CONCORD, N.H. -- State health officials say a 20-year-old Newton woman died Friday of Eastern equine encephalitis.
This marks the fifth confirmed case of Triple E in the state this year but the first time someone has died.
Health officials said the woman was taken to a Boston hospital on Sept. 3 with symptoms of the disease. An initial test was inconclusive, according to Dr. Jose Montero, the state epidemiologist.
A subsequent test confirmed yesterday that she had the disease, he said.
''The death of this young woman is terrible tragedy," Health Commissioner John Stephen said in a statement.
''Our thoughts and prayers are with her family and loved ones at this difficult time. We are currently working to determine where she might have been during the past few weeks to understand where she acquired EEE," the commissioner said.
Montero says testing of mosquitoes in the Kingston-Newton-Plaistow area have made it clear the illness has a foothold there.
''That is clearly an area where there's a lot of endemic activity and people clearly have to be careful," he said.
Four other confirmed cases of the disease in New Hampshire involved people in Londonderry, Goffstown, Manchester, and Concord. All four were treated at area hospitals and have since been released.
State health officials continue to advise people to wear bug repellant along with long sleeves and long pants and to empty any standing water on their property where mosquitoes could breed.
Statistically, about a third of patients who contract the illness die from it. Two of three patients with the illness in Massachusetts have died this year.