State offers mosquito tips amid busy summer season

This year is expected to be an active season for EEE and other mosquito-borne diseases.

A slew of outdoor events across the state this summer — the FIFA World Cup, Sail Boston, the nation’s 250th birthday celebration, and countless fireworks displays — will attract large crowds, as well as some unwanted visitors: mosquitoes.

The Massachusetts Department of Public Health is urging residents and visitors to take simple, effective steps to protect themselves against mosquito-borne illnesses, particularly West Nile and eastern equine encephalitis, the two most common in Massachusetts.

Only a small fraction of mosquitoes carry disease at any given time, so a bite is certainly not a diagnosis, the DPH advises. But the illnesses that mosquitoes can transmit — particularly EEE — can be serious.

The good news is that protecting yourself is easy.

“Mosquitoes are a fact of summer in Massachusetts, but diseases like West Nile and EEE do not have to be,” said Public Health Commissioner Robbie Goldstein in a recent statement. “A little preparation, a little DEET, and little awareness can go a long way toward keeping summer safe, fun, illness-free — and a little less itchy.”

In Massachusetts, regular testing of mosquitoes begins in June, and the epidemiological picture changes week by week throughout the summer.

On June 25, the state announced the first detection of West Nile in Massachusetts this summer, from a mosquito sample taken on June 16 in the Berkshire County town of Clarksburg. So far, no human cases of West Nile have been reported this year, and no evidence of EEE has emerged yet.

Last year, the state recorded nine human cases of West Nile, most of which occurred toward the end of the summer. There were no human cases of EEE in 2025.

The DPH works closely with the mosquito control districts statewide to trap, test and track mosquito populations throughout the season. The risk levels by city and town, and positive results, are posted regularly on the Massachusetts Arbovirus Update page.

The DPH offers the following recommendations to try to avoid mosquito-borne illnesses:
• Repel: Use an EPA-registered repellent (DEET, picaridin, IR3535, or oil of lemon eucalyptus).
• Cover up: Wear long sleeves, long pants, and socks while out in peak areas, especially near wetlands or wooded edges.
• Mind the hours: Mosquitoes are most active from dusk to dawn, so it’s recommended to keep that window in mind when planning evening cookouts and outdoor events.
• Screen your home: Check window and door screens, since a small tear can be an open invitation to an unwanted flying guest.
• Dump standing water: Regularly empty birdbaths, clogged gutters, flowerpot saucers and kids’ toys, since any container holding water can become a mosquito nursery.

For more information, visit the DPH’s Mosquito-borne Diseases page, which is updated with new results, or call the DPH Division of Epidemiology at 617-983-6800. The DPH also has a web page with FAQs about mosquitoes in Massachusetts.