First West Nile Virus Positive Mosquitoes Confirmed in Orange County

Garden Grove, CA, The Orange County Mosquito and Vector Control District (OCMVCD)has confirmed mosquitoes collected in the city of Fullerton 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 near the cross streets of Rosecrans Ave. and N. Gilbert St.

West Nile virus is primarily transmitted to humans through the bite of infected mosquitoes, which acquire the virus when feeding on infected birds. As of now, Orange County has not reported any human cases of West Nile virus.

“Mosquitoes testing positive for West Nile virus is an indication that the virus is circulating in the community. Fullerton is historically a high-risk area for West Nile virus activity. Conditions across the region are favorable for sustained virus activity during the warm summer months,” said Amber Semrow, Director of Scientific and Technical Services.

Orange County Mosquito District staff will continue to conduct surveillance, inspections, and control measures for mosquitoes in the area to prevent additional mosquito breeding. OCMVCD will also post WNV advisory signs alerting residents of WNV activity in the affected area.

“The District is actively monitoring the situation and implementing preventive measures. Proactive involvement from the community in this effort is essential. Simple steps like checking for standing water around your property can help,” said Heather Hyland, OCMVCD Director of Communications. “The best way to protect yourself is using EPA-registered repellent, wearing long-sleeved clothing, and spreading the word to friends and family.”

To prevent mosquito bites, take action and follow these tips:

  • Dump and drain containers filled with water at least once a week
  • Clean and scrub bird baths and pet water bowls weekly
  • Dump water from potted plant saucers
  • Wear repellent containing DEET®, Picaridin, IR3535, or oil of lemon eucalyptus
  • Close all unscreened doors and windows to prevent mosquitoes from entering your home or space; repair broken or damaged screens

For more information about prevention, visit OCMVCD’s website: