/s12936-022-04236-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 06/22/2022] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Malaria remains endemic in Bangladesh, with the majority of cases occurring in forested, mountainous region in the Chittagong Hill Tracts (CHT). This area is home to Bengali and diverse groups of indigenous people (Pahari) residing largely in mono-ethnic villages. METHODS 1002 individuals of the 9 most prominent Pahari and the Bengali population were randomly selected and screened by RDT and qPCR. Parasites were genotyped by msp2 and deep sequencing of 5 amplicons (ama1-D3, cpmp, cpp, csp, and msp7) for Plasmodium falciparum (n = 20), and by microsatellite (MS) typing of ten loci and amplicon sequencing of msp1 for Plasmodium vivax (n = 21). Population structure was analysed using STRUCTURE software. Identity-by-state (IBS) was calculated as a measure of parasite relatedness and used to generate relatedness networks. RESULTS The prevalence of P. falciparum and P. vivax infection was 0.7% by RDT (P. falciparum 6/1002; P. vivax 0/1002, mixed: 1/1002) and 4% by qPCR (P. falciparum 21/1002; P. vivax 16/1002, mixed: 5/1002). Infections were highly clustered, with 64% (27/42) of infections occurring in only two Pahari groups, the Khumi and Mro. Diversity was high; expected heterozygosity was 0.93 for P. falciparum and 0.81 for P. vivax. 85.7% (18/21) of P. vivax and 25% (5/20) of P. falciparum infections were polyclonal. No population structure was evident for either species, suggesting high transmission and gene flow among Pahari groups. CONCLUSIONS High subclinical infection prevalence and genetic diversity mirror ongoing transmission. Control activities should be specifically directed to Pahari groups at greatest risk.
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Affiliation(s)
- Tiffany Huwe
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, USA
| | - Mohammad Golam Kibria
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research Bangladesh (Icddr, B), Dhaka, Bangladesh
| | - Fatema Tuj Johora
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research Bangladesh (Icddr, B), Dhaka, Bangladesh
- Georgia State University, Atlanta, GA, USA
| | - Ching Swe Phru
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research Bangladesh (Icddr, B), Dhaka, Bangladesh
| | - Nusrat Jahan
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research Bangladesh (Icddr, B), Dhaka, Bangladesh
| | - Mohammad Sharif Hossain
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research Bangladesh (Icddr, B), Dhaka, Bangladesh
| | - Wasif Ali Khan
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research Bangladesh (Icddr, B), Dhaka, Bangladesh
| | - Ric N Price
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Benedikt Ley
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Australia.
| | - Mohammad Shafiul Alam
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research Bangladesh (Icddr, B), Dhaka, Bangladesh.
| | - Cristian Koepfli
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, USA.
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23
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Kimenyi KM, Wamae K, Ngoi JM, de Laurent ZR, Ndwiga L, Osoti V, Obiero G, Abdi AI, Bejon P, Ochola-Oyier LI. Maintenance of high temporal Plasmodium falciparum genetic diversity and complexity of infection in asymptomatic and symptomatic infections in Kilifi, Kenya from 2007 to 2018. Malar J 2022; 21:192. [PMID: 35725456 PMCID: PMC9207840 DOI: 10.1186/s12936-022-04213-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 06/03/2022] [Indexed: 11/30/2022] Open
Abstract
Background High levels of genetic diversity are common characteristics of Plasmodium falciparum parasite populations in high malaria transmission regions. There has been a decline in malaria transmission intensity over 12 years of surveillance in the community in Kilifi, Kenya. This study sought to investigate whether there was a corresponding reduction in P. falciparum genetic diversity, using msp2 as a genetic marker. Methods Blood samples were obtained from children (< 15 years) enrolled into a cohort with active weekly surveillance between 2007 and 2018 in Kilifi, Kenya. Asymptomatic infections were defined during the annual cross-sectional blood survey and the first-febrile malaria episode was detected during the weekly follow-up. Parasite DNA was extracted and successfully genotyped using allele-specific nested polymerase chain reactions for msp2 and capillary electrophoresis fragment analysis. Results Based on cross-sectional surveys conducted in 2007–2018, there was a significant reduction in malaria prevalence (16.2–5.5%: P-value < 0.001), however msp2 genetic diversity remained high. A high heterozygosity index (He) (> 0.95) was observed in both asymptomatic infections and febrile malaria over time. About 281 (68.5%) asymptomatic infections were polyclonal (> 2 variants per infection) compared to 46 (56%) polyclonal first-febrile infections. There was significant difference in complexity of infection (COI) between asymptomatic 2.3 [95% confidence interval (CI) 2.2–2.5] and febrile infections 2.0 (95% CI 1.7–2.3) (P = 0.016). Majority of asymptomatic infections (44.2%) carried mixed alleles (i.e., both FC27 and IC/3D7), while FC27 alleles were more frequent (53.3%) among the first-febrile infections. Conclusions Plasmodium falciparum infections in Kilifi are still highly diverse and polyclonal, despite the reduction in malaria transmission in the community. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04213-7.
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Affiliation(s)
- Kelvin M Kimenyi
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya. .,Department of Biochemistry, University of Nairobi, Nairobi, Kenya.
| | - Kevin Wamae
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Joyce M Ngoi
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,West Africa Centre for Cell Biology and Infectious Pathogen, Accra, Ghana
| | | | | | - Victor Osoti
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - George Obiero
- Department of Biochemistry, University of Nairobi, Nairobi, Kenya
| | | | - Philip Bejon
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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24
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Huber JH, Hsiang MS, Dlamini N, Murphy M, Vilakati S, Nhlabathi N, Lerch A, Nielsen R, Ntshalintshali N, Greenhouse B, Perkins TA. Inferring person-to-person networks of Plasmodium falciparum transmission: are analyses of routine surveillance data up to the task? Malar J 2022; 21:58. [PMID: 35189905 PMCID: PMC8860266 DOI: 10.1186/s12936-022-04072-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Accepted: 01/31/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Inference of person-to-person transmission networks using surveillance data is increasingly used to estimate spatiotemporal patterns of pathogen transmission. Several data types can be used to inform transmission network inferences, yet the sensitivity of those inferences to different data types is not routinely evaluated. METHODS The influence of different combinations of spatial, temporal, and travel-history data on transmission network inferences for Plasmodium falciparum malaria were evaluated. RESULTS The information content of these data types may be limited for inferring person-to-person transmission networks and may lead to an overestimate of transmission. Only when outbreaks were temporally focal or travel histories were accurate was the algorithm able to accurately estimate the reproduction number under control, Rc. Applying this approach to data from Eswatini indicated that inferences of Rc and spatiotemporal patterns therein depend upon the choice of data types and assumptions about travel-history data. CONCLUSIONS These results suggest that transmission network inferences made with routine malaria surveillance data should be interpreted with caution.
