ARE MALARIA-INFECTED BIRDS MORE ATTRACTIVE TO MOSQUITO VECTORS?

According to the host manipulation hypothesis, parasites modify the hosts' phenotype to maximise their transmission success. Avian malaria parasites and related haemosporidians are vector-borne parasites infecting birds worldwide. Recent studies have reported a greater attraction of mosquitoes to infected birds, supporting the host manipulation hypothesis. Changes in the composition of the uropygial gland secretion of birds associated with infections have been proposed as the potential mechanisms explaining this pattern. Here we critically review the published information on the host manipulation hypothesis in the context of avian malaria infections. We focus this article on the suggested role of the secretions of the uropygial gland and bird odours as mosquito attractants. The role of uropygial gland secretions as attractants of mosquitoes was poorly supported by available literature. In contrast, changes in the odour profile of infected birds or a reduction in the anti-mosquito behaviour of infected individuals may explain the parasite-mediated effects on mosquito attraction and biting rates. Finally, we propose future research approaches to identify the role of parasite infections on the interaction between birds and insect vectors.

Automated summary

The host manipulation hypothesis suggests that parasites modify hosts' phenotype to increase transmission success. Avian malaria parasites may attract mosquitoes by altering the odor profile of infected birds, supporting this hypothesis.