Bay Area Vector Control Team Investigates West Nile Mosquito Presence

CONCORD, CA - APRIL 09: Contra Costa County Mosquito and Vector Control District technician Joe Hummel prepares to take mosquito larvae samples from a marsh April 9, 2009 in Concord, California. Unseasonably warm weather for Northern California in January appears to have brought female mosquitos out of hibernation and have started to breed months ahead of the normal breeding season. Several groups of mosquitos found in a marsh near the Contra Costa County town of Martinez have tested positive for the West Nile Virus prompting county officials to do more testing and releasing mosquito fish in abandoned pools around the county. (Photo by Justin Sullivan/Getty Images)