What is rabies

Rabies is caused by infection with the rabies virus or other viruses in the lyssavirus family including bats. Rabies is a viral disease of the central nervous system (the brain and the spinal cord) and can be fatal if it is not treated promptly. Rabies is usually acquired from a bite or scratch from an infected animal such as dogs, cats, bats, foxes, raccoons, skunks, wolves, monkeys and mongooses. Rabies can also be contracted from contact with broken skin, or through organ transplantation. The rabies virus is found in the saliva of infected animals and most rabies cases develop from bites or scratches from wild animals that break the skin.

Transmission can also occur when a rabid animal licks abraded or broken skin or the eyes, nose or mouth, although this is rare. There have also been rare cases where rabies acquired from bats may not have come from direct contact, but occurred after people visited caves where rabid bats lived, prompting the idea that rabies may be transmitted through airborne particles.

Animals most likely to transmit rabies in the United States include bats, coyotes, foxes, raccoons and skunks. The vast majority of rabies cases reported to the Centers for Disease Control and Prevention (CDC) each year occur in wild animals like raccoons, skunks, bats, and foxes. Approximately 120,000 animals or more are tested for rabies each year in the United States, and approximately 6% are found to be rabid. The proportion of positive animals depends largely on the species of animal and ranges from <1% in domestic animals to >10% of wildlife species.

In developing countries of Africa, Africa and Central and South America and Southeast Asia, stray dogs are the most likely to spread rabies to people. There are an estimated 15,000 cases of rabies worldwide each year.

The early symptoms of rabies in people are similar to that of many other illnesses, including fever, headache, and general weakness or discomfort. As the disease progresses, more specific symptoms appear and may include insomnia, anxiety, confusion, slight or partial paralysis, excitation, hallucinations, agitation, hypersalivation (increase in saliva), difficulty swallowing, and hydrophobia (fear of water). Death usually occurs within days of the onset of these symptoms.

Once a person begins showing signs and symptoms of rabies, the disease is nearly always fatal. An established infection of rabies in invariably fatal with death occurring in 10-14 days. There have only been 2 reported cases of survival from clinical rabies. However, treatment before this happens is very effective. There’s also a vaccine for people at risk of being infected. For this reason, anyone who may have a risk of contracting rabies should receive rabies vaccines for protection.

You should ensure you do not pat or play with animals when you are overseas in an area where rabies is known to occur. Avoid contact with stray animals including cats and dogs.

Speak to your doctor if you are traveling to a country where there is a rabies virus risk. You may benefit from rabies vaccination – human diploid cell vaccine (HDCV).

If you are bitten or scratched by a bat or mammal including cat or dog, you should:

• Wash the wound thoroughly with water and soap if available
• Apply an antiseptic
• Seek medical attention as soon as possible

Rabies signs and symptoms

The first symptoms include a tingling, itching or cold feeling at the site of the bite, progressing within days to symptoms of cerebral dysfunction, anxiety, confusion, agitation. This may be followed by a low-grade fever and general feeling of illness. These first symptoms of rabies may be very similar to those of the flu including general weakness or discomfort, fever, or headache. These symptoms may last for days. This is then generally followed by chills, difficulty swallowing, restlessness, abnormal behavior (such as outbursts of anger or extreme excitability), drooling and severe muscle spasms. As the disease progresses, the person may experience delirium, abnormal behavior, hallucinations, and insomnia. There may also be convulsions and paralysis. Rabies is also called hydrophobia (meaning fear of water) because it causes painful muscle spasms in the throat that prevent swallowing.

Symptoms may begin between 9 and 90 days after a bite from an infected animal, but it usually takes at least a month before symptoms first appear.

The acute period of disease typically ends after 2 to 10 days. Once clinical signs of rabies appear, the disease is nearly always fatal, and treatment is typically supportive.

The first symptoms of rabies may be very similar to the flu and may last for days can include:

• a high temperature (fever) of 38 °C (100.4 °F) or above
• a headache
• feeling anxious or generally unwell
• in some cases, discomfort at the site of the bite.

Other symptoms appear a few days later, such as:

• confusion or aggressive behavior
• seeing or hearing things (hallucinations)
• producing lots of saliva or frothing at the mouth
• muscle spasms
• difficulty swallowing and breathing
• inability to move (paralysis)

Once symptoms appear, rabies is almost always fatal. In these cases, treatment will focus on making the person as comfortable as possible.

