Related Experiment Video
Updated: Nov 29, 2025
Pan-lyssavirus Real Time RT-PCR for Rabies Diagnosis
Published on: July 10, 2019
Unusual cause at an unusual time-Powassan virus rhombencephalitis
Igor Dumic1, Cristian Madrid2, Danilo Vitorovic3
1Division of Hospital Medicine, Mayo Clinic Health System, Eau Claire, Wisconsin, USA; Mayo Clinic Alix College of Medicine and Science, Rochester, Minnesota, USA.
Abstract:
Powassan virus lineage II (POWV) is an emerging tick-borne neurotropic pathogen, transmitted to humans by the bite of infected Ixodes scapularis ticks. In the United States, the disease is most prevalent in the Northeast and the upper Midwest and occurs mostly during the spring and summer months when tick activity is the highest. Some patients infected with POWV develop severe encephalitis, with high mortality. We report the case of a 42-year-old healthy man who developed progressive diplopia and dysarthria in December following a deer hunting trip. Routine blood work was unrevealing and MRI was normal. Extensive work-up for infectious, autoimmune, and paraneoplastic causes was positive only for POWV. The patient was treated with supportive care and intravenous corticosteroids, with an excellent outcome. We present a rare clinical presentation of a potentially fatal emerging disease that responded favorably to corticosteroids.
Insights
Powassan virus (POWV) is a dangerous tick-borne illness causing severe encephalitis. This case shows a rare presentation of POWV infection in a healthy man, successfully treated with corticosteroids.
Area of Science:
- Neuroscience
- Infectious Diseases
- Public Health
Background:
- Powassan virus lineage II (POWV) is an emerging tick-borne neurotropic pathogen transmitted by Ixodes scapularis ticks.
- POWV infection is prevalent in the Northeastern and upper Midwestern United States, with peak incidence during spring and summer.
- Severe encephalitis and high mortality can occur in some POWV-infected patients.
