West Nile puts County on offensiveBy Will Oremus
So far, no human has caught West Nile virus in San Mateo County, and a team of more than 20 county employees is out spraying every day this summer to keep it that way.
"We feel eventually it will happen, but we're suppressing it the best we can," said James Counts, supervisor for the San Mateo County Mosquito Abatement District.
He and his team spent much of Wednesday spraying marshy sites in Woodside, San Bruno and Pacifica by helicopter. The goal, he said, is to wipe out mosquito breeding sites - typically in and around standing water - so the bugs can't transmit the virus.
Officials know West Nile is present in the county this year, because they found it in a dead squirrel in July in San Mateo, but so far theyhaven't detected any mosquitoes carrying it, Counts said. That may have something to do with the aggressive spraying program, which aims to cover every significant source of standing water in the county on a regular basis.
The number of human cases of West Nile statewide is three times higher than it was at the same time last year, according to the governor's office. Five California residents have died from the virus this year, most in the Central Valley, and two human cases have been reported in Santa Clara County.
The virus affects the central nervous system and about one in 150 people develop severe symptoms, including high fever, convulsions, muscle weakness and paralysis, according to the state government's West Nile Virus Web page.
While several of Wednesday's spraying targets were above ground, Counts said the biggest threat in San Mateo County comes from underground, where mosquitoes can breed in storm drains and catch basins. Eight trucks spray upward of 60,000 such drains in the county every seven to nine days.
Other county employees track down standing water in people's yards, or from broken pipes or uncovered pools.
The West Nile season in the county started early this year, in March, and should continue until November, Counts said.
To avoid the virus, the national Centers for Disease Control and Prevention recommends using insect repellent on exposed skin when outdoors, especially around dawn or dusk. To prevent its spread, they urge people to drain standing water around their homes and report any dead birds.
Potential breeding areas can be reported by calling the mosquito abatement district at (650) 344-8592. To report a dead bird, call (877) 968-2473.
Copyright ©2007 MediaNews. Published 08/09/2007.