Massachusetts Reports Third Human Case of Eastern Equine Encephalitis

BOSTON -- The Massachusetts Department of Public Health (MDPH) today reported eastern equine encephalitis (EEE) in a male Middleboro resident who is in his 20s. The EEE virus (EEEV) infection was established by tests completed at the State Laboratory Institute on Sept. 16, 2004. He was admitted to the hospital on Sept. 8 and remains hospitalized. The two previous human cases were a male Brockton resident in his 60s reported on Aug. 12 and a male Holbrook teen reported on Sept. 2. Both of these cases were fatal.

EEE is a rare human disease, with fewer than 50 cases having been reported in Massachusetts since 1940. Similar to West Nile virus (WNV), the virus that causes EEE is transmitted to humans by bites from infected mosquitoes. Symptoms of EEE infection in humans include a sudden onset of high fever, stiff neck, headache, mental confusion and lack of energy. These symptoms appear two to ten days after infection. Inflammation and swelling of the brain, called encephalitis, is the most dangerous complication. Encephalitis can worsen quickly and patients may go into a coma within a week. The risk of transmission of EEE virus is greatest in August and September and continues until mosquito activity ends after the first hard frost.

MDPH encourages anyone who develops symptoms of EEE infection, such as sudden onset of high fever, stiff neck, headache, mental confusion and lack of energy, to seek medical attention as soon as possible.

MDPH has also previously identified two horses with EEE this year, one from Walpole and another from Middleboro. In 2003, five horses tested positive for the virus that causes EEE.

MDPH has also identified 30 mosquito specimens as positive for the EEE virus to date in 2004. The specimens were collected between July 28 to Sept. 13, 2004 from Bristol, Plymouth and Norfolk counties from the towns of Attleboro, Dartmouth, Easton, Norton, Raynham, Middleborough, Halifax, New Bedford, Holbrook, Walpole, Pembroke, Plymouth, Rockland and Kingston.

Source: Massachusetts Department of Public Health