Rabies

What is rabies?

Rabies is a serious viral infection that attacks the brain and nervous system. It is caused by the rabies virus, which belongs to a group of viruses called lyssaviruses. The virus is almost always passed to people through the saliva of an infected mammal, most often through a bite. Once the virus reaches the brain and a person develops symptoms, rabies is nearly always fatal. This is why the disease is treated as a medical emergency at the moment of exposure, before any symptoms appear, when prompt care can be highly effective at preventing the illness.

Rabies can affect anyone of any age, but it is most common in people who live in or travel to regions where the virus circulates in dogs, and in those who have close contact with wild animals such as bats, raccoons, foxes, or jackals. Children are considered at particular risk because they are more likely to approach animals, may not report a bite, and are more often bitten on the head and neck.

Understanding what rabies is, how it spreads, and how quickly action is needed after a possible exposure can save lives. The rest of this page explains rabies symptoms, rabies causes, how doctors approach rabies diagnosis, and the rabies treatment options that exist today.

Rabies symptoms

Rabies symptoms do not appear right away. After a bite, there is a period without symptoms called the incubation period. This usually lasts several weeks to a few months, although it can be as short as a few days or, rarely, longer than a year. The length depends on where the bite is, how severe it is, and how much virus entered the body. Bites closer to the brain, such as on the face or neck, tend to lead to a shorter incubation period.

Early symptoms are often vague and can look like many other illnesses:

• Fever and headache
• General weakness or discomfort
• Loss of appetite and nausea
• Tingling, itching, burning, or pain at or near the healed bite site
• Anxiety, irritability, or trouble sleeping

As the virus spreads within the brain, the illness usually develops into one of two forms.

Furious (encephalitic) rabies

This is the more common form. Encephalitic means it mainly affects the brain itself. People may experience:

• Agitation, confusion, and hallucinations (seeing or hearing things that are not there)
• Hydrophobia, a fear of water caused by painful throat spasms when trying to swallow
• Aerophobia, a similar spasm triggered by a draft of air on the face
• Excessive saliva and difficulty swallowing
• Periods of aggression alternating with calm
• Seizures

Paralytic rabies

In this form, muscles gradually become weak and then paralyzed, often starting at the site of the bite and spreading through the body. Confusion and agitation are less prominent, so this type is more likely to be mistaken for other neurological conditions. Eventually, the person slips into a coma.

In both forms, once symptoms begin, the illness progresses over days to coma and, in almost all cases, death, usually from breathing or heart failure. Because of this, the appearance of any symptoms after a possible animal exposure is an emergency, although the goal of medical care is always to act long before this stage.

Causes and risk factors

The direct cause of rabies is infection with the rabies virus. The virus lives in the saliva and nervous tissue of infected mammals. It enters the body when infected saliva gets into a wound or onto a mucous membrane, such as the eyes, nose, or mouth. From there, the virus travels slowly along nerves toward the spinal cord and brain.

Common ways the virus is transmitted include:

• Animal bites: By far the most common route. Worldwide, bites from infected dogs cause the vast majority of human cases. In some regions, bats, foxes, raccoons, skunks, mongooses, and jackals are important sources.
• Scratches or licks on broken skin: Less common, but possible if saliva enters a cut or scrape.
• Bat contact: Bat bites can be very small and may go unnoticed, especially if a person was asleep. Any direct contact with a bat is often treated as a possible exposure.
• Organ or tissue transplantation: Extremely rare, but transmission from an infected donor has been documented.

Rabies does not spread through unbroken skin, through petting the fur of an animal, or through contact with an animal’s blood, urine, or feces. Person-to-person spread through ordinary contact has not been documented outside of transplantation.

Factors that raise the risk of exposure include:

• Living in or traveling to areas where rabies is common in dogs, especially rural areas
• Working with animals, for example as a veterinarian, animal control worker, or wildlife researcher
• Laboratory work involving the rabies virus
• Outdoor activities such as camping or cave exploring where bats may be present
• Being a child, because of more frequent unreported bites, often to the head or neck
• Living in an area where stray or unvaccinated dogs are common

Rabies diagnosis

Rabies diagnosis in a living person is difficult, and this is one of the reasons doctors do not wait for confirmation before starting preventive treatment after an exposure. There is no test that can tell whether a person has been infected during the incubation period, before symptoms begin. Decisions at that stage are based on the history of the exposure and, where possible, on the animal.

