Monday, October 20, 2014

Rabies: A Deadly Adirondack Virus

9__ImageFile__nsRajrIkLRjtGkMqkbgskThe recent barrage of publicity regarding ebola has focused everyone’s attention on this particularly deadly virus, however, the relatively isolated nature of the Adirondacks makes our region a most unlikely location for an appearance of such a troublesome disease. In our area there are other viruses that are a much greater threat to the health of the general public than ebola.

At this time of year rabies must be given a top priority, as autumn is the time many infected animals are on the move, and for anyone exposed to this virus who fails to get medical attention the outcome is almost always fatal.

Rabies is a virus that causes the eventual deterioration of the central nervous system, which inevitably leads to death. Transmission occurs when an animal in an advanced stage of the disease bites another mammal. After the virus enters the underlying skin and muscle tissue through infected saliva, it begins to replicate itself by forming various protein molecules within the tissue, and eventually expands into nearby nerve cells. After it invades nerve tissue, the virus slowly progresses through these pathways to the brain, where it becomes firmly established and starts to seriously impact the ability of this critical organ to function properly.

Rabies cartoon circa 1826It often takes several weeks for the virus to become entrenched in the cells beneath the location of the bite, and several more weeks until it can migrate to the nervous system. The location of a bite determines the amount of time the virus needs to reach the brain. For example, should a bite occur on an animal’s hind foot, or ankle, it can take one to two months for the virus to travel the entire length of the body to the brain. For a creature bitten on the neck, ear or face, it may only take a few weeks before the brain is impacted, and the animal’s health begins to rapidly deteriorate.

It is only after the virus invades the brain and starts to replicate itself in massive numbers within the skull that some of this viral material passes into the salivary glands for the continued transmission of this deadly form of life. Prior to this latter stage of the disease, an infected animal is unable to spread the virus, even though the virus may be present in many cells within the nervous system.

Transmission in the wilds almost always occurs from a bite; however, humans have been known to contract rabies when traces of infected saliva are accidentally introduced into a cut or open sore on a person’s hand. This is why trappers are strongly encouraged to wear rubber gloves when handling animals taken from traps, or when removing their hides, as any contact with saliva that may be present on the fur, or in infected tissue exposed during the skinning process can get into a break in the skin and begin the slow, sometimes two month long process, of establishing the virus in their own system. Transmission can also occur if a person with a small amount of infected material on that hand comes in contact with the lining of their eye. This is why it is important to refrain from rubbing your eye immediately after handling the carcass of a recently killed fox, coyote, raccoon, skunk or other wild creature.

220px-Middle_Ages_rabid_dogOnce an infected animal dies, the virus is unable to remain viable and also will perish. The amount of time required to render the virus harmless within the body of a dead animal depends greatly on temperature. Because warmth facilitates the rate of decay, handling an animal that has been dead for a day or two during the summer is deemed safe by some experts. Cold temperatures, on the other hand, tend to preserve the structural form of the virus for a longer period of time. It may take a week or more when near freezing temperatures prevail before the virus experiences enough decay to render it harmless.

Rabies is a disease that is not very common within the Adirondacks, especially this year, but a person can never be too cautious when dealing with wild animals, as it is almost always fatal once the virus progresses into your central nervous system. This is why it is important never to touch a wild animal, no matter how tame the creature may appear to be. Even being scratched by a raccoon or some other critter that you might like to feed from your hand can prove to be potentially fatal, as infected saliva may be present on the claws of the animal, which can introduce the virus into the skin through the scratch.

There is an extremely effective treatment after being exposed to the rabies. However, this treatment must occur soon after the virus was introduced while it is still contained in the skin or muscle cells. Listening to stories of ebola cases that are presented in the news can be disheartening, but I always worry more about rabies here in the Adirondacks.

Illustrations: Above, rabies around the world in 2008 (WHO Map); middle, a cartoon about rabies in London from 1826; and below, a woodcut from the Middle Ages showing a rabid dog.

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Tom Kalinowski is an avid outdoor enthusiast who taught field biology and ecology at Saranac Lake High School for 33 years. He has written numerous articles on natural history for Adirondack Life, The Conservationist, and Adirondack Explorer magazines and a weekly nature column for the Lake Placid News. In addition, Tom’s books, An Adirondack Almanac, and his most recent work entitled Adirondack Nature Notes, focuses on various events that occur among the region’s flora and fauna during very specific times of the calendar year. He also spends time photographing wildlife. Tom’s pictures have appeared in various publications across the New York State.

4 Responses

  1. Paul says:

    Tom, I agree Ebola isn’t a worry for almost everyone in the US. But for rabies it is pretty safe to say that if you can get post-exposure treatment (Igg and vaccination) prior to symptoms you have a very, very, good chance of survival (like close to 100%). W/o that you are toast for sure. So if you think you have been exposed get to the Dr. A bat bite is the most common way for a human to get rabies (if not treated) and die. Often you don’t know you have been bitten. If you or your kids have spent a night in a house or camp with a bat catch it and get it tested, or get treated if you can’t get the bat. Don’t, repeat, don’t let it go!!

    • Tom Kalinowski says:

      Hi Paul:
      You offer great advice. Because of the very small size of the teeth of bats, they often do not leave conspicuous marks after biting. Many people often don’t realize that they have been during the night when they are sound asleep. Thankfully, very few bats that occur in the Adirondacks seem to carry this disease. Fall is the time when bats are migrating toward their wintering sites and they are occasionally known to stray into unfamiliar places in their travels and may encounter people.

  2. Bill says:

    Question. Is there a preventive cleaning one should follow to clean a Haveaheart trap when an animal has been trapped but might have saliva of another animal that might have been infected with rabies?

  3. Tom Kalinowski says:

    Hi Bill: I believe that bleach is quite effective in killing various pathogens, however, from what I understand about the rabies virus, simply leaving the trap in a warm spot for a few days will destroy any rabies virus that may be on it. I could be wrong, but I believe that this virus is not easily transmitted on external objects, especially if it does not come into contact with a break in your skin.

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