Anti-WNV monoclonal antibody, clone C849M

Background: West Nile virus (WNV) is endemic in southeastern Romania and, after the unprecedented urban epidemic in Bucharest in 1996 caused by lineage 1 WNV, cases of West Nile fever have been recorded every year. Furthermore, a new outbreak occurred in 2010, this time produced by a lineage 2 WNV belonging to the Eastern European clade (Volgograd 2007-like strain), which was detected in humans and mosquitoes in the following years. Results: We report here, for the first time, the emergence, in 2015, of lineage 2 WNV belonging to the monophyletic Central/Southern European group of strains which replaced in 2016, the previously endemized lineage 2 WNV Volgograd 2007-like strain in mosquito populations. The emerged WNV strain harbors H249P (NS3 protein) and I159T (E glycoprotein) substitutions, which have been previously associated in other studies with neurovirulence and efficient vector transmission. Conclusions: In 2016, both early amplification of the emerged WNV and complete replacement in mosquito populations of the previously endemized WNV occurred in southeastern Romania. These events were associated with a significant outbreak of severe West Nile neuroinvasive disease in humans.

The introduction of Zika virus to the USA in 2015 engendered heightened interest in its known vectors. Aedes aegypti is the primary vector, with Ae. albopictus considered a potential secondary vector, together with several other possible marginal vectors. In Delaware, Ae. aegypti has been collected rarely, but no breeding populations were detected during past intensive statewide surveillance efforts. However, there is an abundance of Ae. albopictus statewide. Both species are container breeders and are peri-domestic-increasing the risk for virus transmission to humans. From July through September 2017, Delaware Mosquito Control conducted surveillance in 16 container-breeding hot spots to search for Ae. aegypti, and also ascertain the virus-positive pool rates of Ae. albopictus and Ae. triseriatus for West Nile virus (WNV) and Zika virus (ZIKV). The survey concluded that there were no known breeding populations of Ae. aegypti in Delaware, and no WNV- or ZIKV-positive pools were detected among pools of mosquitoes of the aforementioned species.