Can You Recover From Powassan Virus? Four Case Reports

Powassan virus can cause meningitis or encephalitis
Symptoms may include seizures, confusion, weakness, and difficulty walking
Recovery ranges from complete resolution to persistent neurologic deficits

Can you recover from Powassan virus? Yes. Published case reports show that recovery from Powassan virus ranges from complete neurologic recovery to prolonged weakness, persistent symptoms, and the need for rehabilitation.

Powassan virus (POWV) can cause severe disease, including infection of the brain, known as encephalitis, or infection of the membranes surrounding the brain and spinal cord, known as meningitis. Symptoms may include confusion, loss of coordination, difficulty speaking, weakness, seizures, and altered mental status.

Because Powassan virus infection is rare, published case reports provide valuable information about recovery, although they cannot predict the outcome for an individual patient.

An estimated 1 out of 10 people with Powassan virus encephalitis or meningitis will die from the disease, according to the Centers for Disease Control and Prevention.¹ Among survivors of severe disease, long-term neurologic problems may persist.

There is no specific antiviral treatment for Powassan virus infection. Medical care is primarily supportive and may include hospitalization, respiratory support, seizure management, intravenous fluids, and treatment of brain swelling when necessary.

Early recognition remains important because patients may require intensive supportive neurologic care and prolonged rehabilitation.

The study entitled “Powassan virus infection: case series and literature review from a single institution,” by Raval and colleagues, describes four patients with markedly different neurologic presentations and outcomes.²

The cases highlight how Powassan virus infection may initially resemble other neurologic or tick-borne illnesses. They also demonstrate that recovery can range from resolution of symptoms to persistent weakness requiring continued assistance.

Powassan virus presenting with a seizure in an 18-year-old

An 18-year-old man presented to the hospital with a 2-day history of headaches and a single seizure.

He had been cutting trees while suspended from a harness when he suddenly developed clenching of his right upper extremity.

“He was at work, cutting trees, and was suspended from a harness, where he suddenly experienced clenching of his right upper extremity.”

A CT scan was unremarkable. Treatment was not initially prescribed because the young man had experienced only an isolated seizure.

His condition subsequently worsened.

“He subsequently developed right-sided weakness, worsening headaches, and somnolence and was subsequently transferred to our facility to receive a higher level of care,” the authors wrote.

Despite treatment, the young man’s headaches continued to intensify. He then told clinicians that he had previously sustained a tick bite.

Because his presentation could have been caused by several infectious conditions, he was prescribed ceftriaxone, vancomycin, ampicillin, acyclovir, and doxycycline while additional testing was performed.

Testing for more common tick-borne infections, including Lyme disease and anaplasmosis, was negative. However, serum testing was positive for Powassan virus immunoglobulin M.

The patient ultimately recovered without persistent focal neurologic deficits.

“During his follow-up visit, he did not report any focal neurological deficits, seizures, or headaches.”

This case illustrates that Powassan virus may initially present with a single seizure and an unremarkable CT scan before progressing to weakness, worsening headaches, and somnolence.

For additional background about transmission, symptoms, and diagnosis, read what patients and clinicians should know about Powassan virus.

Powassan virus associated with brain hemorrhage in a 60-year-old

A 60-year-old man was admitted to the emergency department with fever, headaches, and dizziness. His initial examination was reportedly unremarkable, and he was discharged.

His condition deteriorated rapidly after leaving the hospital.

On the way home, “he lost consciousness and was found obtunded and unresponsive,” according to the authors.

The man was intubated and transferred to the intensive care unit. A CT scan of the brain revealed an intraparenchymal hemorrhage with a subdural hematoma.

After 7 days, the patient stabilized and was extubated. Although he did not have focal neurologic deficits, he continued to exhibit altered mental status, memory loss, loss of interest or pleasure, and depression.

The patient later tested positive for Powassan virus and received supportive treatment.

Despite the severity of his initial presentation, his neurologic function eventually returned to baseline.

“His neurological function recovered with return of his baseline functional status on further follow-up,” the authors wrote.

This case demonstrates that recovery may be possible even after a severe presentation involving loss of consciousness, intracranial hemorrhage, memory impairment, and altered mental status. However, such an outcome cannot be predicted for an individual patient.

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Powassan encephalitis with altered mental status in a 61-year-old

A 61-year-old man from northwestern Minnesota presented to the hospital with progressive headaches, body aches, high-grade fever, and altered mental status.

He enjoyed outdoor activities and reported frequent tick bites, increasing the suspicion for a tick-borne illness.

Because bacterial meningitis, viral encephalitis, Lyme disease, and other tick-borne infections were initially considered, he was empirically treated with ceftriaxone, vancomycin, and doxycycline while diagnostic testing was underway.

Testing for Lyme disease, anaplasmosis, and ehrlichiosis was negative.

Despite treatment, his neurologic condition continued to deteriorate.

The man’s condition deteriorated and he was intubated and placed on a ventilator.

As his illness progressed, antimicrobial therapy was broadened.

“Antibiotics were changed to vancomycin, acyclovir, piperacillin/tazobactam and micafungin,” the authors wrote.

