Increased temperatures reduce the vectorial capacity of <i>Aedes</i> mosquitoes for Zika virus

Abstract

Rapid and significant range expansion of both Zika virus (ZIKV) and its <i>Aedes</i> vector 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. To understand the effect of diurnal temperature range on the vectorial capacity of <i>Ae. aegypti</i> and <i>Ae. albopictus</i> for ZIKV, longevity, blood-feeding and vector competence were assessed at two temperature regimes following feeding on infectious blood meals. Higher temperatures resulted in decreased longevity of <i>Ae. aegypti</i> [Log-rank test, χ2, df 35.66, 5, <i>P</i> < 0.001] and a decrease in blood-feeding rates of <i>Ae. albopictus</i> [Fisher's exact test, <i>P</i> < 0.001]. Temperature had a population and species-specific impact on ZIKV infection rates. Overall, <i>Ae. albopictus</i> reared at the lowest temperature regime demonstrated the highest vectorial capacity (0.53) and the highest transmission efficiency (57%). Increased temperature decreased vectorial capacity across groups yet more significant effects were measured with <i>Ae. aegypti</i> relative to <i>Ae. albopictus</i>. The results of this study suggest that future increases in temperature in the Americas could significantly impact vector competence, blood-feeding and longevity, and potentially decrease the overall vectorial capacity of <i>Aedes</i> mosquitoes in the Americas.