CONCORD, CALIFORNIA – The Contra Costa Mosquito and Vector Control District (District) reports 11 more dead birds and three more groups of trapped mosquitoes have tested positive for West Nile virus (WNV) in Contra Costa County.
The dead birds were collected from Concord (5), Walnut Creek (2), Martinez, Pleasant Hill, El Cerrito, and Alamo; while the mosquitoes were trapped in Discovery Bay, Martinez, and Holland Tract near Knightsen. So far this year, there have been 22 dead birds, 11 groups of trapped mosquitoes, and three sentinel chickens that have tested positive for WNV in 2023.
As a result of the elevated WNV activity in Concord, where a total of seven dead birds have tested positive for WNV, the District is conducting additional surveillance and evaluating the possibility of conducting an Adult Mosquito Control operation in the area where the infected dead birds have been collected. The District also advises Contra Costa County residents to take the necessary steps to reduce the risk of mosquitoes and mosquito bites over the holiday weekend.
“The combination of an active West Nile virus season and Labor Day weekend keeps District employees busy and it is important that Contra Costa County residents take action to reduce the risk of mosquitoes and mosquito bites. Be sure to wear repellent when outside to reduce the risk of mosquito bites over the holiday weekend. County residents can also deny mosquitoes a place to lay their eggs and develop from egg to adult by dumping out any standing water and scrubbing the inside of the container,” said the District’s Scientific Program Manager Steve Schutz, Ph.D.
The District recommends residents use an EPA-registered insect repellent that includes one of the four most effective active ingredients: DEET, Picaridin, IR3535, or the repellent version of Oil of Lemon Eucalyptus.
In addition to dumping out standing water and scrubbing the inside of the container to remove mosquito eggs, the District also advises Contra Costa County residents to:
- Make sure door and window screens are in good working condition
- Report dead birds to the California West Nile Virus Dead Bird Call Center
- Report neglected swimming pools to the District. Contra Costa County residents may report a neglected swimming pool anonymously.
- Contact the District to request mosquito service
Contra Costa County residents can report dead birds by phone at (877) WNV-BIRD (968-2473) or online. County residents can also request mosquito service for their residential properties by calling (925) 685-9301 or online.
Since 2005, 76 people in Contra Costa County have been diagnosed with West Nile virus. In 2006, two people died from the disease. For human case information, please visit the California Department of Public Health Vector-Borne Disease Section online.
Contra Costa Mosquito & Vector Control District, an independent special district and public health agency, is located at 155 Mason Circle in Concord.
- Aug 26 – West Nile Virus Activity Continues in Contra Costa County
- Aug 19 – West Nile Virus Becomes More Widespread in Contra Costa County
- Aug 11 – West Nile Virus Activity Intensifies in Contra Costa County
- July 15 – West Nile Virus Returns to Contra Costa County