UPDATE: Aerial spraying set for Friday evening in Stanislaus area after West Nile death reported

Aerial spraying is scheduled Friday evening over Turlock and several other communities to control mosquitoes, as health officials deal with a high incidence of West Nile virus cases.

The Turlock Mosquito Abatement District also announced the aerial spraying Friday for Ceres, Hughson, Hickman, Patterson and Newman from 8 to 9 p.m.

County public health officials reported 28 confirmed cases of West Nile disease as of Friday (Sept. 15), including one death. In 19 of those cases, the person struggled with the potentially deadly neuroinvasive form of the illness, said a news releases Friday afternoon.

Stanislaus County had a total of 15 cases of West Nile disease in 2022. No details of the recent West Nile death were released. Statewide, the number of people stricken by West Nile has doubled compared to the previous year.

David Heft, general manager of the Turlock Mosquito Abatement district, said the district is seeing a lot of West Nile virus activity.

“For some reason, because we had so much flooding earlier in the year, it got the (West Nile) virus going at a higher level,” Heft said. “We are seeing an abundance of virus activity now.”

Another reason for the aerial spraying is reducing the population of aedes aegypti mosquitoes, the tiny, dark mosquitoes in back yards that bite people around the ankles, Heft said. The mosquitoes became established in the San Joaquin Valley five years ago and were first detected in Stanislaus County in 2019.

Residents cannot catch West Nile illness from those annoying bites around the ankles, but those mosquitoes will be capable of spreading dengue fever and Zika — if the diseases reach California, Heft said.

The aircraft will spray an insecticide called Dibrom, one of two chemicals authorized for controlling mosquitoes. The district said no precautions are necessary for residents to protect themselves or their vehicles. People with a chemical sensitivity may want to stay indoors, with windows and doors shut, and turn off a mounted air-conditioning unit, the district said.

There’s no reason to turn off central air-conditioning, as those systems do not pull in outside air.

Heft said only a small amount of chemical will be sprayed, about .75 ounces per acre. The droplets are microscopic and are not a danger to people, including those who may be attending a high school football game, he said.

Heft said the mosquito abatement district tries to rotate applications of Dibrom and a second chemical, pyrethrins, between ground and aerial spraying to manage resistance in mosquito populations.

County health officials also advise residents to be aware that mosquitoes are transmitting West Nile virus to people. They can use proactive measures to reduce their risk by draining standing water around their homes. Empty flower pots, bird baths, gutters and other containers.

Use insect repellent or wear long sleeves and long pants when going outside in the morning and evening when mosquitoes are active.

Dead birds, a possible sign the virus is present, can be reported to the California West Nile Virus center by calling 877-968-2473 or going to