Butte County health officials are urging residents to protect themselves from mosquito bites following the county’s first West Nile virus-related death of 2026. File photo.

OROVILLE, CA (MPG) - Butte County has recorded its first West Nile virus-related death of the year as health officials report six human infections and increasing virus activity during the height of mosquito season.

The Butte County Department of Public Health announced Aug. 13 that a person between 80 and 90 years old died from complications related to West Nile virus. The department did not release additional information about the individual.

As of Aug. 13, California had recorded 18 human West Nile virus infections and three deaths this year. Six of those infections occurred in Butte County.

The death follows the detection of Butte County's first West Nile activity of 2026 in early July. Two mosquito pools collected near Dayton and Nelson tested positive for the virus, according to the Butte County Mosquito and Vector Control District.

"It's imperative that county residents be aware that WNV is active and to avoid mosquito bites by whatever means necessary," District Manager Matthew Ball said following the initial detection. "Residents are urged to do their part to prevent mosquitoes from breeding by inspecting and eliminating all standing water from their properties."

West Nile virus has been detected in Butte County every year since 2004. From its arrival through early July, 303 county residents had contracted the virus and 12 had died, according to the mosquito district.

The virus generally remains active from May through October, with August typically marking the peak of West Nile activity in Butte County. Mosquitoes acquire the virus by feeding on infected birds and can transmit it to people and other animals through their bites.

Public health officials said eight in 10 people infected with West Nile virus develop no symptoms. About one in five develop a mild to moderate illness that can include fever, fatigue and body aches.

Fewer than one in 150 infected people develop severe neurological illness, including encephalitis or meningitis. Symptoms of severe illness can last several weeks and some effects may become permanent. Adults older than 50 and people with certain health conditions, including diabetes or high blood pressure, face a greater risk of severe illness.

Officials recommend using an EPA-registered insect repellent, limiting exposure to mosquitoes around dawn and dusk and eliminating standing water where mosquitoes can breed.

Mosquitoes need little water to reproduce. The National Pest Management Association recommends checking gutters, flowerpots, grill covers, children's pools, birdbaths, leaking pipes, tires, trash cans, buckets and ponds for standing water. Butte County Public Health said mosquitoes can produce up to 300 larvae in the amount of water held by a bottle cap.

Residents should drain containers when possible and regularly change water in birdbaths and pet bowls. Gutters should remain clear of debris, leaking faucets should be repaired and pools and ponds should receive proper maintenance.

For water that cannot be drained, public health officials recommend considering mosquito-control products or mosquitofish. Residents with ornamental ponds, livestock troughs and other standing-water features can request free mosquitofish from the Butte County Mosquito and Vector Control District.

Residents can also report dead birds as part of California's West Nile virus surveillance program at 1-877-968-2473 or westnile.ca.gov. The mosquito district advises people not to handle dead birds.

Neglected swimming pools, mosquito breeding sites and other mosquito concerns can be reported to the Butte County Mosquito and Vector Control District at 530-342-7350 or 530-533-6038.