Mosquitoes With West Nile Detected in Coachella Valley

Health officials have detected mosquitoes infected with the West Nile virus in Riverside County’s Coachella Valley, renewing concerns that the disease poses an imminent danger to Los Angeles and Orange counties.

“We know the virus is active when mosquitoes begin to test positive,” said Donald Gomsi, general manager of the Coachella Valley Mosquito and Vector Control District.

“It’s so early in the season, it’s going to give an opportunity for mosquitoes to disperse into O.C. and L.A. It could be going like wildfire throughout Southern California very quickly.”

In April, officials in Orange County captured two wild birds that tested positive for the disease.

It was the first sign that the virus was looming.

Later that month, officials in Riverside and Ventura counties also found birds that tested positive.

But officials in the Coachella Valley say those tests were inconclusive. “The birds that have been found recently have been sparse,” said Robert Mann, a spokesman for the district. “They may not be new infections. The theory is that the birds could be carrying the virus from last season.”

The discovery last week of infected mosquitoes means the virus may spread to neighboring areas.

Mosquitoes “now can bite a bird that hasn’t been infected and the bird can migrate and carry it to an area that hasn’t been infected,” Gomsi said.

Officials urge residents to report fallen birds -- especially crows -- to authorities.

They also ask that any receptacles that can hold water -- even trays under flowerpots -- be turned over to prevent mosquitoes from breeding in them.

Also, Gomsi urges residents to avoid outdoor activities at dawn and dusk -- when mosquitoes are most active -- and to wear mosquito repellent and long-sleeved shirts.

Although in most cases the virus produces few or no symptoms, it can cause fever, headache and nausea. About one in every 150 infected people will develop a serious illness, such as meningitis.

Last year, a Riverside resident was infected with the West Nile virus after being bitten by a mosquito in Moreno Valley. The man was stricken with aseptic meningitis but recovered.

The virus was first detected in the United States in 1999, when it killed seven people in the New York City area. Since then, it has quickly spread west, and is now present in 46 states, according to Mann.

There is no human vaccine for the disease.

Residents are asked to report dead birds to the West Nile Virus Dead Bird Hotline at 1-877-WNV-BIRD.