Please read the Disclaimer at the end of this page.
RABIES OVERVIEW — Rabies is a disease caused by a virus that is nearly always fatal. The virus infects the brain of animals, leading to unusual and often aggressive behavior. The rabies virus is present in the saliva of the infected animal and is spread to humans or other animals when the saliva gets into the body through a bite or scratch or through contact with the eyes, nose, or mouth. The risk of getting rabies is greater if a person is bitten multiple times by an infected animal or if the bites are on the head, neck, or torso. Anyone with a potential rabies exposure should seek medical care; although not everyone who is exposed to rabies gets sick, almost everyone who does get sick from rabies dies.
In resource-limited countries, most rabies cases in humans are caused by dog bites. Many of these countries are in Africa, Asia, the Middle East, Eastern Europe, and to a lesser extent, Mexico and Central and South America.
In the United States, the type of rabies spread primarily by dogs has been largely eliminated because of animal vaccination and stray animal control programs. Bats now pose the greatest risk for rabies exposure to humans in North America. By contrast, raccoons, skunks, and foxes pose the greatest risk for exposing domestic animals, including dogs, to rabies.
This topic discusses strategies to prevent rabies after being bitten or exposed by an animal known to be infected with rabies or an animal suspected of having rabies. The general management of animal bites is discussed in a separate article. (See "Patient education: Animal and human bites (Beyond the Basics)".)
POST-BITE RABIES PREVENTION — Rabies virus infection can be prevented, even after a bite or a scratch from an infected animal occurs.
Wound care — Bite or scratch wounds should be washed thoroughly as soon as possible with soap and lots of water. This will reduce the risk of the rabies virus entering the body. (See "Rabies immune globulin and vaccine".)
Rabies vaccine and immune globulin — A series of injections, which include human rabies immune globulin (RIG) and rabies vaccine, can prevent rabies, even after an exposure (such as a bite or scratch) occurs. This preventive strategy is called post-exposure prophylaxis.
●RIG contains antibodies against the rabies virus, which help provide immediate protection against the spread of rabies virus infection.
●The rabies vaccine, which stimulates the body to produce its own antibodies against the rabies virus, provides protection within approximately two weeks.
In the United States, most people get a series of four doses of vaccine over two weeks, and RIG is given only on the first visit. Side effects of rabies vaccine and RIG are generally mild and self-limiting; they can include pain at the injection site (similar to those that may follow a flu shot), low-grade fever, and mild muscle aches.
For children and pregnant women, there are no contraindications to post-exposure prophylaxis if a rabies virus exposure has occurred. However, if the animal can be tested or observed, rabies may be ruled out, in which case post-exposure prophylaxis is not needed. (See 'When treatment should be delayed during the observation period' below.)
How to determine if rabies prophylaxis is needed? — Certain information is needed to determine if post-exposure rabies prophylaxis is needed or if it can be delayed while the animal is observed or tested for rabies virus. Contacting your local public health agency can be valuable in helping you understand the risk of transmission after a potential exposure.
The information needed includes:
●Whether the person was bitten or scratched, and the location of the wounds.
●The type of animal involved (table 1).
●Whether the exposure was provoked or unprovoked (most animals will attack when provoked, but animals with rabies are more likely to attack even when not provoked).
●Whether the animal was previously vaccinated against rabies.
●The likely presence of rabies virus infection in that animal species in the region.
●The availability of the animal for testing or observation. Public health laboratories offer testing of animals for rabies. The standard tests for rabies in animals are very reliable for identifying rabies virus infection in the animal or ruling it out.
If prophylaxis is recommended — Post-exposure prophylaxis should be given promptly in response to any severe exposure (eg, multiple bites or a bite on the head, neck, or trunk) from an animal likely to be rabid (table 1). If the animal can be safely captured by someone trained in animal handling, the animal should be tested for rabies virus as soon as possible. The state or local health department should be consulted to help determine if post-exposure prophylaxis can wait pending testing results. If it is determined that the vaccination series should be initiated, it can be discontinued if the animal tests negative for rabies virus.
If the type of exposure is of lower risk (eg, bite wound to an arm or leg, or a non-bite exposure), then post-exposure prophylaxis should be delayed if the animal can be tested promptly (ie, within a few days). Delayed treatment is also the preferred option when the biting animal is a healthy pet (such as a dog, cat, or ferret), and is available for observation. (See 'When treatment should be delayed during the observation period' below.)
