San Diego County's health officials Friday confirmed the county's first confirmed human case of West Nile virus in 2018.
The patient is a 91-year-old man from La Jolla, according to the county's Health and Human Services Agency.
The California Department of Public Health on Thursday confirmed the man had West Nile virus and he has been discharged from a hospital. He was originally hospitalized last month for a case of encephalitis. County and state health officials determined that the infection came from a bite by a local mosquito, since the man had not left the county during the month prior to being hospitalized.
California has seen 132 human cases of West Nile virus and two deaths so far this year. San Diego County saw only two cases of the virus last year, a sharp decline from the 22 cases in 2016. The virus is generally carried by birds, but mosquitoes can contract and spread it rapidly after feeding on an infected animal.
"The vast majority of people who become infected with West Nile virus never know it and never suffer any symptoms," a county spokesman said. "About two out of every 10 people who get infected suffer mild symptoms, including headache, fever, nausea, fatigue, skin rash or swollen glands."
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Residents can protect themselves from the virus by preventing optimal mosquito breeding conditions and reporting increased mosquito activity, according to the county. Mosquitoes are drawn to standing water, so residents were advised to empty or remove any household items that hold water, like wheelbarrows, garbage cans and plant saucers.
Residents were urged to report increased or daytime mosquito activity, breeding sources and dead birds to the county's Vector Control Program by calling (858) 694-2888.
