Costs of crowding for the transmission of malaria parasites

Evolutionary Applications

Laura. C. Pollitt²  Thomas S. Churcher⁴  Emma J. Dawes⁴  Shahid M. Khan³  Mohammed Sajid³  María-Gloria Basáñez⁴  Nick Colegrave¹ 

[1] Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK;Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA, USA;Leiden Malaria Research group, Leiden University Medical Center, The Netherlands;Department of Infectious Disease Epidemiology, Imperial College London, London, UK

关键词: Anopheles stephensi;    density dependence;    disease transmission;    fitness costs;    life‐history strategies;    Plasmodium berghei;    programmed cell death;    vector‐borne disease;   

DOI  :  10.1111/eva.12048

来源: Wiley

【 摘 要 】

Abstract

The utility of using evolutionary and ecological frameworks to understand the dynamics of infectious diseases is gaining increasing recognition. However, integrating evolutionary ecology and infectious disease epidemiology is challenging because within-host dynamics can have counterintuitive consequences for between-host transmission, especially for vector-borne parasites. A major obstacle to linking within- and between-host processes is that the drivers of the relationships between the density, virulence, and fitness of parasites are poorly understood. By experimentally manipulating the intensity of rodent malaria (Plasmodium berghei) infections in Anopheles stephensi mosquitoes under different environmental conditions, we show that parasites experience substantial density-dependent fitness costs because crowding reduces both parasite proliferation and vector survival. We then use our data to predict how interactions between parasite density and vector environmental conditions shape within-vector processes and onward disease transmission. Our model predicts that density-dependent processes can have substantial and unexpected effects on the transmission potential of vector-borne disease, which should be considered in the development and evaluation of transmission-blocking interventions.

【 授权许可】

CC BY   
© 2013 The Authors. Evolutionary Applications published by Blackwell Publishing Ltd.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.