November 2025 Newsletter

Staff highlights - Devon and Rachel

We are fortunate to have dedicated staff passionate about protecting San Mateo County residents from mosquitoes and the diseases they can carry. We'd like to let you get-to-know our staff and why they love their work. This month, we are highlighting Devon and Rachel.

Click here to learn more about Devon MacDonald, Vector Control Technician

Click here to learn more about Rachel Curtis-Robles , Communications Director

Vector Control Technician Devon

Communications Director Rachel

Summer Staff

Six people in uniforms stand together in front of a white truck parked in a lot. — Staff Virgil, Evrest, Anthony, Ric, Kyle, and Galen were our seasonal catch basin super stars in summer of 2025!

During the warm summer months, our seasonal catch basin treatments are key to preventing the growth of mosquitoes in the storm drain system. (Learn more about our summer work.) These types of mosquitoes are the main West Nile virus vector in our County. As the weather cools and the winter rains start naturally flushing out these drains, our summer catch basin treatments come to an end. Mosquitoes are not able to grow in the storm drain system when water from the rains regularly flushes the drains and when overnight temperatures are low.

A man in a uniform with name tag "Sean" and patch of "San Mateo County Mosquito & Vector Control" with trees in the background. — Summer laboratory staff Sean was a key part of our invasive Aedes surveillance this summer!

A person in a beige uniform with name tags, standing in front of a mosquito chart. — Summer laboratory staff Alex was a key part of our invasive Aedes surveillance this summer!

We would like to say a big 'THANK YOU' to all of our summer staff. We had 6 staff driving Jeeps to treat catch basins to help prevent West Nile virus. Over the summer, they checked and/or treated 25,768 catch basins throughout the County; many were checked every two weeks. This totaled to 118,769 treatments in summer of 2025. These treatments keep Culex pipiens mosquito populations low, drastically reducing our residents' risk of West Nile virus. Our summer laboratory staff, Sean and Alex, set and checked traps for invasive Aedes aegypti and Culex mosquitoes. They set multiple traps each week, totaling thousands of nights'-worth of traps in summer 2025. All summer staff played critical roles in protecting public health - thank you!

Keeping an Eye Out - Spotting Other Issues

Our staff are always keeping an eye out for vector-related issues. Sometimes we are called out for one type of request, and we find another issue. We do our best to help residents with issues, regardless of whether or not they were aware before our visit. Click here for a few examples.

Check Your Sump Pump and Gutters

Photograph of the edge of a roof and the gutter partially clean but with some leaves and dirt remaining. A gloved hand holds a handful of leaves and dirt that was removed from the gutter. There is a pail in the background where more leaves and dirt are.

As the rains start, be sure to check your sump pump and gutters to prevent expensive damage later! If you have a crawlspace under your home, check to be sure the sump pump works. A sump pump can help your crawlspace stay drier during a big winter storm, preventing mold, damage, and mosquitoes. Check your roof rain gutters to clear out any leaves or debris so that your gutter can work properly during a rain event - this will also help keep your home from collecting water in places that might result in water damage and...you guessed it...mosquitoes. A little preventative maintanence can go a long way to protecting your home from damage and mosquitoes this rainy season.

West Nile Virus updates - Stay informed

Current West Nile virus information for San Mateo County

As of early October residents have reported 494 dead birds in San Mateo County to the West Nile Virus Call center (https://westnile.ca.gov/ or 1-877-WNV-BIRD). Of those, 136 were in testable condition and tested in our laboratory. None of the dead birds collected in San Mateo County have tested positive for West Nile virus so far in 2025. Visit our webpage to stay up-to-date with San Mateo County information. To stay up-to-date with statewide information, visit the webpage with California state-wide data.

No mosquitoes have tested positive for West Nile virus yet this year in San Mateo County. As of early October, our staff have collected and tested over 3,600 mosquitoes in 2025. West Nile virus has been found in mosquitoes in other counties in Calfornia, so if you are traveling don't forget to take your mosquito repellent and follow other tips to prevent mosquito bites and the diseases they can spread.