Chance or choice? Understanding parasite selection and infection in multi-host communities.

Chance or choice? Understanding parasite selection and infection in multi-host communities. Int J Parasitol. 2019 Mar 17;: Authors: Johnson PTJ, Calhoun DM, Riepe TB, Koprivnikar J Abstract Ongoing debate over the relationship between biodiversity and disease risk underscores the need to develop a more mechanistic understanding of how changes in host community composition influence parasite transmission, particularly in complex communities with multiple hosts. A key challenge involves determining how motile parasites select among potential hosts and the degree to which this process shifts with community composition. Focusing on interactions between larval amphibians and the pathogenic trematode Ribeiroia ondatrae, we designed a novel, large-volume set of choice chambers to assess how the selectivity of free-swimming infectious parasites varied among five host species and in response to changes in assemblage composition (four different permutations). In a second set of trials, cercariae were allowed to contact and infect hosts, allowing comparison of host-parasite encounter rates (parasite choice) with infection outcomes (successful infections). Cercariae exhibited consistent preferences for specific host species that were independent of the community context; large-bodied amphibians, such as larval bullfrogs (Rana catesbeiana), exhibited the highest level of parasite attraction. However, because host attractiveness was decoupled from...
Source: International Journal for Parasitology - Category: Parasitology Authors: Tags: Int J Parasitol Source Type: research