Malaria parasite diversity and transmission intensity affect development of parasitological immunity in a mathematical model

Malaria Journal

Research

Philip A Eckhoff¹ 

[1] Intellectual Ventures Laboratory, 1600 132nd Ave NE, 98004, Bellevue, WA, USA;

关键词: Malaria;    Parasite Density;    Transmission Intensity;    Vector Population;    Parasite Population;   

DOI  :  10.1186/1475-2875-11-419

 received in 2012-09-23, accepted in 2012-12-13,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundThe development of parasitological immunity against malaria affects the ability to detect infection, the efficiency of the local human parasite reservoir at infecting mosquitoes, and the response to reintroduction of parasites to previously cleared areas. Observations of similar age-trends in detected prevalence and mean parasitaemia across more than an order-of-magnitude of variation in baseline transmission complicate simple exposure-driven explanations.MethodsMathematical models often employ age-dependent immune factors to match the observed trends, while the present model uses a new detailed mechanistic model of parasite transmission dynamics to explain age-trends through the mechanism of parasite diversity. Illustrative simulations are performed for multiple field sites in Tanzania and Nigeria, and observed age-trends and seasonality in parasite prevalence are recreated in silico, proffering possible mechanistic explanations of the observational data.ResultsObserved temporal dynamics in measured parasitaemia are recreated for each location and age-prevalence outputs are studied. Increasing population-level diversity in malaria surface antigens delays development of broad parasitological immunity. A local parasite population with high diversity can recreate the observed trends in age-prevalence across more than an order of magnitude of variation in transmission intensities.ConclusionsMechanistic models of human immunity and parasite antigen diversity can recreate the observed temporal patterns for the development of parasitological immunity across a wide range of transmission intensities. This has implications for the distribution of disease burden across the population, the human transmission reservoir, design of elimination campaigns, and development and roll-out of potential vaccines.

【 授权许可】

CC BY   
© Eckhoff; licensee BioMed Central Ltd. 2012