Press release

California Mosquito and Vector Awareness Week Serves to Remind Residents of a Different Threat to Public Health

Apr. 20th, 2020

While your mind is likely on a different virus right now, San Mateo County Mosquito and Vector Control District, along with the Mosquito and Vector Control Association of California (MVCAC) and mosquito and vector control districts across the state, are observing California Mosquito and Vector Awareness Week this week. While they do NOT transmit COVID-19, mosquitoes do transmit other diseases, including West Nile virus.

Mosquitoes are present year-round in the Bay Area, but the risk of West Nile virus is highest in the summer, when warm weather and standing water create ideal conditions for mosquito emergence. Mosquitoes can lay their eggs in sources of water as small as a bottle cap and can complete their life cycle, from egg to adult, in about a week.

West Nile virus remains the largest mosquito-related public health threat in the state. In 2019, there were 225 human West Nile virus disease cases from 27 counties in California, including six human deaths. Since 2003, more than 7,000 human disease cases were reported including more than 300 deaths.

“An outbreak of West Nile virus will only add to the challenges we’re all facing today,” said San Mateo County Mosquito and Vector Control District’s Public Health Education and Outreach Officer Megan Sebay. “It’s very important right now for everyone to help out by dumping and draining standing water around their homes.”

To minimize exposure to mosquito bites and reduce the risk of West Nile virus:

  • Apply insect repellent containing EPA-registered active ingredients, including DEET, picaridin, oil of lemon eucalyptus, or IR3535, according to label instructions. Repellents keep mosquitoes from biting. DEET can be used safely on infants and children 2 months of age and older.
  • Dress in loose-fitting long sleeves and pants.
  • Install screens on windows and doors and keep them in good repair.
  • Eliminate all sources of standing water on your property, including in flower pots, old tires, buckets, pet dishes, and trash cans.
  • Repair leaking faucets and broken sprinklers.
  • Clean rain gutters clogged with leaves.
  • Report neglected swimming pools and day-biting mosquitoes to SMCMVCD by calling (650) 344-8592 or visiting

Beyond the risks posed by West Nile virus, climate change has facilitated the spread of two invasive mosquito species, Aedes albopictus and Aedes aegypti, throughout the state. These invasive mosquitoes are now established in 16 counties in California. Invasive Aedes exploit small and cryptic water sources and are vectors of Zika, dengue, chikungunya, yellow fever, and dog heartworm.  There are no human vaccines for chikungunya and Zika viruses, both of which are costly to treat and can have long-term health and financial consequences.

For more information on steps residents can take to prevent mosquito breeding, visit our website at or call (650) 344-8592.


Megan Sebay, Public Health Education and Outreach Officer

1351 Rollins Rd.

Burlingame, CA 94010

(650) 350-9360