First positive test samples of West Nile virus found in Sacramento County mosquitoes

Four cases of West Nile virus have been confirmed in Sacramento County, including the first mosquito, the Sacramento-Yolo Mosquito and Vector Control District announced Monday.

The district said the three dead birds and the mosquito sample were collected in Isleton, a small city on the Sacramento-San Joaquin Delta. The virus was first detected this year on May 17 when a pair of dead birds were found on Florin Road in south Sacramento.

Last year in California, there were 225 confirmed human cases of the disease, including 15 fatalities, according to the district and California Department of Public Health officials.

No human cases have been identified yet in California this year.

“As we expected, the very warm weather we’ve had recently increased the number of mosquitoes and accelerated virus activity,” district manager Gary Goodman said in a news release. “Summer is around the corner and as more people enjoy outdoor activities it’s important to remember that the best protection against mosquito bites is an effective insect repellent.”

Virus activity is highest from June to October.

Mild or moderate symptoms include fever and fatigue. Severe symptoms in humans include neurological conditions such as encephalitis and meningitis.

Yuba-Sutter officials said last year that severe illness from West Nile virus is rare, affecting only about one in 150 people who become infected. Roughly 80% who contract the virus remain asymptomatic, according to health officials, which means many cases go unreported.

The district encourages people to avoid contracting the virus by draining standing water, avoiding being outdoors at dawn and dusk, dressing in long sleeves and pants when outside and making sure their doors and windows are in good, working condition.

Those who see dead birds can report them to state health officials’ West Nile virus hotline at 877-968-2473.

Residents can direct mosquito problems to the district at 800-429-1022 or fightthebite.net.

They can also subscribe to mailing lists to receive email notifications for upcoming mosquito treatments by ZIP code. To sign up, go to Spray Notifications on the website.