Genetic diversity and population structure of Plasmodium falciparum in Thailand, a low transmission country

Abstract Background The population structure of the causative agents of human malaria, Plasmodium sp., including the most serious agent Plasmodium falciparum , depends on the local epidemiological and demographic situations, such as the incidence of infected people, the vector transmission intensity...

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Bibliographic Details
Published in:Malaria Journal
Main Authors: Sitthi-amorn Chitr, Suegorn Aree, Siripoon Napaporn, Kanchanakhan Naowarat, Durand Patrick, Arnathau Céline, Pumpaibool Tepanata, Renaud François, Harnyuttanakorn Pongchai
Format: Article in Journal/Newspaper
Language:English
Published: BMC 2009
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Online Access:https://doi.org/10.1186/1475-2875-8-155
https://doaj.org/article/611c15364b894167b5a3480fd47f4065
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Summary:Abstract Background The population structure of the causative agents of human malaria, Plasmodium sp., including the most serious agent Plasmodium falciparum , depends on the local epidemiological and demographic situations, such as the incidence of infected people, the vector transmission intensity and migration of inhabitants (i.e. exchange between sites). Analysing the structure of P. falciparum populations at a large scale, such as continents, or with markers that are subject to non-neutral selection, can lead to a masking and misunderstanding of the effective process of transmission. Thus, knowledge of the genetic structure and organization of P. falciparum populations in a particular area with neutral genetic markers is needed to understand which epidemiological factors should be targeted for disease control. Limited reports are available on the population genetic diversity and structure of P. falciparum in Thailand, and this is of particular concern at the Thai-Myanmar and Thai-Cambodian borders, where there is a reported high resistance to anti-malarial drugs, for example mefloquine, with little understanding of its potential gene flow. Methods The diversity and genetic differentiation of P. falciparum populations were analysed using 12 polymorphic apparently neutral microsatellite loci distributed on eight of the 14 different chromosomes. Samples were collected from seven provinces in the western, eastern and southern parts of Thailand. Results A strong difference in the nuclear genetic structure was observed between most of the assayed populations. The genetic diversity was comparable to the intermediate level observed in low P. falciparum transmission areas (average H S = 0.65 ± 0.17), where the lowest is observed in South America and the highest in Africa. However, uniquely the Yala province, had only a single multilocus genotype present in all samples, leading to a strong geographic differentiation when compared to the other Thai populations during this study. Comparison of the genetic structure of ...