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Affiliation(s)
- John H Huber
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA.
| | - Michelle S Hsiang
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Malaria Elimination Initiative, Global Health Group, University of California, San Francisco, CA, USA.,Department of Pediatrics, University of California, San Francisco,, CA, USA
| | - Nomcebo Dlamini
- National Malaria Elimination Programme, Ministry of Health, Manzini, Eswatini
| | - Maxwell Murphy
- Department of Medicine, University of California, San Francisco, CA, USA
| | | | - Nomcebo Nhlabathi
- National Malaria Elimination Programme, Ministry of Health, Manzini, Eswatini
| | - Anita Lerch
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Rasmus Nielsen
- Department of Integrative Biology and Statistics, University of California, Berkeley, CA, USA
| | | | - Bryan Greenhouse
- Department of Medicine, University of California, San Francisco, CA, USA.,Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - T Alex Perkins
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA.
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25
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Wu L, Hsiang MS, Prach LM, Schrubbe L, Ntuku H, Dufour MSK, Whittemore B, Scott V, Yala J, Roberts KW, Patterson C, Biggs J, Hall T, Tetteh KK, Gueye CS, Greenhouse B, Bennett A, Smith JL, Katokele S, Uusiku P, Mumbengegwi D, Gosling R, Drakeley C, Kleinschmidt I. Serological evaluation of the effectiveness of reactive focal mass drug administration and reactive vector control to reduce malaria transmission in Zambezi Region, Namibia: Results from a secondary analysis of a cluster randomised trial. EClinicalMedicine 2022; 44:101272. [PMID: 35198913 PMCID: PMC8851292 DOI: 10.1016/j.eclinm.2022.101272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 12/20/2021] [Accepted: 01/06/2022] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Due to challenges in measuring changes in malaria at low transmission, serology is increasingly being used to complement clinical and parasitological surveillance. Longitudinal studies have shown that serological markers, such as Etramp5.Ag1, can reflect spatio-temporal differences in malaria transmission. However, these markers have yet to be used as endpoints in intervention trials. METHODS Based on data from a 2017 cluster randomised trial conducted in Zambezi Region, Namibia, evaluating the effectiveness of reactive focal mass drug administration (rfMDA) and reactive vector control (RAVC), this study conducted a secondary analysis comparing antibody responses between intervention arms as trial endpoints. Antibody responses were measured on a multiplex immunoassay, using a panel of eight serological markers of Plasmodium falciparum infection - Etramp5.Ag1, GEXP18, HSP40.Ag1, Rh2.2030, EBA175, PfMSP119, PfAMA1, and PfGLURP.R2. FINDINGS Reductions in sero-prevalence to antigens Etramp.Ag1, PfMSP119, Rh2.2030, and PfAMA1 were observed in study arms combining rfMDA and RAVC, but only effects for Etramp5.Ag1 were statistically significant. Etramp5.Ag1 sero-prevalence was significantly lower in all intervention arms. Compared to the reference arms, adjusted prevalence ratio (aPR) for Etramp5.Ag1 was 0.78 (95%CI 0.65 - 0.91, p = 0.0007) in the rfMDA arms and 0.79 (95%CI 0.67 - 0.92, p = 0.001) in the RAVC arms. For the combined rfMDA plus RAVC intervention, aPR was 0.59 (95%CI 0.46 - 0.76, p < 0.0001). Significant reductions were also observed based on continuous antibody responses. Sero-prevalence as an endpoint was found to achieve higher study power (99.9% power to detect a 50% reduction in prevalence) compared to quantitative polymerase chain reaction (qPCR) prevalence (72.9% power to detect a 50% reduction in prevalence). INTERPRETATION While the observed relative reduction in qPCR prevalence in the study was greater than serology, the use of serological endpoints to evaluate trial outcomes measured effect size with improved precision and study power. Serology has clear application in cluster randomised trials, particularly in settings where measuring clinical incidence or infection is less reliable due to seasonal fluctuations, limitations in health care seeking, or incomplete testing and reporting. FUNDING This study was supported by Novartis Foundation (A122666), the Bill & Melinda Gates Foundation (OPP1160129), and the Horchow Family Fund (5,300,375,400).
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Affiliation(s)
- Lindsey Wu
- London School of Hygiene and Tropical Medicine, Faculty of Infectious Tropical Diseases, Department of Infection Biology, London, United Kingdom of Great Britain
- Corresponding author.