Disease prevention includes administration of both passive antibody, through an injection of human immune globulin and a round of injections with rabies vaccine.

Once a person begins to exhibit signs of the disease, survival is rare. To date less than 10 documented cases of human survival from clinical rabies have been reported and only two have not had a history of pre- or postexposure prophylaxis.

Rabies in humans causes

Rabies infection is caused by the rabies virus. The virus is spread through the saliva of infected animals. Infected animals can spread the virus by biting another animal or a person. In rare cases, rabies can be spread when infected saliva gets into an open wound or the mucous membranes, such as the mouth or eyes. This could occur if an infected animal were to lick an open cut on your skin.

Animals that can transmit the rabies virus

Any mammal (an animal that suckles its young) can transmit the rabies virus. The animals most likely to transmit the rabies virus to people include:

Pets and farm animals

• Cats
• Cows
• Dogs
• Ferrets
• Goats
• Horses

Wild animals

• Bats
• Beavers
• Coyotes
• Foxes
• Monkeys
• Raccoons
• Skunks
• Woodchucks

In rare cases, the virus has been transmitted to tissue and organ transplant recipients from an infected organ.

Risk factors for human rabies

Factors that can increase your risk of rabies include:

• Traveling or living in developing countries where rabies is more common, including countries in Africa and Southeast Asia
• Activities that are likely to put you in contact with wild animals that may have rabies, such as exploring caves where bats live or camping without taking precautions to keep wild animals away from your campsite
• Working in a laboratory with the rabies virus
• Wounds to the head or neck, which may help the rabies virus travel to your brain more quickly.

The Rabies Virus

Rabies virus belongs to the order Mononegavirales, viruses with a nonsegmented, negative-stranded RNA genomes. Within this group, viruses with a distinct “bullet” shape are classified in the Rhabdoviridae family, which includes at least three genera of animal viruses, Lyssavirus, Ephemerovirus, and Vesiculovirus. The genus Lyssavirus includes rabies virus, Lagos bat, Mokola virus, Duvenhage virus, European bat virus 1 & 2 and Australian bat virus.

Structure

Rhabdoviruses are approximately 180 nm long and 75 nm wide. The rabies genome encodes five proteins: nucleoprotein (N), phosphoprotein (P), matrix protein (M), glycoprotein (G) and polymerase (L). All rhabdoviruses have two major structural components: a helical ribonucleoprotein core (RNP) and a surrounding envelope. In the ribonucleoprotein core, genomic RNA is tightly encased by the nucleoprotein. Two other viral proteins, the phospoprotein and the large protein (L-protein or polymerase) are associated with the ribonucleoprotein core.

The glycoprotein forms approximately 400 trimeric spikes which are tightly arranged on the surface of the virus. The M protein is associated both with the envelope and the ribonucleoprotein core and may be the central protein of rhabdovirus assembly. The basic structure and composition of rabies virus is depicted in the longitudinal diagram below.

Rabies is an RNA virus. The genome encodes 5 proteins designated as N, P, M, G, and L. The order and relative size of the genes in the genome are shown in the figure below. The arrangement of these proteins and the RNA genome determine the structure of the rabies virus.

Replication

The fusion of the rabies virus envelope to the host cell membrane (adsorption) initiates the infection process. The interaction of the G protein and specific cell surface receptors may be involved.

After adsorption, the virus penetrates the host cell and enters the cytoplasm by pinocytosis (via clathrin-coated pits). The virions aggregate in the large endosomes (cytoplasmic vesicles). The viral membranes fuse to the endosomal membranes, causing the release of viral ribonucleoprotein core into the cytoplasm (uncoating). Because lyssaviruses have a linear single-negative-stranded ribonucleic acid (RNA) genome, messenger RNAs (mRNAs) must be transcribed to permit virus replication.

A viral-encoded polymerase (L gene) transcribes the genomic strand of rabies RNA into leader RNA and five capped and polyadenylated mRNAs, which are translated into proteins. Translation, which involves the synthesis of the N, P, M, G and L proteins, occurs on free ribosomes in the cytoplasm. Although G protein synthesis is initiated on free ribosomes, completion of synthesis and glycosylation (processing of the glycoprotein), occurs in the endoplamsic reticulum (ER) and Golgi apparatus. The intracellular ratio of leader RNA to N protein regulates the switch from transcription to replication. When this switch is activated, replication of the viral genome begins. The first step in viral replication is synthesis of full-length copies (postive strands) of the viral genome. When the switch to replication occurs, RNA transcription becomes “non-stop” and stop codons are ignored. The viral polymerase enters a single site on the 3’ end of the genome, and proceeds to synthesize full-length copies of the genome. These positive strands of rabies RNA serve as templates for synthesis of full-length negative strands of the viral genome.

