SAN DIEGO -- Four dead birds discovered around San Diego County have tested positive for West Nile virus, bringing the total number to 14 this year, county health officials said Thursday.

The birds were found in Mira Mesa, Carmel Valley and Rancho Bernardo, according to the San Diego County Department of Environmental Health.

"As the number of birds testing positive for West Nile virus increases, it is more important than ever for residents to protect themselves," said Gary Erbeck, director of the county DEH.

"There are a few simple steps residents can take, such as preventing mosquito breeding, wearing protective clothing and using insect repellent to protect yourself from mosquito bites, and reporting mosquito breeding (sites) and dead birds to county Vector Control," he said.

Dead birds can be reported, and more information on West Nile virus obtained, on the county's Web site at www.SDFightTheBite.com, or by calling 888-551-4636.