| | - Michelle S. Hsiang
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States of America
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, United States of America
- Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
| | - Lisa M. Prach
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, United States of America
| | - Leah Schrubbe
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, United States of America
| | - Henry Ntuku
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, United States of America
| | - Mi-Suk Kang Dufour
- Division of Prevention Science, University of California San Francisco, San Francisco, CA, USA
| | - Brooke Whittemore
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States of America
| | - Valerie Scott
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, United States of America
| | - Joy Yala
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, United States of America
| | - Kathryn W. Roberts
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, United States of America
| | - Catriona Patterson
- London School of Hygiene and Tropical Medicine, Faculty of Infectious Tropical Diseases, Department of Infection Biology, London, United Kingdom of Great Britain
| | - Joseph Biggs
- London School of Hygiene and Tropical Medicine, Faculty of Infectious Tropical Diseases, Department of Infection Biology, London, United Kingdom of Great Britain
| | - Tom Hall
- St. George's University of London, London, UK
| | - Kevin K.A. Tetteh
- London School of Hygiene and Tropical Medicine, Faculty of Infectious Tropical Diseases, Department of Infection Biology, London, United Kingdom of Great Britain
| | - Cara Smith Gueye
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, United States of America
| | - Bryan Greenhouse
- Division of Experimental Medicine, Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Adam Bennett
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, United States of America
| | - Jennifer L. Smith
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, United States of America
| | - Stark Katokele
- National Vector-Borne Diseases Control Programme, Namibia Ministry of Health and Social Services, Windhoek, Namibia
| | - Petrina Uusiku
- National Vector-Borne Diseases Control Programme, Namibia Ministry of Health and Social Services, Windhoek, Namibia
| | - Davis Mumbengegwi
- Multidisciplinary Research Centre, University of Namibia, Windhoek, Namibia
| | - Roly Gosling
- Malaria Elimination Initiative, Global Health Group, University of California San Francisco, San Francisco, CA, United States of America
| | - Chris Drakeley
- London School of Hygiene and Tropical Medicine, Faculty of Infectious Tropical Diseases, Department of Infection Biology, London, United Kingdom of Great Britain
| | - Immo Kleinschmidt
- London School of Hygiene and Tropical Medicine, Faculty of Epidemiology and Population Health, Department of Infectious Disease Epidemiology, London, UK
- Research Council Collaborating Centre for Multi-Disciplinary Research on Malaria, School of Pathology, Wits Institute for Malaria Research, Faculty of Health Science, University of Witwatersrand, Johannesburg, South Africa
- Southern African Development Community Malaria Elimination Eight Secretariat, Windhoek, Namibia
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26
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Sy M, Deme AB, Warren JL, Early A, Schaffner S, Daniels RF, Dieye B, Ndiaye IM, Diedhiou Y, Mbaye AM, Volkman SK, Hartl DL, Wirth DF, Ndiaye D, Bei AK. Plasmodium falciparum genomic surveillance reveals spatial and temporal trends, association of genetic and physical distance, and household clustering. Sci Rep 2022; 12:938. [PMID: 35042879 PMCID: PMC8766587 DOI: 10.1038/s41598-021-04572-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Accepted: 12/24/2021] [Indexed: 11/15/2022] Open
Abstract
Molecular epidemiology using genomic data can help identify relationships between malaria parasite population structure, malaria transmission intensity, and ultimately help generate actionable data to assess the effectiveness of malaria control strategies. Genomic data, coupled with geographic information systems data, can further identify clusters or hotspots of malaria transmission, parasite genetic and spatial connectivity, and parasite movement by human or mosquito mobility over time and space. In this study, we performed longitudinal genomic surveillance in a cohort of 70 participants over four years from different neighborhoods and households in Thiès, Senegal—a region of exceptionally low malaria transmission (entomological inoculation rate less than 1). Genetic identity (identity by state, IBS) was established using a 24-single nucleotide polymorphism molecular barcode, identity by descent was calculated from whole genome sequence data, and a hierarchical Bayesian regression model was used to establish genetic and spatial relationships. Our results show clustering of genetically similar parasites within households and a decline in genetic similarity of parasites with increasing distance. One household showed extremely high diversity and warrants further investigation as to the source of these diverse genetic types. This study illustrates the utility of genomic data with traditional epidemiological approaches for surveillance and detection of trends and patterns in malaria transmission not only by neighborhood but also by household. This approach can be implemented regionally and countrywide to strengthen and support malaria control and elimination efforts.
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Affiliation(s)
- Mouhamad Sy
- Laboratory of Parasitology and Mycology, Cheikh Anta Diop University, Aristide le Dantec Hospital, Dakar, Senegal
| | - Awa B Deme
- Laboratory of Parasitology and Mycology, Cheikh Anta Diop University, Aristide le Dantec Hospital, Dakar, Senegal.,Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | - Joshua L Warren
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA
| | - Angela Early
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,The Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Stephen Schaffner
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,The Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Rachel F Daniels
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Baba Dieye
- Laboratory of Parasitology and Mycology, Cheikh Anta Diop University, Aristide le Dantec Hospital, Dakar, Senegal
| | - Ibrahima Mbaye Ndiaye
- Laboratory of Parasitology and Mycology, Cheikh Anta Diop University, Aristide le Dantec Hospital, Dakar, Senegal
| | - Younous Diedhiou
- Laboratory of Parasitology and Mycology, Cheikh Anta Diop University, Aristide le Dantec Hospital, Dakar, Senegal
| | - Amadou Moctar Mbaye
- Laboratory of Parasitology and Mycology, Cheikh Anta Diop University, Aristide le Dantec Hospital, Dakar, Senegal
| | - Sarah K Volkman
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,The Broad Institute of MIT and Harvard, Cambridge, MA, USA.,College of Natural, Behavioral and Health Sciences, Simmons University, Boston, MA, USA
| | - Daniel L Hartl
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,The Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Dyann F Wirth
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,The Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Daouda Ndiaye
- Laboratory of Parasitology and Mycology, Cheikh Anta Diop University, Aristide le Dantec Hospital, Dakar, Senegal
| | - Amy K Bei
- Laboratory of Parasitology and Mycology, Cheikh Anta Diop University, Aristide le Dantec Hospital, Dakar, Senegal. .,Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA. .,Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA.
