Mosquitoes collected during routine monitoring near San Carlos have tested positive for West Nile virus, marking the first detection of the virus in San Diego County mosquitoes this year, according to the County of San Diego Communications Office.

County officials are urging residents to follow the county's "Prevent, Protect, Report" guidance: remove standing water from items such as plant saucers, buckets, garbage cans, toys, old tires and wheelbarrows; wear long sleeves or use insect repellent outdoors; and check window and door screens.

The county said its Vector Control Program is inspecting and treating sites in the San Carlos area and conducting follow-up trapping. Residents can report increased mosquito activity, unmaintained green pools, mosquito-breeding sources or dead birds to Vector Control at 858-694-2888 or vector@sdcounty.ca.gov.

For Santee residents, the alert is close enough to matter. San Carlos sits just west of Santee and Mission Trails, and warm weather, irrigated yards and small containers of water can turn into mosquito breeding spots quickly during summer.

West Nile virus spreads when certain mosquitoes bite infected birds and then bite people. The county says many infected people have no symptoms or mild symptoms, but rare cases can lead to severe illness.