Name Powassan Virus (POW)
Do I have Powassan Virus?
Initial symptoms of Powassan Virus include a headache, fever, vomiting, weakness, seizures, confusion, memory loss that lead to other long-term neurological problems like muscle wasting, trouble speaking, confusion and in 10% of cases, death. POW can be transmitted by an infected Deer Tick in just 15 minutes of feeding on a host body. POW cases in Canada are transmitted by the bites of Black-Legged Ticks (Deer Ticks) and Groundhog Ticks, although Groundhog Ticks rarely come into contact with humans.
What should I do if I think I have Powassan Virus?
If you have been bitten by a tick and you think you need emergency care, immediately call 911. Tick bites can in some cases trigger a severe allergic reaction called anaphylaxis. If epinephrine is available, use it. Symptoms of anaphylaxis include hives all over your body, swelling around the throat, lips or tongue, difficulty breathing, loss of consciousness, confusion, restlessness, and weakness.
Although it typically takes ticks upwards of 24 hours to successfully transmit Lyme Disease, Black-Legged Ticks are capable of transmitting Powassan Virus in just 15 minutes.
A feeding tick has the appearance of having submerged its entire head into the host. If you find a tick on a person or pet:
Grasp the tick behind the head using tweezers and slowly and cautiously remove it from the host (fingers can be carefully used if an appropriate tool is not on hand, wash hands thoroughly before and after tick removal). Do not crush the tick; crushing may lead to the release of dangerous fluids. Ensure that the mouthparts of the tick are fully removed and thoroughly wash the infected area. Ticks withdrawn from the body of a person or pet can be sent for testing by your doctor or by one of Toronto’s Public Health Offices. More information can be found here.
If you develop signs of an infection due to a tick bite, call your doctor or seek emergency medical attention. Tick bites can cause the transmission of a range of dangerous illnesses. Signs of an infection due to a tick bite include redness, swelling, warmth and increasing pain around the bite, red streaks beneath the skin or pus draining from the wound typically coupled with a fever.
Tick-borne illnesses often require an incubation period of several days before disease symptoms begin to emerge. These may include body aches and joint pain, an expanding bullseye rash or another skin rash, lack of energy and flu-like symptoms. If new symptoms develop and worsen, seek medical attention.
Initial symptoms of Powassan Virus are not unlike the symptoms of other infectious insect bites, but after one week to one month incubation period, will progress to symptoms indicating a brain infection; trouble speaking, lack of coordination and confusion. 10% of POW cases causing brain infection and inflammation result in fatalities; 50% of survivors develop chronic neurological problems including memory loss, recurrent headaches and muscle wasting. At this time there is no specific treatment for POW and hospitalization is usually required to support respiration, receive intravenous fluids and reduce swelling of the brain.
Diagnosis involves blood and spinal fluid sampling and tick-body analysis.
When, where and how did I contract Powassan Virus?
The first diagnosed case of Powassan Virus occurred in the 1958 and resulted in the death of a boy in Powassan, ON. Almost all diagnosed cases of Powassan Virus have occurred in the Northeast and Great Lakes Region. Although only 25 cases have been identified in Canada (75 in the United States), the recent expansion of Deer Tick populations in North America makes this tick-borne illness cause for concern. Deer Ticks were first recognized to be vectors of the flavivirus in the mid-1990’s.
Active in temperatures above 4 degrees Celsius and now often populating city parks in addition to the trails of more densely wooded and leaf-littered areas, poppy seed-sized Black-Legged nymphs and even larger adults, are dangerously inconspicuous. Unable to fly or jump, ticks will instead ‘quest’ for hosts. In response to carbon dioxide or heat and vibration stimuli, ticks will climb a blade of grass or move to the edges of leaves, stretch their front legs forward, and mount an unsuspecting host as it brushes past. Once mounted onto its host, a tick will move around the body and select a preferred feeding site typically a warm and moist area around the neck, head, armpits, groin and knees.
Again, Powassan Virus can be transmitted in just 15 minutes. It is imperative to be fastidious in checking for ticks when in tick-populated areas. Ticks are easily unnoticed, and their bites are often painless.
How serious is Powassan Virus?
Closely related to West Nile, Powassan Virus is a serious, relatively unknown and deadly virus and all Ontario residents who frequent leaf-littered and forested areas are at risk of infection. Approximately half of survivors have chronic neurological problems, and it is fatal in 10% of victims.
How Addison can help prevent Powassan Virus
When entering a suspected tick populated, or heavily-wooded area:
Wear light clothing, long sleeves and long pants tucked into socks. Repellents:
Deet-based skin repellent helps repel them, and Permethrin clothing treatment can kill ticks. Contact your veterinarian about available preventative treatments for ticks and other ectoparasites.
Ticks and other ectoparasites can enter the home on just about anything, on clothing, pets, people, and plants. In general, when returning from any densely vegetated, wooded or infested area where tick harbourages and activity are suspected, it is crucial to perform thorough checks of all incoming living and non-living objects. Ticks are drawn to moist and warm areas on their host bodies; be sure to check the scalp, nape, behind the ears, armpits, groin, navel and knees. Always check twice. Immediately wash and dry all clothing on high heat and be sure to shower as soon as possible. Bathe and groom your pets and regularly check for ticks and other parasites.
Certain preventative measures can be taken as part of a system of physical controls:
Keep your home clean, check under furniture and the areas that pets may frequent. Repair crevices and gaps around the structure, paying particular attention to possible entry points from outdoors. Keep your grass cut and maintain an organic free barrier of at least 1m around the exterior walls of the structure using gravel or woodchips. Dispose of all animal nesting material, and evict other pest populations in and around your property as ticks parasitize most rodent and avian pest species. Keep your lawn free of debris and leaf litter, keep children’s playsets clear of wooded areas.