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27
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Markwalter CF, Menya D, Wesolowski A, Esimit D, Lokoel G, Kipkoech J, Freedman E, Sumner KM, Abel L, Ambani G, Meredith HR, Taylor SM, Obala AA, O'Meara WP. Plasmodium falciparum importation does not sustain malaria transmission in a semi-arid region of Kenya. PLOS GLOBAL PUBLIC HEALTH 2022; 2:e0000807. [PMID: 36962553 PMCID: PMC10021402 DOI: 10.1371/journal.pgph.0000807] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 07/17/2022] [Indexed: 11/19/2022]
Abstract
Human movement impacts the spread and transmission of infectious diseases. Recently, a large reservoir of Plasmodium falciparum malaria was identified in a semi-arid region of northwestern Kenya historically considered unsuitable for malaria transmission. Understanding the sources and patterns of transmission attributable to human movement would aid in designing and targeting interventions to decrease the unexpectedly high malaria burden in the region. Toward this goal, polymorphic parasite genes (ama1, csp) in residents and passengers traveling to Central Turkana were genotyped by amplicon deep sequencing. Genotyping and epidemiological data were combined to assess parasite importation. The contribution of travel to malaria transmission was estimated by modelling case reproductive numbers inclusive and exclusive of travelers. P. falciparum was detected in 6.7% (127/1891) of inbound passengers, including new haplotypes which were later detected in locally-transmitted infections. Case reproductive numbers approximated 1 and did not change when travelers were removed from transmission networks, suggesting that transmission is not fueled by travel to the region but locally endemic. Thus, malaria is not only prevalent in Central Turkana but also sustained by local transmission. As such, interrupting importation is unlikely to be an effective malaria control strategy on its own, but targeting interventions locally has the potential to drive down transmission.
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Affiliation(s)
| | - Diana Menya
- School of Public Health, Moi University College of Health Sciences, Eldoret, Kenya
| | - Amy Wesolowski
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Daniel Esimit
- Department of Health Services and Sanitation, Turkana County, Kenya
| | - Gilchrist Lokoel
- Department of Health Services and Sanitation, Turkana County, Kenya
| | - Joseph Kipkoech
- Academic Model Providing Access to Healthcare, Eldoret, Kenya
| | - Elizabeth Freedman
- Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Kelsey M Sumner
- Duke University School of Medicine, Durham, North Carolina, United States of America
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Lucy Abel
- Academic Model Providing Access to Healthcare, Eldoret, Kenya
| | - George Ambani
- Academic Model Providing Access to Healthcare, Eldoret, Kenya
| | - Hannah R Meredith
- Duke Global Health Institute, Durham, North Carolina, United States of America
| | - Steve M Taylor
- Duke Global Health Institute, Durham, North Carolina, United States of America
- Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Andrew A Obala
- School of Medicine, Moi University College of Health Sciences, Eldoret, Kenya
| | - Wendy P O'Meara
- Duke Global Health Institute, Durham, North Carolina, United States of America
- Duke University School of Medicine, Durham, North Carolina, United States of America
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28
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Khan SN, Ali R, Khan S, Rooman M, Norin S, Zareen S, Ali I, Ayaz S. Genetic Diversity of Polymorphic Marker Merozoite Surface Protein 1 ( Msp-1) and 2 ( Msp-2) Genes of Plasmodium falciparum Isolates From Malaria Endemic Region of Pakistan. Front Genet 2021; 12:751552. [PMID: 34868223 PMCID: PMC8635745 DOI: 10.3389/fgene.2021.751552] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 10/04/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Understanding the genetic diversity of Plasmodium species through polymorphic studies can assist in designing more effective control strategies of malaria like new drug formulation and development of a vaccine. Pakistan is moderate endemic for Plasmodium falciparum, but little is known about the genetic diversity of this parasite. This study aimed to investigate the molecular diversity of P. falciparum based on msp-1 and msp-2 genes in the malaria-endemic regions of Khyber Pakhtunkhwa, Pakistan. Methods: A total of 199/723 blood samples, tested positive by microscopy for falciparum malaria, were collected from four districts (Dera Ismail Khan, Karak, Mardan, and Peshawar) of Khyber Pakhtunkhwa. Nested PCR amplification technique was employed to target block 2 of msp-1 and the central domain of msp-2 genes, including their respective allelic families K1, MAD20, RO33, FC27, and 3D7/IC, and to detect the extent of genetic diversity of P. falciparum clinical isolates. Results: Among the 199 microscopy-positive P. falciparum samples, a total of 192 were confirmed using PCR. Ninety-seven amplicons were observed for msp-1 and 95 for msp-2. A total of 33 genotypes, 17 for msp-1 (eight K1, six MAD20, and three RO33) and 16 for msp-2 (nine FC27 and seven 3D7/IC), were identified. The specific allelic frequency of the K1 family was higher (44.3%) than that of MAD20 (33.0%) and RO33 (23.0%) for msp-1, while the FC27 allelic family was dominant (60.0%) compared with 3D7/IC (40.0%) for msp-2. No polyclonal infection was observed in msp-1 and msp-2. The expected heterozygosity was 0.98 and 0.97 for msp-1 and msp-2, respectively. Conclusion: It was concluded that the P. falciparum populations are highly polymorphic, and diverse allelic variants of msp-1 and msp-2 are present in Khyber Pakhtunkhwa, Pakistan.
