March 2022 Newsletter

New technicians and new zones

This month, we welcomed two new vector control technicians to our team. Justin has worked with the District in various roles since 2016; Vanessa has a background in envrionmental health. We are glad to have them on our team!

Every few years, our staff rotate their coverage zones; the start of this month was time for one of our zone changes. You may see a different friendly face in your neighborhood. You can see the new technician for your area here.

A photo of 12 people in uniforms and clothing with San Mateo County Mosquito and Vector Control branding. The people are standing in front of a tan wall and all looking at the camera. — Our Operations staff consists of 10 technicians, 1 supervisor, and 1 director. Our Operations team has over 100 combined years of experience conducting mosquito and vector control in San Mateo County.

Tick Collecting and Outreach

Laboratory staff continued winter surveillance for adult western black-legged ticks (Ixodes pacificus) in February. Ticks are collected by dragging a one-meter square sheet of white flannel over the vegetation alongside trails, using a technique called “flagging.” The ticks will be tested for the presence of Borrelia burgdorferi, the pathogen responsible for Lyme disease, as well as other disease causing bacteria, Borrelia miyamotoi and Anaplasma phagocytophilum.

In addition to our usual tick collections, our staff have been conducting tick-bite prevention educational outreach to scout groups, parks and open space staff, and others in outdoor environments. Presentations are tailored to each audience and can include an interactive activity teaching how to choose a safe and effective repellent. If your group would like a tick-bite prevention talk, please reach out to our Public Health Education and Outreach Officer, Rachel Curtis-Robles (rcurtis@smcmvcd.org).

Top-down view of some small children looking down at a white cloth lying on the ground along a trail. — A group of elementary-school aged Girl Scouts looking at a tick collected from along a trail.

Person in tan uniform walking away from the camera down a wooded trail. The person is holding out a stick that has a square white cloth about 3ft tall by 3ft wide on it. The cloth is being dragged over the vegetation along the edge of the trail. — Vector Ecologist Tara Roth flags for ticks along a trail using a white cloth to collect 'questing' ticks (ticks seeking a blood meal source).

Image showing four circles in a circular shape. The top circle has an adult mosquito, with the word "adult", then there is a small arrow pointing to the next right circle, which contains a photo of many tiny mosquito eggs, with the word "egg", another small arrow points down and to the left to the next circle, which is a photo of a mosquito larvae hanging upside down in the water (it looks a little like a caterpillar - long and thin with some small hairs), then a small arrow to the left and up pointing to the final circle, which says "pupa" and has a photo of a mosquito pupa (looks a little like a small oval with an eye spot and tiny horn). A final arrow points back to the adult mosquito. The egg, larve, and pupa circles are on a blue background, meant to show how these three stages need to be in water to survive. — The mosquito lifecycle can occur in as little as one week! Don't forget to dump or drain standing water around your house at least once a week!

Mosquito Surveillance

Adult Mosquitoes

Culex pipiens abundance was higher than average this February (average of 8.5 mosquitoes per night of trapping compared to a five-year average of 1.0 mosquito per night of trapping). The elevated numbers of Culex pipiens were from a source at a water treatment plant in Redwood Shores, combined with unusually warm temperatures. The mosquito breeding source is now under control. All other abundances are low and close to the five-year average. Read more about mosquito surveillance here.

Larval Mosquitoes

This February, 141 larval samples were collected in the field by vector control technicians and submitted to the lab. A District vector control technician uses a dipper to take a sample of the water and visually inspects it for mosquito larvae. If larvae are present, the technician transports the sample to the laboratory for counts and identification. Read more about mosquito surveillance here.

Service Requests

The most common service requests in February 2022 were for mosquito issues and rodent.

West Nile Virus

West Nile virus activity is generally very low during the winter months. For up-to-date information about West Nile virus in California during the winter, visit CDPH's website.