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First West Nile Virus Positive Mosquitoes Confirmed in Orange County

July 9, 2020

UPDATE (7/14/20; 11:55AM)

The Orange County Mosquito and Vector Control District has confirmed another West Nile virus positive in the area of Monarch Street and Blades Avenue. Inspectors will be out in the area to check known sources of mosquito breeding and try to identify any unknown sources.

West Nile virus advisory posters will be placed in the affected areas. If positive mosquito samples continue, adult mosquito control may be conducted in the future.

View the West Nile virus July 13 activity map.


The Orange County Mosquito and Vector Control District (OCMVCD) has confirmed that mosquito samples in three cities have tested positive for West Nile virus (WNV). These are the first samples to test positive in the county this year. The positive mosquitoes were collected on July 7, 2020 in Cypress, at Cerritos Avenue and Lexington Drive; in Anaheim at E. Sycamore Street and East Street; and in Garden Grove at Garden Grove Boulevard and Safford Street. The OCMVCD has also confirmed that one dead bird with WNV was collected in Irvine.

“West Nile virus positive mosquito samples indicates that the virus is active in Orange County and there is an increased risk for residents to become infected with WNV through a mosquito bite,” Said Robert Cummings, Director of Scientific Services.

West Nile virus is most commonly spread to people by the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds. There are no confirmed cases of human infections currently in Orange County.

The OCMVCD staff will continue to conduct surveillance, inspections, and control measures for mosquitoes in the areas to prevent additional mosquito breeding. OCMVCD will post WNV advisory signs alerting residents of high WNV activity in the affected areas.

“It is essential for residents to do their part and take charge of their yard,” said Lora Young, Director of Communications. “The best way to protect yourself is by applying EPA-registered repellent, wearing long sleeved clothing and eliminating potential breeding sources around your property.”

To learn more about West Nile virus visit, ocvector.org/west-nile-virus or visit ggcity.org/west-nile-virus.

Mosquito control is a shared responsibility. Orange County residents need to do their part to control mosquito breeding around their properties and prevent bites. Eliminating mosquito breeding sources is critical to preventing the spread of West Nile virus.

To prevent mosquito bites, take action and follow these tips:
o Dump and drain containers filled with water at least once a week
o Clean and scrub bird baths and pet water bowls weekly
o Dump water from potted plant saucers