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Affiliation(s)
- Shahid Niaz Khan
- Department of Zoology, Faculty of Biological Sciences, Kohat University of Science and Technology, Kohat, Pakistan
| | - Rehman Ali
- Department of Zoology, Faculty of Biological Sciences, Kohat University of Science and Technology, Kohat, Pakistan
| | - Sanaullah Khan
- Department of Zoology, University of Peshawar, Peshawar, Pakistan
| | - Muhammad Rooman
- Department of Zoology, Hazara University, Mansehra, Pakistan
| | - Sadia Norin
- Department of Zoology, Faculty of Biological Sciences, Kohat University of Science and Technology, Kohat, Pakistan
| | - Shehzad Zareen
- Department of Zoology, Faculty of Biological Sciences, Kohat University of Science and Technology, Kohat, Pakistan
| | - Ijaz Ali
- Department of Biosciences, COMSATS University Islamabad, Islamabad, Pakistan
| | - Sultan Ayaz
- College of Veterinary Sciences and Animal Husbandry, Abdul Wali Khan University Garden Campus Mardan, Mardan, Pakistan
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29
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Argyropoulos DC, Ruybal‐Pesántez S, Deed SL, Oduro AR, Dadzie SK, Appawu MA, Asoala V, Pascual M, Koram KA, Day KP, Tiedje KE. The impact of indoor residual spraying on Plasmodium falciparum microsatellite variation in an area of high seasonal malaria transmission in Ghana, West Africa. Mol Ecol 2021; 30:3974-3992. [PMID: 34143538 PMCID: PMC8456823 DOI: 10.1111/mec.16029] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 05/26/2021] [Accepted: 06/01/2021] [Indexed: 01/16/2023]
Abstract
Here, we report the first population genetic study to examine the impact of indoor residual spraying (IRS) on Plasmodium falciparum in humans. This study was conducted in an area of high seasonal malaria transmission in Bongo District, Ghana. IRS was implemented during the dry season (November-May) in three consecutive years between 2013 and 2015 to reduce transmission and attempt to bottleneck the parasite population in humans towards lower diversity with greater linkage disequilibrium. The study was done against a background of widespread use of long-lasting insecticidal nets, typical for contemporary malaria control in West Africa. Microsatellite genotyping with 10 loci was used to construct 392 P. falciparum multilocus infection haplotypes collected from two age-stratified cross-sectional surveys at the end of the wet seasons pre- and post-IRS. Three-rounds of IRS, under operational conditions, led to a >90% reduction in transmission intensity and a 35.7% reduction in the P. falciparum prevalence (p < .001). Despite these declines, population genetic analysis of the infection haplotypes revealed no dramatic changes with only a slight, but significant increase in genetic diversity (He : pre-IRS = 0.79 vs. post-IRS = 0.81, p = .048). Reduced relatedness of the parasite population (p < .001) was observed post-IRS, probably due to decreased opportunities for outcrossing. Spatiotemporal genetic differentiation between the pre- and post-IRS surveys (D = 0.0329 [95% CI: 0.0209 - 0.0473], p = .034) was identified. These data provide a genetic explanation for the resilience of P. falciparum to short-term IRS programmes in high-transmission settings in sub-Saharan Africa.
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Affiliation(s)
- Dionne C. Argyropoulos
- School of BioSciencesBio21 InstituteThe University of MelbourneMelbourneVic.Australia
- Department of Microbiology and ImmunologyBio21 Institute and Peter Doherty InstituteThe University of MelbourneMelbourneVic.Australia
| | - Shazia Ruybal‐Pesántez
- School of BioSciencesBio21 InstituteThe University of MelbourneMelbourneVic.Australia
- Present address:
Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical ResearchMelbourneVic.Australia
- Present address:
Department of Medical Biology and Bio21 InstituteThe University of MelbourneMelbourneVic.Australia
- Present address:
Burnet InstituteMelbourneVic.Australia
| | - Samantha L. Deed
- School of BioSciencesBio21 InstituteThe University of MelbourneMelbourneVic.Australia
- Department of Microbiology and ImmunologyBio21 Institute and Peter Doherty InstituteThe University of MelbourneMelbourneVic.Australia
| | - Abraham R. Oduro
- Navrongo Health Research CentreGhana Health ServiceNavrongoGhana
| | - Samuel K. Dadzie
- Noguchi Memorial Institute for Medical ResearchUniversity of GhanaLegonGhana
| | - Maxwell A. Appawu
- Noguchi Memorial Institute for Medical ResearchUniversity of GhanaLegonGhana
| | - Victor Asoala
- Navrongo Health Research CentreGhana Health ServiceNavrongoGhana
| | - Mercedes Pascual
- Department of Ecology and EvolutionUniversity of ChicagoChicagoUSA
| | - Kwadwo A. Koram
- Noguchi Memorial Institute for Medical ResearchUniversity of GhanaLegonGhana
| | - Karen P. Day
- School of BioSciencesBio21 InstituteThe University of MelbourneMelbourneVic.Australia
- Department of Microbiology and ImmunologyBio21 Institute and Peter Doherty InstituteThe University of MelbourneMelbourneVic.Australia
| | - Kathryn E. Tiedje
- School of BioSciencesBio21 InstituteThe University of MelbourneMelbourneVic.Australia
- Department of Microbiology and ImmunologyBio21 Institute and Peter Doherty InstituteThe University of MelbourneMelbourneVic.Australia
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30
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Agaba BB, Anderson K, Gresty K, Prosser C, Smith D, Nankabirwa JI, Nsobya S, Yeka A, Namubiru R, Arinaitwe E, Mbaka P, Kissa J, Lim CS, Karamagi C, Nakayaga JK, Kamya MR, Cheng Q. Genetic diversity and genetic relatedness in Plasmodium falciparum parasite population in individuals with uncomplicated malaria based on microsatellite typing in Eastern and Western regions of Uganda, 2019-2020. Malar J 2021; 20:242. [PMID: 34059047 PMCID: PMC8165787 DOI: 10.1186/s12936-021-03763-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 05/11/2021] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Genetic diversity and parasite relatedness are essential parameters for assessing impact of interventions and understanding transmission dynamics of malaria parasites, however data on its status in Plasmodium falciparum populations in Uganda is limited. Microsatellite markers and DNA sequencing were used to determine diversity and molecular characterization of P. falciparum parasite populations in Uganda. METHODS A total of 147 P. falciparum genomic DNA samples collected from cross-sectional surveys in symptomatic individuals of 2-10 years were characterized by genotyping of seven highly polymorphic neutral microsatellite markers (n = 85) and genetic sequencing of the Histidine Rich Protein 2 (pfhrp2) gene (n = 62). ArcGIS was used to map the geographical distribution of isolates while statistical testing was done using Student's t-test or Wilcoxon's rank-sum test and Fisher's exact test as appropriate at P ≤ 0.05. RESULTS Overall, 75.5% (95% CI 61.1-85.8) and 24.5% (95% CI14.2-38.9) of parasites examined were of multiclonal (mixed genotype) and single clone infections, respectively. Multiclonal infections occurred more frequently in the Eastern region 73.7% (95% CI 48.8-89.1), P < 0.05. Overall, multiplicity of infection (MOI) was 1.9 (95% CI 1.7-2.1), P = 0.01 that was similar between age groups (1.8 vs 1.9), P = 0.60 and regions (1.9 vs 1.8), P = 0.43 for the < 5 and ≥ 5 years and Eastern and Western regions, respectively. Genomic sequencing of the pfhrp2 exon2 revealed a high level of genetic diversity reflected in 96.8% (60/62) unique sequence types. Repeat type AHHAAAHHATD and HRP2 sequence Type C were more frequent in RDT-/PCR + samples (1.9% vs 1.5%) and (13% vs 8%), P < 0.05 respectively. Genetic relatedness analysis revealed small clusters of gene deleted parasites in Uganda, but no clustering with Eritrean parasites. CONCLUSION High level of genetic diversity of P. falciparum parasites reflected in the frequency of multiclonal infections, multiplicity of infection and variability of the pfhrp2 gene observed in this study is consistent with the high malaria transmission intensity in these settings. Parasite genetic analysis suggested spontaneous emergence and clonal expansion of pfhrp2 deleted parasites that require close monitoring to inform national malaria diagnosis and case management policies.
