From the Humboldt County Department of Health and Human Services:

An American Crow in Humboldt County has tested positive for West Nile Virus (WNV). This is the first WNV-positive bird reported in the county this year. 

Statewide, a total of 15 birds have tested positive for WNV already this year, according to the California Department of Public Health. No human cases have been reported.

Healthy American crow. Photo: Wikimedia.

“It’s early in the season to be seeing positive birds,” said Melissa Martel, Director of the Department of Health & Human Services’ Division of Environmental Health. “It takes several weeks of warm temperatures for the virus to intensify and several cycles of disease transmission for the virus to cause illness.”

According to the Centers for Disease Control and Prevention (CDC), most people get infected with WNV after being bitten by an infected mosquito.  Mosquitos become infected when they feed on infected birds and can then spread the virus to other animals. 

While the prevalence of WNV is low in Humboldt County due to our climate, residents are still advised to follow safety measures, especially when traveling to areas where WNV is more common.

One of the best ways to prevent WNV is to avoid mosquito bites and mosquito-infested areas, according to the CDC, especially at dawn and dusk when insects are most active. People who are going to be outside during dawn and dusk are advised to wear long-sleeved shirts, long pants, shoes and socks.

The CDC also recommends using EPA-registered insect repellants, such as DEET, Picaridin or oil of lemon eucalyptus for long-lasting protection against mosquito bites. Always follow directions for use by the manufacturer.

People are also encouraged to mosquito-proof their homes. Good safeguards include installing or repairing screens on windows and doors to keep mosquitoes out and emptying standing water from flower pots, gutters, buckets, pet dishes, tires and bird baths.

“Standing water is a breeding ground for mosquitoes,” Martel said. “Limiting the number of places for mosquitoes to lay eggs limits propagation.”

To report dead birds or tree squirrels, both of which can carry the disease, call the California West Nile Virus Surveillance Program hotline at 877-968-2473. For more information, visit