Fourth Human EEE Case Confirmed In MA In Worst Outbreak In 5 Years

MASSACHUSETTS — A fourth human case of Eastern equine encephalitis was confirmed in Massachusetts on Monday in what the state Department of Health is saying is the worst outbreak of the mosquito-borne disease in five years.

The latest confirmed case is a man in his 50s from an area of Middlesex County already designated as being at high risk for EEE.

The last outbreak of EEE in Massachusetts occurred in 2019-2020 and resulted in 17 human cases with seven deaths. In addition to this year's four human cases, EEE has also been identified in two horses in Massachusetts.

"This year's EEE season has been particularly active and is generating a lot of concern in communities across Massachusetts," said Public Health Commissioner Robbie Goldstein, MD, PhD. "While EEE remains a rare disease, the risk level is elevated in multiple communities. With the weather forecast showing warm, sunny weather for the rest of the week, we recommend that people take necessary precautions in areas of elevated risk.

"This includes recommending that residents and towns in areas at high risk for EEE reschedule their evening outdoor events to avoid peak mosquito biting hours from dusk to dawn."

• Peabody To Spray For Mosquitoes At Parks, Fields After EEE Detected

There have been 91 EEE-positive mosquito samples in Massachusetts this year. While most activity has been focused in Plymouth and Worcester counties, infected mosquitoes have also been found in Bristol, Essex, and Middlesex counties.

There were no additional risk level changes associated with Monday's announcement.

EEE is transmitted to humans through the bite of an infected mosquito.

Residents throughout the state are advised to avoid going outdoors, especially in wooded areas, around the hours of dusk and dawn when mosquito activity is highest and to wear long clothing when out at those times.

The state DPH advised the use of a repellent with DEET, permethrin, picaridin or oil of lemon eucalyptus, according to the instructions on the product label.

Residents are also asked to clear standing water on properties that can be used as mosquito breeding areas.

(Scott Souza is a Patch field editor covering Beverly, Danvers, Marblehead, Peabody, Salem and Swampscott. He can be reached at [email protected]. X/Twitter: @Scott_Souza.)