If post-exposure prophylaxis is needed and the person has not received a rabies vaccine series in the past:
●One dose of RIG is given immediately. As much of the RIG dose as possible is injected into and around the wound(s). RIG should not be given in the same body part as the vaccine.
●The rabies vaccine should also be given as soon as possible. The rabies vaccine is given into a muscle, usually in the upper arm. The vaccine is given again on the 3rd, 7th, and 14th days after the exposure. A fifth dose of rabies vaccine is recommended 28 days after the exposure if the person has a medical condition that is likely to interfere with their ability to respond to the vaccine (eg, a weak immune system).
Some people have received rabies prophylaxis before an exposure (eg, veterinarians, veterinary technicians, animal control officers, people visiting places of higher risk for rabies exposure). These people, as well as those who have received a full course of rabies vaccine after a past exposure, only require two doses of rabies vaccine after exposure. RIG should not be given to people who have previously received a recommended course of rabies vaccine.
When treatment should be delayed during the observation period — State or local health departments should be consulted to help make decisions about when treatment can be delayed during the observation period. If the exposure occurred through contact (eg, bite, multiple scratches) with a healthy dog, cat, or ferret, and the animal is available for observation, rabies prophylaxis should generally be delayed while the animal is observed for 10 days. There is no specific recommendation about an observation period for other species of animals.
A rabid animal will usually show signs of rabies within several days of having the rabies virus in its saliva. If the animal develops signs of rabies, post-exposure prophylaxis should be started immediately. If the animal tests negative, prophylaxis can be discontinued. (See 'Rabies vaccine and immune globulin' above.)
If the animal remains healthy during the 10-day observation, then the animal did not have rabies virus in its saliva at the time of the potential exposure, and the bite victim does not need vaccine or RIG. Animals that have been vaccinated against rabies are very unlikely to be rabid. However, because vaccine failures can occur, dogs, cats, and ferrets should be observed for 10 days following the exposure regardless of vaccination history.
Indirect exposure — Many people receive post-exposure prophylaxis following an "indirect exposure." For example, if a pet dog gets into a fight with a rabid or potentially rabid wild animal, the owner will frequently comfort their pet immediately. If there is infectious saliva from the attacking animal on the pet and this saliva gets into the owner's body (eg, through a scratch or wound or by getting into the eyes, nose, or mouth), there may be a possible risk for rabies. However, there has never been a documented case of human rabies resulting from this type of exposure.
Although post-exposure prophylaxis in cases of indirect exposure is rarely indicated, specific situations should be discussed with a local public health official. In the United States, further information is available online from the Centers for Disease Control and Prevention.
RABIES AND TRAVEL — Rabies in dogs is still common in many resource-limited countries. When traveling to countries where rabies is common, you should avoid approaching, touching, or feeding all wild and domestic animals. If you are bitten or scratched, you should wash the area immediately and seek expert advice about the need for post-exposure prophylaxis.
In resource-limited countries, the availability and type of rabies vaccine and immune globulin vary considerably. If a person has a high-risk exposure to rabies, he or she should consult with someone who can provide reliable information and care, such as a knowledgeable health care provider at a hospital or university, or a consular or diplomatic official representing your country. If a travel agency or service was used to help plan your trip, the staff may be able to identify someone who can provide appropriate consultation.
In some cases, vaccination before a potential exposure (ie, "pre-exposure prophylaxis") may be recommended, for example, if you are traveling to a resource-limited country and might be living in conditions in which exposure to rabid and potentially rabid animals is possible and immediate access to post-exposure prophylaxis may be limited. The decision to have pre-exposure rabies vaccination should be discussed with a health care provider who is knowledgeable about travel medicine (eg, a travel medicine or infectious disease clinician).
It is important to know that receiving pre-exposure rabies vaccination does not eliminate the need for post-exposure prophylaxis if you are exposed to rabies. However, if you have previously had a full course of rabies vaccine (either pre-exposure or post-exposure) and are exposed to a rabid animal, you only need two additional doses of rabies vaccine and no rabies immune globulin. (See "Patient education: Vaccines for travel (The Basics)".)
ADVICE REGARDING SPECIFIC ANIMALS AND RABIES — Contact with wild animals and unfamiliar domestic animals should always be avoided. Wild animals should not be kept as pets and should never be handled by people who are not properly trained and vaccinated.
Domestic animals — In the United States, dogs, cats, and ferrets that have received rabies vaccination are very unlikely to be infected with rabies. The number of rabies cases among domestic animals, such as dogs and cats, declined markedly in the United States in the 1930s and 40s due to rabies vaccination and stray animal control programs.