Cerebrospinal fluid (CSF) testing was ultimately positive by polymerase chain reaction (PCR), confirming Powassan virus encephalitis.

The patient required prolonged hospitalization followed by inpatient rehabilitation.

“The patient stayed in rehabilitation facility for over a month and eventually showed gradual improvement and was discharged home,” according to the authors.

This case illustrates that Powassan virus encephalitis may resemble other serious central nervous system infections early in the illness. Progressive neurologic decline despite broad-spectrum antimicrobial therapy should prompt clinicians to consider less common tick-borne viral infections in the appropriate clinical setting.

Learn more about Powassan virus encephalitis, including its clinical presentation and complications.

Powassan virus causing persistent weakness in a 69-year-old

A 69-year-old man with a history of tick bites presented to the emergency department with progressive weakness, headaches, and fever.

He was initially diagnosed with a urinary tract infection and treated with ciprofloxacin.

“He was diagnosed with a urinary tract infection and was treated with ciprofloxacin,” according to the authors.

Despite treatment, his condition continued to worsen. He experienced persistent fever, increasing weakness, difficulty walking, and involuntary movements of his limbs.

An extensive infectious disease evaluation, including testing for common tick-borne illnesses, was negative.

Because clinicians remained concerned about a possible tick-borne infection, he was treated empirically with intravenous doxycycline while awaiting additional diagnostic studies.

Three weeks after hospitalization, serum testing confirmed Powassan virus infection.

Three weeks after he was admitted to the hospital, he tested positive for Powassan virus.

His neurologic condition gradually improved, although recovery was incomplete.

Four months after hospitalization, he continued to have quadriceps muscle weakness, requiring him to push himself up from a chair with his arms. He also had persistent limitation in knee movement because of residual weakness.

This case demonstrates that although patients may improve after acute Powassan virus infection, recovery can be prolonged and residual neurologic deficits may persist for months.

What these four Powassan virus cases teach us

These four published cases demonstrate the broad clinical spectrum of Powassan virus infection. Patients presented with seizures, encephalitis, altered mental status, intracranial hemorrhage, progressive weakness, and gait impairment. Several patients initially appeared to have more common bacterial or tick-borne infections before the diagnosis became apparent.

Although these reports cannot predict the outcome for an individual patient, they illustrate that recovery from Powassan virus ranges from complete neurologic recovery to prolonged rehabilitation and persistent weakness.

The outcomes also varied considerably. Two patients recovered to their baseline neurologic function, while others required prolonged rehabilitation or experienced persistent muscle weakness months after infection. These reports emphasize that recovery from Powassan virus is possible, but the severity of neurologic involvement often influences the pace and extent of recovery.

The authors concluded:

“This study serves to highlight the increased detection of Powassan virus infection in the central north United States.”

“There is a need for clinician vigilance and public attention due to its increasing detection, westward progression and varied clinical presentations.”

Frequently Asked Questions

Can you recover from Powassan virus?

Yes. Recovery is possible, but outcomes vary widely. In this case series, some patients returned to their baseline neurologic function, while others required prolonged rehabilitation or experienced persistent muscle weakness months after the infection.

Is there a treatment for Powassan virus?

There is currently no specific antiviral treatment for Powassan virus infection. Treatment is supportive and may include hospitalization, intravenous fluids, seizure management, respiratory support, and measures to reduce complications of encephalitis or meningitis.

Can Powassan virus cause permanent neurologic problems?

Yes. Survivors of severe Powassan virus infection may experience long-term neurologic complications, including weakness, memory problems, difficulty walking, cognitive impairment, or other neurologic deficits. Recovery may continue for months after the acute illness.

How is Powassan virus diagnosed?

Diagnosis is typically based on clinical suspicion, a history of possible tick exposure, and laboratory testing of blood or cerebrospinal fluid. Because Powassan virus symptoms can resemble Lyme disease, anaplasmosis, bacterial meningitis, or other causes of encephalitis, diagnosis may be delayed while other conditions are excluded.

Clinical Takeaway

In my experience, Powassan virus infection is uncommon but should remain in the differential diagnosis for patients presenting with encephalitis, meningitis, seizures, or progressive neurologic decline after possible tick exposure, particularly in endemic regions. Because no specific antiviral therapy is currently available, early recognition can help guide appropriate supportive neurologic care and avoid delays caused by focusing exclusively on more common tick-borne infections.

The four published cases described by Raval and colleagues illustrate the broad clinical spectrum of Powassan virus infection. While some patients recovered fully, others required prolonged rehabilitation or experienced persistent neurologic deficits. These reports reinforce that recovery from Powassan virus is possible, but the severity of neurologic involvement often determines the pace and extent of recovery.

Related Articles

Learn more about Powassan virus and other tick-borne neurologic infections:

Powassan Virus Encephalitis Contracted in Winter Months
Powassan Virus in Children: Case Reports
Case Report: Powassan Meningoencephalitis
Tick-Borne Encephalitis: Symptoms and Diagnosis

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Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.

Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention