May 3, 2017 -- Cases of a rare but potentially life-threatening tick-borne disease called Powassan are expected to rise in the United States this year as warmer winters lead to rising tick populations, experts say.
There have been 75 cases of Powassan reported over the past decade in the northeastern states and the Great Lakes region, according to the Centers for Disease Control and Prevention, CNN reported.
The disease is transmitted by three types of ticks, including the one that carries Lyme disease.
"About 15 pecent of patients who are infected (with Powassan) and have symptoms are not going survive," Dr. Jennifer Lyons, chief of the Division of Neurological Infections and Inflammatory Diseases at Brigham and Women's Hospital in Boston, told CNN.
"Of the survivors, at least 50 percent will have long-term neurological damage that is not going to resolve," she added.
Most infected people never develop symptoms. Those who do become ill typically do so within a few days to a week after the tick bite, Lyons said.
"You basically feel nonspecific flu-like stuff," including "muscle aches and pains; maybe you have a little rash on your skin, but almost certainly, you'll have a fever and the headache," she told CNN.
People who develop a more serious illness will do so "very quickly over the next couple of days," she said. "You start to develop difficulties with maintaining your consciousness and your cognition. ... You may develop seizures. You may develop inability to breathe on your own," Lyons said.
There is no vaccines or cure for Powassan. Intravenous fluids are a standard treatment, but antiviral drugs, systemic corticosteroids and other medications have been tried in some patients, CNN reported.
Experts are also predicting an increase in Lyme disease infections in the U.S. this year.