Division of Environmental Health

CONTACT INFORMATION: Our Environmental Health Services office at 10777 Main Street in Fairfax is open during regular business hours 8 a.m. - 4:30 p.m., Monday - Friday. Clinic services are not offered at this location.
703-246-2201 TTY 711
10777 Main Street
Fairfax, VA 22030
Pieter A. Sheehan, REHS
Director, Division of Environmental Health

Disease Carrying Insects Program Activities

Two Disease Carrying Insect Program staff members sit at desk. One is looking into a microscope.Fairfax County Health Department’s Disease Carrying Insects Program works to lower the threat of diseases spread by mosquitoes and ticks. The program uses an integrated approach to pest management that includes active monitoring, control measures, and public outreach and education to help protect county residents. Learn more about the work we do and how we can help you.

Vector Monitoring

What Is a Vector?

Vectors are animals or insects that spread infections by transmitting pathogens from one host to another. Fairfax County’s Disease Carrying Insects Program is focused on disease spread by mosquitoes and ticks.


The Health Department collects mosquitoes and ticks as part of routine monitoring activities. The data we get helps inform our program activities, including mosquito control and outreach messaging.

We trap hundreds of thousands of mosquitoes. From May to October, we set more than 4,000 traps throughout the county to collect mosquitoes. Mosquito samples, or pools, are tested at the Health Department Laboratory for West Nile and Zika.

We monitor mosquito breeding sites. We monitor mosquito "breeding sites" or larval habitats for evaluation and control purposes.

We collect and analyze ticks. We collect ticks and then test them for pathogens such as  Lyme disease. Collected ticks are identified by species and life stage (larvae, nymph, or adult) before being sent to the Health Department laboratory for testing.

Read more about the Health Department’s mosquito and tick monitoring activities.

Human Case Monitoring

Human cases of mosquito- and tick-borne diseases are reported to the Health Department through passive and active monitoring activities, which are described in the Health Department's Communicable Disease Summary Report.

Vector-borne diseases commonly reported in Fairfax County include:

Other vector-borne diseases that are not commonly reported or may be identified in travelers returning from other states or countries where these diseases may occur include:

Whether you are traveling across Virginia, across the U.S. or internationally, take steps to protect your health when traveling. Pack to protect yourself against vector-borne diseases.

Mosquito Management

Mosquito management uses source reduction techniques and larvicides to control mosquitoes on public property. “Spraying” for adult mosquitoes is carried out only when circumstances warrant.

Proactive Mosquito Control

County-maintained stormwater dry ponds are routinely inspected by Health Department staff for mosquito breeding from April through October. These sites are treated with larvicides (insecticides that kill mosquitoes before they become flying adults) to control immature mosquitoes as needed. We also encourage county residents to eliminate mosquito larval habitats around their homes, in their communities and neighborhoods.

Reactive Mosquito Control

Routine surveillance activities may indicate the need for additional mosquito control activities. If the risk of disease transmission to humans is high, the County coordinates larval and/or adult mosquito control measures in public areas as necessary. The Health Department does not spray for nuisance mosquitoes. Only under exceptional circumstances will the Health Department spray insecticides to control adult mosquitoes, and in these rare cases, the spray will target only those mosquitoes that transmit disease to humans. All products used by our program are registered for such use by the U.S. Environmental Protection Agency.

Community Outreach and Education

We are out in the community all year long, educating people about protecting themselves against vector-borne illnesses. Want one of our insect biologists to visit your school? Need education materials? A table at your next event? Let us know how we can get involved.

Annual Reports

The Disease Carrying Insects Program's Annual Report provides a summary of program activities for each year and a framework for the upcoming year.

2017 | 2016


Contact Us

If you would like more information on any of our services, would like to request a free yard inspection or have any other questions, please email us or call 703-246-2201, TTY 711.

Report a Stormwater Drainage Problem

  • To report a problem with a county storm drain, or for a determination of who maintains a storm drain, use the storm drain flooding report form or call the Maintenance and Stormwater Management Division at 703-877-2800, TTY 711. Additional information is available on the Storm Drainage System web page.
  • For issues involving storm drains in or along public streets, please contact the Virginia Department of Transportation (VDOT) at 1-800-367-7623, TTY 711, or use their online work request form.

Request Stormwater Retention Pond Maintenance

  • If you notice that a public stormwater management facility does not appear to be functioning properly, please call the county’s Maintenance and Stormwater Management Division at 703-877-2800, TTY 711, to report the specific problems. You may also submit a maintenance request form online. When submitting a complaint, please include the facility identification (ID) number usually found on the pond sign for publicly maintained facilities. Having the ID number helps employees speed up their response.

Report a Problem With Property Maintenance

  • To report an unmaintained, private, residential swimming pool or to water that might be pooling on a residential lot, please call Department of Code Compliance at 703-324-1300, TTY 711.

Other Disease Carrying Insect Program Information

Complaints may be reported to the Health Department through the county's Planning and Land Use System.


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