Animal bites, non-bite exposure, or human-to-human exposure are all ways in which rabies can be transmitted. In most cases, transmission of the virus is caused by the bite of a rabid animal. Rabies cannot be spread through casual contact, such as touching a person with the disease, or contact with noninfectious fluid or tissue.
Rabies transmission can occur in one of a few ways, including:
- Non-bite exposure
- Human-to-human transmission.
A bite from a rabid animal (an animal infected with the rabies virus) is the most common form of rabies transmission. Non-bite exposure and human-to-human exposure are both rare.
Rabies Transmission From Bites
Rabies transmission usually begins when infected saliva of an animal is passed to an uninfected animal, through a bite. From the saliva's point of entry, the rabies virus travels along nerve cells to the brain. It multiplies there and moves to the salivary glands. In a rabid animal, the cycle is repeated when the animal bites a person or another animal.
Rabies Transmission Through Non-Bite Exposure
Rabies transmission from non-bite exposures is rare. Scratches, abrasions, open wounds, or mucous membranes contaminated with saliva or other potentially infectious material (such as brain tissue) from a rabid animal, constitute non-bite exposures. Occasionally reports of non-bite exposure are such that post-exposure prophylaxis is given.
Inhalation of aerosolized rabies virus is also a potential non-bite route of exposure, but with the exception of laboratory workers, most people are unlikely to encounter an aerosol version of the rabies virus.
Other contact, such as petting a rabid animal, or contact with the blood, urine, or feces (e.g., guano) of a rabid animal, does not constitute an exposure and is not an indication for prophylaxis.