New signs of West Nile virus have surfaced this week in Contra Costa County, the Mosquito and Vector Control District said. Groups of infected mosquitoes were found in traps in Martinez and Oakley, while an infected bird was found dead in Brentwood, the district said in a statement Friday. In response, the district is conducting additional inspections and mosquito surveillance in Oakley and Brentwood.
In Martinez, the district is conducting adult mosquito control north of Pacheco Boulevard along the Martinez waterfront closest to the Benicia Bridge, according to officials with the district. In addition to these mosquitoes and the dead bird, there have already been four groups of mosquitoes and five dead birds that have tested positive for the virus, and eight sentinel chickens have tested positive for antibodies in 2024, according to the district. An East County man died from West Nile virus on July 16 , marking the first death from the disease reported in Contra Costa County since 2006.
"It is important for residents to use an insect repellent if they are outdoors in the evening or early morning, and to report mosquito issues to the district because it only takes one bite from an infected mosquito to transmit West Nile virus to a person," Steve Schutz, the district's scientific program director, said in a statement. To reduce the risk of a bite, the district recommends insect repellant with one of the following ingredients: DEET, Picaridin, the repellent version of Oil of Le.