Health

First 2015 Human West Nile Virus Case Reported in County

A 73-year-old Del Mar man has been confirmed as the first locally acquired human case of West Nile virus this year, the San Diego County Health and Human Services Agency announced today.

The man was admitted to a local hospital on Aug. 2 after experiencing symptoms of encephalitis, an inflammation of the brain that can be caused by viral or bacterial infection. He remains hospitalized. Testing by the California Department of Public Health Viral and Rickettsial Disease Laboratory confirmed late last week that he has West Nile virus.

West Nile virus is carried by mosquitoes. County Department of Environmental Health Vector Control Program staff conducted inspections near the ill man’s home to check for potential sources of mosquito breeding. Vector Control also set up traps in the area and is sending notifications to residents.

Although this is the first confirmed human infection with West Nile virus here in San Diego County so far this year, the County Vector Control Program has collected more infected dead birds and batches of mosquitoes with the virus in 2015 than it has in recent years. Mosquitoes can transmit West Nile virus to people by feeding on infected birds and then biting humans.

Environmental Health has identified 95 dead birds and 18 batches of mosquitoes that tested positive for West Nile virus so far this year. The County collected a total of 41 dead birds and six mosquito batches that tested positive for the virus in 2014. That year 11 county residents were diagnosed with the disease and two died.

“The late summer is when we expect West Nile virus to peak, and there were cases diagnosed through October last year, so people need to protect themselves from this potentially deadly disease,” said Wilma Wooten, M.D., M.P.H., County public health officer.

Eighty percent of individuals who become infected with West Nile virus will have no symptoms. Twenty percent of those who do get sick have mild symptoms of headache, fever, nausea, fatigue, skin rash or swollen glands. One in 150 of those infected with the virus will have serious neurologic complications that can be life threatening. The risk of complications increases for those over age 50 and people with weakened immune systems.

County officials reminded the public that they can protect themselves by following the County’s “Prevent, Protect, Report” advice.

Prevent Mosquito Breeding: Dump out or remove any item inside or outside of homes that can hold water, such as plant saucers, rain gutters, buckets, garbage cans, toys, old tires, and wheelbarrows. Mosquito fish, available for free by contacting the Vector Control Program, may be used to control mosquito breeding in backyard water sources such as unused swimming pools, ponds, fountains and horse troughs.

Protect Yourself from Mosquito Bites: Protect yourself from West Nile virus by staying inside when most mosquitoes are most active, at dusk and dawn. Wear long sleeves and pants or use repellent when outdoors. Use insect repellent that contains DEET, picaridin, oil of lemon eucalyptus, or IR3535. Make sure screens on windows and doors are in good condition and secured to keep insects out.

Report Dead Birds and Green Swimming Pools: Report dead crows, ravens, jays, hawks and owls, and green swimming pools to environmental health’s Vector Control Program by calling (858) 694-2888 or emailing vector@sdcounty.ca.gov.

For more information about West Nile virus, go to San Diego County’s “Fight the Bite” website.

Tom Christensen is a communications specialist with the County of San Diego Communications Office. Contact