This is the first confirmed detection of the virus in local mosquitoes in both Los Angeles County and California. 

Santa Fe Springs, CA (November 20, 2025) – The Greater Los Angeles County Vector Control District (GLACVCD/District) has confirmed the presence of dengue in Aedes mosquitoes in Los Angeles County. The dengue-positive mosquito was collected from surveillance traps in the community of Sun Valley, marking the first confirmed detection of dengue in the Aedes mosquito population in both the county and state. The District is working collaboratively with the Los Angeles County Department of Public Health to deploy targeted mosquito control measures aimed at reducing the risk of disease transmission.

 The Los Angeles County Department of Public Health has confirmed seven infections of locally acquired dengue in Los Angeles County for 2025. These individuals were detected in the areas of La Puente, Sun Valley, and North Hollywood. Although the risk for widespread dengue virus transmission in Los Angeles County remains low, everyone in the county should take proactive steps to prevent mosquito breeding and mosquito bites.

“The District is conducting enhanced surveillance, community outreach, and mosquito control efforts, including intensive door-to-door inspections and targeted treatments to reduce mosquito populations and limit further spread,” said Susanne Kluh, GLACVCD General Manager. “While the District is working hard to control mosquitoes, we need residents to do their part by taking preventative steps, including using insect repellent and eliminating all standing water around their home to keep themselves and their families safe.”

The detection of dengue-positive mosquitoes indicates increased risk of human infection in the Sun Valley area. The Los Angeles County Department of Public Health recommends that those who are experiencing symptoms or have been ill recently should visit their primary care providers and discuss dengue testing. Sun Valley residents without access to a provider can get a nursing appointment for dengue testing at a Public Health Clinic. To make an appointment, people in the area can call the Public Health InfoLine at 833-540-0473, 7 days a week from 8 a.m. to 8 p.m.

“Dengue can be prevented, and our most powerful tool is community action,” said Muntu Davis, MD, MPH, Los Angeles County Health Officer.

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

• Eliminate standing water inside and outside your home once a week.
• Toss unneeded containers that can hold standing water.
• Use insect repellent with any of the following CDC-recommended active ingredients at 15% or higher: DEET, Picaridin, IR3535, or Oil of Lemon Eucalyptus.

For more information regarding mosquito control, residents can contact the Greater Los Angeles County Vector Control District at 562-944-9656, online at www.GLAmosquito.org, or on social media: Facebook, X, Instagram, Nextdoor, and YouTube.

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About Dengue:

Dengue is a disease caused by a virus that spreads through the bite of an infected mosquito. Dengue is common in tropical and subtropical regions such as the Caribbean (including Puerto Rico), Central and South America, Southeast Asia, and the Pacific islands. Because the types of mosquitoes that spread dengue are common throughout many areas of the United States, including Los Angeles County, local spread of dengue can occur. Most cases in the county have been identified among those who have traveled to areas where dengue commonly occurs. However, local transmission has been a concern annually since 2023. Symptoms of dengue typically last two to seven days. Most people will recover after about a week. About one in twenty people with dengue can develop severe disease which can be life threatening. For more information, visit: ph.lacounty.gov/dengue.

About GLACVCD:

The Greater Los Angeles County Vector Control District is an independent special district formed under the authority of the California State Health & Safety Code to provide comprehensive mosquito and vector control services throughout the Greater Los Angeles area. Our mission is to promote healthy communities within the District's service area by countering the threat of mosquito and other vector-borne diseases through exceptional service, rigorous surveillance strategies, conscientious control measures, and comprehensive education efforts.