How is rabies transmitted from animals to people?
Rabies spreads to people from the saliva of an infected animal through a bite, a scratch, or contact with the mucous membranes of the eyes, nose, or mouth. Bites to the head or neck are most likely to lead to transmission of the virus. Animals that can be infected with rabies include all mammals, but in particular:
In Canada, rabies is also found in wolves, coyotes, and other meat-eating animals. It is rarely found in rodents such as mice, squirrels, chipmunks, groundhogs, rabbits, rats, hamsters, or gerbils, so their bites are not usually a risk for rabies.
- context Wild animals - mostly foxes, skunks, bats, and raccoons.
- context Livestock - mostly cattle but occasionally horses, sheep, goats, and pigs.
- context Pets - mostly cats and dogs, and occasionally ferrets.
What occupations have an increased risk of rabies exposure?
Rabies is an occupational risk for people who work with wild animals, livestock, or pets. Examples of the risks and occupations include:
- context Exposure to wild animals - hunters, trappers, forestry personnel, wildlife biologists, forest rangers, conservation officers, taxidermists, veterinarians and their assistants, zoo personnel, scientists working in caves, hydro workers, and pest control workers.
- context Exposure to livestock - farmers, farm workers, ranchers, veterinarians and assistants, artificial insemination technicians, laboratory animal researchers and technicians, slaughterhouse workers, and meat packers and processors.
- context Exposure to infected pets - veterinarians and their assistants, pet groomers, letter carriers, meter readers, delivery personnel, laboratory animal researchers and technicians, animal control officers, and hunters.
What are some signs of rabies in people and animals?
Workers who may have been exposed to rabies must never wait until they develop signs of the disease. Once the signs appear, the disease is almost inevitably fatal within weeks of symptoms appearing, if not treated.
It is important to recognize the signs of rabies in animals and take precautions immediately following bites, scratches, or other potentially infectious contact.
In people, rabies progresses through several stages. Initially, a person who is bitten may notice unusual feelings or tingling around the wound. Soon afterwards, there is a period of tiredness, possibly with lack of appetite, headache, fever, cough, sore throat, abdominal pain, nausea, vomiting, and diarrhea. A period of extreme worry, irritability, inability to sleep, and depression follows, possibly with hallucinations. "Furious rabies" may follow, for which the signs are strange behaviour, including biting other people. At this stage, victims have an uncontrollable fear of water. This fear is why rabies has sometimes been called "Hydrophobia." Sometimes "paralytic rabies" develops instead of furious rabies. With this form of the disease, the muscles gradually become paralyzed, starting at the site of the bite or scratch. A coma slowly develops, and eventually, death occurs.
In animals, rabies appears in two different forms. It may appear as furious rabies in which the animal changes behaviour, becomes restless, wanders aimlessly, and bites any animal, person, or object in its way. Eventually, the animal becomes paralyzed in the throat and hind legs and dies. Or it may appear as paralytic rabies in which an animal changes behaviour, becomes withdrawn or more affectionate, tries to hide, has difficulty swallowing, and dies after a few days without ever becoming violent.
Not all animals behave in the same manner when they have rabies.
Any animal exhibiting unusual behaviour should be considered a potential rabies hazard for humans.
- context Foxes and skunks may lose their shyness and fear of people, pets, or livestock.
- context Cattle usually become restless and aggressive, bellow loudly, and drool. They may show gradual weakness in the hind legs and appear to be choking.
- context Bats may become active during the day, show up in unusual places such as inside a home or on the ground, be unable to fly or be easy to approach, or make contact with people.
- context Raccoons often appear thin with rough, dirty fur, may foam at the mouth, make unusual noises, walk slowly or with difficulty, and may seem confused and disoriented.
- context Cats can often become extremely vicious.
- context Dogs usually become excitable, and may be vicious, wander aimlessly, and bite for no reason.
How can workers be protected from rabies?
In Canada, rabies management is a shared responsibility among the public, veterinarians, provincial and territorial authorities, the Public Health Agency of Canada, and the Canadian Food Inspection Agency.
Vaccination programs, established to immunize dogs and cats, have effectively reduced rabies in pets. However, rabies will continue to be a threat until the virus can be eliminated from the wild animals that spread the virus to pets and people.
