West Nile virus has been found in Sonoma County mosquitoes for the first time in 2017, officials said Thursday morning.

The Marin/Sonoma Mosquito & Vector Control District said the mosquitoes were trapped in Rohnert Park, in an area near Wilfred and Whistler avenues.

“The results of our surveillance data suggest an elevated risk for disease transmission to residents in the vicinity,” Angie Nakano, scientific programs manager for the mosquito control district, said in a statement.

Nakano said it is important for residents to protect themselves from mosquito bites by wearing protective clothing, such as pants and long sleeve shirts, as well as using insect repellent.

Nizza Sequeira, a district spokeswoman, said the adult mosquitoes were caught in surveillance traps located in the Laguna de Santa Rosa flood control channel.

The traps are set weekly from spring through fall and mosquitoes are tested for West Nile, St. Louis encephalitis and Western Equine encephalitis.

Repellents should contain an active ingredient registered with the U.S. Environmental Protection Agency, the district said. Additional surveillance will be conducted in the area where the infected mosquitoes were found.

Officials encourage local residents to report cases of standing water and other mosquito-related issues by calling 800-231-3236 or visiting msmosquito.com.

The county’s first case of West Nile virus this year was detected in a dead bird found in northeast Santa Rosa in August. West Nile virus generally spreads through mosquitoes who feed on infected birds and then bite humans.