SAN DIEGO (CNS) - A San Marcos woman's death last week was likely the result of West Nile virus, and would be the region's first reported fatality from the mosquito-borne disease this year, the county Health and Human Services Agency reported Monday.
State health officials are working to confirm the cause of death of the woman, who died Thursday and had underlying medical conditions. Her name was withheld.
"The unfortunate death of this woman is a reminder that the public should take precautions to avoid being bitten by mosquitoes, which transmit West Nile and other viruses," said Dr. Wilma Wooten, the county's public health officer.
There have been eight confirmed and three probable cases of West Nile virus in county residents so far this season, all of which were acquired locally, according to the HHSA.
Mosquitoes transmit West Nile virus to people by feeding on infected birds and then biting humans. The mosquito species that transmit West Nile virus are different from those capable of transmitting the Zika virus.
The county Department of Environmental Health's Vector Control Program staff is inspecting the area around the woman's home to check for potential sources of mosquito breeding. Vector Control also set traps in the area and is sending notifications to nearby residents.
The Vector Control Program has already collected more infected dead birds and batches of mosquitoes carrying the virus this year than it has in recent years -- 250 dead birds and 99 batches of mosquitoes.
At this point in 2015, the county had collected a total of 182 dead birds and 29 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 best protection against WNV is to empty out areas of standing water where mosquitoes breed, stay indoors at dusk and dawn when the insects are most active, and wear long sleeves and pants or use repellent when outdoors.
About 80 percent of people with WNV don't get symptoms, while the remainder will have headaches, fever, nausea, fatigue, a skin rash or swollen glands.
An estimated one in 150 cases are life-threatening, with the risk going up for patients over age 50, according to the county Health and Human Services Agency.
County officials also urged residents to contact vector control when they find dead birds or green swimming pools, by calling (858) 694-2888 or emailing email@example.com.