Vertical Transmission of Zika Virus by Florida and .

The Zika virus pandemic of 2015, with mosquitoes and as the putative vectors, prompted public health concerns and the need to improve our understanding of both the horizontal and vertical transmission of Zika virus. Local transmission is especially concerning for Florida, where these two mosquito species are abundant and widespread throughout much of the year. Here, we evaluate the relative vertical transmission and filial infection rate of progeny of Florida and following ingestion of infected blood by parental mosquitoes at either 6 or 7 log plaque forming units/mL of Zika virus. Florida exhibited higher rates of disseminated infection than , consistent with other studies indicating greater permissibility of Zika virus in We observed low vertical transmission in both (1.1-3.2%) and (0-0.3%) mosquitoes, despite imbibing infected blood at titers that yielded high susceptibility to infection and modest horizontal transmission rates. Filial infection rates, testing individual mosquitoes for and , were 6-10% and 0-6.4%, respectively. Both these invasive mosquitoes were capable of vertically transmitting Zika virus under laboratory conditions, and approximately 5% of female progeny of were capable of transmitting Zika virus upon first bite.