Powassan Virus Disease Symptoms & Signs
Powassan virus disease is a rare viral infection. Powassan (POW) virus is a Flavivirus, a genus in the family of Arbovirus; it is related to the West Nile virus. The virus is named after Powassan, Ontario, where it was discovered in 1958. Most cases in the U.S. have been reported in the Northeast and Great Lakes areas.
The infection does not always cause symptoms but can cause meningitis and encephalitis. If symptoms and signs do occur, these may vary in severity and can include
- fever,
- headache,
- vomiting,
- weakness,
- confusion,
- loss of coordination,
- difficulty speaking, and
- seizures.
What are the two types of Powassan virus (POW virus)?
Powassan (POW) virus is a Flavivirus, a genus in the family of Arbovirus; it is related to viruses such as West Nile virus. The virus is named after Powassan, Ontario, where it was first discovered in 1958. Two types of Powassan virus have been found in North America, including lineage 1 and lineage 2 (deer tick virus) types of POW viruses.
- Lineage 1 type is associated with Ixodes cookeri, Ixodes marxi, and Ixodes scapularis tick species,
- while lineage 2 virus is only associated with Ixodes scapularis ticks.
Unfortunately, the tick that usually bites humans and is infected is Ixodes scapularis so humans can be infected with either virus type.