HARTFORD, Connecticut (WABC) -- Connecticut officials say a second person has died after testing positive earlier this month for a rare, mosquito-borne disease.
Democratic Lt. Gov. Susan Bysiewicz confirmed Tuesday the adult who tested positive for eastern equine encephalitis during the second week of September was from Old Lyme.
Officials outlined their game plan for handling Eastern equine encephalitis, or EEE, Tuesday, days after an East Lyme resident who tested positive for the mosquito-borne disease had died.
The rare virus can cause inflammation in the brain and is potentially deadly. About one-third of patients who develop it die, and many who survive end up having mild to severe brain damage, according to the Centers for Disease Control and Prevention.
It is transmitted through the bite of a mosquito.
There have been seven recorded cases of EEE in Massachusetts and three in Michigan, including one patient who died, according to health officials. Usually, about five to 10 cases are reported annually. At least three New Jersey residents have been sickened.
In July, health officials in Orange County, Florida, announced an uptick in the virus among sentinel chickens, which show the presence of viruses such as EEE and West Nile but don't develop the symptoms associated with them.
Officials say the outbreak is likely the result of mosquitos feeding on infected birds that have migrated north.
Unlike West Nile virus, which can spread in urban and rural areas, the mosquitos that transmit EEE are usually limited to swampy areas. The only defense is to avoid being bitten, which is why residents are being reminded to take precautions.
"Using repellant, covering bare skin, and to be decreasing the amount of time that we are outside, starting from an hour before dusk, and between dusk and dawn," said Renee Coleman-Mitchell of the Connecticut Department of Public Health.
Theodore Andreadis, director of the Connecticut Agricultural Experiment Station, says Connecticut has "never seen this much activity" regarding mosquitoes carrying the virus. The last time there was a death in Connecticut from the virus was 2013.
He says the good news is the mosquito population is dropping as colder weather nears.
ABC News and the Associated Press contributed to this story.
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Connecticut responds to mosquito-borne disease outbreak after 2 die in state