During the assembly process, the N-P-L complex encapsulates negative-stranded genomic RNA to form the ribonucleoprotein core, and the M protein forms a capsule, or matrix, around the ribonucleoprotein core. The ribonucleoprotein core-M complex migrates to an area of the plasma membrane containing glycoprotein inserts, and the M-protein initiates coiling. The M-ribonucleoprotein core complex binds with the glycoprotein, and the completed virus buds from the plasma membrane. Within the central nervous system (CNS), there is preferential viral budding from plasma membranes. Conversely, virus in the salivary glands buds primarily from the cell membrane into the acinar lumen. Viral budding into the salivary gland and virus-induced aggressive biting-behavior in the host animal maximize chances of viral infection of a new host.

How is rabies transmitted

Rabies occurs in 2 main epidemiological settings:

• Urban rabies: which is most commonly transmitted to humans through rabid dogs and sometimes cats; and
• Sylvan (wild) rabies: maintained in the wild by a number of animal reservoirs including foxes, skunks, jackals, mongooses and bats.

Rabies is usually transmitted through animal bites, however, bites leading to rabies varies from 10% on the legs to 80% on the head.

It is also possible, but quite rare, that people may get rabies if infectious material from a rabid animal, such as saliva, gets directly into their eyes, nose, mouth, or a wound.

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 postexposure prophylaxis is given.

Inhalation of aerosolized rabies virus is also a potential non-bite route of exposure, but except for laboratory workers, most people won’t encounter an aerosol of rabies virus.

Other contact, such as petting a rabid animal or contact with the blood, urine or feces of a rabid animal, does not constitute an exposure.

The only well-documented cases of rabies caused by human-to-human transmission occurred among eight recipients of transplanted corneas, and recently among three recipients of solid organs. Guidelines for acceptance of suitable cornea and organ donations, as well as the rarity of human rabies in the United States, reduce this risk.

In addition to transmission from cornea and organ transplants, bite and non-bite exposures inflicted by infected humans could theoretically transmit rabies, but no such cases have been documented. Casual contact, such as touching a person with rabies or contact with non-infectious fluid or tissue (urine, blood, feces) does not constitute an exposure and does not require postexposure prophylaxis. In addition, contact with someone who is receiving rabies vaccination does not constitute rabies exposure and does not require postexposure prophylaxis.

Once the virus has entered the body, it replicates in the muscle cells near the entry wound. It then penetrates the nerve endings and travels in the oxoplasm to the spinal cord and brain. In the central nervous system (brain and spinal cord), the virus again proliferates before spreading to the salivary glands, lungs, kidneys and other organs via the autonomic nerves.

What happens once the Rabies virus has entered your body

The Infectious Path of the Rabies Virus:

1. An animal is bitten by a rabid animal.
2. Rabies virus from the infected saliva enters the wound.
3. Rabies virus travels through the nerves to the spinal cord and brain. This process can last approximately 3 to 12 weeks. The animal has no signs of illness during this time.
4. When it reaches the brain, the virus multiplies rapidly and passes to the salivary glands. The animal begins to show signs of the disease.
5. The infected animal usually dies within 7 days of becoming sick.

Rabies incubation period

From numerous studies conducted on rabid dogs, cats, and ferrets, scientists know that when the rabies virus is introduced into a muscle through a bite from another animal, it travels from the site of the bite to the brain by moving within nerves. The animal does not appear ill during this time.

The time between the bite and the appearance of symptoms is called the incubation period and it may last for weeks to months. A bite by the animal during the incubation period does not carry a risk of rabies because the virus has not yet made it to the saliva.

The Virus Reaches the Brain

Late in the disease, after the virus has reached the brain and multiplied there to cause an inflammation of the brain, it moves from the brain to the salivary glands and saliva.

Also at this time, after the virus has multiplied in the brain, almost all animals begin to show the first signs of rabies. Most of these signs are obvious to even an untrained observer, but within a short period of time, usually within 3 to 5 days, the virus has caused enough damage to the brain that the animal begins to show unmistakable signs of rabies.

