Los Angeles County reports year’s 1st confirmed West Nile virus cases

Three people were hospitalized this month with Los Angeles County’s first confirmed illnesses from West Nile virus in the 2008 season, public health officials said.

The three – two men and a boy – are recovering. A fourth, asymptomatic case was detected in a male blood donor during a routine screening for the virus, officials said in a statement released Thursday.

The four individuals lived in the eastern and southern sections of the county. But Dr. Jonathan Fielding, the county’s director of public health, warned that the virus can be found in any part of the state. Vector-control agencies last week detected the virus in nine dead birds in the eastern county and in 11 mosquito pools, primarily in the San Fernando Valley. He advised residents to remove sources of standing water, where mosquitoes breed.

Humans and animals contract the virus from bites of infected mosquitoes, which contract it by feeding on birds that have the virus in their blood.

Although the virus is now considered endemic to California, most mosquitoes do not carry it. And most people who become infected with the virus do not develop symptoms or become seriously ill. But for the nearly one in five who are sickened, symptoms can include fever, headache, nausea, tiredness, swollen glands or skin rash.

Deaths from the virus are rare, but the risk of complications increases for people over age 50 and those who may have preexisting health problems or weakened immune systems.

In warm months when mosquitos are active, public health officials advise residents to wear long sleeves and long pants or use repellents containing DEET, picaridin, or oil of lemon when outdoors.

To report dead birds or squirrels, call (877) 747-2243. Additional information is available at the California Department of Public Health’s West Nile Virus website.

mary.engel@latimes.com