SLO County reports first case of locally acquired West Nile Virus

October 17, 2023

By KAREN VELIE

Two San Luis Obispo County residents tested positive for West Nile Virus this year, including one case that was acquired locally, according to the SLO County Health Department.

This is the first confirmed case of a person becoming infected with West Nile virus here in SLO County. In prior cases, residents became infected while traveling to other areas where the virus is more widespread.

“We want our community to be aware that West Nile virus has spread here in SLO County, but it does not appear to be spreading widely and the risk to the public remains very low,” said Dr. Penny Borenstein, county health officer. “Together, we can take simple steps to prevent further spread, like protecting against mosquito bites and keeping an eye out for sources of standing water that make it easy for mosquitoes to breed.”

West Nile Virus is a mosquito-borne disease that most often spreads through the bite of an infected mosquito. The virus can be passed on to others through transfusions, and an infection is potentially fatal.

Most people infected with West Nile do not show symptoms. Approximately 20% of those infected develop mild symptoms, such as fever and body aches, which typically last a few days. About one in 150 people who become infected with the virus develop severe illness.