Mosquito Activity Uptick In Los Angeles County Increases Risk Of West Nile And Other Viral Infections


The Greater Los Angeles Vector Control District is warning residents that mosquito season in the area is not over just yet.

Ongoing mosquito activity is continuing to bring additional human West Nile infections, along with the threat of other illnesses transmitted by new invasive populations of Aedes mosquitoes.

The district collected 49 West Nile-positive mosquito samples this year compared to 309 from the same period last year. However, the Los Angeles County Department of Public Health Department has reported 28 human infections this year, and that the number is expected to increase.

West Nile virus is transmitted by the native Culex mosquitoes that are most active and bite between dusk and dawn. Residents are urged to use mosquito repellents with DEET in them if they are spending time outdoors during the early morning and evening hours.

This month, public health officials in San Bernardino County confirmed the first locally acquired human case of West Nile virus in the High Desert. This is the first human case in the county since 2013.

Aedes mosquitoes

Vector control officials are also saying that the Aedes mosquitoes are being increasingly detected in more San Fernando Valley communities. These mosquitoes typically tend to strike during the day.

So far, no serious illnesses have been reported. But Aedes mosquitoes can transmit viruses that cause Zika, dengue fever, chikungunya and yellow fever.

Southern California is dealing with “a new normal” when it comes to mosquito activity, said Kelly Middleton with the Greater Los Angeles Vector Control Department.

“These are the same mosquitoes that make the summers miserable in the southeast United States. There is no magic bullet to get rid of them, and control is extremely difficult unless everyone works together to remove standing water from around homes, schools, businesses, and public areas.”