A second person has contracted the West Nile virus in Contra Costa County and is recovering, health officials said Thursday.
The unidentified woman lives in East County and began having symptoms Aug. 3.
Earlier this week, Contra Costa health officials reported the Bay Area's first known human case of West Nile virus in 2012: a central county woman who had a mild illness and has recovered.
Last year, the county had three human cases of the disease and all survived. The county has had no West Nile fatalities since 2006.
The mosquitoe-borne virus can cause fever, head and body aches, nausea and vomiting, swollen lymph nodes and a skin rash.
To avoid infection, experts advise people to wear insect repellent when outdoors, avoid going outside when mosquitoes are most active at dawn or dusk, and to dump and drain standing water where mosquitoes can breed.