Tick-borne virus reported in Massachusetts

Boston — A confirmed case of the tick-borne Powassan virus has been reported in the Bay State, according to officials who are warning residents to take precautions against the disease.

The Sharon Health Department has confirmed the town’s first case of Powassan virus — which like Lyme disease, is transmitted through infected ticks.

Although still rare, the number of reported cases of people sick from Powassan virus has jumped in recent years.

“Powassan virus is closely related to West Nile virus and while cases are rare compared to the other diseases spread by the same tick, the virus can invade the central nervous system (brain and spinal cord) and cause severe disease,” the Massachusetts Department of Public Health said in a statement.

Most people exposed to Powassan virus never feel ill, but others may become severely ill with meningitis (inflammation of the covering of the brain and spinal cord) or encephalitis (inflammation of the brain).

Symptoms usually begin between one week and one month after the bite of an infected tick.

Signs and symptoms include fever, headache, vomiting, weakness, confusion, loss of coordination, speech difficulties and seizures.

The most common tickborne diseases in Massachusetts are Lyme disease, anaplasmosis and babesiosis. All three of these diseases are spread by the black-legged tick, also known as the deer tick.

This tick also carries and can spread two additional diseases that occur less commonly in Massachusetts: Borrelia miyamotoi and Powassan virus.

The risk from tick-borne diseases in Massachusetts is high every year, and people are urged to be aware that ticks are most active March through October, but can be out any time temperatures are above freezing.