West Nile Arrives Early in O.C.

West Nile virus season is starting earlier in Orange County, with two dead birds already testing positive for the disease, county investigators said.

Last year, the earliest findings of the West Nile virus in birds didn’t occur until March 31.

Vector control officials are blaming this season’s early start on heavy winter rains.

“Most of the mosquitoes last year came out of backyards and smaller sources,” said Mike Hearst, a vector control district spokesman. “This year the wetlands, marshes and riparian areas are filling up and that’s where the disease-carrying mosquitoes live.”

The birds that tested positive for the mosquito-borne virus, a snowy egret and an American crow, were found Jan. 14 and Feb. 15 in Orange by passers-by. The egret is a wading bird that spends much of its time in the wetlands and marsh areas.

Test results from the district’s wild bird capture-and-release program showed that the virus has remained active all winter in the bird population. Eight other counties, including Los Angeles, have reported the disease, six weeks earlier than last year.

“We’re guessing it’ll be much more widespread throughout the state this year,” Hearst said.

At least 20 human deaths related to West Nile virus were confirmed throughout the state last year, three in Orange County. The virus, which is spread by mosquitoes that feed on infected birds, was first seen in this country on the East Coast in 1999.

Most infected people do not develop symptoms, but 1% become severely ill with symptoms that can lead to coma, convulsions or death.

County vector officials said their biggest challenge remains standing water. The district is asking residents to dump any standing water around their homes or workplace, keep their window screens in good shape and wear mosquito repellent.