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Back when “Help” was a song and Johnny Quest was the only hero around, grown-ups would keep kids from petting stray dogs by telling us that it was a sure-fire way to get rabies. Back then, rabies didn’t seem so bad, but the thought of 2 foot long needles slowly injected into my stomach every day for a year to treat it was enough to ensure that stray dogs were left alone. Rabies continues to be a formidable viral illness. In Canada, death due to rabies is almost unheard of anymore with less than two dozen deaths recorded during the last century. But the rest of the globe sees up to 50,000 people succumbing to the viral illness on an annual basis. The reservoir of this potential killer is found mostly in bats, but foxes and skunks can also be carriers. Rabies is on the increase in Canada for some reason. Domestic animals are targeted far more commonly than people. There are several strains of rabies virus that can cause illness in humans. They all belong to the Rhabdoviridae family. Illness is caused by the virus gaining entry into our body tissue, usually through a bite or scratch. Once inoculation occurs, the virus follows our nerve cells back to the brain where it multiplies en masse. It continues to spread and invades our organs, and tends to concentrate in the salivary glands. The diagnosis is very difficult and requires a high degree of suspicion. You also need to have the intact brain of the culprit animal, which is sent for confirmation using electron microscopy.
In the classical case, invasion of the brain results in encephalitis and occurs some time after the initial infection. Fevers, seizures, hyperactivity and diminished consciousness are all signs. Errant signals are sent to various organs including the salivary glands which produce plentiful saliva. Fever and saliva production both consume water resulting in thirst. The muscles in our neck and around the esophagus become sensitized and go into painful spasm when attempting to drink or even breathe. Soon, a fear of water develops. Eventually things progress towards a coma with a very high fatality rate.
Our skin is a wonderful barrier against invasion of rabies. You really need to breach the skin to cause inoculation. Handling nests and excrement from infected animals does not pose a greater risk, but aerosol inhalation is theoretically possible. Caring for infected patients does not increase the risk for medical workers. Veterinarians and wildlife workers are considered to be at risk. Similarly, some travelers who engage in research and teaching activities centered on animals are also at risk. There has been a simple three-dose vaccine available for years which affords protection and is recommended for high risk individuals.
When bitten by an animal which appears to behave unusually, rabies should be suspected. The animals should be isolated, the health department notified and immediate medical attention sought. Plentiful washing of the wound with soap is advised. In suspicious cases, rabies vaccine is administered along with immune globulin. The vaccine is a simple shot in the arm and the immune globulin is generally infiltrated around the wound. Stomach needles are a thing of the past. As always, prevention is the best medicine and it is imperative that the domestic animals be vaccinated against rabies to stem the rising rate. I consider it tragic when children are bitten by an unrestrained pet, but it is almost criminal to be bitten by a non-immunized pet!
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