August 18, 2004

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Publication Date: Wednesday, August 18, 2004

Cover story: Don't get bitten, get MAD

By Andrea Gemmet
Almanac Staff Writer

Stan Kamiya dips his finger into the murky, greenish water of a horse trough, and points to one of the two small black specks, scarcely bigger than grains of sand, clinging to his skin.

"That black spot is an egg raft," he says. "There are about 150 mosquito eggs in there."

He pats the velvety nose of the paddock's inquisitive inhabitant, then moves to the next trough at Webb Ranch near Portola Valley, where the water checks out OK but the resident horse tries to nibble the mosquito-emblazoned patch off his uniform.

A mosquito-control technician with the San Mateo County Mosquito Abatement District for more than 14 years, Mr. Kamiya has a keen eye for finding the places where mosquitoes breed, and a truck full of gear designed to eliminate the winged pests.

A drop of a highly refined oil in the trough, which dissipates after about five days, is enough to suffocate the mosquitoes and won't harm the horses, he explains.

With its expansion earlier this year to encompass the entire county, and with last week's announcement that the mosquito-borne West Nile virus was discovered in San Mateo County, the Mosquito Abatement District is busier than ever in its efforts to root out the watery hiding places where the bloodsucking bugs breed.

Funded by a minuscule share of property taxes, averaging homeowners less than $4 a year, the special district, which goes by the apt acronym of MAD, regularly patrols the fountains and storm drains, creeks and construction sites, fish ponds and stables of San Mateo County. On an annual budget of just over $2 million, the district's technicians investigate mosquito complaints, treat everything from ponds to tree hollows where mosquitoes breed, deliver larvae-gobbling mosquito fish upon request and dispatch ground-nesting wasps -- all free of charge.

"This is cheap. It's just a little of the money out of your tax bill, about $3.54," says Woodside resident Dick Tagg, a member of MAD's board of trustees. "When you call a local exterminator, see where $3.54 will get you."

The district's khaki uniforms give technicians a quasi-law-enforcement appearance, and there is certainly an element of detective work that comes with the job. Mr. Kamiya, who used to be assigned to Menlo Park and Atherton, says that finding the source of a mosquito problem can take some sleuth work. He once traced complaints about mosquitoes in downtown Menlo Park to the bottom basin of a fountain outside of St. Raymond church on Santa Cruz Avenue, which he happened to notice while driving by, Mr. Kamiya says.

At Webb Ranch, he scans the ground with a practiced eye, noting where a leaking trough has created a perpetual mud puddle in a paddock, checking the areas where weeds are green and lush for pooled water, and making sure that the huge piles of composting manure aren't leaking liquid into depressions in the ground. Thanks to a cooperative ranch manager, most of the ranch's mosquito problems have been addressed, Mr. Kamiya says.

Uncooperative residents are rare, he says, but every few years they will run across a person with a broken wastewater pipe, for instance, who will refuse to get it repaired.

"Sometimes, people will do whatever they can not to get contacted by us," he says.

The Mosquito Abatement District doesn't have the authority to force anyone to fix a chronic problem, but they do work in concert with county health department officials, who can start code-enforcement proceedings against recalcitrant property owners.

"Some run the risk of losing the property if they continue," Mr. Kamiya says. "It's an extreme measure, but it has happened."

With the rapid spread of West Nile virus, mosquito-abatement measures have taken on a more urgent tone. The disease, which was first found in the U.S. in New York five years ago, spread across the country and invaded Southern California last year. Infected birds have been found in most Bay Area counties, and the presence of the disease was confirmed in an American crow found in Redwood City on July 28.

West Nile virus is remarkable for its incredibly rapid spread, and for being more deadly to humans and birds than the first strain of the disease, says Chindi Peavey, the vector ecologist for MAD.

Raptors such as hawks, members of the crow family, including ravens and jays, and finches are all susceptible to West Nile virus, which is transmitted either by mosquito bites or from eating infected birds, Ms. Peavey says.

"It's the first time we've seen such a huge impact on the crow population -- that we've seen an epidemic of this magnitude spread so rapidly over such a huge geographic area," she says. "We have other viruses that are transmitted by mosquitoes, but those are restricted to specific regions."

While the vast majority of people who become infected with West Nile virus do not become seriously ill, it can be deadly, particularly in the elderly, says Ms. Peavey.

"People shouldn't be panicked," she says. "Only one person out of 150 gets infected severely, and one in 20 will experience flu-like symptoms."

For that unlucky one person out of the 150 who have contracted the disease, West Nile virus will cause neurological symptoms, such as encephalitis or meningitis, and even paralysis, says Dr. Scott Morrow, the San Mateo County health officer.

"There's no treatment anyone knows about. There are a few clinical trials, but it's all experimental," Dr. Morrow says. "There can be very serious long-term consequences, and a small subset of those people die."

As of last week, West Nile virus had claimed the lives of five people in California.

A lot is still unknown about West Nile virus, he says. Humans can contract it from a virus-infected mosquito or through transfusions of infected blood, and there are still questions about whether it can pass from mother to child via breast milk, Dr. Morrow says.

"We don't know why people do or don't get sick, or why it does tend to affect the elderly more, even more so than kids," he says.

The West Nile virus is more serious for horses.

"About one-third of horses that get infected will die," says Ms. Peavey.

Although no vaccine exists for people, there is an equine vaccine, and the most important thing horse owners can do is make sure their horses are vaccinated, she says. In all the equine cases of West Nile virus, the horses either weren't vaccinated at all or hadn't received the full course of three vaccination shots followed by an annual booster, she says.

The most effective method of preventing West Nile virus is controlling the mosquito population, says Dr. Morrow.

