Four Connecticut residents are confirmed to have Powassan virus.
Two patients were men in their 60s from Middlesex and Litchfield County. The other two were women in their 50s from Windham and Litchfield County.
According to the state Department of Public Health, the illness is especially dangerous because there is no vaccine or cure.
Powassan is transmitted to a human from an infected deer tick in less than 15 minutes. While most cases are mild, the illness can be fatal.
According to state health commissioner Dr. Manisha Juthani, symptoms appear between a week to a month after the bite and can be flu-like but also include confusion, loss of coordination and seizures.
She said older adults are particularly at risk.
“If you find that you have an older adult who has a fever, and is very confused, that is somebody who you absolutely want to get some medical attention to,” Juthani said. “It could be a prolonged virus, it could be West Nile virus, it could be meningitis, it could be any number of things. And so you really want to get that person evaluated.”
Powassan virus can only be transmitted by ticks, not from contact with an infected person who is resting at home. Severe illness is treated in hospitals with respiratory support and hydration.
Since 2016, the state has recorded 19 cases of Powassan. Last year, six people were positive for the virus, and two died.
The state’s tick surveillance program has already received almost double the amount of deer ticks for testing this summer than in 2022.
Juthani said climate change is partly to blame for the increase.
“With milder winters, what's happening is that many of the ticks are surviving, and they're surviving throughout the year,” Juthani said. “And so when that happens, we have the potential to be bitten by a tick, or infected by a tick for many more months of the year than we used to think was possible.”
If you are bitten by a tick and over the next month experience fever, vomiting, weakness, confusion or seizures — contact your doctor.
