Rabies is uncommon in the US, but globally its impact is still felt. In 2010, an estimated 26,000 people died from rabies, down from 54,000 in 1990. Most of these deaths were in India and Africa.
Rabies is a serious illness. By the time the symptoms of rabies have become apparent, it is generally too late to save the patient.
Rabies is a virulent killer that can spread using any mammal species as a host.1
- What is rabies?
- Symptoms of rabies
- Causes of rabies
- Tests and diagnosis of rabies
- Rabies progression
- Treatment for rabies
- Prevention of rabies (for individuals)
- Prevention of rabies (countrywide)
- Global prevalence of rabies
Here are some key points about rabies. More detail and supporting information is in the main article.
- Rabies is nearly always transmitted by an infected animal bite.
- Rabies is a viral disease.
- For rabies treatment to be successful, it must be given before any symptoms appear.
- Rabbits very rarely carry rabies.
- If bitten, medical help should be sought immediately.
- A fear of light and water are among rabies' symptoms.
- India is the country most affected by rabies.
- People can help prevent rabies by getting your pet vaccinated.
- Puppy pregnancy syndrome has increased the rabies death toll in India.
What is rabies?
The majority of human rabies cases are the result of a bite from a dog infected with the virus.
Rabies is a viral infection spread via saliva. If someone presents with rabies symptoms, it is almost always fatal. In countries where stray dogs are present in large numbers, they are the biggest rabies threat.
Predominantly, in the US, rabies is spread by raccoons, coyotes, bats, skunks and foxes.2 Bats carrying rabies have been found in all 48 contiguous states.
Dr. Joseph Lennox Pawan first discovered animal-to-human transmission of rabies in the vampire bat in Trinidad in 1932.3
It is now known that any mammal can harbor and transmit the virus. However, smaller mammals such as rodents very rarely become infected or transmit rabies.
Symptoms of rabies
The symptoms of rabies can present themselves just a few days after a bite, or they might take as long as 12 weeks. Some rare cases report a number of years between the bite and the onset of symptoms.
The closer the bite is to your brain, the quicker the effects are likely to appear.4
If you are bitten by a wild animal, it is essential that you seek medical advice as soon as possible.
When the initial symptoms of rabies occur, they can be similar to flu and last 2-12 days, becoming progressively stronger.
From the early flu-like symptoms, the condition worsens and symptoms can include the following:
- Excess salivation
- Fear of water (hydrophobia) due to difficulty in swallowing
- Priapism (permanent erection)
- Partial paralysis.
Causes of rabies
Rabies is a virus and, as mentioned, it is predominantly spread by a bite from an infected animal.
However, it is also possible to become infected if saliva from an infected animal gets into an open wound or through a mucous membrane, such as the eyes or mouth.
Tests and diagnosis of rabies
At the time of a bite, there is no way to tell for sure whether an animal is rabid, or whether it has infected you.
The doctor will suggest moving straight to treatment; there is no benefit in waiting.
Rabies virus has a distinct cylindrical shape.
The rabies virus is an RNA virus in the rhabdovirus family. The virus has five distinct stages:
- Incubation period: this can vary in length exceptionally, from days to years
- Prodrome: early flu-like symptoms
- Acute neurologic period: neurological symptoms begin. These can include hyperactivity, or paralysis, as well as rigid neck muscles, involuntary muscle twitching, convulsions, hyperventilation and hypersalivation. Toward the end of this phase, breathing becomes rapid and inconsistent
- Coma: unless attached to a ventilator, death will come within a matter of hours
- Death: or, rarely, recovery.5
The rabies virus can enter the peripheral nervous system directly and migrate to the brain, or it can replicate within muscle tissue (safe from the host's immune system) and enter the nervous system through the neuromuscular junctions.
Once within the nervous system, the virus produces acute inflammation of the brain, swiftly causing coma followed by death.
Rabies used to be referred to as hydrophobia because of the fear of water produced in sufferers. Intense spasms in the throat are triggered when trying to swallow. In fact, the spasms can be triggered by the mere thought of swallowing water, hence the fear.
Excess saliva is produced, probably due to the rabies virus assimilating in the salivary glands. If the individual were able to swallow saliva easily, the virus' chance of moving to a new host would be minimized.
