San Gabriel Valley mosquito district briefs Temple City on dengue, West Nile and new control tools

Ana Medina Diaz, director of communications for the San Gabriel Valley Mosquito & Vector Control District, told the Temple City City Council on May 19 that the district’s work centers on surveillance and prevention to reduce mosquito-borne disease risk.

"Our mission is very simple. It is to protect the community from mosquitoes and other vectors that can spread disease," Medina Diaz said, describing the agency’s surveillance (trapping, dead-bird collection and testing) and operations that prioritize larval control in standing water and inspections of thousands of local pools.

She told council members the district serves about 1.5 million residents across 26 cities and responds to public-health threats including West Nile virus and an increase in locally acquired dengue. The district uses targeted operations, resident consultations and education programs for schools. For emergency events—Medina Diaz cited recent wildfire burn areas with many abandoned pools—the district said it coordinated with state and local partners to treat pools and limit mosquito breeding.

Medina Diaz also described pilot programs for invasive Aedes mosquitoes that can carry dengue. One example is a sterile-insect technique pilot launching this year in the Bassett area, she said, in which mass-released, non-biting male mosquitoes are intended to reduce future hatch rates.

Council members asked about blackflies and disease risk, and Medina Diaz clarified that biting blackflies (sometimes called buffalo gnats) are distinct from household flies and are chiefly a foothill/riverine issue; they are not known to transmit disease locally. She explained symptoms of West Nile virus (generally mild, with older or immunocompromised residents at higher risk for severe illness) and said dengue can cause high fever and severe pain; treatment focuses on symptom management. Medina Diaz emphasized there is no general-population vaccine for West Nile and that dengue virus vaccines are only available in endemic areas.

On code enforcement and 'green' or stagnant pools, Medina Diaz said district technicians coordinate with local code enforcement officers: staff make multiple outreach attempts and seek voluntary compliance before abatement, and the district provides free property consultations and mosquito-fish for ponds as biological control.

Medina Diaz closed by offering the district as a free, funded public resource and inviting residents to report standing water or request consultations; she said the district issues real-time alerts when disease activity is detected.

The council did not take formal action on the presentation; the district’s materials were received and council members thanked the presenter for the briefing.