West Nile Virus is carried by mosquitoes.

SAN DIEGO–The cause of the recent death of a 78-year-old La Mesa man was confirmed as West Nile virus, the County Health and Human Services Agency said on Friday.

The man was admitted to a local hospital on October 6 after experiencing symptoms of encephalitis, an inflammation of the brain that can be caused by viral or bacterial infection. He died on October 10. Testing by the California Department of Public Health Viral and Rickettsial Disease Laboratory confirmed that he had the disease.

This is the first death from the virus in San Diego County since 2007 and the seventh confirmed case this year. Three more individuals in San Diego with suspected virus infections are currently under investigation. One person was a recent blood donor with no symptoms, and the other two have recovered from mild illnesses.

Only two human cases of West Nile Virus were reported in San Diego between 2009 and 2013, with both of those cases occurring in 2012. The highest number of cases occurred in 2008 when 36 were reported in San Diego.

“The calendar might say that we are past the peak West Nile Virus season of August and September, but it is clear that this potentially deadly disease is still active in our community,” said Bruce Haynes, M.D., medical director of County Emergency Medical Services.

West Nile virus is carried by mosquitoes. The County Department of Environmental Health Vector Control conducted inspections in the vicinity of where the human cases were reported to check for potential areas of mosquito breeding. Vector Control also set up traps in those areas and sent notifications to residents.

Of those individuals who become infected with the virus, 80 percent will have no symptoms. Most 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.

California is experiencing the highest numbers of West Nile Virus cases in nearly a decade.  The Department of Public Health has reported 608 human cases so far this year, including 20 deaths. This is the highest number of cases since 2005 when 880 cases were reported. Orange County has seen 216 cases this year and Los Angeles County has had 159 cases.

Health officials urge the public to protect itself by practicing “Prevent, Protect, Report.”

  • Prevent Mosquito Breeding: Dump out or remove any backyard item that can hold water, such as plant saucers, rain gutters, buckets, garbage cans, toys, old tires and wheelbarrows. Mosquito fish 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 WNV by staying inside when mosquitoes are most active, between dusk and dawn. Wear long sleeves and pants when outdoors. Use insect repellent containing DEET, picaridin, oil of eucalyptus or IR3535 when outside. Make sure screens on windows and doors are in good condition and secured.
  • Report Dead Birds and Green Swimming Pools: Please report dead crows, ravens, jays, hawks and owls, and green pools to the Vector Control Program online or by using the “Fight the Bite”app.