"We're very fortunate to have just expanded the district to cover the entire county," he says. "We have a state-of-the-art, excellent, excellent mosquito control program. That's the best thing anyone can do."

The next best defense is for people to drain any standing water near their homes, avoid being outdoors at dusk and dawn, dress in long sleeves and pants when that's unavoidable, and use an insect repellent containing DEET, Dr. Morrow says.

"Hopefully people are taking more precautions," he says. "I know I'm more cognizant of not wanting to get a mosquito bite, and I'm more likely to use a repellent and not stay out from dusk to dawn."

While East Coast natives may scoff at the idea of the balmy Bay Area having a mosquito problem, San Mateo County was so besieged by mosquitoes in the early part of the last century that it was virtually uninhabitable during the summer, says Dr. Morrow.

The county provides a good variety of mosquito-breeding hotspots. In rural areas, creeks and stables harbor insects. Near homes, everything from a clogged rain gutter to a kiddie pool, a koi pond, and saucers under potted plants are suspect. By the Bay, freshwater pools on top of salt marshes, providing breeding grounds. The Midpeninsula's ubiquitous residential construction projects, many of which drag on for more than a year, also provide puddles a-plenty for mosquito eggs to thrive in.

Three of the mosquito species present on the Peninsula transmit the virus, and all are summer mosquitoes that are at their peak from now until October, Ms. Peavey says. Two of them inhabitant marshes, and aren't much of a problem, but the one that breeds in storm drains and catch basins is the district's biggest concern, she says.

During the summer, MAD has six to eight people treating catch basins throughout the county five days a week, and sends out a three-man crew on Saturdays, she says.

"Cities are sitting on a hotbed of mosquitoes," says MAD district manager Robert Gay. "We treat up to 3,000 catch basins every day, about 12,000 to 15,000 a week."

The district also has a special permit that allows technicians to treat the county's 29 creeks with pellets containing hormones that prevent mosquitoes from breeding, he says. To get access to the tule mosquitoes that inhabit Searsville Lake, MAD uses a helicopter every three weeks, at a cost of about $1,000 an hour, Mr. Gay says. The district also keeps one of its three flocks of sentinel chickens there. The chickens are tested every other week for West Nile virus, and spend the rest of their time eating and laying eggs, says Mr. Kamiya.

As for the free mosquito fish the district gives away -- "Oh my gosh, that program has escalated unbelievably," Mr. Gay says. "In the old days, we used to go once a year to get fish. Now we have people coming by the hundreds, we deliver to all the fish ponds and fountains and horse troughs and wine barrels people have."

MAD, along with other "non-enterprise" special districts that don't charge fees for their services, narrowly avoided losing 25 percent of its revenues this year to help shore up the state's budget, Mr. Gay says. Timing for such a cut was especially bad, he says.

"Because of West Nile virus and the human deaths, I don't think any legislator would want that to happen on their watch, so they authorized an exemption," he says. "We lost 17 percent of our budget in 1992, and that still hurts. We lost 30 percent of our staff."

In the meantime, MAD is understaffed since expanding its boundaries to include the Coastside and the county's northernmost cities. Hiring new technicians isn't easy, because it requires a lot of training -- current mosquito-abatement techniques are not exactly taught in school, Mr. Gay says, and the district gives new hires two years to earn all of the state certifications required.

The district's holistic approach to mosquito abatement is more complicated than just "pest control," says Mr. Kamiya. Technicians must consider the conditions, sources, causes and development of mosquito problems; they don't just come and spray pesticides, he says. In fact, sprays are rarely used in favor of less-toxic products that often have to be applied more frequently, he says.

"You'll never get rid of them all, but I think we have a big impact," Ms. Peavey says.

The 'four Ds' of avoiding mosquito bites

The San Mateo County Health Services Agency recommends that people follow the "four Ds" to prevent bites from mosquitoes that may be carrying the West Nile virus. They are:

** DRAIN standing water around the house weekly since that's where mosquitoes lay eggs. This includes tires, cans, flowerpots, clogged rain gutters, rain barrels, toys and puddles.

** DUSK and DAWN are when mosquitoes that carry the virus are most active, so limit outdoor activities or take precautions to prevent mosquito bites.

** DEET is an effective ingredient to look for in insect repellents. Always follow label instructions carefully.

** DRESS in long sleeves and pants during dawn and dusk or in areas where mosquitoes are active.

If there is a significant mosquito problem where you live or work in San Mateo County, call the Mosquito Abatement District at (650) 344-8592.

West Nile virus symptoms and resources

West Nile virus disease is rare, but, according to the San Mateo County Health Services Agency, anyone with symptoms that include a high fever, severe headache and stiff neck should contact his or her health-care provider immediately.

While no vaccine against West Nile virus has been approved for human use, horse owners interested in vaccinating their horses with the equine vaccine should contact their veterinarians for details.

More information about the West Nile virus can be found on the following Web sites: San Mateo County Health Department, www.smhealth.org/fightthebite; San Mateo County Mosquito Abatement District, www.smcmad.org; state of California, www.westnile.ca.gov; Center for Disease Control and Prevention, www.cdc.gov.

Contacting MAD

To report a mosquito problem, to have ground-nesting yellow jackets removed, or to get mosquito fish delivered in San Mateo County, call the Mosquito Abatement District at 344-8592. Information about the district's programs, history, and links to other helpful sites are found on its Web site, www.smcmad.org.

The site also features "instant gratification" for anyone frustrated by mosquitoes -- a computer game that lets you squash mosquitoes by using your mouse to operate a big fly-swatter.

Residents are encouraged to help track and control West Nile virus by reporting recently dead birds to the state online at www.westnile.ca.gov or by calling 877-WNV-BIRD (877/968-2473). Bird remains that have begun to decay cannot be tested for the virus.

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