West Nile virus has muscled its way into the holiday conversation in Orange County this week, after infected mosquito samples were confirmed in Costa Mesa and Westminster just days before July 4. The finds land during a mosquito season that local vector-control officials say is already running well above the five-year average, a worrying backdrop for residents planning barbecues and park time this weekend.
"We are seeing a lot of mosquito activity in general this year, considerably more than usual," said Brian Brannon, spokesman for the Orange County Mosquito and Vector Control District. The agency has logged positive West Nile detections in multiple cities and, for now, has held off on rolling out truck-mounted adulticiding while it tracks trap results and sends inspectors to hunt for breeding sites, according to NBC Los Angeles.
Where positive mosquitoes were found
The Orange County Mosquito and Vector Control District's latest trap data shows West Nile-positive mosquito pools in Newport Beach, Buena Park, Costa Mesa, Garden Grove, Santa Ana, Seal Beach, Huntington Beach, Cypress, Fullerton and Westminster. Fullerton recorded five positive pools and Buena Park four, while most other cities turned up a single positive pool. Officials say these results line up with a broader spike in mosquito counts across the county this season, according to the Orange County Mosquito and Vector Control District.
In Costa Mesa, a positive mosquito sample was collected near Fairview Park. City officials say inspectors will be combing the park and nearby neighborhoods to track down breeding sites. "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," Robert Cummings, the district's director of scientific services, said in a city release, according to the City of Costa Mesa. The release also urges residents to dump and drain containers of standing water and to clean bird baths and pet bowls weekly.
In Westminster, surveillance traps placed in a neighborhood bordered by Hazard Avenue, Magnolia Street, Bolsa Avenue and Newland Street turned up a positive mosquito sample. The city says inspectors will be in the area looking for stagnant water and other breeding sources. If more positive samples keep coming in, "adult mosquito control may be conducted in the future," according to the City of Westminster.
Statewide picture
The regional trend is not much more comforting. The California Arbovirus Surveillance Bulletin recently reported 68 new West Nile-positive mosquito pools in a single week and listed Orange County among the counties with recent detections. In total, the bulletin shows 135 positive mosquito pools so far this year across California, a reminder that WNV activity is widespread; the full breakdown is available in the weekly update from the California Department of Public Health.
How to protect yourself
Officials are repeating a familiar but important checklist: dump standing water at least once a week, scrub out bird baths and pet water bowls, repair or replace torn window and door screens, and use EPA-registered mosquito repellent when spending time outside. Those specific steps are laid out in the city release from the City of Costa Mesa.
For an extra layer of protection, Brannon recommends using a fan to help keep weak-flying mosquitoes away and choosing repellents that are effective against species that can bite through clothing, according to NBC Los Angeles.
So far, no human West Nile virus cases have been reported in Orange County this year, according to the Orange County Health Care Agency's epidemiology page. Health officials say residents who develop fever, severe headache, confusion or other concerning symptoms should contact a healthcare provider. Updated maps of local virus activity and reporting guidance are available from the Orange County Health Care Agency and the Orange County Mosquito and Vector Control District.