Some workers who are at higher risk of close contact with rabid animals, such as veterinarians or animal control officers, should be immunized before having contact with any animal to ensure they have protection against the rabies virus. For other workers, who are much less likely to encounter rabid animals, it might be sufficient to provide education on the risks and training on protection if they encounter an animal with rabies.
Specific recommendations depend on the individual situation and workplace. The following general recommendations apply to all workers who risk contacting rabid animals:
- requirement Proper precautions for dealing with rabid animals and the possibility of contracting the rabies virus.
- administrative Training to recognize the signs of rabid animals, and to understand reporting procedures and the importance of quick intervention.
- requirement Immunization of workers either before or immediately after exposure to the virus.
- requirement Maintaining good workplace hygiene.
What should I do if I have come into contact with an animal suspected of having rabies?
Workers who have come into contact with the saliva or brain and nervous system tissue or fluids of animals suspected of having rabies must take the following steps without delay:
- context Remove any contaminated clothing, place the clothing in a properly labelled plastic bag, and wash it promptly and separately from other clothing.
- context Immediately clean and flush the area (even if there is no obvious bite or scratch) with soap and water for at least 15 minutes. Use hand sanitizer if soap and water are not available. Cleaning will help wash out the virus. Washing the area or wound is probably the most effective procedure in the prevention of rabies. While cleaning is being done, shield the eyes, nose, and mouth from spray. After cleaning, follow with 70% ethanol or an iodine-containing solution when available.
- context Get medical advice as soon as possible.
- context Avoid suturing (stitching) or covering the wound if one is present.
- context Contact your local public health unit and district veterinarian or local office of the Canadian Food Inspection Agency. If possible, provide them with information related to the name and address of the person exposed, the time and place of the incident, and any other information to help find and identify the offending animal.
Immunizing after contact
People who have had contact with the rabies virus require both the rabies immune globulin (RabIg) and the rabies vaccine (HDCV or PCECV) as soon as possible.
Immunization may be considered after contact in the following situations:
Immunization is usually recommended if the animal makes contact by biting, or if the animal's saliva, body fluid or tissue makes contact with a rash, scratch, open wound, eyes, nose, or mouth.
Wild animals or unwanted dogs or cats suspected of having rabies are humanely euthanized without delay. Vaccination may be discontinued if laboratory tests confirm that the animal involved in the attack is negative for the rabies virus.
Medical professionals generally do not recommend immunization if the animal has had no contact with a person's skin or mucous membranes. Nor is immunization recommended if workers have had only casual contact with the animal, such as petting, with no possible contamination of broken skin or mucous membranes.
Healthy dogs or cats involved in biting incidents are held in confinement for at least 10-14 days, according to provincial regulations. If rabies does not develop within that time, no immunization is required for the injured worker. If signs of rabies do develop, the Canadian Food Inspection Agency should be notified, the animal euthanized and analyzed, and the person's immunization started without delay.
- context The animal appeared to have rabies.
- context The animal may possibly have had rabies.
- context The animal was wild, from a region where rabies is known to be a problem.
- context The animal was a dog or cat that escaped after the contact without being tested.
What is recommended for workplace hygiene?
Workplaces should have a policy and procedures in place to help protect workers. Actions may include to:
- context Develop procedures to prevent contact with the rabies virus in the workplace. Where appropriate, have workplace procedures posted for disinfecting or sterilizing areas that may be contaminated with the rabies virus.
- context Quarantine all wild animals before introducing them into an animal research program. Avoid using animals obtained from a pound in research studies.
- context Use caution if handling animals that have died in vehicle incidents (roadside) since they may have had rabies.
- context Wear protective face masks, gloves, clothes, and shoes when handling anything from an animal suspected of having rabies or when cleaning areas where suspected rabid animals are confined.
- context The rabies virus does not survive long outside of animals. It is generally destroyed by heat, sunlight, or air. If needed, decontaminate all materials for disposal by steam sterilization, chemical disinfection, or incineration.
- context Routinely disinfect working surfaces, tools and instruments, floors and walls that may have been contaminated with fluids from animals, using procedures established for infection control.
- context Use ultraviolet light for disinfecting areas such as laboratories where the rabies virus may become airborne. Always follow the manufacturer's instructions when using ultraviolet equipment.
- context Package infected waste in puncture-proof, leakproof containers. Clearly label and sterilize containers before disposal according to procedures developed for biological hazards.