Bats and Rabies: Separating Fact from Fiction

This past month has seen an influx of news reports from across the country concerning bats and rabies, like these news reports from: British Columbia, New Brunswick, and Ontario.

These serve as a reminder that it is important to evaluate your risk of rabies infection and what precautions you need to take if you ever have an interaction with a bat. However, while bats do represent a risk to human health, it is essential to weigh that risk against the incredible amount of good they do for us and our environment in their role as insect eaters and the pest management services (among other things) they provide.

Little brown myotis – photo by Jordi Segers

Let’s begin with a brief overview of the rabies virus. When people think of rabies, they often think of what we call “terrestrial mammal rabies”, or rabies that affects a wide variety of mammals that roam the earth. Types, or “variants”, of terrestrial mammal rabies include those of raccoons, foxes, and skunks, although each type can also infect all other species of mammals, including wildlife, domestic animals, and humans. Terrestrial mammal rabies tends to cycle in particular species to which it is best adapted (e.g., the raccoon variant primarily affects raccoons), and often presents as isolated outbreaks in those species. Terrestrial mammal rabies has not been detected in every province and territory in Canada (check with your provincial or territorial government to find out if terrestrial mammal rabies is present in your province or territory).

Additionally, there is also “bat variant rabies” which can be found in bat populations throughout North America. Unlike terrestrial mammal rabies, bat rabies does not usually cause outbreaks; rather, it maintains a constant background rate of infectivity in bat populations. It is generally considered that in a healthy bat population in Canada, 0.5 –1.0% of bats may carry rabies at any given point in time (i.e., 1 bat with rabies out of 100–200 bats). So while this is certainly a low risk, it is important to understand that if there are bats present in a province or territory, then bat variant rabies is also assumed present, even if it has never been detected. This means that bat variant rabies is in every province and territory in Canada.

But hold on; don’t grab your pitchforks and torches just yet. While rabies is almost always fatal once symptoms begin presenting themselves, it is also almost always preventable if dealt with immediately following a potential exposure:

1. Never touch a bat (dead or alive) with your bare hands. If you need to remove a bat from a building, or collect a dead bat for testing, ensure that you wear thick gloves that the bat cannot bite through. It is ideal to have your forearms covered as well, to minimise the risk of contact.

2. If your bare skin is in contact with a bat, immediately wash the area for fifteen minutes with soap and water, 70% ethanol, or a povidone-iodine solution, and call the appropriate health authorities (e.g., your family doctor, an emergency clinic, or the provincial public health department). They will evaluate the potential risk of rabies exposure and determine whether you need to seek treatment. If the bat is still available, it should be kept for rabies testing if necessary (i.e., do not release a live bat or dispose of a dead bat that has come into contact with a human or a domestic animal until health authorities have assessed the risk).

*Note: treatment comes in the form of post-exposure prophylaxis (PEP). This is a series of injections given over the course of several days (the injection site is typically your upper arm).

3. Additionally, even if there is no known contact with a bat, it is recommended that you consult with a health authority to determine if PEP is necessary if a bat has been found in a room with: an unattended child, a sleeping person, a mentally impaired person, or a person under the influence of drugs or alcohol to the extent that it could impair their judgment.

4. If a domestic animal (such as a cat, dog, pig, cow, etc.) comes into contact with a bat, or even if contact is merely suspected, it is necessary to contact your family veterinarian or the provincial veterinarian to assess the risk of exposure, even if your animal is already vaccinated against rabies. Depending on the situation, an animal with an up-to-date rabies vaccination may still need to be re-vaccinated after a potential exposure. If the animal has never been vaccinated against rabies, or its rabies vaccination is not up-to-date, they may need a rabies vaccination.

So, the take-home messages are the following:

• Rabies is always a risk wherever bats are present.
• Humans acquiring bat rabies is a rare occurrence. Since 1950, there have only been 11 cases of humans with a rabies virus infection in Canada: 6–7 of these individuals were likely exposed from contact with a bat.
• Rabies is entirely preventable if you seek appropriate medical advice and treatment immediately after coming into contact with a bat.
• Bats that are behaving strangely have an increased risk of rabies infection. Such behaviours include: being out in the daylight, being found on the ground, or allowing people to handle or touch them without defending themselves.
• Bats are amazing animals that benefit us in many ways (e.g., pest control); however, as with all wildlife, it is best to appreciate them at a safe distance.
  

  Myotis species flying in the evening sun – photo by Jordi Segers

  Submitted by:
  Tessa McBurney, CWHC-Atlantic