Extensive studies on dogs, cats, and ferrets show that the rabies virus can be excreted in the saliva of infected animals several days before illness is apparent. Such extensive studies have not been done for wildlife species, but it is known that wildlife species do excrete rabies virus in their saliva before the onset of signs of illness. The excretion of virus may be intermittent, and the relative amount of excreted virus may vary greatly over time, before and after the onset of clinical signs.

The reason there is so much variation in the time between exposure and the onset of the disease is that many factors come into play, including the site of the exposure, the type of rabies virus, and any immunity in the animal or person exposed.

Risk factors for Rabies

Being in contact with an infected dog, namely receiving a bite from said dog, is the main risk factor in contracting Rabies. Worldwide, dogs still pose a significant risk for transmitting rabies, however. Bats, skunks, raccoons, foxes and other animals can also be sources of rabies virus.

What to do if you’ve been bitten or scratched

If you’ve been bitten or scratched by an animal in an area with a risk of rabies:

• immediately clean the wound with running water and soap for several minutes
• disinfect the wound with an alcohol- or iodine-based disinfectant and apply a simple dressing, if possible
• go to the nearest medical center, hospital or doctor surgery as soon as possible and explain that you’ve been bitten or scratched

If this happens while you’re abroad, get local medical help immediately. Don’t wait until you’ve returned to the US.

If you’ve already returned to the US without getting medical advice, it’s still a good idea to get help – even if it’s been several weeks since you were bitten or scratched.

It’s unlikely that you’ve been infected, but it’s best to be safe. Post-exposure treatment is nearly 100% effective if it’s started before any symptoms of rabies appear.

Treatment after a bite or scratch

If you’ve been bitten, scratched or licked by an animal that might have rabies, you may need specialist medical treatment to stop you getting rabies. This is called post-exposure treatment.

Post-exposure treatment involves:

• cleaning and disinfecting the wound
• a course of the rabies vaccine – you’ll need to have five doses over a month if you haven’t been vaccinated before, or two doses a few days apart if you have
• in some cases, a medicine called immunoglobulin given into and around the wound – this provides immediate but short-term protection if there’s a significant chance you’ve been infected

Treatment should be started as soon as possible, ideally within a few hours of being bitten or scratched.

But it’s often safe to delay treatment until the next day if the vaccine and/or immunoglobulin need to be specially ordered in by your doctor.

Rabies prevention

Rabies in humans is 100% preventable through prompt appropriate medical care. Yet, more than 55,000 people, mostly in Africa and Asia, die from rabies every year – a rate of one person every ten minutes.

The most important global source of rabies in humans is from uncontrolled rabies in dogs. Children are often at greatest risk from rabies. They are more likely to be bitten by dogs, and are also more likely to be severely exposed through multiple bites in high-risk sites on the body. Severe exposures make it more difficult to prevent rabies unless access to good medical care is immediately available.

This major source of rabies in humans can be eliminated through ensuring adequate animal vaccination and control, educating those at risk, and enhancing access of those bitten to appropriate medical care.

What can you do?

• Vaccinate your pet
• Keep your pets confined. Keep your pets inside and supervise them when outside. This will help keep your pets from coming in contact with wild animals.
• Spay or neuter to decrease the number of stray animals
• Protect small pets from predators. Keep rabbits and other small pets, such as guinea pigs, inside or in protected cages so that they are safe from wild animals. These small pets can’t be vaccinated against rabies.
• Report stray animals to local authorities. Call your local animal control officials or other local law enforcement to report stray dogs and cats.
• Don’t approach wild animals. Wild animals with rabies may seem unafraid of people. It’s not normal for a wild animal to be friendly with people, so stay away from any animal that seems unafraid.
• Keep bats out of your home. Seal any cracks and gaps where bats can enter your home. If you know you have bats in your home, work with a local expert to find ways to keep bats out.
• Consider the rabies vaccine if you’re traveling. If you’re traveling to a country where rabies is common and you’ll be there for an extended period of time, ask your doctor whether you should receive the rabies vaccine. This includes traveling to remote areas where medical care is difficult to find.

How to avoid being bitten or scratched

All mammals (including monkeys) can carry rabies, but it’s most common in:

• dogs
• bats
• raccoons
• foxes
• jackals
• cats
• mongooses

They can spread the infection if they bite or scratch you, or in rare cases if they lick an open wound or their saliva gets into your mouth or eyes. Rabies isn’t spread through unbroken skin or between people.

