The rabies virus is transmitted through saliva or brain/nervous system tissue of an animal infected with rabies. The infectious material then needs to pass into the body, usually through a bite wound, open cuts in skin, or less commonly through mucous membranes such as the mouth or eyes.
A person can only get rabies by coming in contact with these specific excretions and tissues. Rabies virus becomes noninfectious when it dries out, for example, when infected saliva or other material is exposed to sunlight.
You have not been exposed to rabies if
• the animal doesn't have rabies itself – most dogs do not have rabies
• you have petted or handled an animal
• you have had contact with blood, urine or feces
In extremely rare cases, humans have been infected because they inhaled aerosoled saliva that contained the virus (e.g., in caves with very large bat populations) and through organ transplants from donors with rabies infections.
If you been bitten or scratched by an animal that is unknown to you and/or that appears unwell, you may have been exposed to rabies.
Please take any potential exposure seriously. Thoroughly wash the wound with soap and water and seek urgent medical attention.
Immediately after transmission of the virus (e.g. through a bite), there are no symptoms. The virus then travels through the nervous system, again without causing any symptoms, until it reaches the brain. Once in the brain (usually 1-3 months after the bite) the virus causes a variety of non-specific problems: general malaise, fatigue, headache and general weakness or discomfort. There may also be discomfort or a prickling or itching sensation at the site of bite. As the brain infection progresses, more specific symptoms are apparent and include: insomnia, anxiety, confusion, slight or partial paralysis, excitation, hallucinations, agitation, hypersalivation (increase in saliva), difficulty swallowing, and hydrophobia (fear of water). Eventually the patient falls into a coma and dies.
Early rabies symptoms can be easily confused with other diseases, and often rabies goes unrecognized. However, if rabies is suspected (usually because of a potential exposure to rabies in the previous few months), several tests are necessary to diagnose rabies ante-mortem (before death) in humans. Tests are performed on samples of saliva, serum, spinal fluid, and skin biopsies of hair follicles at the nape of the neck, and analyzed for the presence of virus or antibodies to it.
Unfortunately, by the time a patient has clinical symptoms of rabies there is very little that can be done except palliative care. Medical teams can use sedation and tranquilizers to prevent the patient suffering from the distressing symptoms, but no cure exists.
A handful of people with early symptoms of rabies have recovered using the Milwaukee protocol. This is an intensive procedure where a coma is induced to protect the brain whilst the body fights off the rabies virus. However, even with intensive care facilities, the success rate remains extremely low.
Bites or and contact with saliva from a person infected with rabies during the symptomatic stage of the disease could theoretically transmit rabies, and people who have been exposed to rabies patients should be offered post- exposure prophylaxis. Documented cases of rabies known to be caused by human-to-human transmission have occurred among recipients of transplanted corneas and other solid organs, when rabies infection in the donor was not suspected.
Casual contact with a person infected with symptomatic rabies (touching unbroken skin or contact with non-infectious tissues or bodily fluids) cannot transmit the rabies virus to another person. Puncture wounds due to needle sticks penetrating neural tissue during the care of a rabies patient does constitute an exposure to rabies and requires treatment. It may be possible to transmit the virus from a symptomatic rabies patient through mouth-to-mouth contact or kissing. The virus has been reported to be present in sperm or vaginal secretions, so transmission through sexual intercourse with an infected person may be possible. Oral sex with a person infected with the rabies virus may also carry a risk.
If you have risky contact with an infectious person 14 days prior to the onset of clinical symptoms, post-exposure prophylaxis is recommended. Risky behaviors include: bites, kisses or other direct contact between saliva and mucous membranes or broken skin, sexual activity, and sharing eating or drinking utensils or cigarettes.
No, patients who are undergoing preventative vaccination against rabies are not able to transmit the virus to others. The vaccine does not contain live virus but rather a killed form of the virus and is non-infectious.
Worldwide, the main reservoir of the rabies virus is the dog. Rabies can also be present in different wildlife species, such as raccoons, skunks, mongooses, jackals, foxes, coyotes, raccoon dogs and bats. The animals that can act as reservoirs of rabies infections vary across countries, but because of the less common contact between humans and wildlife, transmission to people is most commonly from dogs.
Cats are not natural reservoirs of the virus, but they can become readily infected by rabies and can transmit the disease. Any mammal can theoretically be infected with rabies and can therefore transmit the disease to humans if exposure occurs.
Small rodents are not reservoirs of rabies, and are rarely reported to be infected with rabies, so a bite from a squirrel, rat, mouse, guinea pig, hamster, rabbit, chipmunk or gerbil generally does not usually require post exposure prophylaxis. However, larger rodents such as groundhogs and beavers have occasionally been reported to be rabid.
Bats can be infected with rabies, and bats that are behaving abnormally (e.g. venturing out during the daytime, crawling on the ground, flying aggressively into a human, or trapped in a room) have a high chance of being rabid.
In general, any unprovoked mammal that bites a person could be rabid, and PEP should be considered for the bite victim, based upon medical advice and laboratory test results. When the animal is not available for testing, medical advice should be sought regarding the need for rabies vaccination.
Experiments on dogs, cats, and ferrets have shown that rabies virus can be excreted in the saliva of infected animals several days before they show signs of illness. Extensive studies have not been done for wildlife species, but it is known that wildlife species also excrete rabies virus in their saliva before the onset of signs of illness. This means that animals can transmit rabies to other animals and people even if they are not yet sick because of their infection.
Do not attempt to capture the bat yourself, unless you are well-equipped to do so. Leave the room and close the door.Contact an animal control officer, and determine if anyone in the household (including pets) could have possibly been exposed to the bat. Contact a medical professional, veterinarian, or public health official to report the exposure and ask about rabies vaccination.
Often a person is not aware that they were bitten by a bat. If you should awaken from sleep and notice a bat in the room, contact a medical professional immediately. Bite marks from bats are sometimes hard to see due to the relatively small size of their teeth, and it is possible for transmission through a bat bite to go unnoticed as a result. Watch our Bats and rabies video for more information.