Health officials last week confirmed the first San Diego case of Zika virus acquired through sexual transmission. But so far, there have been no mosquito-transmitted cases in the continental U.S.
It's a different story with West Nile virus.
Last year, San Diego County saw 43 people infected with the virus and five related deaths. In contrast, there were no human cases in the county in 2013.
As it stands now, West Nile remains a bigger threat than Zika in San Diego. That's because the type of mosquito that carries Zika, Aedes aegypti, is not widespread here. In contrast, West Nile is carried by 65 species of mosquitoes, some of which are prevalent in the region.
Chris Conlan, supervising vector ecologist with the San Diego County Department of Environmental Health, discusses West Nile and Zika and describes the mosquito-control efforts planned in the coming months on Midday Edition Wednesday.
