American Aedes vexans Mosquitoes are Competent Vectors of Zika Virus

Abstract

AbstractStarting in 2013-2014, the Americas have experienced a massive outbreak of Zika virus (ZIKV) which has now reached at least 49 countries. Although most cases have occurred in South America and the Caribbean, imported and autochthonous cases have occurred in the United States. <i>Aedes aegypti</i> and <i>Aedes albopictus</i> mosquitoes are known vectors of ZIKV. Little is known about the potential for temperate <i>Aedes</i> mosquitoes to transmit ZIKV. <i>Aedes vexans</i> has a worldwide distribution, is highly abundant in particular localities, aggressively bites humans, and is a competent vector of several arboviruses. However, it is not clear whether <i>Ae. vexans</i> mosquitoes are competent to transmit ZIKV. To determine the vector competence of <i>Ae. vexans</i> for ZIKV, wild-caught mosquitoes were exposed to an infectious bloodmeal containing a ZIKV strain isolated during the current outbreak. Approximately 80% of 148 mosquitoes tested became infected by ZIKV, and approximately 5% transmitted infectious virus after 14 days of extrinsic incubation. These results establish that <i>Ae. vexans</i> are competent ZIKV vectors. Their relative importance as vectors (i.e., their vectorial capacity) depends on feeding behavior, longevity, and other factors that are likely to vary in ecologically distinct environments.