Many people who become infected with Powassan (POW) virus do not develop any symptoms.
The incubation period (time from tick bite to onset of illness) ranges from about 1 week to 1 month.
POW virus can infect the central nervous system and cause encephalitis (inflammation of the brain) and meningitis (inflammation of the membranes that surround the brain and spinal cord).
Symptoms can include fever, headache, vomiting, weakness, confusion, loss of coordination, speech difficulties, and seizures.
Approximately half of survivors have permanent neurological symptoms, such as recurrent headaches, muscle wasting and memory problems.
Approximately 10% of POW virus encephalitis cases are fatal.
Treatment
There are no vaccines or medications to treat or prevent POW virus infection.
If you think you or a family member may have POW virus disease, see your health care provider for evaluation and diagnosis.
Persons with severe POW illnesses often need to be hospitalized. Treatment may include respiratory support, intravenous fluids, and medications to reduce swelling in the brain.