Logo courtesy of Solano County

SOLANO COUNTY, CA (MPG) - The Solano County Department of Health and Social Services, Public Health Division, and the Solano County Mosquito Abatement District (SCMAD) have confirmed that two mosquito pools (mosquitoes collected in a trap) have tested positive for West Nile virus (WNV). These are the first mosquito samples to test positive for WNV in Solano County in 2026.

“This is an important reminder that mosquito-borne illnesses like West Nile Virus are present in our area,” said Dr. Cameron Kaiser, acting health officer for the Solano County Health & Social Services, Public Health Division. “You can take simple precautions to avoid mosquito bites, particularly when spending time outdoors, and reduce mosquitoes breeding where you live.”

The first positive sample was collected on Aug. 11, 2026, from the Grizzly Island Wildlife Area. The second sample was collected on Aug. 19, 2026, in a rural area of northern Dixon. There are currently no confirmed human cases of WNV in Solano County. As of Aug. 14, 2026, the California Department of Public Health reports that there have been 30 human cases statewide this year. 

West Nile virus is transmitted to humans and animals through the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds. People may reduce the risk of contracting mosquito-borne illness by following these guidelines:

Dawn and dusk

Mosquitoes are most active in the early morning and evening. Residents should avoid being outside at these times. If you are outdoors, wear a long-sleeved shirt and long pants and use insect repellent.

Drain standing water

Mosquitoes lay their eggs on standing water. Residents should eliminate all sources of standing water on their property and drain empty flowerpots, buckets, barrels, old car tires, rain gutters and pet bowls. If you have an ornamental pond, contact SCMAD at (707) 437-1116 for free mosquito fish.

DEET and other repellents

Insect repellents help keep mosquitoes from biting. Apply an EPA-registered insect repellent containing DEET, picaridin, oil of lemon eucalyptus, IR3535 or para-menthane-diol products per the manufacturer's instructions.

Doors and windows

Residents should ensure that their doors and windows have tight-fitting screens to keep mosquitoes out. Repair or replace screens with tears or holes.

Most people (about four out of five) infected with the West Nile virus will not develop any symptoms. About one out of five will develop mild flu-like symptoms, including fever, headache, body aches, nausea, vomiting and swollen lymph glands. However, about one percent (about 1 in 150) of persons with WNV infections will develop severe neurological disease. In rare cases, WNV infection can be fatal.

Anyone can be infected with WNV, but people who are 60 years of age and older, and those with certain medical conditions, like cancer, diabetes, hypertension, kidney disease and people who have received organ transplants or medications that alter their immune system, are at greater risk of developing severe illness and complications.

The SCMAD staff are taking additional steps to monitor and control mosquito activity in the affected areas.

“The Solano County Mosquito Abatement District (SCMAD) will respond to these WNV detections by continuing surveillance efforts in the areas where the mosquitoes were originally collected,” stated Bret Barner, the Solano County Mosquito Abatement District Biologist. “This will include setting mosquito traps, sampling mosquitoes, and inspecting mosquito breeding sources throughout the area. District staff will focus on reducing the mosquito population through treatment applications. Residents should protect themselves from mosquito bites by draining sources of standing water around their homes and reporting any increased mosquito activity or neglected swimming pools to us at (707) 437-1116. Helpful resources, including tips and recommendations, can be found on our website at SolanoMosquito.com.”

Residents are encouraged to report dead birds online at www.WestNile.Ca.Gov or by calling 1-877-WNV-BIRD (1-877-968-2473).