The first human infected with the West Nile virus in San Diego County, has been confirmed. A 51-year-old El Cajon woman has become the first locally acquired human case of West Nile virus this year according to the San Diego County Health and Human Services Agency, announced today.

The woman donated blood on July 27 and was found to have evidence of active infection. All blood donations in the United States are screened for West Nile virus and other diseases that can be transmitted in a transfusion. She developed symptoms of fever and headache this week and was diagnosed with West Nile fever, but has not hospitalized.

The County Vector Control Program has already collected more infected dead birds and batches of mosquitoes infected with the virus in 2016 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 185 dead birds and 77 batches of mosquitoes that tested positive for West Nile virus to date in 2016. At this point in 2015, the County had collected a total of 69 dead birds and 14 mosquito batches that tested positive for the virus. Last year was also the deadliest year ever in San Diego for West Nile virus, with six deaths among the 44 human cases reported.

"The numbers of dead birds and positive mosquito batches positive for West Nile virus has increased from what was found last year, so it's important for the public to know the facts about how to prevent mosquito breeding and protect against mosquito bites," 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 age 50 and over 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.