Journal article
Maintenance of high temporal Plasmodium falciparum genetic diversity and complexity of infection in asymptomatic and symptomatic infections in Kilifi, Kenya from 2007 to 2018
- Abstract:
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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.
- Publication status:
- Published
- Peer review status:
- Peer reviewed
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(Preview, Version of record, pdf, 954.5KB, Terms of use)
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- Publisher copy:
- 10.1186/s12936-022-04213-7
Authors
- Publisher:
- BioMed Central
- Journal:
- Malaria Journal More from this journal
- Volume:
- 21
- Article number:
- 192
- Publication date:
- 2022-06-20
- Acceptance date:
- 2022-06-03
- DOI:
- EISSN:
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1475-2875
- Pmid:
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35725456
- Language:
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English
- Keywords:
- Pubs id:
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1278615
- Local pid:
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pubs:1278615
- Deposit date:
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2022-09-21
Terms of use
- Copyright holder:
- Kimenyi et al.
- Copyright date:
- 2022
- Rights statement:
- ©2022 The Author(s). Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.
- Licence:
- CC Attribution (CC BY)
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