Rabies is an infectious viral disease that is almost always fatal following the onset of clinical symptoms. In up to 99% of cases, domestic dogs are responsible for rabies virus transmission to humans. Yet, rabies can affect both domestic and wild animals. It is spread to people through bites or scratches, usually via saliva.
Rabies is present on all continents, except Antarctica, with over 95% of human deaths occurring in the Asia and Africa regions.
Rabies is one of the neglected tropical diseases that predominantly affects poor and vulnerable populations who live in remote rural locations. Although effective human vaccines and immunoglobulins exist for rabies, they are not readily available or accessible to those in need.
Globally, rabies deaths are rarely reported and children between the ages of 5–14 years are frequent victims. Treating a rabies exposure, where the average cost of rabies post-exposure prophylaxis (PEP) is US$ 40 in Africa, and US$ 49 in Asia, can be a catastrophic financial burden on affected families whose average daily income is around US$ 1–2 per person.
Every year, more than 15 million people worldwide receive a post-bite vaccination. This is estimated to prevent hundreds of thousands of rabies deaths annually.
How to avoid being bitten or scratched
All mammals (including monkeys) can carry rabies, but it’s most common in:
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 is not spread through unbroken skin or between people.
While travelling 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 travelling 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.
Eliminating rabies in dogs
Rabies is a vaccine-preventable disease. Vaccinating dogs is the most cost-effective strategy for preventing rabies in people. Dog vaccination reduces deaths attributable to rabies and the need for PEP as a part of dog bite patient care.
Awareness on rabies and preventing dog bites
Education on dog behavior and bite prevention for both children and adults is an essential extension of a rabies vaccination program and can decrease both the incidence of human rabies and the financial burden of treating dog bites.
Increasing awareness of rabies prevention and control in communities includes education and information on responsible pet ownership, how to prevent dog bites, and immediate care measures after a bite. Engagement and ownership of the program at the community level increases reach and uptake of key messages.
Preventive immunization in people
Human rabies vaccines exist for pre-exposure immunization. These are recommended for people in certain high-risk occupations such as laboratory workers handling live rabies and rabies-related (lyssavirus) viruses; and people (such as animal disease control staff and wildlife rangers) whose professional or personal activities might bring them into direct contact with bats, carnivores, or other mammals that may be infected.
Pre-exposure immunization is also recommended for travelers to rabies-affected, remote areas who plan to spend a lot of time outdoors involved in activities such as caving or mountain-climbing. Expatriates and long-term travelers to areas with a high rabies exposure risk should be immunized if local access to rabies biologics is limited. Finally, immunization should also be considered for children living in, or visiting, remote, high-risk areas. As they play with animals, they may receive more severe bites, or may not report bites.
The incubation period for rabies is typically 2–3 months but may vary from 1 week to 1 year, dependent upon factors such as the location of virus entry and viral load. Initial symptoms of rabies include a fever with pain and unusual or unexplained tingling, pricking, or burning sensation (paraesthesia) at the wound site. As the virus spreads to the central nervous system, progressive and fatal inflammation of the brain and spinal cord develops. There are two forms of the disease:
- People with furious rabies exhibit signs of hyperactivity, excitable behaviour, hydrophobia (fear of water) and sometimes aerophobia (fear of drafts or of fresh air). Death occurs after a few days due to cardio-respiratory arrest.
- Paralytic rabies accounts for about 20% of the total number of human cases. This form of rabies runs a less dramatic and usually longer course than the furious form. Muscles gradually become paralyzed, starting at the site of the bite or scratch. A coma slowly develops, and eventually death occurs. The paralytic form of rabies is often misdiagnosed, contributing to the under-reporting of the disease.
- Current diagnostic tools are not suitable for detecting rabies infection before the onset of clinical disease, and unless the rabies-specific signs of hydrophobia or aerophobia are present, clinical diagnosis may be difficult. Human rabies can be confirmed intra-vitam and post mortem by various diagnostic techniques that detect whole viruses, viral antigens, or nucleic acids in infected tissues (brain, skin, urine, or saliva).
- People are usually infected following a deep bite or scratch from an animal with rabies, and transmission to humans by rabid dogs accounts for 99% of cases. Africa and Asia have the highest rabies burden in humans and account for 95% of rabies deaths, worldwide.
- In the Americas, bats are now the major source of human rabies deaths as dog-mediated transmission has mostly been broken in this region. Bat rabies is also an emerging public health threat in Australia and Western Europe. Human deaths following exposure to foxes, raccoons, skunks, jackals, mongooses and other wild carnivore host species are very rare, and bites from rodents are not known to transmit rabies.
- Transmission can also occur when infectious material – usually saliva – comes into direct contact with human mucosa or fresh skin wounds. Human-to-human transmission through bites is theoretically possible but has never been confirmed.
- Contraction of rabies through inhalation of virus-containing aerosols or through transplantation of infected organs is rare. Contracting rabies through consumption of raw meat or animal-derived tissue has never been confirmed in humans.
Factors that can increase the risk of rabies including:
- Going aboard or live in countries that rabies growing rapidly like Africa and South East Asia
- Activities that allow you to connect with wild animals that may have rabies disease, such as exploring caves where there is a large population of bats, or camping without doing it carefully to drive wild animals into your campsite
- Work in a laboratory with the rabies
- Virus, head, neck or hand wounds, which can help spread the rabies virus faster
Once a rabies infection is established, there’s no effective treatment. Though a small number of people have survived rabies, the disease is usually fatal. For that reason, if you think you’ve been exposed to rabies, you must get a series of shots to prevent the infection from taking hold.
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.
Rabies shots include:
- A fast-acting shot (rabies immune globulin) to prevent the virus from infecting you. Part of this injection is given near the area where the animal bit you if possible, as soon as possible after the bite.
- A series of rabies vaccines to help your body learn to identify and fight the rabies virus. Rabies vaccines are given as injections in your arm. You receive four injections over 14 days.
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.