County Finds West Nile in Mosquitoes

—By Bay City News Service

Santa Clara County officials confirmed Tuesday that mosquitoes caught in a section of South San Jose tested positive for the West Nile virus.

The Santa Clara County Vector Control District will spray insecticides in the affected neighborhoods starting Thursday night to prevent the spread of West Nile to humans, the agency's acting manager Russ Parman said.

The mosquitoes, of the Culex variety, were found in the district's traps last Friday and tested positive for the virus, which can lead to a fever and severe flu-like symptoms for about one on five people infected, Parman said.

Last year, of the 479 people reported to be suffering from serious cases of West Nile virus in California, 20 died, Parman said.

The adult mosquitoes were recovered in an area bordered mainly by Monterey Highway to the north, Santa Teresa Boulevard to the south, Blossom Avenue west and Cottle Road to the east.

The district's exterminators will drive out to neighborhoods within that area in four trucks to spray insecticides in very low doses in a fine mist that clings to the tiny mosquitoes and kills them, Parman said.

Starting at 11 p.m. Thursday and ending at about 2 a.m. Friday, the workers will spray the "fog" along neighborhood streets while driving about 10 to 15 miles per hour, Parman said.

The insecticides, pyrenone-25-5 and Zenivex, are at such small doses they are not toxic to humans and mammals and low enough not to harm fish like koi some people have in their yards, he said.

"We do it in very low volumes because we can," Parman said. "We just want the fog to drift in the wind and stick to any mosquitoes there on the ground."

The mosquitoes may breed in any kind of standing water, and people should make sure to drain buckets, rain gutters and other neglected pools of water, Parman said.

The Culex, which bite people at dusk, dawn and at nighttime, is not the only type of mosquito of concern these days, Parman said.

Two other species, the Asian Tiger and Yellow Fever mosquitoes, could make their way to Santa Clara County, Parman said.

The Asian Tiger, which can carry the disease dengue fever, has been found in Southern California, and the Yellow Fever, which can spread the serious chikungunya virus, was discovered in Madera and Clovis, Parman said.

Both mosquitoes are potentially more harmful than Culex because they bite during the daytime when more people are outside and only need "a bottle cap full of water" to breed in, Parman said.

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