The Contra Costa Mosquito and Vector Control District reported some mosquitoes, dead birds and chickens in the area that have recently tested positive for West Nile virus. To avoid bites, people can stay indoors and wear mosquito repellent when outside. According to the District's Scientific Programs Manager Steve Schutz, Ph.D., "As we enter the peak of West Nile virus season we're starting to see more widespread activity. People in all areas of Contra Costa County should be protecting themselves against mosquito bites." To further reduce the risk of contracting West Nile virus and other mosquito-borne diseases report dead birds to the state hotline: 1877-968-2473. Additional Information.