WEST NILE VIRUS HERE L.A.-AREA WOMAN TESTS POSITIVE FOR ILLNESS; RESULTS AWAITED FOR 3 OTHERS.

Byline: Troy Anderson Staff Writer

A Los Angeles County woman has tested positive for West Nile virus - the first reported case of a person contracting the potentially deadly illness in the western United States, authorities said Friday.

The unidentified woman - officials would say only that she's young and lives in the southwestern part of the county - was hospitalized in August with a mild case of meningitis and has since recovered.

Final results to confirm she has the West Nile virus are expected early next week, and officials are awaiting test results on three other people who might have contracted the disease.

The woman who tested positive did not any mosquito bites, blood transfusions or organ transplants, nor had she traveled to areas where West Nile virus has been confirmed. But preliminary laboratory results indicate that she has been exposed to the virus.

Tests conducted regularly on mosquitoes, chickens and dead birds have shown no evidence of the virus in California.

``Los Angeles County is investigating the first probable case of a locally acquired West Nile virus,'' said Dr. Jonathan Fielding, public health director and county health officer. ``Based on laboratory results, we think it's highly likely this is the first case in California.''

Fielding said health workers have tested five other people in the county who developed symptoms of the virus. Two tested negative, and officials are awaiting the results on the three others.

Officials said two of the people may have traveled here from other parts of the world and one person was visiting from Texas.

``We have been anticipating the arrival of West Nile virus in California as reports of the disease have progressed steadily westward across the United States,'' said Diana M. Bonta, director of the state Department of Health Services.

``Although we have no other evidence that the virus has arrived, mosquito surveillance and control efforts are being increased,'' Bonta said.

West Nile virus is typically spread to humans by the bite of an infected mosquito; a small percentage of people bitten will become ill in five to 15 days. Symptoms include fever, headache, nausea, body aches, mild skin rash or swollen lymph nodes.

In a few cases, the disease will progress to encephalitis, or inflammation of the brain. It is estimated that one in 150 people who are infected will require hospitalization.

The virus was first detected in the United States in New York in 1999 and has been found in 42 states and the District of Columbia. The mosquito-borne virus has been found in parts of Asia, eastern Europe, Africa and the Middle East.

So far in the United States, 842 cases have been confirmed and 43 people have died.

``In most cases, people who are infected never become sick or have only very mild symptoms for a few days,'' Fielding said. ``The virus can in rare cases cause encephalitis and death. The elderly are most at risk for severe cases of the disease.''

There is no specific treatment for West Nile virus. In serious cases, an individual may be hospitalized to ensure good supportive care.

Officials said hospitals throughout the state have been alerted to be on the lookout for symptoms that may indicate someone is infected, but so far no other cases have been reported. The virus is most prevalent from May to October, when mosquitoes are most abundant.

``We are increasing our surveillance to identify any other cases,'' Fielding said. ``We are also increasing surveillance in birds, chickens and horses.''

West Nile virus is spread to humans from the bite of an infected mosquito. A mosquito is infected by biting a bird that carries the virus. The virus is not spread by person-to-person contact or directly from birds to humans.

An investigation into possible West Nile virus infection in organ transplant recipients is currently under way. Most mosquitoes do not carry the virus and most people bitten by a mosquito have not been exposed to the virus.

``Less than 1 percent of infected persons become seriously ill,'' Bonta said. ``There has been no evidence that dogs or cats become ill from West Nile virus. Dogs and cats can't transmit the disease to people.''

The risk of the disease is higher for individuals 50 years of age and older.

On Friday, Gov. Gray Davis signed legislation toughening the state's mosquito abatement and vector control laws in light of the new threat from the spread of the West Nile virus and Asian tiger mosquitoes.

``This law gives mosquito abatement and vector control districts the tools they need to stand as guardians against epidemics, public health emergencies and economic disasters,'' Davis said. ``California needs this additional protection to help prevent the spread of diseases carried by mosquitoes.''

The law increases the maximum civil penalty for failure to abate a public nuisance - an area where mosquitoes can breed - from $500 to $1,000.

Tony Bell, spokesman for county Supervisor Michael D. Antonovich, said the supervisor will ask the county health department Tuesday to investigate how prepared the county is to deal with exposure to the virus.

For more information about the virus in Los Angeles County, call [phone]. Information can also be obtained on the Internet at www.ladhs.org or www.cdc.gov.

Many species of birds get infected and die from the virus. Members of the public are encouraged to call [phone] if they find a recently dead bird, such as crows, ravens, magpies or jays.

WEST NILE VIRUS AWARENESS

To reduce exposure to the virus, Fielding said county residents should avoid mosquito-infested areas at dawn and dusk when the insects are most active. People should also:

--Wear long-sleeved shirts and long pants whenever outdoors.

--Use insect repellent products with no more than 35 percent DEET for adults and less than 10 percent for children.

--Ensure windows have screens that do not have holes.

--Don't allow water to stagnate in old tires, flowerpots, trash containers, swimming pools, birdbaths and pet bowls.

--Clean and chlorinate swimming pools and drain water from pool covers.

--Stock garden ponds with goldfish or mosquito fish to eat the mosquito eggs and larvae.

--Empty and wash birdbaths and wading pools weekly.

CAPTION(S):

box

Box:

WEST NILE VIRUS AWARENESS (see text)