Multilocus haplotypes reveal variable levels of diversity and population structure of Plasmodium falciparum in Papua New Guinea, a region of intense perennial transmissionReportar como inadecuado

Multilocus haplotypes reveal variable levels of diversity and population structure of Plasmodium falciparum in Papua New Guinea, a region of intense perennial transmission - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Malaria Journal

, 9:336

First Online: 23 November 2010Received: 06 August 2010Accepted: 23 November 2010


BackgroundThe South West Pacific nation of Papua New Guinea has intense year round transmission of Plasmodium falciparum on the coast and in the low-lying inland areas. Local heterogeneity in the epidemiology of malaria suggests that parasites from multiple locations will need to be surveyed to define the population biology of P. falciparum in the region. This study describes the population genetics of P. falciparum in thirteen villages spread over four distinct catchment areas of Papua New Guinea.

MethodsTen microsatellite loci were genotyped in 318 P. falciparum isolates from the parasite populations of two inland catchment areas, namely Wosera number of villages n = 7 and Utu n = 1 and; and two coastal catchments, Malala n = 3 and Mugil n = 3. Analysis of the resultant multilocus haplotypes was done at different spatial scales 2-336 km to define the genetic diversity allelic richness and expected heterozygosity, linkage disequilibrium and population structure throughout the study area.

ResultsAlthough genetic diversity was high in all parasite populations, it was also variable with a lower allelic richness and expected heterozygosity for inland populations compared to those from the more accessible coast. This variability was not correlated with two proxy measures of transmission intensity, the infection prevalence and the proportion multiple infections. Random associations among the microsatellite loci were observed in all four catchments showing that a substantial degree of out-crossing occurs in the region. Moderate to very high levels of population structure were found but the amount of genetic differentiation FST did not correlate with geographic distance suggesting that parasite populations are fragmented. Population structure was also identified between villages within the Malala area, with the haplotypes of one parasite population clustering with the neighbouring catchment of Mugil.

ConclusionThe observed population genetics of P. falciparum in this region is likely to be a consequence of the high transmission intensity combined with the isolation of human and vector populations, especially those located inland and migration of parasites via human movement into coastal populations. The variable genetic diversity and population structure of P. falciparum has important implications for malaria control strategies and warrants further fine scale sampling throughout Papua New Guinea.

Electronic supplementary materialThe online version of this article doi:10.1186-1475-2875-9-336 contains supplementary material, which is available to authorized users.

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Autor: Lee Schultz - Johanna Wapling - Ivo Mueller - Pilate O Ntsuke - Nicolas Senn - Joe Nale - Benson Kiniboro - Caroline O B


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