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West Nile Virus Found in Mosquitoes in the Valley But Drought May Be Helping To Keep Illness At Bay PDF Print E-mail
Written by Alex Garcia, Sun Contributing Writer   
Thursday, 17 July 2014 01:28

Photo Courtesy of Greater Los Angeles County Vector Control District.

GLACVCD underground team monitoring mosquito populations in storm drains

Canoga Park, Encino, North Hills and Panorama City are some of the areas in the San Fernando Valley where mosquitoes carrying the dangerous — and sometimes deadly — West Nile Virus have been detected for the first time this year.

“Any time we get a positive reading in the area, we post signs to make people aware,” said Levy Sun, public information officer for the Greater Los Angeles County Vector Control District (GLACVCD), the agency in charge of monitoring and treating mosquitoes in the county.

Apart from the posted signs, GLACVCD has also set up traps in the area and captured mosquitoes are tested every two weeks.

“We work with UC Davis to test mosquitoes for West Nile Virus,” said Sun.

A mosquito’s life cycle lasts a week.

At present there are no plans for extra monitoring or spraying in these areas.

“If we see a spike in West Nile Virus activity, we may take extra steps,” Sun said.

West Nile Virus is transmitted by mosquitoes and can cause fever, headache, body aches, joint pains, vomiting, diarrhea or rash. Symptoms usually occur between five and 15 days and can last for several weeks to months. Most people recover completely; however, 70 to 80 percent of those who become infected do not develop any symptoms.

Less than one percent of those infected develop encephalitis (inflammation of the brain) or meningitis (inflammation of the lining of the brain and spinal cord), which could lead to death. People with certain medical conditions, such as cancer, diabetes, hypertension and kidney disease are at greater risk for serious illness.

Currently, there is no vaccine for the disease.

The incidence of West Nile Virus has shown a steady growth in the last three years, according to GLACVCD statistics. In 2011, 44 people were infected in the area covered by the agency, and two of them died. That figure rose to 95 infected in 2012 with two fatalities. Last year, 104 people tested positive for the disease and there were five recorded deaths.

So far in 2014, 11 mosquitoes and three birds have been infected by the disease, but there have been no recorded human infections or deaths.

“The incidence of West Nile Virus is pretty much as expected,” Sun said. “West Nile Virus is endemic in this area. We will see it every year in the San Fernando Valley.”

California’s recordbreaking drought, which has left lawns brown and parched, may be helping to keep down the number of reported West Nile Virus cases at least for now, Sun said.

“The drought will reduce the population of mosquitoes,” he said, but also added that “we still pose a problem” with people who overwater.

“If people can conserve water, it will help reduce the mosquito presence,” Sun said.

GLACVCD advises residents to protect themselves from mosquitoes by spraying themselves with insect repellent containing active ingredients such as DEET, Picaridin or oil of lemon eucalyptus when outdoors, particularly in the early morning and late afternoon when mosquito activity is higher. People should also wear long sleeves to reduce the risk of mosquito bites.

Sun also recommends dumping and draining any standing water left unattended for at least three days. This includes water left in buckets, birdbaths and plant saucers.

Properly maintained swimming pools, spas and ponds can reduce or eliminate breeding grounds for mosquitos. Make sure window and door screens are used and kept in good repair. And you can request free mosquitofish from GLACVCD for placement in ornamental ponds.

If you find a dead bird, particularly a crow or other corvid (i.e. raven, jay, or magpie), please call the California Department of Public Health hotline at (877) 968-2473.

Last Updated on Thursday, 17 July 2014 19:35