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Affiliation(s)
- Bosco B Agaba
- College of Health Sciences, Makerere University, Kampala, Uganda. .,National Malaria Control Division, Kampala, Uganda.
| | - Karen Anderson
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.,Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | - Karryn Gresty
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.,Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | - Christiane Prosser
- Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | - David Smith
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.,Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
| | - Joaniter I Nankabirwa
- College of Health Sciences, Makerere University, Kampala, Uganda.,Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Sam Nsobya
- College of Health Sciences, Makerere University, Kampala, Uganda.,Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Adoke Yeka
- College of Health Sciences, Makerere University, Kampala, Uganda.,Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Rhoda Namubiru
- College of Health Sciences, Makerere University, Kampala, Uganda
| | | | - Paul Mbaka
- World Health Organization Country Office, Kampala, Uganda
| | - John Kissa
- National Health Information Division, Ministry of Health, Kampala, Uganda
| | - Chae Seung Lim
- Department of Laboratory Medicine, College of Health Sciences, Korea University, Seoul, South Korea
| | - Charles Karamagi
- College of Health Sciences, Makerere University, Kampala, Uganda
| | - Joan K Nakayaga
- College of Health Sciences, Makerere University, Kampala, Uganda
| | - Moses R Kamya
- College of Health Sciences, Makerere University, Kampala, Uganda.,Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Qin Cheng
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.,Australian Defence Force Malaria and Infectious Disease Institute, Brisbane, Australia
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31
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Gwarinda HB, Tessema SK, Raman J, Greenhouse B, Birkholtz LM. Parasite genetic diversity reflects continued residual malaria transmission in Vhembe District, a hotspot in the Limpopo Province of South Africa. Malar J 2021; 20:96. [PMID: 33593382 PMCID: PMC7885214 DOI: 10.1186/s12936-021-03635-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 02/05/2021] [Accepted: 02/06/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND South Africa aims to eliminate malaria transmission by 2023. However, despite sustained vector control efforts and case management interventions, the Vhembe District remains a malaria transmission hotspot. To better understand Plasmodium falciparum transmission dynamics in the area, this study characterized the genetic diversity of parasites circulating within the Vhembe District. METHODS A total of 1153 falciparum-positive rapid diagnostic tests (RDTs) were randomly collected from seven clinics within the district, over three consecutive years (2016, 2017 and 2018) during the wet and dry malaria transmission seasons. Using 26 neutral microsatellite markers, differences in genetic diversity were described using a multiparameter scale of multiplicity of infection (MOI), inbreeding metric (Fws), number of unique alleles (A), expected heterozygosity (He), multilocus linkage disequilibrium (LD) and genetic differentiation, and were associated with temporal and geospatial variances. RESULTS A total of 747 (65%) samples were successfully genotyped. Moderate to high genetic diversity (mean He = 0.74 ± 0.03) was observed in the parasite population. This was ascribed to high allelic richness (mean A = 12.2 ± 1.2). The majority of samples (99%) had unique multi-locus genotypes, indicating high genetic diversity in the sample set. Complex infections were observed in 66% of samples (mean MOI = 2.13 ± 0.04), with 33% of infections showing high within-host diversity as described by the Fws metric. Low, but significant LD (standardised index of association, ISA = 0.08, P < 0.001) was observed that indicates recombination of distinct clones. Limited impact of temporal (FST range - 0.00005 to 0.0003) and spatial (FST = - 0.028 to 0.023) variation on genetic diversity existed during the sampling timeframe and study sites respectively. CONCLUSIONS Consistent with the Vhembe District's classification as a 'high' transmission setting within South Africa, P. falciparum diversity in the area was moderate to high and complex. This study showed that genetic diversity within the parasite population reflects the continued residual transmission observed in the Vhembe District. This data can be used as a reference point for the assessment of the effectiveness of on-going interventions over time, the identification of imported cases and/or outbreaks, as well as monitoring for the potential spread of anti-malarial drug resistance.
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Affiliation(s)
- Hazel B Gwarinda
- Malaria Parasite Molecular Laboratory, Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield, 0028, Pretoria, South Africa
| | - Sofonias K Tessema
- Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Jaishree Raman
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, a Division of the National Health Laboratory Service, Gauteng, South Africa.,Wits Research Institute for Malaria, Faculty of Health Sciences,, University of Witwatersrand, Johannesburg, Gauteng, South Africa
| | - Bryan Greenhouse
- Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California San Francisco, San Francisco, CA, USA.
| | - Lyn-Marié Birkholtz
- Malaria Parasite Molecular Laboratory, Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Private Bag X20, Hatfield, 0028, Pretoria, South Africa.