Assessing the exposure

When a person comes in after an animal bite or scratch, the doctor will ask detailed questions: what kind of animal was involved, whether it was a pet or wild, whether it appeared sick or behaved strangely, whether it could be observed or tested, how the exposure happened, and where on the body the wound is. This assessment is the most important step in deciding on treatment.

Testing the animal

If the animal is available, it may be observed or tested. A healthy domestic dog, cat, or ferret can often be watched for a set period, typically about ten days, by animal health authorities; if it stays healthy, it could not have passed rabies at the time of the bite. Wild animals or animals that die are tested by examining brain tissue in a laboratory. A negative result in the animal usually means treatment can be stopped.

Testing a person with symptoms

Once symptoms have started, no single test is completely reliable, so doctors usually use several together:

• Saliva testing using a method called RT-PCR, which detects the genetic material of the virus.
• Skin biopsy from the nape of the neck, where the virus can be found in nerve endings around hair follicles.
• Blood and spinal fluid tests to look for antibodies to the virus. Spinal fluid is obtained through a lumbar puncture, a procedure in which a needle is placed in the lower back.
• Brain imaging such as MRI (magnetic resonance imaging), mainly to rule out other causes of brain inflammation rather than to confirm rabies.

A definitive diagnosis is often only made after death, by testing brain tissue directly. Because early symptoms mimic many other conditions, doctors also consider other causes of encephalitis (inflammation of the brain) such as herpes, tetanus, or Guillain-Barré syndrome, a condition in which the immune system attacks the nerves.

Rabies treatment options

Rabies treatment options fall into two very different categories: treatment given after an exposure but before symptoms, which is highly effective, and treatment once symptoms have begun, which is mainly supportive.

Post-exposure prophylaxis (PEP)

Post-exposure prophylaxis, often shortened to PEP, is a series of steps taken to stop the virus before it reaches the brain. It should begin as soon as possible after a possible exposure, ideally the same day, but it is still recommended even if days or weeks have passed, as long as symptoms have not started. PEP generally involves:

• Immediate wound care. The wound should be washed thoroughly with soap and running water for around fifteen minutes and then cleaned with an antiseptic if available. This simple step significantly reduces the amount of virus in the wound and should be done right away, even before reaching a clinic.
• Rabies vaccine. A course of injections given over several weeks, usually into the upper arm muscle. The vaccine teaches the immune system to recognize and destroy the virus. Modern rabies vaccines are considered safe, and the older, painful injections into the abdomen are no longer used.
• Rabies immune globulin (RIG). Ready-made antibodies against the virus, injected into and around the wound to give immediate protection while the vaccine takes effect. RIG is generally recommended for people who have never been vaccinated against rabies before and who have had a higher-risk exposure, such as a bite that breaks the skin or contact with a bat.
• Other wound management. Doctors may consider antibiotics to prevent bacterial infection and a tetanus booster if needed. Bite wounds are often not stitched closed immediately, to reduce the risk of trapping infection.

People who have previously completed a full course of rabies vaccination usually need a shorter series of booster doses and do not need RIG. When PEP is given promptly and correctly, it is considered extremely effective at preventing rabies.

Pre-exposure vaccination

For people at ongoing risk, such as veterinarians, animal handlers, laboratory workers, and some travelers to areas where rabies is common, doctors may recommend vaccination before any exposure. This does not remove the need for medical care after a bite, but it simplifies later treatment and gives some protection if a bite goes unnoticed. Travel-related vaccination is often discussed as part of a broader review of health risks, for example through check-up and preventive medicine services.

Treatment after symptoms begin

Once rabies symptoms have appeared, there is no proven cure. Care is provided in an intensive care unit and focuses on comfort and support: sedation to reduce agitation and distress, medication to control seizures, help with breathing using a ventilator (a breathing machine), fluids, and nutrition. Experimental approaches have been tried, and a very small number of people have survived, usually with significant lasting brain damage, but these outcomes are rare and no treatment protocol has been shown to reliably work. At Acibadem, suspected exposures are usually assessed in the emergency department, with infectious disease and intensive care teams involved when needed.

Living with rabies and outlook

The outlook for rabies depends almost entirely on timing. For a person who receives thorough wound cleaning and a complete course of post-exposure prophylaxis before symptoms develop, the outlook is very good, and the infection is generally prevented. Side effects of the vaccine and immune globulin are usually mild, such as soreness at the injection site, headache, or a low-grade fever, and completing the full series is important even if the animal cannot be found.