Treatment for rabies
As the disease is generally fatal (although a small number of people have survived), there is no treatment for the illness per se. Once symptoms have arisen, there are no medications that can provide help.
As soon as a bite is received, a series of shots will be prescribed to prevent the virus from thriving. The shots include:
- A fast-acting shot consisting of rabies immune globulin; this will prevent the virus from infecting the individual and will be delivered as soon as possible, close to the bite wound.
- A series of rabies vaccines to train your body to fight the virus whenever it finds it. These will be given over the following 2 weeks and delivered into the arm.
In most cases, finding out whether the animal has rabies will not be possible. It is safest to assume the worst and begin the course of shots.
Prevention of rabies (for individuals)
The following are general safety rules to lessen your chances of contracting rabies:
- Vaccinate pets: cats, dogs and ferrets can all easily be vaccinated, preventing them from catching and passing the virus on
- Keep pets confined: ensure pets are safely confined and supervised when outside
- Report stray animals to local authorities: local animal control officials or police departments can remove any animals seen roaming
- Do not approach wild animals: animals with rabies are less cautious and more likely to approach you
- Keep bats out of the home: seal your home to prevent bats from nesting. If bats are already present, experts can safely remove them
- Wash the wound: if you have been bitten, washing bites and scratches for 15 minutes with soapy water, povidone iodine or detergent might minimize the number of viral particles (medical help should still be sought)
- Vaccination: if you have plans to travel, especially in Africa or India, vaccination is a good idea.
Prevention of rabies (countrywide)
Because rabies is such an adept killer, many nations have carried out projects in an effort to wipe out, or at least minimize, the amount of rabies in their animal populations.
Chicken heads laced with a vaccine helped the Swiss rid their country of rabies.
These projects can include widespread vaccinations of humans in affected areas or simply the dissemination of educational information to remote populations.
In rural Canada and the US, agencies have dropped baits impregnated with oral vaccine to curtail the number of wild raccoons with rabies. This approach has generated positive results and a reduction in rabies infections.
Switzerland's historical rabies problem was almost exclusively due to infected foxes. The government decided on a large-scale intervention. They distributed vaccine-laced chicken heads throughout the Swiss Alps. The foxes effectively immunized themselves, and the country is now virtually rabies free.
Global prevalence of rabies
The prevalence of rabies varies wildly from country to country. In nations without a feral dog population, the rates are significantly lower.
Many smaller islands - for instance, Mauritius, Réunion and the Seychelles - have no cases of rabies thanks to their natural isolation. Australia and New Zealand have never had the disease on their soil.
Other countries, like the UK, have stamped out rabies by licensing pets, muzzling, vaccination and designing strict laws regarding the transportation of animals in and out of the country.
Africa and Asia are the continents worst affected by rabies. The individual country with most cases, by far, is India. An estimated 20,000 people die of rabies per year, making up roughly one-third of total global deaths. Vietnam and Thailand are the second and third worst affected countries. 6
There are a number of factors which worsen India's struggle with rabies. Firstly, they have a huge stray dog population; secondly, in 2001, a law was passed making it illegal to kill dogs. Thirdly, puppy pregnancy syndrome:
Puppy pregnancy syndrome
In rural areas of India where education levels are low, puppy pregnancy syndrome, a type of mass hysteria, is hindering rabies elimination.
People who have been bitten by a dog report that they have contracted puppy pregnancy syndrome (especially if the dog is sexually aroused). The individuals believe that they have puppies growing in their stomach.
Tens of thousands of Indians have reported suffering from the condition. Victims may bark like dogs, claim to be able to see the puppies inside them when looking at water, and hear them growling in their abdomen. The victims believe the illness is terminal, especially men, who think they will give birth to the puppies through their penis.
Witchdoctors have a concoction to "heal" the sickness and allow the puppies to be broken down and passed through the body without pain. Individuals believe that the remedy will work and therefore do not go for treatment and receive the rabies shots.7
The global war against rabies seems set to continue for many years. We have the tools necessary to defeat the virus; the key is deployment and education.
Researchers have found that around the world, 160 people die each day from canine rabies. An estimated 59,000 people are thought to die every year as a result of this preventable disease.
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