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Oboh MA, Ndiaye T, Diongue K, Ndiaye YD, Sy M, Deme AB, Diallo MA, Yade MS, Volkman SK, Badiane AS, Amambua-Ngwa A, Ndiaye D. Allelic diversity of MSP1 and MSP2 repeat loci correlate with levels of malaria endemicity in Senegal and Nigerian populations. Malar J 2021; 20:38. [PMID: 33436004 PMCID: PMC7805152 DOI: 10.1186/s12936-020-03563-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 12/20/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Characterizing the genetic diversity of malaria parasite populations in different endemic settings (from low to high) could be helpful in determining the effectiveness of malaria interventions. This study compared Plasmodium falciparum parasite population diversity from two sites with low (pre-elimination) and high transmission in Senegal and Nigeria, respectively. METHODS Parasite genomic DNA was extracted from 187 dried blood spot collected from confirmed uncomplicated P. falciparum malaria infected patients in Senegal (94) and Nigeria (93). Allelic polymorphism at merozoite surface protein 1 (msp1) and merozoite surface protein- 2 (msp2) genes were assessed by nested PCR. RESULTS The most frequent msp1 and msp2 allelic families are the K1 and IC3D7 allelotypes in both Senegal and Nigeria. Multiplicity of infection (MOI) of greater that 1 and thus complex infections was common in both study sites in Senegal (Thies:1.51/2.53; Kedougou:2.2/2.0 for msp1/2) than in Nigeria (Gbagada: 1.39/1.96; Oredo: 1.35/1.75]). The heterozygosity of msp1 gene was higher in P. falciparum isolates from Senegal (Thies: 0.62; Kedougou: 0.53) than isolates from Nigeria (Gbagada: 0.55; Oredo: 0.50). In Senegal, K1 alleles was associated with heavy than with moderate parasite density. Meanwhile, equal proportions of K1 were observed in both heavy and moderate infection types in Nigeria. The IC3D7 subtype allele of the msp2 family was the most frequent in heavily parasitaemic individuals from both countries than in the moderately infected participants. CONCLUSION The unexpectedly low genetic diversity of infections high endemic Nigerian setting compared to the low endemic settings in Senegal is suggestive of possible epidemic outbreak in Nigeria.
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Affiliation(s)
- Mary A Oboh
- Medical Research Council Unit, the Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia.
| | - Tolla Ndiaye
- Laboratory of Parasitology and Mycology, Aristide Le Dantec University Hospital, Cheikh Anta Diop University of Dakar, PO Box 5005, Dakar, Senegal.
| | - Khadim Diongue
- Laboratory of Parasitology and Mycology, Aristide Le Dantec University Hospital, Cheikh Anta Diop University of Dakar, PO Box 5005, Dakar, Senegal
| | - Yaye D Ndiaye
- Laboratory of Parasitology and Mycology, Aristide Le Dantec University Hospital, Cheikh Anta Diop University of Dakar, PO Box 5005, Dakar, Senegal
| | - Mouhamad Sy
- Laboratory of Parasitology and Mycology, Aristide Le Dantec University Hospital, Cheikh Anta Diop University of Dakar, PO Box 5005, Dakar, Senegal
| | - Awa B Deme
- Laboratory of Parasitology and Mycology, Aristide Le Dantec University Hospital, Cheikh Anta Diop University of Dakar, PO Box 5005, Dakar, Senegal
| | - Mamadou A Diallo
- Laboratory of Parasitology and Mycology, Aristide Le Dantec University Hospital, Cheikh Anta Diop University of Dakar, PO Box 5005, Dakar, Senegal
| | - Mamadou S Yade
- Laboratory of Parasitology and Mycology, Aristide Le Dantec University Hospital, Cheikh Anta Diop University of Dakar, PO Box 5005, Dakar, Senegal
| | - Sarah K Volkman
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA, USA
| | - Aida S Badiane
- Laboratory of Parasitology and Mycology, Aristide Le Dantec University Hospital, Cheikh Anta Diop University of Dakar, PO Box 5005, Dakar, Senegal
| | - Alfred Amambua-Ngwa
- Medical Research Council Unit, the Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Daouda Ndiaye
- Laboratory of Parasitology and Mycology, Aristide Le Dantec University Hospital, Cheikh Anta Diop University of Dakar, PO Box 5005, Dakar, Senegal
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA, USA
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Spatial and genetic clustering of Plasmodium falciparum and Plasmodium vivax infections in a low-transmission area of Ethiopia. Sci Rep 2020; 10:19975. [PMID: 33203956 PMCID: PMC7672087 DOI: 10.1038/s41598-020-77031-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 11/02/2020] [Indexed: 11/23/2022] Open
Abstract
The distribution of malaria infections is heterogeneous in space and time, especially in low transmission settings. Understanding this clustering may allow identification and targeting of pockets of transmission. In Adama district, Ethiopia, Plasmodium falciparum and P. vivax malaria patients and controls were examined, together with household members and immediate neighbors. Rapid diagnostic test and quantitative PCR (qPCR) were used for the detection of infections that were genetically characterized by a panel of microsatellite loci for P. falciparum (26) and P. vivax (11), respectively. Individuals living in households of clinical P. falciparum patients were more likely to have qPCR detected P. falciparum infections (22.0%, 9/41) compared to individuals in control households (8.7%, 37/426; odds ratio, 2.9; 95% confidence interval, 1.3–6.4; P = .007). Genetically related P. falciparum, but not P. vivax infections showed strong clustering within households. Genotyping revealed a marked temporal cluster of P. falciparum infections, almost exclusively comprised of clinical cases. These findings uncover previously unappreciated transmission dynamics and support a rational approach to reactive case detection strategies for P. falciparum in Ethiopia.
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Tessema SK, Hathaway NJ, Teyssier NB, Murphy M, Chen A, Aydemir O, Duarte EM, Simone W, Colborn J, Saute F, Crawford E, Aide P, Bailey JA, Greenhouse B. Sensitive, highly multiplexed sequencing of microhaplotypes from the Plasmodium falciparum heterozygome. J Infect Dis 2020; 225:1227-1237. [PMID: 32840625 PMCID: PMC8974853 DOI: 10.1093/infdis/jiaa527] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 08/24/2020] [Indexed: 01/28/2023] Open
Abstract
Background Targeted next-generation sequencing offers the potential for consistent, deep coverage of information-rich genomic regions to characterize polyclonal Plasmodium falciparum infections. However, methods to identify and sequence these genomic regions are currently limited. Methods A bioinformatic pipeline and multiplex methods were developed to identify and simultaneously sequence 100 targets and applied to dried blood spot (DBS) controls and field isolates from Mozambique. For comparison, whole-genome sequencing data were generated for the same controls. Results Using publicly available genomes, 4465 high-diversity genomic regions suited for targeted sequencing were identified, representing the P. falciparum heterozygome. For this study, 93 microhaplotypes with high diversity (median expected heterozygosity = 0.7) were selected along with 7 drug resistance loci. The sequencing method achieved very high coverage (median 99%), specificity (99.8%), and sensitivity (90% for haplotypes with 5% within sample frequency in dried blood spots with 100 parasites/µL). In silico analyses revealed that microhaplotypes provided much higher resolution to discriminate related from unrelated polyclonal infections than biallelic single-nucleotide polymorphism barcodes. Conclusions The bioinformatic and laboratory methods outlined here provide a flexible tool for efficient, low-cost, high-throughput interrogation of the P. falciparum genome, and can be tailored to simultaneously address multiple questions of interest in various epidemiological settings.
