Park Users Warned of West Nile Virus

By Cindy Frazier
Senior Writer

July 28 -- At the height of summer --and just days after the first announced death from West Nile Virus (WNV) in the state -- park users in Santa Monica are being warned to take precautions against the mosquito-borne disease.

“We are finding extensive West Nile Virus activity in dead birds, mosquitoes and chickens, so there is a greater risk of transmission to humans,” said Vicki Kramer, chief of Vector-Borne Disease section of the California Department of Health Services.

“We are advising people to wear [mosquito] repellent and long sleeves,” she added.

The Los Angeles County West Vector Control District --the local agency responsible for “vector-borne” illnesses, those that infect humans through animals or insects -- is posting all Santa Monica parks with warning signs about the virus, which is transmitted to humans through mosquito bites.

Mosquitoes are most active at dawn and in the first two hours after sunset, when people enjoying the outdoors are most at risk of being bitten, according to the health agency.

On July 22, state health officials announced that a 57-year-old Orange County man had succumbed to the virus, the first such death in California.

Since then, five more cases of WNV infection have been discovered, bringing the total this year to 44, according to Kramer.

Health officials say that most people infected with WNV have no effects, with about 15 percent experiencing mild to moderate symptoms, including fever, headache and body aches.

Less than one percent will develop serious neurological illness, such as encephalitis or meningitis, and of those, seven percent will die, Kramer said. The elderly and those with compromised immune systems are more susceptible to serious illness.

The recent cases of illness were in areas not close to Santa Monica, including Imperial and Kern Counties.

One of the recent cases -- in Bakersfield – was discovered when the victim attempted to donate blood, Kramer said. All blood donors are now screened for WNV.

To keep track of the spread of the disease, health agencies are asking the public to report findings of certain types of dead birds – crows, ravens, magpies, jays, and raptors (which include owls and hawks), Kramer said. These birds are susceptible to the virus.

Anyone finding a dead bird of those types is asked to call the health services hotline, (877) WVN-BIRD.

In addition, health officials are advising residents to eliminate standing water, and to frequently change bird baths, and take other measures to reduce mosquito breeding.

Health agencies are supplying mosquito fish at no charge to those who have ponds, Kramer said. The fish – Gambusia affinis – originated in South America and are adept at eating mosquito larvae that sit on top of the water.

“They are top-feeders, which means they have their mouths on their backs, so they can easily catch things that float on top of the water,” Kramer said. The fish are also especially hardy and reproduce quickly, giving birth to live young who immediately begin feeding on larvae, according to West Vector Control.

Kramer said the fish --which do not grow beyond two-to-three inches in length and live two to three years -- blend in with other pond fish, such as carp or koi.