Powassan Virus Disease - Management and Treatment

Introduction

Powassan disease is an emerging rare but severe viral disease. It is spread through infected deer ticks or black-legged ticks. It is also called bear ticks in some parts of the United States. The virus was named after the place it was first discovered, Powassan, a municipality in Ontario, Canada. It was discovered in the year 1958. Powassan virus comes under the flavivirus (enveloped, positive, single-stranded, RNA or ribonucleic acid virus family). The virus was first isolated in 1952 but was described and learned about in 1958 when a five-year-old boy got infected and died.

What Is Powassan Virus Disease?

Powassan virus disease is a re-emerging viral disease that develops neural complications. Surveys have shown that Powassan disease cases have increased in recent years. The risk group of people includes anyone who got bitten by an infected black-legged tick. The possibility of getting bitten is higher in those residing or working in brushy or wooded areas. The deer ticks get infected by the virus when they depend on rodents containing virus-infected blood for food. The rodents, including mice and squirrels, are called amplifying hosts, acting as hosts through which the infectious organism multiplies. The infected ticks then bite humans and animals, passing on the infection. Humans do not allow further transmission of the disease as the content of the virus in their blood will be less. Therefore they are called dead-end-host.

What Are the Symptoms of Powassan Virus Disease?

The symptoms of Powassan virus disease show up within one week to one month after the infectious bite. Many cases of Powassan virus disease have not shown recognizable signs. The following are the symptoms of the illness if ever they appear:

• Fever.

• Vomiting.

• Headache.

• Tiredness.

• Loss of coordination.

• Speech disturbances.

• Confusion.

• Difficulty in walking.

• Seizures (an episode of sudden and uncontrolled electrical activity within the brain leading to violent contractions of the muscles and loss of consciousness).

• Fifty percent chance of developing long-term health problems, like persistent headaches, issues of focus and memory, and loss of muscle strength and mass.

• Neurological symptoms like meningitis (inflammation or swelling of the membranes covering the brain and the spinal cord) and encephalitis (swelling or inflammation of the brain due to an underlying infection).

• About ten percent of the infections can be fatal.

Is Powessan Virus Disease Treatable?

So far, no medications have been found to cure Powessan virus disease. There are no vaccines too for this purpose. If symptoms arise, the patient should be hospitalized and given supportive care, including respiratory support. The only relief can be achieved by taking adequate steps to prevent getting infected by the virus. Some of the preventive measures are:

• To reduce the risk of getting bitten by the ticks, staying away from vulnerable areas like brushy or wooded areas is necessary. If the person goes to such places, the clothes should be well-observed and flounced to remove the insects stuck to them. Subjecting the clothes to increased temperature may also help remove ticks.

• The peak active times of the ticks are April to July and September to October. Staying vigilant during this period will also be helpful.

• The use of safe and effective tick repellants can also be considered.

• The pets should be observed frequently for any ticks, and required actions should be taken for their removal.

• Trails and lawns should be frequently mowed and maintained.

How to Manage Powassan Virus Disease?

Since no medicines or vaccines are available against Powassan disease, management steps focus on managing the symptoms or complications developed due to the disease. Most severe symptoms of Pawassan disease arise due to neurological effects. The symptoms can be controlled in the following ways:

• Headaches can be managed by taking pain control medicines. These medicines temporarily relieve headaches, primarily due to meningitis.

• Supportive care given in hospitals may provide fluids through different routes. Intravenous or IV (through the vein) fluids help treat or prevent dehydration due to vomiting. It is a safe procedure that helps in rehydration and relieves tiredness. In some cases, the patients may not be able to consume food orally, as they get nauseous and may vomit. This can lead to fatigue and tiredness, which can be managed by IV fluids.

• The doctors may prescribe corticosteroids or other medicines to reduce swelling in the brain. Steroids may be given orally or intravenously to reduce inflammation.

• Vomiting due to Powassan virus disease can be controlled by taking antiemetic medicines. The patient may be advised to eat bland and light foods and avoid sweet and greasy foods. Since digestion gets impaired, the patient should not consume excess fat-containing foods. The patient should drink water intermittently to stay hydrated and prevent dehydration-related symptoms.

• Fever can be managed by taking antipyretic medicines. Tiredness associated with increased body temperature may subside with these medications. In case of severe fever, nonprescription drugs like Acetaminophen can be used.

• The patients may develop mild to severe seizures, and the doctors may prescribe anticonvulsant drugs to get relief.

• In most cases, the symptoms subside after proper supportive care. In some cases, the sign may persist for a longer time, and the patient may require taking medicines for prolonged periods to get relief from the pain, swellings, and other discomforts.

• Hospital staff may also provide respiratory support to the patient. They may take responsibility for giving symptomatic care to the patient, especially when the symptoms get severe and intolerable.

• Muscle strength can be improved by doing workouts for specific muscles and performing slow-paced stretches or yoga.

Conclusion

Powassan virus disease is a re-emerging viral disease that spreads through infected black-legged tick bites. It develops neurologic symptoms and can be fatal in rare cases. Meningitis and encephalitis caused due to Powassan viral disease can be severe and causes extreme symptoms in the patient. Some signs in certain patients may stay for a prolonged period and can affect the quality of their life. So far, no medicines or vaccines have been found to cure the disease. The best way is to stay protected from getting bitten by the infected ticks.