There have been no positive samples of West Nile Virus in animals or humans in California, but officials are making preparations as the disease appears to be moving westward across the United States. Most recent westernmost cases have been reported in Montana and New Mexico

“It is probably only a matter of time before testing shows the presence of the virus in animals or humans in California,” stated Dr. John Walker, Public Health Officer for the Stanislaus County Health Services Agency. “The medical community will be prepared and we want our communities to be armed with information,” Walker added.

West Nile is transmitted through the bite of a mosquito that has picked up the virus by feeding on an infected bird. In turn, the mosquito can pass the virus to humans. The virus is not classified as a bio-terrorist agent.

Most mosquitoes do not carry the virus and most people bitten by a mosquito have not been exposed to the virus. Less than one out of one hundred people who get bitten by an infected mosquito and become infected will get severely ill. Of the few who become infected, most people will have no symptoms at all or display only mild symptoms, according to the federal Centers for Disease Control and Prevention.

Symptoms of the West Nile Virus include, flu-like symptoms such as fever, headache, weakness, swollen glands and rash. According to Walker, “In most cases, the virus causes only a mild disease. Many people who are exposed to the virus might never become sick or they have such mild symptoms, they don’t realize it’s West Nile,” he noted. “However,” Walker cautioned, “in rare cases, the virus can cause encephalitis and even death.”

To reduce the risk of exposure to West Nile, people can avoid being outdoors during times that mosquitoes are most active—dusk and dawn. If they are outside during these times, they should cover up by wearing long-sleeved shirts and pants, and use mosquito repellent.

It’s also important to eliminate mosquito breeding sites, such as standing water in tires, plastic containers, or similar water-holding containers, Walker said.

The California State Department of Health Services has set up a hotline for reporting dead birds at 877-WNV-BIRD. Birds such as crows, ravens, magpies and jays are the primary birds of concern.

The greatest risk for infection is during late summer and early fall because the mosquitoes that transmit the virus increase during the summer, Walker noted.

Some people may have no symptoms when they are infected with West Nile. Some may become ill, usually three to 15 days after being bitten by an infect mosquito. Symptoms can include muscle weakness, inflammation of the brain (encephalitis), stiff neck, stupor, disorientation, tremors, convulsions, paralysis, coma or death. The elderly are especially vulnerable

The West Nile virus first appeared in New York City in 1999 and has expanded in all directions, affecting humans, horses and birds. Thirty-nine states, including the District of Columbia, have identified the presence of the virus.

For more information on West Nile Virus, visit the Stanislaus County Health Services Agency’s website at www.hsahealth.org.

The Stanislaus County Health Services Agency (HSA) is an outpatient medical system with 10 medical offices located throughout Stanislaus County. The HSA operates the Public Health Department, an Urgent Care Center and multiple programs serving over 500,000 patients and clients each year in Stanislaus County. The HSA also is in local partnerships for the MOMobile project and the Stanislaus Family Practice Residency Program. The HSA has extensive community health information available at its web site www.hsahealth.org