While traveling in an area where rabies is a risk:

avoid contact with animals – some infected animals may behave strangely, but sometimes there may be no obvious signs they’re infected
avoid touching any dead animals

If you’re traveling with a child, make sure they’re aware of the dangers and that they should tell you if they’ve been bitten, scratched or licked by an animal. Check them for any wounds if they come into contact with an animal.

Rabies shots

You should consider getting vaccinated against rabies if:

• you’re traveling to an area where rabies is common and you plan to stay for a month or more or there’s unlikely to be quick access to appropriate medical care
• you’re traveling to an area where rabies is common and you plan to do activities that could put you at increased risk of exposure to animals with rabies, such as running or cycling

Visit your doctor or a travel clinic if you think you may need the vaccine. It’s sometimes free, but most people have to pay.

Even if you’ve been vaccinated, you should still take precautions to avoid coming into contact with rabies if you’re traveling in an area where rabies is found and get medical advice straight away if you’ve been bitten or scratched.

A few people may need the rabies vaccine because they could come into contact with rabies through their work. If you think this applies to you, speak to your occupational health department.

Rabies vaccine for humans

A regimen of four 1-mL doses of Human Diploid Cell Vaccine (HDCV) or Purified Chick Embryo Cell Vaccine (PCEC) should be administered intramuscularly to previously unvaccinated persons.

The first dose of the four-dose course should be administered as soon as possible after exposure. Additional doses should be administered on days 3, 7, and 14 after the first vaccination. For adults, the vaccination should always be administered intramuscularly in the deltoid area (arm). For children, the anterolateral aspect of the thigh is also acceptable. The gluteal area should never be used for rabies vaccine injections because observations suggest administration in this area results in lower neutralizing antibody titers.

The rabies vaccination is given as injections into your upper arm.

You’ll need three doses of the vaccine. The second dose is given seven days after the first. The third dose is given 14 or 21 days after the second.

If you’re planning to travel to an area where rabies is found, you should complete the full course of three doses before your departure.

Booster doses

If you’ve been vaccinated against rabies before but you continue to be at risk (for example, through your job), you may need further “booster” doses to ensure you stay protected.

Speak to your occupational health department about this.

For travelers, a booster dose may be considered if you were first vaccinated 10 or more years ago and you’re traveling to a high-risk area again.

Side effects of the rabies vaccine

After having the rabies vaccine, some people have temporary soreness, redness and swelling at the injection site for 24-48 hours.

In rare cases, some people also experience:

• a mild high temperature (fever)
• a headache
• muscle aches
• vomiting
• a rash

It takes three to four weeks to complete the vaccine course, so you ideally need to start it at least a month before you plan to leave.

Pregnant women are advised to have the rabies vaccine if the risk of exposure to rabies is thought to be high and there’s limited access to medical care.

People at risk through their work

Vaccination is also recommended for anyone at risk of being exposed to rabies through their job, such as:

• people who regularly handle bats
• people who handle imported animals – such as workers at zoos or animal quarantine centers
• laboratory workers who handle rabies samples

If you think this applies to you, speak to your occupational health department.

Human Rabies Immune Globulin

Human rabies immune globulin (HRIG) is administered only once, at the beginning of anti-rabies prophylaxis, to previously unvaccinated persons. This will provide immediate antibodies until the body can respond to the vaccine by actively producing antibodies of its own. If possible, the full dose of human rabies immune globulin should be thoroughly infiltrated in the area around and into the wounds. Any remaining volume should be injected intramuscularly at a site distant from vaccine administration.

Human rabies immune globulin should never be administered in the same syringe or in the same anatomical site as the first vaccine dose. However, subsequent doses of vaccine in the four-dose series can be administered in the same anatomic location where the human rabies immune globulin dose was administered.

If human rabies immune globulin was not administered when vaccination was begun, it can be administered up to seven days after the administration of the first dose of vaccine. Beyond the seventh day, human rabies immune globulin is not recommended since an antibody response to the vaccine is presumed to have occurred.

Because human rabies immune globulin can partially suppress active production of antibody, no more than the recommended dose should be administered. The recommended dose of human rabies immune globulin is 20 IU/kg body weight. This formula is applicable to all age groups, including children.

