Death from locally acquired West Nile Virus within Los Angeles County

Aug 11 2004

Los Angeles County Department of Health Services is reporting a death from locally acquired West Nile Virus within Los Angeles County.

Laboratory tests confirmed the presence of WNV antibodies in a 91-year-old San Fernando Valley resident who passed away late last week. This is the third reported death for WNV in California and the first for Los Angeles County.

“West Nile virus is a mosquito-borne disease that can be prevented by taking several precautions,” said Laurene Mascola, M.D., M.P.H., Chief of Acute Communicable Disease Control Program. “The risk of infection can be reduced through elimination of sources of standing water, and attention to personal protection, including the use of insect repellant containing DEET, wearing long sleeves and long pants in areas with mosquitoes and avoiding mosquito infested areas, especially around dusk and dawn.

The total number of confirmed cases of WNV infection in the county is 32; 29 cases have been symptomatic and 3 cases are asymptomatic blood donors.

Exposure to West Nile Virus WNV is spread to humans from the bite of an infected mosquito; biting a bird that carries the virus infects a mosquito. Most mosquitoes do not carry the virus and most people bitten by a mosquito have not been exposed to the virus. The virus is NOT spread by person-to-person contact or directly from birds to humans.

Fewer than one out of 150 people who are bitten by an infected mosquito get severely ill, according to the Centers for Disease Control and Prevention. In most cases people who are infected never become sick or have only very mild symptoms that include fever, headache, nausea, body aches and a mild skin rash. 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 the West Nile virus. In a serious case, an individual may be hospitalized to ensure good supportive care.

The health department strongly advises residents follow the precautions recommended for all mosquito-borne diseases:

• Avoid mosquito-infested areas at dawn and dusk.
• Wear long-sleeved shirts and long pants whenever you are outdoors.
• Use insect repellent products with no more than 35 % DEET for adults and less than 10% for children.
• Ensure your window screens don’t have holes.
• Do not allow water to stagnate in old tires, flowerpots, trash, swimming pools, birdbaths, pet bowls, etc.
• Clean and chlorinate swimming pools; drain water from pool covers.
• Stock garden ponds with goldfish or mosquito fish. They eat the mosquito eggs and larvae.
• Empty and wash birdbaths and wading pools weekly.