"Residents should continue to take precautions to avoid mosquito bites.”State health officials announced Tuesday that the first human case of West Nile virus and the first animal case of Eastern Equine encephalitis, or EEE, of the season have been diagnosed in Massachusetts.
The person diagnosed with West Nile virus is a man in his 40s who was exposed in Hampden County, according to the Massachusetts Department of Public Health.
A horse was diagnosed with EEE in Plymouth, which has prompted the state to raise the risk level for the virus to high in the town and to low in Dedham, where mosquito samples also tested positive for EEE.
According to the state, there are currently two other communities — Carver and Middleborough — designated as high risk for EEE, a potentially fatal mosquito-borne infection that has no cure and reemerged in Massachusetts in recent years. Amesbury, Groveland, Halifax, Haverhill, Kingston, Merrimac, Newburyport, Plymouth, Plympton, Salisbury, Wareham, and West Newbury are all considered moderate risk for EEE, according to the state. The virus was detected for the first time this year in Carver in early July and has since been located in mosquitoes in Halifax, Kingston, Barnstable, Amesbury, and Haverhill.
The first mosquitoes carrying West Nile virus were detected on the South Shore in early July. Currently, the risk for the virus is considered moderate in the Greater Boston area and in parts of Bristol, Essex, Hampden, Plymouth, and Worcester counties, according to the state, which has a dashboard tracking risk for the mosquito-borne illnesses.
“Historically, August and September are the months when most people are exposed to West Nile virus in Massachusetts,” Public Health Commissioner Robbie Goldstein said in a statement. “This is also the first year with elevated EEE activity since our last outbreak in 2019 and 2020. Populations of mosquitoes that can carry and spread these viruses are large this year and we continue to see increases in the number of EEE- and WNV-positive mosquito samples throughout the state. Residents should continue to take precautions to avoid mosquito bites.”
In 2019, there were 12 cases of EEE in the state and six people died. In 2020, there were five human cases and one death from the virus. So far, there have been no human cases of EEE since 2020.
State health officials are urging residents to take steps to avoid mosquito bites, including by using insect repellent, being aware of peak biting times (dusk to dawn), and wearing long sleeves, pants, and socks to cover your skin. Draining standing water around your home and installing or repairing screens can also help protect against mosquito bites, officials said.
“Animal owners should reduce potential mosquito breeding sites on their property by eliminating standing water from containers such as buckets, tires, and wading pools – especially after heavy rains,” the state advises. “Water troughs provide excellent mosquito breeding habitats and should be flushed out at least once a week during the summer months to reduce mosquitoes near paddock areas.”