What is rabies?
Rabies virus (RABV) is transmitted through direct contact (for example, through broken skin or the mucous membranes of the eyes, nose, or mouth) with saliva or brain/nervous system tissue from an infected animal. Rabies is fatal but preventable. People and pets can be infected if they are bitten or scratched by a rabid animal.
What happens when you get rabies?
The rabies virus enters your body when saliva (spit) from an infected animal gets into an open wound (usually from a bite). It moves very slowly along the nerves to the central nervous system (the brain and spinal cord). When it reaches your brain, the damage causes neurological symptoms. From there, rage leads to coma and death.
How common is rabies?
Some 59,000 people around the world die each year from rabies. In the US, cases of human rabies are rare: fewer than three people get rabies each year. This is because many people get vaccinated soon after exposure.
Who does rabies affect?
Rabies is most common in rural Asia and Africa, although it is found on every continent except Antarctica. In the US, rabies is commonly found in wild animals. But dogs transmit rabies in many other countries. Children are more likely to get rabies than adults.
How does rabies affect your body?
Rabies passes from an infected wound to his brain over time. There are several phases that most people go through incubation, prodromal phase, acute neurological phase, and coma.
The rabies virus can spend days to weeks in your body before entering your nervous system (incubation). You do not have any symptoms during this time. If you receive treatment early in the incubation period, you will not get rabies.
- Prodromal phase
RABV travels through nerve cells to the brain and spinal cord, causing nerve damage as it goes. The prodromal phase begins when the rabies virus has entered your nervous system. Your immune system tries to fight back, causing flu-like symptoms. Nerve damage can cause tingling, pain, or numbness at the bite site. This lasts from two to 10 days. There are no effective treatments when rabies reaches this stage.
- Acute neurological phase
In this phase, the rabies virus begins to damage the brain and spinal cord. About two-thirds of people have furious rage, with symptoms such as aggression, seizures, and delirium. Others have paralytic rabies, with weakness and paralysis progressing from the bite wound to the rest of the body. Furious rage can last anywhere from a few days to a week. Paralytic rabies can last up to a month.
Many people go into a coma in the final stages of a rabies infection. The rage eventually leads to death.
What are the symptoms of rabies in humans?
You usually don’t have rabies symptoms for several weeks after it enters your body. When rabies reaches your central nervous system (prodromal phase), you experience flu-like symptoms. In the final stages, you have neurological (brain) symptoms.
Prodromal symptoms of rabies
- Tiredness (fatigue).
- Bite wound burning, itching, tingling, pain, or numbness.
- Sore throat.
- Muscle pain.
- Nausea and vomiting.
Acute neurological symptoms of rabies.
The neurological symptoms of rabies are anger or paralytic. The symptoms of raging rage can come and go with periods of calm in between (raging episodes).
Furious symptoms of rabies
- Agitation and aggression.
- Muscle jerks (fasciculations).
- Racing heart (tachycardia).
- Fast breathing (hyperventilation).
- Excessive salivation.
- Two pupils of different sizes (anisocoria).
- Facial paralysis (facial paralysis).
- Fear of water/drinking (hydrophobia).
- Fear of air being blown into the face/drafts (aerophobia).
Symptoms of paralytic rabies
- Neck stiffness.
- Weakness, especially starting in the part of the body that was bitten and progressing to other parts of the body.
- Tingling, “pins and needles” or other strange sensations.
What causes rabies in humans?
The RABV virus causes rabies in humans and animals. It moves around your body through your nerves, causing nerve damage. It hides from your immune system until it reaches your brain, where it causes brain damage and eventually leads to death.
How do you get rabies?
Rabies is transmitted by warm-blooded animals (mammals) and accumulates in their saliva (spit). You usually contract rabies through a bite from an infected animal. Rabies is most commonly found in bats, skunks, raccoons, and foxes, but other animals, including your dog or cat, can become infected. If a break in your skin comes into contact with the saliva of an infected animal, you could contract rabies. On rare occasions, people have contracted rabies from receiving donated organs.
How is rabies diagnosed?
Unlike most diseases, you don’t have to wait for symptoms to diagnose rabies. If you have been bitten or scratched by a wild animal or pet that might have rabies, talk to your healthcare provider right away. They will examine your wound and ask you questions to determine if you need rabies treatment. You may also be tested for signs of rabies.
Your provider may ask you:
- How did you hurt yourself?
- What kind of animal scratched or bit you.
- If they can taste or observe the animal.
If the animal might have rabies, it will be observed for signs or tested if possible. The animals have to be euthanized (humanely killed) to test them.
What tests will be done to diagnose this condition?
Tests for rabies may include:
- Saliva test. You will spit into a tube. It will be sent to a lab to look for signs of rabies.
- Skin biopsy. Your provider will take a small sample of skin from the back of your neck. Your skin sample will be sent to a lab to look for signs of rabies.
- Cerebrospinal fluid examination (lumbar puncture). Your provider will use a needle to draw cerebrospinal fluid (CSF) from your lower back. Your CSF sample will be sent to a lab to look for signs of rabies.
- Blood test. Your provider will use a needle to draw blood from your arm. Your blood will be sent to a lab to look for signs of rabies.
- MRI. You will lie in a machine that takes pictures of your brain. Your provider will use the images to help determine what is causing your symptoms.
How is rabies treated?
There is no approved treatment for rabies once you have symptoms. If you have been exposed to rabies (were bitten or in contact with an infected animal), contact a healthcare provider as soon as possible. Clean the wound gently but thoroughly with soap and water. Ask your provider for additional instructions on how to clean the wound. Your provider will give you a series of shots (shots) to prevent the virus from causing rabies. They will also give you an antibody treatment directly into the wound if you have never been vaccinated before.