SOLANO COUNTY (KRON) — Three people are infected with West Nile Virus in Solano County, the county’s top health officer said Thursday.

Three cases in children and adults in Rio Vista, Dixon and Vacaville have been confirmed, Deputy Health Officer Dr. Michael Stacey said.

It’s not certain if the infections occurred within or outside Solano County.

“What we do know is that WNV infects people of all ages and the virus is found all across Solano County,” Stacey said in a news release.

The virus was detected in a bird in Fairfield in April and in other areas of the county since then, health officials said.

The virus was found in mosquitoes, birds and chickens, Solano County Mosquito Abatement District Manager Richard Snyder said.

The California Department of Public Health said there have been 276 human cases of West Nile Virus in 28 counties as of Sept. 30.

The virus is transmitted to humans and animals through the bite of a mosquito that became infected while feeding on infected birds.

Most infected people do not develop symptoms, but the virus can cause fever, headache, body aches, nausea, vomiting and swollen lymph glands. Less than one percent of infections will progress to neurological disease and very rarely lead to death, according to health officials.

Prevention methods include wearing long sleeve shirts and pants outside at dawn and dusk, using mosquito repellant, draining standing water where mosquitoes breed and ensuring doors and windows have tight-fitting screens.Bay City News contributed to this report