Four cases of Eastern Equine Encephalitis were confirmed in Massachusetts as of late September, and two—including one in a 5-year-old child—have been fatal, according to the Massachusetts Department of Public Health.
Five cases—four adults and one 4-year-old child—were confirmed in New Hampshire, according to New Hampshire's Department of Health and Human Services. One adult case, in a 20-year-old woman, has proved fatal.
Although Eastern Equine Encephalitis (EEE) is rare, it is a serious illness. The disease spreads to humans through a bite from an infected mosquito. Birds are the original source of infection, and mosquitoes can transmit the infection to horses, other animals, and humans after biting infected birds.
“We are advising people to limit their dusk and dawn activities,” said Elizabeth A. Talbot, M.D., deputy state epidemiologist of New Hampshire, in an interview. The department also has advised schools and day care centers to drain standing water on their property and encouraged parents to use insect repellent with DEET on children who are involved in outdoor activities after school. “It may be appropriate to spray to kill mosquitoes in some population-dense areas with high mosquito activity,” Dr. Talbot said.
Since there is no specific treatment for EEE, patients are treated with standard supportive care. Symptoms of EEE generally occur 4–10 days after being bitten by an infected mosquito. People at increased risk for disease include children younger than 15 years and adults older than age 50 years, according to the Centers for Disease Control and Prevention.
The disease can cause congestion of blood vessels and changes in nerve cells in all major parts of the brain. The symptoms include headache, sore throat, and mild flulike illness.
A sudden spike in fever, along with a headache and stiff neck, can be followed rapidly by a seizure or coma. Many patients who suffer seizures or comas experience permanent brain damage.