Once symptoms have started, rabies is almost always fatal, usually within one to two weeks. The rare survivors described in medical literature have mostly been left with serious neurological problems. Because of this stark difference, doctors err on the side of caution and treat uncertain exposures, such as waking up to find a bat in the room, as if they were real exposures.

For families and communities, living with the threat of rabies often means practical prevention: keeping pets vaccinated, avoiding contact with stray or wild animals, teaching children never to approach unfamiliar animals, and knowing that any bite or scratch from a mammal should be washed immediately and assessed by a healthcare professional. People who have completed post-exposure treatment do not need to change their daily lives afterward, and the vaccine does not cause rabies or make a person infectious to others.

Frequently asked questions

What is rabies and how do people get it?

Rabies is a viral infection of the brain and nervous system spread through the saliva of infected mammals, most often by a bite from an infected dog or wild animal such as a bat or fox. The virus travels along nerves to the brain over weeks or months. It cannot spread through intact skin or through casual contact with an animal’s fur.

What are the first rabies symptoms in humans?

The first rabies symptoms are usually nonspecific and include fever, headache, tiredness, and sometimes tingling, itching, or pain at the site of the earlier bite. These may be followed by anxiety, confusion, trouble swallowing, fear of water or air on the face, or gradually spreading weakness. By the time these symptoms appear, the illness is very advanced, which is why treatment after a bite should never wait for symptoms.

How long after a bite do rabies symptoms appear?

In many cases, rabies symptoms appear one to three months after exposure, but the range is wide: sometimes less than a week, and in rare cases more than a year. Bites to the head, neck, or hands, deep bites, and multiple bites tend to shorten this period. Because the timing is unpredictable, post-exposure treatment is recommended regardless of how much time has passed, as long as the person is still symptom-free.

How is rabies diagnosed?

Rabies diagnosis in a symptom-free person is not possible with current tests, so doctors rely on the details of the exposure and, when possible, on observing or testing the animal. In a person with symptoms, doctors may use saliva testing, a small skin biopsy from the back of the neck, and blood and spinal fluid antibody tests, often repeated, along with brain imaging to rule out other conditions. Confirmation is frequently only possible after death.

What are the rabies treatment options if I have been bitten?

After a possible exposure, the standard rabies treatment options are immediate and thorough wound washing with soap and water, a series of rabies vaccine injections over several weeks, and, for people not previously vaccinated, rabies immune globulin injected around the wound. Your doctor may also address tetanus protection and bacterial infection. Started promptly, this approach is considered highly effective at preventing the disease.

Can rabies be cured once symptoms start?

There is currently no proven cure for rabies once symptoms have begun, and the illness is almost always fatal despite intensive care. Treatment at that stage focuses on comfort and support. A very small number of survivors have been reported, most with lasting disability, but no treatment has been shown to work reliably. Prevention through prompt post-exposure care remains the only dependable approach.

Is a bite from a vaccinated pet a rabies risk?

A bite from a healthy, fully vaccinated pet carries a very low risk, but it should still be cleaned well and assessed by a healthcare professional, who may also want the animal checked and observed by a veterinarian or local authorities for a set period. Your doctor will weigh the animal’s vaccination status, behavior, and the local rabies situation when deciding whether post-exposure treatment is needed.

When to see a doctor

Seek medical care the same day, after washing the wound thoroughly with soap and running water, if any of the following apply:

• You have been bitten or scratched by any mammal whose rabies vaccination status you do not know, including dogs, cats, monkeys, bats, foxes, raccoons, or livestock
• Saliva from an animal has come into contact with a cut, scrape, or your eyes, nose, or mouth
• You have had any direct contact with a bat, or you woke to find a bat in the room, even if you cannot see a bite
• You were bitten by an animal that was behaving strangely, was unusually aggressive or unusually tame, was foaming at the mouth, or later died or disappeared
• You were bitten while traveling in a region where rabies is common, even if the bite seemed minor
• A child reports, or you suspect, an unwitnessed bite or scratch from an animal

Seek emergency care immediately if, in the weeks or months after an animal exposure, you or someone close to you develops any of these red-flag signs:

• Unexplained fever with headache and tingling, itching, or pain around a previous bite site
• Difficulty swallowing, painful throat spasms, or fear of drinking water
• Sudden confusion, agitation, hallucinations, or unusual aggression
• Weakness or paralysis that begins in one limb and spreads
• Seizures or decreasing alertness

Rabies is one of the few infections where acting quickly after an exposure can make the difference between a fully preventable illness and a fatal one. When in doubt, it is safer to be assessed than to wait.