Eastern Equine Encephalitis (EEE) and West Nile virus (WNV) have been detected in mosquitoes in Massachusetts and Connecticut for the first time this year. The Massachusetts Department of Public Health reported the detection of EEE in mosquito samples collected on June 30, 2024, from Carver, Plymouth County. No human or animal cases have been reported yet. In response, six towns in Massachusetts - Carver, Kingston, Middleborough, Plymouth, Plympton and Wareham - have increased their EEE risk level to 'moderate'. The last time EEE infected humans in Massachusetts was in 2020 when five people contracted the illness and one died. In contrast, Connecticut Governor Ned Lamont announced the first positive West Nile virus test results for the season on June 27, 2024, from New Haven. No human cases have been reported yet.
EEE is a rare but serious and potentially fatal disease that is generally spread to humans through the bite of an infected mosquito. The last outbreak cycle in Massachusetts occurred in 2019-2020 when there were 12 human cases and six deaths. WNV can also cause serious illness, and there are no vaccines or medicine to prevent or treat these diseases.
To prevent mosquito bites, health officials recommend using mosquito repellent with DEET or picaridin when spending time outdoors. Long sleeves, pants, and socks should also be worn. Rescheduling outdoor activities during peak mosquito feeding times around dawn and dusk in high-risk areas is advised. Homeowners should check their properties for standing water where mosquitoes lay their eggs and empty unused flower containers, wading pools, rain gutters, and drains.
Animal owners are required to report animals that may have West Nile virus or EEE to the state Department of Agricultural Resources and the Department of Public Health. Horse owners should keep horses in indoor stalls at night to reduce their risk of exposure. Animal owners should also flush out water troughs at least once a week during the summer.
Symptoms of EEE include fever, headache, vomiting, diarrhea, seizures, behavioral changes and drowsiness. WNV symptoms include fever with severe headache and body aches. In some cases, it can cause neurological symptoms such as disorientation or paralysis.
The peak time for mosquito bites is between dusk and dawn.
