West Nile Virus
West Nile virus (WNV) is a potentially serious illness. Experts believe WNV is established as a seasonal epidemic in North America that flares up in the summer and continues into the fall. WNV season runs June 1-Nov. 1.
How WNV IS Spread to Humans?
WNV is transmitted to humans and animals through a mosquito bite. Mosquitos become infected when they feed on infected birds. Human-to-human transmission of WNV does not occur. However, human WNV infections have been associated with blood transfusions and organ transplants.
Control Activities in Alameda County
As of October 17, 2012 there were 301 human cases of WNV, including one death. Some 1,569 dead birds and 2,704 mosquito pools tested positive for WNV in 42 California counties. Alameda County has 15 dead birds that have tested positive for WNV, and no human cases. During WNV season, Alameda County’s Mosquito Abatement program works to limit risks to residents by monitoring ponds and other possible mosquito breeding sites; trapping to detect high numbers of mosquitoes; treating sewer catch-basins to prevent breeding; collecting birds for testing; and educating residents and owners about removing standing water from private property to limit mosquito breeding and mosquito bites.