Rabies diagnosis

Several tests are necessary to diagnose rabies (before death) in humans; no single test is sufficient. Tests are performed on samples of saliva, serum, spinal fluid, and skin biopsies of hair follicles at the nape of the neck. Saliva can be tested by virus isolation or reverse transcription followed by polymerase chain reaction (RT-PCR). Serum and spinal fluid are tested for antibodies to rabies virus. Skin biopsy specimens are examined for rabies antigen in the cutaneous nerves at the base of hair follicles.

Rabies antigens can be detected by fluorescent antibody from corneal impressions or in salivary secretions. The biting animal should be diagnosed pathologically.

Determining whether the animal that bit you has rabies

In some cases, it’s possible to determine whether the animal that bit you has rabies before beginning the series of rabies shots. That way, if it’s determined the animal is healthy, you won’t need the shots.

Procedures for determining whether an animal has rabies vary by situation. For instance:

• Pets and farm animals. Cats, dogs and ferrets that bite can be observed for 10 days to see if they show signs and symptoms of rabies. If the animal that bit you remains healthy during the observation period, then it doesn’t have rabies and you won’t need rabies shots. Other pets and farm animals are considered on a case-by-case basis. Talk to your doctor and local public health officials to determine whether you should receive rabies shots.
• Wild animals that can be caught. Wild animals that can be found and captured, such as a bat that came into your home, can be killed and tested for rabies. Tests on the animal’s brain may reveal the rabies virus. If the animal doesn’t have rabies, you won’t need the shots.
• Animals that can’t be found. If the animal that bit you can’t be found, discuss the situation with your doctor and the local health department. In certain cases, it may be safest to assume that the animal had rabies and proceed with the rabies shots. In other cases, it may be unlikely that the animal that bit you had rabies and it may be determined that rabies shots aren’t necessary.

Rabies treatment

Treating clinical rabies patients can either offer supportive therapy or an aggressive treatment plan. There is no single effective treatment for rabies once clinical signs are evident.

A large number of case reports but only a few series of treated patients have been published ¹. In all of these reports, only 5 of the patients mentioned survived their acute illness ², ³), ⁴), ⁵, ⁶, ⁷; only one of them had a satisfactory neurologic outcome ² and another died within 4 years as a result of complications of the severe neurologic sequelae ⁶. There may be debate as to whether some of these patients actually had rabies. Postvaccination encephalomyelitis (due to vaccine of nervous tissue origin) is a possibility in ⩾1 of the patients described ⁵. All of these possible survivors had received a rabies vaccine either before or soon after their exposure and before the onset of their illness. None of these patients had rabies virus isolated or rabies virus antigen detected.

Even with intensive care, the majority of patients with rabies do not survive for >3 weeks ⁸, although 1 patient died 133 days after the onset of illness ⁹. For previously unvaccinated patients with rabies, reports to date have indicated agonizing symptoms and a 100% mortality rate.

Treatment is symptomatic as death is virtually inevitable. The patient should be nursed in a quiet, darkened room. Nutritional, respiratory and cardiovascular support may be necessary. Morphine, diazepam and chlorpromazine can be used in excitable patients.

The disease can be prevented using HDCV (human diploid cell vaccine).

Pre-exposure prophylaxis is given to individuals at a high risk of contracting the disease (e.g. lab workers, animal handlers and vets). HDCV 1.0mL deep subcutaneously or intramuscularly is given twice, 4 weeks apart. Another dose is given 12 months after that and then every 1-3 years depending on the risk of exposure.

Postexposure prophylaxis consists of 5 one mL doses given intramuscularly at days 0, 3, 7, 14 and 28. The wound should be cleaned, debrided and left open. Human rabies immunoglobulin should be given immediately with half injected around the area of the wound and half given intramuscularly (20 IU/kg).

Domestic animals should also be vaccinated if there is any risk of rabies in the country.

Rabies treatment for humans

Wound Care

Regardless of the risk of rabies, bite wounds can cause serious injury such as nerve or tendon laceration and local and system infection. Your doctor will determine the best way to care for your wound, and will also consider how to treat the wound for the best possible cosmetic results.

For many types of bite wounds, immediate gentle irrigation with water or a dilute water povidone-iodine solution has been shown to markedly decrease the risk of bacterial infection.

Wound cleansing is especially important in rabies prevention since, in animal studies, thorough wound cleansing alone without other postexposure prophylaxis has been shown to markedly reduce the likelihood of rabies.

