Powassan (POW) virus is a flavivirus that is linked to West Nile, St. Louis encephalitis, and other tick-borne encephalitis viruses. It bears the name of the city of Powassan, Ontario, where the first confirmed case of the illness was found in 1958..

The Powassan virus infects people when an infected tick bites them. Fortunately, the Powassan (POW) virus seldom infects people. Typically, ticks and small animals like woodchucks, skunks, squirrels, and white-footed mice spread the illness back and forth in a cycle.


Two types of Powassan (POW) virus have been found in North America. These are lineage 1 and lineage 2 (deer tick virus) types of POW viruses.

  • Lineage 1 – Ixodes cookeri, Ixodes marxi, and Ixodes scapularis tick species are linked to type.
  • Lineage 2 – Ixodes scapularis ticks are the only ones connected to a virus.

Unfortunately, any virus type may infect people since Ixodes scapularis is the tick that often bites and infects humans.


Many Powassan (POW) virus carriers may not exhibit any symptoms. When a tick bites a person, it may take anywhere between a week and a month before they start to feel unwell.

  • fever
  • headache
  • nausea
  • encephalitis
  • meningitis
  • confusion
  • lack of coordination
  • trouble speaking
  • trouble speaking
  • other cognitive issues
  • loss of muscular
  • strength/weakness

Extremely rare cases result in immediate death.


Medical professionals use the following criteria to determine if a patient has the Powassan (POW) virus:

  • History of residing in or visiting a region where the Powassan virus is known to be present
  • History of probable tick encounter that might have exposed you to the Powassan virus
  • Testing of spinal fluid or blood in a lab

Other than that, your doctor may request testing to check for the Powassan (POW) virus or other illnesses that could be causing your symptoms.


Unfortunately, Powassan virus cannot be prevented or treated. Moreover, antibiotics cannot cure viruses.

What you can do to help alleviate its symptoms include drinking sufficient water, taking OTC painkillers, and being well-rested.

For some severe cases, hospitalization may be required so that patients can be helped to breathe, keep hydrated, and reduce the swelling of their brain.

Related Articles


Overview and FactsTypes and SymptomsDiagnosis & MedicationsOverview and Facts Xeroderma pigmentosum (XP) is a congenital disorder that causes excessive sun [...]


Overview and FactsTypes and SymptomsDiagnosis & MedicationsOverview and Facts Squamous cell carcinoma is a form of skin cancer resulting from [...]


Overview and FactsTypes and SymptomsDiagnosis & MedicationsOverview and Facts Sebaceous carcinoma is a rare skin cancer originating in the skin's [...]