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Affiliation(s)
- Sofonias K Tessema
- EPPIcenter research program, Division of HIV, ID, and Global Medicine, Department of Medicine, University of California, San Francisco, CA, USA
| | - Nicholas J Hathaway
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Noam B Teyssier
- EPPIcenter research program, Division of HIV, ID, and Global Medicine, Department of Medicine, University of California, San Francisco, CA, USA
| | - Maxwell Murphy
- EPPIcenter research program, Division of HIV, ID, and Global Medicine, Department of Medicine, University of California, San Francisco, CA, USA
| | - Anna Chen
- EPPIcenter research program, Division of HIV, ID, and Global Medicine, Department of Medicine, University of California, San Francisco, CA, USA
| | - Ozkan Aydemir
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - Elias M Duarte
- EPPIcenter research program, Division of HIV, ID, and Global Medicine, Department of Medicine, University of California, San Francisco, CA, USA
| | - Wilson Simone
- Centro de Investigação em Saúde de Manhiça (CISM), Manhiça, Mozambique
| | - James Colborn
- Clinton Health Access Initiative, Maputo, Mozambique
| | - Francisco Saute
- Centro de Investigação em Saúde de Manhiça (CISM), Manhiça, Mozambique
| | - Emily Crawford
- Chan Zuckerberg Biohub, San Francisco, California, United States
| | - Pedro Aide
- Centro de Investigação em Saúde de Manhiça (CISM), Manhiça, Mozambique
| | - Jeffrey A Bailey
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - Bryan Greenhouse
- EPPIcenter research program, Division of HIV, ID, and Global Medicine, Department of Medicine, University of California, San Francisco, CA, USA.,Chan Zuckerberg Biohub, San Francisco, California, United States
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Strengthening Surveillance Systems for Malaria Elimination by Integrating Molecular and Genomic Data. Trop Med Infect Dis 2019; 4:tropicalmed4040139. [PMID: 31816974 PMCID: PMC6958499 DOI: 10.3390/tropicalmed4040139] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/05/2019] [Accepted: 11/28/2019] [Indexed: 12/20/2022] Open
Abstract
Unprecedented efforts in malaria control over the last 15 years have led to a substantial decrease in both morbidity and mortality in most endemic settings. However, these progresses have stalled over recent years, and resurgence may cause dramatic impact on both morbidity and mortality. Nevertheless, elimination efforts are currently going on with the objective of reducing malaria morbidity and mortality by 90% and malaria elimination in at least 35 countries by 2030. Strengthening surveillance systems is of paramount importance to reach those targets, and the integration of molecular and genomic techniques into routine surveillance could substantially improve the quality and robustness of data. Techniques such as polymerase chain reaction (PCR) and quantitative PCR (qPCR) are increasingly available in malaria endemic countries, whereas others such as sequencing are already available in a few laboratories. However, sequencing, especially next-generation sequencing (NGS), requires sophisticated infrastructure with adequate computing power and highly trained personnel for data analysis that require substantial investment. Different techniques will be required for different applications, and cost-effective planning must ensure the appropriate use of available resources. The development of national and sub-regional reference laboratories could help in minimizing the resources required in terms of equipment and trained staff. Concerted efforts from different stakeholders at national, sub-regional, and global level are needed to develop the required framework to establish and maintain these reference laboratories.
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Tessema SK, Raman J, Duffy CW, Ishengoma DS, Amambua-Ngwa A, Greenhouse B. Applying next-generation sequencing to track falciparum malaria in sub-Saharan Africa. Malar J 2019; 18:268. [PMID: 31477139 PMCID: PMC6720407 DOI: 10.1186/s12936-019-2880-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 07/11/2019] [Indexed: 01/13/2023] Open
Abstract
Next-generation sequencing (NGS) technologies are increasingly being used to address a diverse range of biological and epidemiological questions. The current understanding of malaria transmission dynamics and parasite movement mainly relies on the analyses of epidemiologic data, e.g. case counts and self-reported travel history data. However, travel history data are often not routinely collected or are incomplete, lacking the necessary level of accuracy. Although genetic data from routinely collected field samples provides an unprecedented opportunity to track the spread of malaria parasites, it remains an underutilized resource for surveillance due to lack of local awareness and capacity, limited access to sensitive laboratory methods and associated computational tools and difficulty in interpreting genetic epidemiology data. In this review, the potential roles of NGS in better understanding of transmission patterns, accurately tracking parasite movement and addressing the emerging challenges of imported malaria in low transmission settings of sub-Saharan Africa are discussed. Furthermore, this review highlights the insights gained from malaria genomic research and challenges associated with integrating malaria genomics into existing surveillance tools to inform control and elimination strategies.
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Affiliation(s)
- Sofonias K Tessema
- EPPIcenter Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California San Francisco, San Francisco, CA, USA.
| | - Jaishree Raman
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Disease, Sandringham, Gauteng, South Africa
| | - Craig W Duffy
- Department of Infection Biology, University of Liverpool, Liverpool, UK
| | - Deus S Ishengoma
- National Institute for Medical Research, Tanga Research Centre, Tanga, Tanzania
| | | | - Bryan Greenhouse
- EPPIcenter Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California San Francisco, San Francisco, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
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