You should receive a tetanus shot if you have not been immunized in ten years. Decisions regarding the use of antibiotics, and primary wound closure should be decided together with your doctor.

Treatment for people bitten by animals with rabies

If you’ve been bitten by an animal that is known to have rabies, you’ll receive a series of shots to prevent the rabies virus from infecting you. If the animal that bit you can’t be found, it may be safest to assume that the animal has rabies. But this will depend on several factors, such as the type of animal and the situation in which the bite occurred.

For people who have never been vaccinated against rabies previously, postexposure anti-rabies vaccination should always include administration of both passive antibody and vaccine.

In the United States, postexposure prophylaxis consists of a regimen of one dose of immune globulin and four doses of rabies vaccine over a 14-day period. Rabies immune globulin and the first dose of rabies vaccine should be given by your health care provider as soon as possible after exposure. Additional doses or rabies vaccine should be given on days 3, 7, and 14 after the first vaccination. Current vaccines are relatively painless and are given in your arm, like a flu or tetanus vaccine.

The combination of human rabies immune globulin (HRIG) and vaccine is recommended for both bite and nonbite exposures, regardless of the interval between exposure and initiation of treatment.

People who have been previously vaccinated or are receiving preexposure vaccination for rabies should receive only vaccine.

Adverse reactions to rabies vaccine and immune globulin are not common. Newer vaccines in use today cause fewer adverse reactions than previously available vaccines. Mild, local reactions to the rabies vaccine, such as pain, redness, swelling, or itching at the injection site, have been reported. Rarely, symptoms such as headache, nausea, abdominal pain, muscle aches, and dizziness have been reported. Local pain and low-grade fever may follow injection of rabies immune globulin.

The vaccine should be given at recommended intervals for best results. Talk to your with your doctor or state or local public health officials if you will not be able to have shot at the recommended interval. Rabies prevention is a serious matter and changes should not be made in the schedule of doses.

People cannot transmit rabies to other people unless they themselves are sick with rabies. The prophylaxis you are receiving will protect you from developing rabies, and therefore you cannot expose other people to rabies. You should continue to participate in your normal activities.

1. Intensive care in rabies therapy. Clinical observations. Lancet. 1976 Jul 3;2(7975):6-8. http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(76)92965-2/abstract[↩]
2. Hattwick MAW, Weis TT, Stechschulte CJ, Baer GM, Gregg MB. Recovery from rabies: a case report, Ann Intern Med , 1972, vol. 76 (pg. 931-42) https://www.ncbi.nlm.nih.gov/pubmed/5063659[↩][↩]
3. Tillotson JR, Axelrod D, Lyman DO. Rabies in a laboratory worker—New York, MMWR Morb Mortal Wkly Rep , 1977, vol. 26 (pg. 183-4[↩]
4. Tillotson JR, Axelrod D, Lyman DO. Follow-up on rabies—New York, MMWR Morb Mortal Wkly Rep , 1977, vol. 26 (pg. 249-50[↩]
5. Porras C, Barboza JJ, Fuenzalida E, Adaros HL, Oviedo AM, Furst J. Recovery from rabies in man, Ann Intern Med , 1976, vol. 85 (pg. 44-8) https://www.ncbi.nlm.nih.gov/pubmed/180860[↩][↩]
6. Alvarez L, Fajardo R, Lopez E, et al. Partial recovery from rabies in a nine-year-old boy, Pediatr Infect Dis J , 1994, vol. 13 (pg. 1154-5) https://www.ncbi.nlm.nih.gov/pubmed/7892092[↩][↩]
7. Madhusudana SN, Nagaraj D, Uday M, Ratnavalli E, Kumar MV. Partial recovery from rabies in a six-year-old girl [letter], Int J Infect Dis , 2002, vol. 6 (pg. 85-6) http://www.ijidonline.com/article/S1201-9712(02)90144-X/pdf[↩]
8. Noah DL, Drenzek CL, Smith JS, et al. Epidemiology of human rabies in the United States, 1980 to 1996, Ann Intern Med , 1998, vol. 128 (pg. 922-30) https://www.ncbi.nlm.nih.gov/pubmed/9634432[↩]
9. Emmons RW, Leonard LL, DeGenaro FJr, et al. A case of human rabies with prolonged survival, Intervirology , 1973, vol. 1 (pg. 60-72) https://www.karger.com/Article/Abstract/148833[↩]