A cohort study of Plasmodium falciparum infection dynamics in Western Kenya Highlands

作者:Baliraine Frederick N*; Afrane Yaw A; Amenya Dolphine A; Bonizzoni Mariangela; Vardo Zalik Anne M; Menge David M; Githeko Andrew K; Yan Guiyun
来源:BMC Infectious Diseases, 2010, 10: 283.
DOI:10.1186/1471-2334-10-283

摘要

Background: The Kenyan highlands were malaria-free before the 1910s, but a series of malaria epidemics have occurred in the highlands of western Kenya since the 1980s. Longitudinal studies of the genetic structure, complexity, infection dynamics, and duration of naturally acquired Plasmodium falciparum infections are needed to facilitate a comprehensive understanding of malaria epidemiology in the complex Kenyan highland ecoepidemiological systems where malaria recently expanded, as well as the evaluation of control measures.
Methods: We followed a cohort of 246 children residing in 3 villages at altitudes 1430-1580 m in western Kenya. Monthly parasitological surveys were undertaken for one year, yielding 866 P. falciparum isolates that were analyzed using 10 microsatellite markers.
Results: Infection complexity and genetic diversity were high (H(E) = 0.787-0.816), with >= 83% of infections harboring more than one parasite clone. Diversity remained high even during the low malaria transmission season. There was no significant difference between levels of genetic diversity and population structure between high and low transmission seasons. Infection turn-over rate was high, with the average infection duration of single parasite genotypes being 1.11 months, and the longest genotype persistence was 3 months.
Conclusions: These data demonstrate that despite the relatively recent spread of malaria to the highlands, parasite populations seem to have stabilized with no evidence of bottlenecks between seasons, while the ability of residents to clear or control infections indicates presence of effective anti-plasmodial immune mechanisms.

  • 出版日期2010-9-24