Influencing random transmission is a neutral character in hosts

Publication Type:Journal Article
Year of Publication:2000
Authors:L. Rózsa
Journal:Journal of Parasitology
Pagination:1032 - 1035
Date Published:1999

This study introduces an individual-based model on a host-parasite assemblage to investigate whether hosts are necessarily selected for obstructing the transmission of virulent parasites to conspecifics. Contrary to the widespread notion, a host’s ability to influence parasite transmission within the host population is a neutral character provided that parasite transmission routes are random, with no reference to genetic relatedness. Due to a lack of selection pressure under such circumstances, hosts may fail to evolve counter-adaptations against manipulations by parasites to enhance transmission. However, vertically-biased transmission (biased toward kins) selects hosts for a decrease of parasite transmission, while it is also known to select parasites to decrease virulence. Horizontally-biased transmission routes (biased toward non-related conspecifics) select hosts to increase parasite transmission. In this case, their interest coincide with that of their virulent parasites in enhancing transmission to conspecifics. This finding yields the predictions that hosts infected by virulent pathogens, but unable to recover from disease, should be prone to emigrate from their natal territories and also to enhance transmission at a distance from their natal ranges. These results may considerably improve our understanding of the epidemiology of contagious pathogens, and the evolution of social and sexual behavior in host species.

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Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith