More mosquito-borne illnesses reported in Mass.: Here’s the latest tally

New cases of EEE and West Nile virus were found in Middlesex County, as officials warn the public to take precautions.

Massachusetts public health officials announced Thursday that they had detected one new case of eastern equine encephalitis (EEE) and one new case of West Nile virus.

Both cases are men in their 70s, the Department of Public Health said in a release. The man with EEE was exposed in central Middlesex County, while the man with West Nile virus was exposed in southern Middlesex County.

Both mosquito-borne viruses have been on the rise in Massachusetts and nearby areas lately. The West Nile case announced Thursday is the seventh in the state this year, and the EEE case is the third.

DPH officials raised the EEE risk level to “high” in Acton, Ayer, Boxborough, Carlisle, Littleton, and Harvard. The West Nile risk levels were raised to “high” in Stoneham and Wakefield.

The DPH publishes interactive maps online that lay out where the risk levels are highest. The current risk level for EEE is currently “critical,” the highest level, in four Worcester County towns: Oxford, Douglas, Sutton, and Webster. No towns are currently labeled with a “critical” risk level for West Nile, but Boston and other parts of eastern Massachusetts are at a “high” risk level.

Both viruses can be very dangerous. News broke earlier this week that a New Hampshire man is fighting for his life after testing positive for EEE, West Nile, and St. Louis encephalitis. He was hooked up to a ventilator in the intensive care unit for weeks and underwent a tracheotomy. A GoFundMe page has raised almost $38,000.

In August, a New Hampshire man died at Massachusetts General Hospital after contracting EEE. Steven Perry was just 41.

EEE is rare but very serious. About 30% of people who develop severe eastern equine encephalitis die, and many survivors suffer from ongoing neurologic problems, according to the CDC. Most people infected with EEE do not develop symptoms. Those that do can get a fever with accompanying chills and body aches or, in more serious cases, neurologic disease.

West Nile virus is the leading mosquito-borne disease in the continental U.S. Most people infected do not feel sick, but about one in five develop a fever or other symptoms. About one out of 150 infected people develop a serious, and sometimes fatal, illness.

There have been 88 EEE-positive mosquito samples collected in Massachusetts this year, mostly in Plymouth and Worcester counties. There have been 299 West Nile-positive mosquito samples found throughout the state this year. The last major outbreak of EEE occurred in 2019 and 2020, resulting in 17 human cases and seven deaths.

“Mosquito behavior starts to change in September,” State Epidemiologist Catherine Brown said in a statement Thursday. “They will be less active during cooler temperatures. However, during periods of warmer weather, such as are being forecast for the end of next week, mosquitoes will be out and looking for their next meal.”

There are no vaccines to prevent either EEE or West Nile, but measures can be taken to protect oneself from mosquito bites. Repellents with EPA-registered ingredients like DEET, permethrin, picaridin, or oil of lemon eucalyptus can be effective but should not be used on young children. Wearing long sleeves, long pants, and high socks while outdoors is recommended.

The hours between dusk and dawn are peak mosquito hours, and people should consider rescheduling outdoor activities set to take place during evening or early morning hours.

Mosquitoes lay eggs in standing water, so officials recommend that people limit the number of places that they can breed around one’s home. Items that hold water should be drained or discarded. Rain gutters and drains should be checked regularly. Screens on doors and windows should be checked and repaired if needed.

Animals can also contract EEE and West Nile, so owners should monitor their animals for symptoms and take measures to keep them indoors or away from standing water.