WASHINGTON — Health experts are warning about the potential spread of a tick-borne disease called the Powassan virus in the summer, as warmer winters have increased the tick population.

The Powassan virus is a potentially life-threatening disease transmitted by ticks, including the deer tick, which is also the primary vector of Lyme disease.

Although most people will not develop symptoms, about 15% of those who do will die, at least 50% of the survivors will have long-term neurological damage, and the rest may have symptoms including fever and headache.

According to the Centers of Disease Control and Prevention, there are no vaccines to prevent or medications to cure an infection of the Powassan virus.