Increased temperatures reduce the vectorial capacity of Aedes mosquitoes for Zika virus

Rapid and significant range expansion of both ZIKV and its Aedes host species has resulted in ZIKV being declared a global health threat. Mean temperatures are projected to increase globally, likely resulting in alterations of the transmission potential of mosquito-borne pathogens. The relationship between temperature and ZIKV transmission has not been well characterised for Aedes aegypti and Aedes albopictus.\n\nTo understand the effect of diurnal temperature range on the vectorial capacity of Aedes aegypti and Aedes albopictus for ZIKV, factors contributing to transmission potential were measured at different temperature regimens. Their longevity and blood feeding rates were assessed, and vector competence was determined following feeding on blood meals with 8.3 log10 PFU/ml ZIKV.\n\nHigher temperature resulted in decreased longevity of Ae. aegypti [Log-rank (Mantel-Cox) Test, Chi-square, df 35.66, 5 P (<0.0001)] and a significant decrease in blood feeding rates across groups [Z score (-5.8478) P (0.0444)]. Temperature had a population and species-specific impact on ZIKV infection rates. Overall, Ae. albopictus reared at the lowest temperature regimen demonstrated the highest vectorial capacity (1.63) and the highest transmission efficiency (57%). Temperature increases decreased vectorial capacity across groups, yet the largest decreases were measured for Ae. aegypti.\n\nThe results of this study suggest that future climate change could significantly impact vector competence, blood feeding behavior and longevity, and therefore decrease the overall vectorial capacity of Aedes mosquitoes. It is also clear that this impact is likely to be both species and population-specific.