Powassan virus in Wisconsin: 3 hospitalizations, One death
The Wisconsin Department of Health Services (DHS) has reported three cases of the tick borne disease, Powassan virus disease year to date. All three were adult Wisconsin residents, all required hospitalization and one died.
According to health authorities in the state, Powassan virus is a rare illness in Wisconsin spread by the blacklegged (deer) tick. The number of cases reported each year has recently increased.
The first case of Powassan virus in Wisconsin was identified in 2003. In 2024, Wisconsin had 12 reported cases of Powassan virus. There have been 67 probable and confirmed cases of Powassan virus in Wisconsin from 2003 through 2024.
Cases of Powassan virus are more common in the northern half of Wisconsin, where the blacklegged (deer) tick is found in higher numbers.
Symptoms of Powassan can show up one week to one month after being bitten by an infected tick. Many people who become infected with Powassan virus don’t have any symptoms.
Common early signs and symptoms include:
Fever
Headache
Nausea
Vomiting
Muscle weakness
Stiff neck
Severe illness can include:
Confusion
Loss of coordination
Paralysis
Speech difficulty
Seizures
Memory loss
Encephalitis (inflammation of the brain)
Meningitis (inflammation of the membranes around the brain and spinal cord)
Powassan virus causes death in about 10% of severe cases. Half of those who survive severe disease have permanent or long-term neurologic symptoms. These can include recurring headaches, memory problems, and muscle weakness or loss.
Currently, there isn’t a treatment or vaccine for Powassan virus. Over-the-counter pain relievers may help with symptoms. In severe cases, patients may need supportive treatment in a hospital.
