The Greater Los Angeles Vector Control District (GLACVCD) is alerting residents to heightened West Nile virus (WNV) activity across Los Angeles County and reminding the public to take precautions against mosquito bites. WNV-positive mosquito samples and dead birds have surpassed last year’s levels and are trending above the five-year average, while the Los Angeles County Dept. of Public Health has reported over 100 human cases and five deaths. The elevated activity comes amid increased WNV activity across California and other parts of the country. 

“West Nile virus is cyclical and the level of activity we see can look different each year,” said Steve Vetrone, the district’s assistant general manager of Vector Management Services. “This year, we have seen increased disease activity across the region, with activity beginning earlier than usual. An extremely mild winter where rainfall was interspersed with unusually warm weather earlier in the year are among the environmental factors that have contributed to these conditions.” 

Native Culex mosquitoes can transmit WNV and are most active from dusk to dawn. Although Culex mosquito abundance within the district remains below the five-year average, WNV activity is significantly elevated. So far this year, the district has detected 384 WNV-positive mosquito samples and 78 WNV-positive dead birds, compared with 104 positive mosquito samples and two positive dead birds at this time last year. In response to the elevated activity, GLACVCD mobilized staff across its Operations, Scientific-Technical, and Communications departments. 

“After seeing increased activity early in the season, we stepped up inspection and control efforts along with mosquito monitoring, and public outreach,” added Vetrone. “The control efforts have helped keep WNV transmitting Culex mosquito populations low. With WNV activity high, our work continues, and residents can do their part by preventing mosquito bites and eliminating standing water.” 

With no human vaccine currently available for WNV, preventing mosquito bites is the most important step residents can take to reduce their risk. Residents should use an effective insect repellent when outdoors, particularly from dusk to dawn when Culex mosquitoes are the most active. Simple actions can help protect individuals, families, and communities from WNV: 

Use insect repellent containing at least 15% DEET, Picaridin, IR3535, or oil of lemon eucalyptus. 

Wear loose-fitting, long-sleeved shirts and pants. 

Remove standing water around the home to prevent mosquitoes from breeding. 

Report neglected or green swimming pools in your neighborhood to your local vector control agency. 

Report dead birds to the California Dept. of Public Health at westnile.ca.gov 

 or by calling 1-877-WNV-BIRD. 

For more mosquito control information, residents can contact the Greater Los Angeles County Vector Control District at (562) 944-9656 visit GLAmosquito.org, or follow the district on social media.

Submitted by GLACVCD