State Sees First Human W. Nile Case of Year

The state reported its first human case of West Nile virus on Wednesday in Northern California, as Orange County coped with its own problems with the disease -- so far, only among birds and mosquitoes.

More than 100 infected birds have been found in Orange County this year, the highest number of any county in the nation, officials said, due in part to its many wetlands and winter rains.

Officials are on alert as the Fourth of July holiday weekend approaches. With outdoor activities planned, the county’s mosquito abatement agency urged residents to use insect repellent while outside.

“Our hope is that people will take precautions, especially this July Fourth weekend,” said Michael Hearst, a spokesman for the Orange County Vector Control District.

Hearst’s comments came the same day the state announced that a 47-year-old Tulare County man had been infected with the virus, the first reported human case in California and the second in the nation this year.

The man sought medical care for a fever and headache early this month and is recovering, state Sandra Shewry, director of the state Department of Health Services.

Kansas reported the first case last week.

The disease has appeared in birds, horses and mosquitoes -- the insect that carries West Nile -- in 14 states this year, according to the Centers for Disease Control and Prevention.

In 2004, 830 West Nile virus infections in humans were reported in 23 counties in California; 28 people died. The first of the fatalities occurred in Orange County.

However, the chance that a person will become ill from a single mosquito bite remains low, officials said. People over 50 are most at risk of severe illness and death, though people of all ages can become ill.

People who are exposed to the virus generally show flu-like symptoms, Hearst said.

The agency advises residents to wear long pants and long-sleeved shirts when outdoors at dawn and dusk, when mosquitoes are likely to be out.

Hearst advises using insect-repellent spray or lotion, especially one that contains the chemical DEET. So far, 11 batches of captured mosquitoes carrying the virus have been found in Orange County and 107 birds have tested positive for the disease, Hearst said.

By contrast, the agency reported only 49 infected birds at this time a year ago.

Vector officials said one reason for the increase in bird infections was that the county has many coastal and inland wetlands, and that winter storms have increased water levels there.

The agency also didn’t hesitate adding more inspectors this year. By April, it had tripled its field inspectors to 68, a month earlier than usual for the mosquito season that runs through October, Hearst said.

This year, Irvine has the highest number of infected captured mosquito batches in the county with five areas around a marsh at UC Irvine, Hearst said.

Huntington Beach had two batches of mosquitoes, at a residence and Central Park.

Seal Beach had two at the Bolsa Chica wetlands, Garden Grove had one near the vector control’s office and Santa Ana had one near the Garden Grove Freeway and the Santa Ana River, Hearst said.