Last-come, best served? Mosquito biting order and Plasmodium transmission

A pervasive characteristic of parasite infections is their tendency to be overdispersed. Understanding the mechanisms underlying this overdispersed distribution is of key importance as it may impact the transmission dynamics of the pathogen. Although multiple factors ranging from environmental stochasticity to inter-individual heterogeneity may explain parasite overdispersion, parasite infection is also observed to be overdispersed in inbred host population maintained under laboratory conditions, suggesting that other mechanisms at play. Here, we show that the aggregated distribution of malaria parasite within mosquito vectors is partially explained by a temporal heterogeneity in parasite infectivity triggered by the bites of mosquitoes. The transmission of the parasite was tripled between the first and the last blood fed mosquito in a period of only three hours. Surprisingly the increase in transmission is not associated with an increase in parasite investment in the production of the ...