Lower survival rate, longevity and fecundity of Aedes aegypti (Diptera: Culicidae) females orally challenged with dengue virus serotype 2.

摘要

As the pathogenic effects of a parasite on its hosts can strongly influence its epidemiology, we compared the life-histories of dengue virus serotype 2 (DENV-2)-infected and uninfected Aedes aegypti females. Unexposed mosquitoes lived longer than exposed ones, but those infected lived longer than exposed but negative (as assayed by Real-Time quantitative Reverse Transcription PCR [qRT-PCR]) mosquitoes. Infected mosquitoes from a long-established laboratory colony presented more viral RNA copies at death than those from the F1-generation of a field population from Rio de Janeiro. The mortality of infected colony-mosquitoes was independent of the number of viral RNA copies at death, whereas in the field population, longevity decreased with the number of viral RNA copies, suggesting that F1 of field mosquitoes are less tolerant to infection than the laboratory-colony. Infected females had a lower fecundity than controls. F1 of field mosquitoes were more likely to lay eggs than the colony; egg-laying success was strongly affected by mosquito age for both mosquito populations: from 49.28 in the first clutch to 20.7 in the fifth. Overall, DENV-2 reduced Aedes aegypti survival and fecundity, clearly affecting vectorial capacity and consequently transmission intensity.