Somerville Health and Human Services is sharing that testing by the Massachusetts Department of Public Health (MDPH) has detected West Nile Virus (WNV) in mosquitoes collected from Somerville. Somerville remains at a “Low” risk level for WNV. The first WNV-positive mosquitoes in the state this year were collected on June 16, and 21 mosquito samples have now tested positive for WNV. There have been no animal or human cases of WNV reported in the state so far this season.

WNV is usually transmitted to humans by the bite of an infected mosquito. While WNV can infect people of all ages, people over the age of 50 are at higher risk for severe infection. Although Somerville’s risk is low, community members are still encouraged to take precautions to protect themselves from mosquito bites and mosquito-borne diseases. MDPH recommends the following safety measures:

Avoid Mosquito Bites

• Use insect repellent when you go outdoors. Products with DEET may be used on skin but should not be used on infants under two months of age and should be used in concentrations of 30% or less on older children. Use permethrin products on items such as clothing, shoes, bed nets, and camping gear. Permethrin should not be applied to skin. Other repellents, such as picaridin, oil of lemon eucalyptus, and IR 3535 have also been found to provide protection against mosquitos. Oil of lemon eucalyptus should not be used on children under three years of age. More information on choosing and safely using repellents can be found at mass.gov/info-details/mosquito-repellents.
• If weather permits, wear long sleeves, long pants, and socks outdoors to help keep mosquitoes away from your skin.
• If you can, schedule outdoor activities to avoid the hours from dusk to dawn when mosquitoes are most active. If you cannot schedule activities around these times, take steps to avoid being bitten by moving indoors, wearing protective clothing, or using repellent.

Mosquito-Proof Your Home

• Drain standing water from around your home. Many mosquitoes lay their eggs in standing water. Limit the number of places around your home for mosquitoes to breed by either draining or getting rid of items that hold water. Check rain gutters and drains, empty unused flowerpots and wading pools, and change water in birdbaths frequently.
• Install tightly fitting window and door screens or repair damaged screens to help keep mosquitoes outside.

Mosquito-borne Illnesses

Both WNV and Eastern equine encephalitis (EEE) are usually transmitted to people through the bite of an infected mosquito. Only a small number of mosquitoes are infected at any given time, so being bitten by a mosquito does not mean you will get sick. For more information on preventing mosquito-borne diseases, visit mass.gov/mosquito-borne-diseases.

The state does seasonal testing for WNV and EEE and updates town-specific risk levels where WNV- or EEE-positive mosquitoes are found. You can check risk maps throughout the summer at mass.gov/info-details/massachusetts-arbovirus-update.