Domestic animals should be kept up-to-date regarding rabies booster vaccination to assure their ongoing protection. Rabies booster vaccines are given every one to three years, depending upon the vaccine used.
Although the likelihood of rabies in domestic animals is small, it varies by region. In the United States, rabies is most often reported in dogs along the United States-Mexico border and in Puerto Rico, and in cats in areas of rabid raccoon activity. However, sporadic cases of rabies occur in domestic animals outside of these areas. In addition, domestic animals that have been imported from areas of the world where rabies is more common have occasionally developed rabies after arrival; these animals can pose a risk to humans and other animals.
Wild animals — Bites from certain kinds of wild animals are considered to carry a risk for rabies unless the animal is proven not to be infected by testing. Post-exposure prophylaxis should be given immediately to anyone who is bitten or scratched unless the animal is caught and tested promptly. (See 'Rabies vaccine and immune globulin' above.)
In the United States, raccoons, skunks, foxes, bats, and coyotes are the most commonly infected species. Among large rodents, rabies has been reported in woodchucks and beavers in areas where raccoon rabies is common.
Small rodents, such as squirrels, chipmunks, rats, hamsters, gerbils, guinea pigs, mice, and lagomorphs, such as rabbits, are almost never found to be rabid, and there has never been a reported case of rabies transmission to a human from one of these animals. Although these animals are at risk for developing rabies, this is rarely observed because small animals are usually killed or severely injured during an initial attack by a rabid animal.
However, pet rabbits and rodents that are caged outdoors could potentially get infected with rabies virus. These pets are at risk for exposure to rabid wild animals, and under certain circumstances the pet could survive an exposure. Decisions about post-exposure prophylaxis for people bitten by such animals must be made based on the individual situation; you should consult local or state public health authorities for advice.
Bats — Rabies occurs in many species of bats, and most cases of rabies in humans in the United States are caused by exposure to bats. To prevent rabies:
●Anyone who is bitten or scratched by a bat should receive post-exposure prophylaxis, unless the bat can be safely captured and tests negative for rabies.
●Sometimes, bats can bite and transmit rabies without the victim being aware of the bite. As a result, the following precautions are recommended:
•Post-exposure prophylaxis is recommended if a person has direct physical contact with a bat, unless the exposed individual is certain that there was no bite or scratch, or the bat was tested and found not to be rabid.
•If there is any uncertainty about possible contact (eg, a bat got into a room where a person was sleeping or was found in a room with a child or other person who may not be able to recall or report contact), advice should be sought from the state or local health department.
●Bats should never be kept as pets and should not be picked up or handled, except by a person who has been trained and has received rabies vaccination. If a bat is found in a home, avoid touching it. If no person or pet was exposed to the bat, it should be allowed to escape outdoors. If it is not feasible to allow the bat to escape, advice about safely capturing the bat is available at www.cdc.gov. Individuals can also contact their state or local health department with questions about assessing a potential rabies exposure and/or testing captured bats.
Livestock — Among domestic livestock, rabies is most likely to occur in cows. Horses, goats, and other livestock species are rarely affected. Anyone who is bitten by, or has other saliva exposure to, a potentially rabid livestock species should be managed individually, in consultation with state or local public health authorities.
WHERE TO GET MORE INFORMATION — Your health care provider is the best source of information for questions and concerns related to your medical problem. This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for health care professionals, are also available. Some of the most relevant are listed below.
Patient level information — UpToDate offers two types of patient education materials.
The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.
Patient education: Rabies (The Basics)
Patient education: Animal and human bites (The Basics)
Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.
Patient education: Vaccines for travel (The Basics)
Patient education: Animal and human bites (Beyond the Basics)
Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.
Diagnostic approach to the patient with a suspected spider bite: An overview
Bites of recluse spiders
Clinical manifestations and diagnosis of rabies
Immunizations for travel
Pasteurella infections
Rabies immune globulin and vaccine
Animal bites (dogs, cats, and other animals): Evaluation and management
Indications for post-exposure and pre-exposure rabies prophylaxis
Zoonoses: Cats
Zoonoses: Dogs
Zoonoses: Animals other than dogs and cats
The following organizations also provide reliable health information.
●National Library of Medicine
(https://medlineplus.gov/healthtopics.html)
●Centers for Disease Control and Prevention (CDC)
Toll-free: (800) 311-3435
●World Health Organization
(www.who.int/health-topics/rabies)
[1-6]
