Bay Area gearing up for West NileBy April Lynch
With West Nile virus already detected in California this year, mosquito collectors, chickens and bug-eating fish are gearing up to limit the disease in the Bay Area.
This week, state health officials announced they had spotted the deadly virus in birds from Los Angeles and Orange counties. So far in 2004, the only other states to find infected birds -- an early sign of West Nile -- are Louisiana, New York, Texas and Florida.
These states all have deeply rooted West Nile problems, and health officials say California's addition to that list indicates the mosquito-borne virus has a strong head start here. Only three people were diagnosed with West Nile in the state last year, all in Southern California, but now the threat is broader as the virus gets time to spread.
"More virus will be available to be picked up by mosquitoes," said Vicki Kramer, a top West Nile expert with the California Department of Health Services. "We expect it to spread through other parts of the state, virtually statewide, in 2004."
That means Bay Area mosquito control groups, also known as "vector control," are already at work before late spring and summer bring the warm weather that mosquitoes love. Vector control agencies handle common pests that range from rats to cockroaches, but now tiny humming bloodsuckers are getting much of their attention.
West Nile virus first appeared in the United States in 1999 and has quickly traveled across the country. Mammals such as birds, horses and people are all vulnerable. In many people, infection usually causes no symptoms or only mild ones, including fever, headache and nausea.
But some develop life-threatening illnesses that often effect the brain. In 2003, more than 9,800 Americans were diagnosed with some form of West Nile, and 264 of them died, according to federal health statistics.
Workers are already setting out traps all over the Bay Area to catch mosquitoes and, in some cases, turn them over for virus testing. The biting insects breed in standing water, and storm drains and other underground waterways are getting checked.
Starting in about a week, flocks of "sentinel chickens" will be set out in Santa Clara, San Mateo and Alameda counties. The birds are vulnerable to West Nile and will get regular testing to see if they've contracted the virus.
The counties will also be offering mosquito-eating fish for ponds, delivering them to homeowners' doors in many cases. If people see mosquitoes or get bitten by them, county vector control districts want to know right away so they can track down the source of the problem.
"In 25 years of doing this, I've never had anything like this coming through," said John Rusmisel, district manager for Alameda County's mosquito control program. "We just had a couple of weeks of very hot weather, an above-average snowpack, and now there are early signs of virus activity. It all points to this being a very active year."
Different counties are also honing plans to fit their own locales. In Santa Clara County, vector control officials will take a tougher approach to bodies of water where they find mosquito eggs or larvae, considering the use of bacterial or hormonal insecticides more quickly. Such bug-killers only work on mosquitoes still small enough to be swimming rather than flying.
"We're going to take a zero-tolerance policy," said Kriss Costa, spokeswoman for the Santa Clara County program. "We have to hit them in the water, because it's useless once they're in the air."
San Mateo County mosquito crews will be covering more territory than ever. Last fall, property owners in northern and coastal parts of the county that had gone without vector control services voted for a tax of about $15 a year to pay for pest help. Vector control crews will start covering these areas, which include Half Moon Bay and Daly City, this year.
Alameda County officials already have started handing out bags of mosquito-eating fish in more rural parts of the county, and will be watching marshes near Fremont and Oakland. One of the county's sentinel chicken flocks will be set on the county's eastern edge, near the Central Valley, as the virus is expected to move north along inland routes before hitting the coast.
Anyone who finds a dead bird is being asked to report it to state health officials. All over the Bay Area, residents are already being urged to get rid of standing water near their homes. Clogged gutters, hot tub covers and back-yard tarps can all hold puddles that might breed mosquitoes.
"Focus on preventing problems," said Sasha Porshnikoff, assistant vector ecologist with San Mateo County. "Taking away the sources where mosquitoes reproduce is the most effective way."
West Nile Facts
How the virus is spread and its effects
The virus is spread by mosquitoes and can infect birds, horses and other animals. Most of the time it results in a flu-like illness with fever, headache and muscle pain lasting two or three days. People who have symptoms and know they have been bitten by a mosquito should contact their physicians.
In severe cases, West Nile causes a potentially fatal brain inflammation. The elderly and people with compromised immune systems are most at risk. Infections are more prevalent in summer and fall when mosquitoes are more active.
Stopping mosquitoes at home
Getting rid of standing water will help prevent your yard from becoming a breeding ground for mosquitoes.
Decorative ponds, water gardens: Stock with mosquito fish, available free from many county vector control programs.
Bird baths, wading pools: Change water weekly.
Swimming pools/spas: Operate filter and skimmer every day to remove eggs and larva. Keep covers clear of standing water.
Rain gutters: Clean frequently to remove leaf litter and pools of water that may have formed behind them.
Unused containers: Turn upside down or store indoors.
Boats: Keep tightly covered. Drain cover weekly if necessary.
In-ground utility boxes: Check for standing water and drain.
Old tires: Remove, or drill drainage holes.
Avoiding West Nile virus
There is no vaccine approved for humans. The best prevention is to avoid being bitten by mosquitoes.
Avoid outdoor activities during dusk and dawn, when mosquitoes are most active.
Wear long pants and long-sleeved shirts when in mosquito territory, and use insect repellent containing DEET.
Who can help
Santa Clara County Vector Control District: www.sccvector.org or (408) 792-5010
San Mateo County Vector Control District: www.smcmad.org or (650) 344-8592
Alameda County Vector Control District: www.mosquitoes.org or (510) 783-7744
Santa Cruz County Vector Control District: (831) 454-2590.
State program for reporting dead birds, especially crows, ravens, magpies, jays, sparrows, finches and raptors: (877) 968-2473
Source: Bay Area vector control districts, California Department of Health Services, Centers for Disease Control and Prevention, Mercury News research
Copyright ©2004 San Jose Mercury News. Published 04/03/2004.