Rabies

Rabies is a viral infection of animals that can be transmitted to humans. It is caused by a virus, which attacks the central nervous system and eventually affects the brain. The virus is usually found in the saliva of an infected animal. Rabies is almost always fatal once symptoms occur. Rabies can occur in any warm-blooded animal, domestic and wild- commonly, dogs, cats, foxes, raccoons, skunks, wolves and bats. Animals having potential interactions with people such as cattle and horses can acquire rabies and may transmit the disease to humans.

You cannot tell if an animal has rabies by how it looks. Animals with rabies often act strangely. Dogs, cats, and raccoons, for instance, may become mean and bite for no reason. Rabid bats rarely become aggressive. A bat may be rabid if it is active by day, it is found in a place where bats are not usually seen, and/or is unable to fly. These bats are often easily approached, but should never be touched.

Animals with rabies may show a variety of clinical signs. The disease can appear in two forms:

Dumb rabies

• Domestic animals may become depressed and try to hide in isolated places.
• Wild animals may lose their fear of humans and appear unusually friendly.
• Wild animals that usually only come out at night may be out during the day.
• Animals may have paralysis. Areas most commonly affected are the face or neck (which causes abnormal facial expressions or drooling) or the hind legs.

Furious rabies

• Animals may become very excited and aggressive.
• Periods of excitement usually alternate with periods of depression.
• Animals may attack objects or other animals. They may even bite or chew their own limbs.

Symptoms can take 20 to 60 days to appear, although this may vary from days to years, and may depend on wound severity, wound site in relation to nerve supply and distance from the brain, amount and strain of virus, protection provided by clothing, and other factors.

Symptoms progress quickly as the central nervous system is attacked, and the illness generally presents in 1 of 2 ways: “furious rabies” and “dumb rabies”. Furious rabies is more common and is characterized by anxiety and psychological disturbances confusion, agitation, delirium, rage, hallucinations, and hydrophobia. Dumb rabies occurs in approximately 20% of patients and presents with paralysis. In both furious and dumb rabies, death usually occurs within 7 days due to breathing failure caused by paralysis of the respiratory system.

The virus is transmitted through close contact with the saliva of infected animals, most often by a bite or scratch or by licks on broken skin or mucous membranes, such as the eyes, nose or mouth. Person-to-person transmission is theoretically possible, but rare and not well documented. Organ (corneal) transplants from persons dying of undiagnosed central nervous system (CNS) disease have resulted in rabies in recipients. Airborne spread has been demonstrated in a cave where bats were roosting and in laboratory settings, but this occurs very rarely.

Medical professionals can administer post-exposure prophylaxis (vaccination) to a person following exposure to an animal suspected of carrying the disease. There is no treatment for rabies once clinical signs appear.

Wash the bite or scratch thoroughly with soap and water right away. Call your family doctor or go to the nearest hospital emergency department for treatment right away. Call Public Health Sudbury & Districts at 705.522.9200 (toll-free 1.866.522.9200) to report the incident as soon as possible so that an investigation can be conducted.

Pre-exposure Vaccination is recommended for anyone involved in occupations that put them at high risk of rabies exposure. People with continuing high risk of exposure, such as veterinarians, should have their serum tested for rabies antibodies every 2 years; others working with live rabies virus in laboratories or vaccine production facilities who are at risk of inapparent exposure should be tested every 6 months. Those with a titre level of <0.5 IU/mL should be given a booster dose of either HDCV OR PCECV.

All domestic animals should be vaccinated in areas where rabies is known to occur. Canada is not rabies free. Animal owners should consult with their veterinarian about an appropriate vaccination schedule for their pets and livestock.

If you have had a rabies exposure, visit Animal Bites and Scratches or call Public Health Sudbury & Districts at 705.522.9200 as soon as possible.