A mosquito-borne disease is spread to people by the bite of an infected mosquito. West Nile virus and eastern equine encephalitis (EEE) are two mosquito-borne diseases present in Massachusetts. The Cambridge Public Health Department (CPHD) leads the city’s response to the risks posed by mosquito-borne diseases.

The Massachusetts Department of Public Health Mosquito-Borne Disease page provides a risk map and testing results for Cambridge and the state. Additionally, the Center for Disease Control (CDC) provides general information for both West Nile virus and EEE.

What You Can Do

You can protect yourself from mosquito-borne diseases during spring, summer and fall by avoiding mosquito bites and preventing mosquitoes from breeding in or around your home.

Protect Yourself and Your Family

  • Apply Insect Repellent when Outdoors. Apply a thin coat of insect repellent containing DEET or Picaridin to clothing and exposed skin.* Read the instructions on the label carefully before using the product. Do not use on children under two months of age.
  • DEET Alternatives are available. Massachusetts Department of Public Health provides an excellent overview of repellent options and safety tips.
  • Be Aware of Peak Mosquito Hours. The hours from dusk to dawn are peak biting times for many mosquitoes. Consider rescheduling outdoor activities that occur during the evening or early morning.
  • Clothing Can Help Reduce Mosquito Bites. Wearing long-sleeves, long pants and socks when outdoors will help keep mosquitoes away from your skin.
  • Cover your baby stroller or playpen with breathable netting when outdoors.
  • For more information on how to protect yourself, see the Massachusetts Department of Public Health’s Prevention Tips.

*When using repellent on a child, apply it to your own hands and then rub it on your child. Avoid your child’s eyes and mouth, and use it sparingly around the ears. Remember to keep repellents out of reach of children.

Related information

Insect Repellent Use and Safety (CDC)

Insect Repellent Fact Sheets (MA Dept. of Public Health)

Online Tool to Find the Repellent Right for You (EPA)

Mosquito Bite Prevention Handout (CDC)

Mosquito Bite Symptoms & Treatment (CDC)

Reduce Mosquito Breeding Areas

Protect Your Home

Prevent mosquitoes from entering your home by making sure your window and door screens are in good repair and are tightly attached.

Protect Your Yard

Mosquitoes lay their eggs in still water. Reduce mosquito breeding places in your yard by emptying or covering any items that hold water. More tips:

  • Empty any items that hold water, such as flower pots, birdbaths, swimming pool covers, buckets, cans, and barrels.
  • Clean rain gutters, leaves in downspouts, and pooled water on flat roofs.
  • Remove unused tires and other items that could collect water.
  • Remove containers that may hold water in places that are hard to see, such as under bushes, porches, decks, or stairs.
  • Mosquito Dunk is a natural bacterium sold in hardware stores. These tablets can be added to stagnant water that cannot be emptied easily such as rain barrels or small pools of water, and they do not harm people nor beneficial pollinators (bees, butterflies, beetles, and many other insects).

When you can’t get rid of stagnant water by sweeping or other methods (such as Mosquito Dunk), please report the address or location of the puddle or still water source to the appropriate city department:

  • Private property: Cambridge Public Health Department, 617-665-3838
  • Public property: (roads, parks): Cambridge Department of Public Works, 617-349-4800
  • Construction sites: Cambridge Inspectional Services Department, 617-349-6100

Protecting Our Neighborhoods

CPHD leads the city’s response to the risks posed by mosquito-borne diseases. The health department works closely with the city’s Department of Public Works and Inspectional Services Department to reduce mosquito-borne risk during the mosquito season (May through early November).

The use of mosquito larvicides—which stops mosquitoes from maturing to adulthood—is generally considered more effective than spraying for adult mosquitoes. Through an agreement with the East Middlesex Mosquito Control Project, the city’s larviciding activities include:

  • Treating the city’s municipal storm drains with larvicide and coordinating with Harvard and MIT to ensure store drain treatment on these properties.
  • Applying hand-held non-chemical larvicide to treat areas that are considered prime habitats for mosquito breeding. 

Updated: August 11, 2022