(CNN) - A person in their 60s has died of Eastern equine encephalitis, Connecticut health officials said Tuesday.
The death is the third in Connecticut this year and brings the total of EEE deaths in four states this year to 10.
The Connecticut Department of Public Health said another person, who is in their 40s, is hospitalized with the rare virus that is transmitted by mosquitoes.
In addition to the Connecticut deaths, three people have died in Massachusetts, three in Michigan and one person has died in Rhode Island.
EEE causes brain infections. There are typically only 5 to 10 human cases reported in the United States each year, according to the US Centers for Disease Control and Prevention. About 30% of all cases result in death. This year, there has been an unusual uptick in the number of reported cases and deaths.
There is a vaccine on the market for EEE for horses, but not for humans.
There have been six confirmed cases among horses in Connecticut this year. Lt. Gov. Susan Bysiewicz has attributed the spread of the virus to climate change, citing the number of infections in nearby states and the number of cases that have happened so late in the year.
The state health department's epidemiologist said this has been an unprecedented year.
"Before this year, we have had only one human case of EEE in Connecticut, and that was in 2013," Dr. Matthew Cartter said.
CNN's Jen Christensen contributed to this report
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