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

BMC Infectious Diseases

Research Article

Yaw A Afrane¹  Andrew K Githeko¹  Anne M Vardo-Zalik²  Frederick N Baliraine³  Dolphine A Amenya⁴  Guiyun Yan⁵  Mariangela Bonizzoni⁵  David M Menge⁶ 

[1] Center for Vector Biology and Control Research, Kenya Medical Research Institute, Kisumu, Kenya;Department of Biology, Pennsylvania State University, York, PA, USA;Department of Medicine, Division of Infectious Diseases, University of California - San Francisco, P.O. Box 0811, 94143-0811, San Francisco, CA, USA;Liverpool School of Tropical Medicine, Liverpool, UK;University of California - Irvine, 92697, Irvine, CA, USA;University of Minnesota, Minneapolis, MN, USA;

关键词: Malaria;    Parasite Population;    Entomological Inoculation Rate;    Transmission Season;    Infection Dynamic;   

DOI  :  10.1186/1471-2334-10-283

 received in 2009-11-13, accepted in 2010-09-24,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundThe 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 eco-epidemiological systems where malaria recently expanded, as well as the evaluation of control measures.MethodsWe 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.ResultsInfection complexity and genetic diversity were high (HE = 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.ConclusionsThese 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.

【 授权许可】

CC BY   
© Baliraine et al; licensee BioMed Central Ltd. 2010