One person in the U.S. state of New Hampshire has died after being infected with the mosquito-borne eastern equine encephalitis virus.

The New Hampshire Department of Health and Human Services said the infection was the first in the state in a decade.

The person, an adult, had been hospitalized due to severe central nervous system symptoms.

A report by The Associated Press says about a third of those who develop encephalitis from the virus die from the infections, and survivors can suffer lifelong mental and physical disabilities.

There is no vaccine or antiviral treatment available for infections, which can cause flu-like symptoms and lead to severe neurological disease along with inflammation of the brain and membranes around the spinal cord.

The Centres for Disease Control and Prevention says there are typically about 11 human cases of eastern equine encephalitis in the U.S. per year.