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West Nile Virus Positive Mosquitoes Confirmed in Los Angeles County

PDF - PR_20230605_WNVMosquitoSample

This is the first positive West Nile virus mosquito sample within the Greater Los Angeles County Vector Control District service area for this year

Santa Fe Springs, CA (June 5, 2023) – The Greater Los Angeles County Vector Control District (GLACVCD/District) has confirmed a West Nile virus (WNV) positive mosquito sample in Los Angeles County. The positive mosquito sample was collected from a mosquito trap in the City of Burbank, confirming the presence of the virus in mosquito populations within the community.

“West Nile virus is spread among the wild bird populations and transmitted to humans through the bite of an infected mosquito,” said Steve Vetrone, director of scientific-technical services at GLACVCD. “This virus is endemic in our region which means we will always see virus activity in Los Angeles County.”

The native Culex mosquito is capable of transmitting West Nile virus and it is most active during dusk and dawn. Because there is no human vaccine for West Nile virus, residents must be proactive against mosquito bites by wearing insect repellent. There are different kinds of mosquito repellents available, but they do not all work equally well. The Centers for Disease Control and Prevention recommends products with the active ingredients DEET, Picaridin, IR3535, or oil of lemon eucalyptus as being safe and effective when used according to the labels.

“We encourage residents to protect themselves by applying insect repellent with one of the recommended active ingredients at 15% or higher when outdoors, particularly at dusk and dawn,” said Vetrone. “Residents can also wear loose-fitting long sleeves and pants to help deter bites.”  

Mosquito control is a shared responsibility and residents must take an active role in reducing the threat of WNV in their neighborhoods by taking these additional steps:

  • Eliminate standing water in clogged rain gutters, rain barrels, discarded tires, buckets, watering troughs or anything that holds water for over a week.
  • Ensure that swimming pools, spas, and ponds are properly maintained.
  • Change the water in pet dishes, bird baths and other small containers weekly.
  • Request mosquitofish from your local vector control district for placement in ornamental ponds.
  • Report neglected (green) swimming pools in your neighborhood to your vector control district.

For an extensive list of common indoor and outdoor sources and recommended solutions, visit For more information, residents can contact the Greater Los Angeles County Vector Control District at 562-944-9656, online at, or on social media: Facebook, Twitter, Instagram


Media Contacts

Caroline Gongora, Acting Public Information Officer | | 562-967-9030