Mosquitoes with Dangerous EEE Virus Found in Massachusetts for the First Time in 2024

For the first time this year, mosquitoes in Massachusetts have tested positive for the Eastern equine encephalitis (EEE) virus, according to the state’s Department of Public Health.

The virus was detected in samples collected on June 30 in Carver, increasing the EEE risk level to moderate in Carver, Kingston, Middleborough, Plymouth, Plympton, and Wareham.

EEE is a rare but severe disease affecting people of all ages, transmitted through the bite of an infected mosquito. Massachusetts had 12 cases in 2019, resulting in six deaths, and five cases in 2020, with one death. There were no reported cases from 2021 to 2023.

“EEE activity in Massachusetts tends to occur in cycles,” said Dr. Catherine Brown, state epidemiologist. “Finding EEE in mosquitoes early in the season means the risk might increase as the summer progresses. Our mosquito surveillance program is essential for tracking the virus and alerting the public.”

This announcement comes shortly after West Nile virus was also found in mosquitoes earlier this week. Public Health Commissioner Robbie Goldstein highlighted the need for precautions to avoid mosquito bites.

How to Prevent Mosquito Bites:

• Apply insect repellent when outside.
• Be aware that mosquitoes are most active from dusk to dawn.
• Wear long sleeves, pants, and socks when outdoors to reduce exposure.
• Make your home mosquito-proof by removing standing water from containers like buckets and wading pools.
• Install or repair screens to keep mosquitoes out.

Protecting Your Animals:

• Flush out water troughs weekly during summer to reduce mosquito breeding.
• Keep horses in indoor stalls at night to reduce their risk.
• Talk to vets about mosquito repellents for animals and vaccinations for West Nile Virus and EEE.
• Report suspected cases of West Nile Virus or EEE in animals to the Department of Agricultural Resources, Division of Animal Health, and the Department of Public Health.