CAROLYN GRANT
Spring has sprung, birds have returned, bees and other insects are reappearing. And so are bats.
Interior Health is warning that bats can put you at risk for rabies, and whether you are fascinated or fearful, the bottom line is you should avoid physical contact with bats as they are the primary carrier of the rabies virus in B.C.
Rabies is a very serious disease that affects the nervous system. It is almost always fatal if not treated in time. Last year, 32 people in the Interior Health region were treated for potential exposure to rabies.
"Many people will be bringing summer gear out of storage or heading out to open the cabin. Activities like these can lead to unexpected encounters with bats," said Jennifer Jeyes, Communicable Disease Specialist with Interior Health. "Bats often fly into poorly sealed cabins and homes, they roost in attic spaces and they can even be found hanging inside closed patio umbrellas."
Juliet Craig from the Kootenay Community Bat Project agrees that people should be cautious about coming into contact with bats, and the health authority should be notified if you have any contact.
"We also promote the messages that bats are very important in our ecosystems, they are not dangerous — if you don't touch them — and that half of the bat species in BC are of conservation concern," Craig said.
According to IH, between four and eight per cent of the bats that are tested after coming into contact with people are found to have the rabies virus. Infected bats can transmit rabies to humans when their saliva comes into contact with a person's mucus membranes (eyes, nose, mouth) or through a break in the skin.
Craig says the overall number of infected bats is very small.
"Scientists estimate that the incidence of rabies in the free flying bat population is less than one per cent, and this rate varies between species. This risk is low and negligible if proper precautions are taken (i.e., never handle bats, keep pet vaccinations up to date and keep human living areas sealed tightly from areas where there are bats). There is no link between having a bat-house or bats in a building and a higher incidence of rabies. Since 1950, there have been only six cases of bat-related rabies mortality in Canada."
To contract rabies you must come into direct contact with an animal carrying the virus, Craig says. Direct contact means that you must have contact with infected blood or saliva and exposure means contact through a break in your skin. This could be a very small (almost invisible) break in the skin or internally (mouth or nose). Avoid direct contact with bats. In all cases where there has been potential exposure (i.e., contact with bat saliva or blood) to humans, contact your local health authority immediately. If possible, collect the bat that has come into direct contact with a person so it can be submitted for rabies testing. Live bats should be placed in a sealable container (equipped with air holes) and kept in a cool, dry place away from pets or humans until testing can be arranged. Use leather gloves to collect the bat, whether it is dead or alive. For more information, see http://www.healthlinkbc.ca/healthfiles/hfile07.stm. Note that Interior Health has changed its policy and no longer requires post-exposure rabies vaccinations if a bat is simply found in a bedroom.
Pet owners should make sure that rabies vaccinations are up-to-date for all pets. Local veterinarians should be consulted whenever pets have been exposed to a bat or any other potentially rabid animal.
Interior Health offers these tips to help protect yourself and your family:
Never touch live or dead bats. Tell children not to play with or touch bats.
Make your home or cabin “bat proof.” Keep doors and windows closed, make sure window screens don’t have any holes, and keep the attic area free of bats by keeping all vents properly screened and by closing off other openings.
If you find a live bat in a room of your home, open the window and close interior doors until the bat leaves.
Seek professional bat-control advice (from a pest control or wildlife specialist) if your home or workplace or is inhabited by bats.
Avoid locations or activities where bats are likely to be found (e.g., caves).
If you have a pet dog, cat, or ferret, make sure they are vaccinated regularly against rabies. Pets that were born and raised in B.C. pose a very low risk of transmitting rabies to humans; however, vaccinating your pets will protect them from rabies.
If you have been bitten or scratched:
Thoroughly wash the wounds with soap and water.
Early treatment is crucial to prevent rabies from progressing. Treatment involves a two-week period of vaccinations that must be administered as soon as possible after exposure.
Facts about bats from the Kootenay Community Bat Project
Bats are not rodents but rather belong to their own group of mammals or “Order” called Chiroptera which means “hand-wing”. The wing of a bat is two layers of skin and the bones look like a human hand with elongated fingers. In fact, bats are far more closely related to primates (such as monkeys and humans) than they are to rodents.
Bats eat huge amounts of flying insects, sometimes more than their own weight in insects per night. That’s like a 150 lb person eating 600 “quarter-pounder” burgers in one day! Many of the insects that bats eat are likely to be mosquitoes.
Different groups of bats eat different things. There are groups of bats that eat fruit, nectar, insects, mammals, fish, or blood. Only three species of bats in the world eat blood and these are the vampire bats of Central and South America. All bats in Canada eat nothing but insects (and other arthropods) and in most cases, only flying insects.
The saliva of vampire bats contains an anti-coagulant that allows the blood to keep flowing after a bite so that the bat can lap up the blood. This chemical is being used as a treatment for strokes because it can help dissolve blood clots in the brain. There is a drug developed called “draculin”.
Bats are not blind. They have eyes and can see, likely better than we can under dimly lit conditions. Some bats (flying foxes found in the old world) navigate using vision alone and appear to be able to see even better than owls!
Bats in Canada navigate and find prey mostly using echolocation. Bats emit regular calls (at the intensity of screams) and then listen to the echo of their voice. By the sound and timing of the echo, they can determine the range, the size and type of objects in front of them, if they are flying, and how fast they are moving. It is such an amazing system that the US Navy studies bats to improve human-developed sonar systems.
There are 16 species of bats in BC (17 if you count the one record of a Big Free-tailed Bat that washed up in 1938 in New Westminster) and half of them are considered vulnerable or threatened.
Bats in Canada either hibernate or migrate in winter. Little is known about bat hibernation sites, especially in western Canada. Bats are extremely sensitive to disturbance when they are hibernating and should be left alone.
Bats expend a huge amount of energy to fly. As a result, they try to save energy when they can. They regularly use a system called torpor where they lower their heart rate, metabolism and body temperature and go into a deep sleep-like condition. It is like a mini-hibernation bout. They do this periodically through the night and during the day depending on local conditions.