Rabies is an acute viral infection that causes inflammation of the spinal cord and the brain (encephalomyelitis). Rabies virus is present in the saliva of infected animals. People are usually exposed to rabies through a bite or scratch from a rabid animal. The virus may also enter the body through a lick on broken skin or a lick on the eyes, nose or mouth.
Dogs are the most common source of infection to humans. In many parts of the world other animals such as bats, monkeys and cats are a source of potential exposure to the disease.
Rabies is found in all continents of the world except Antarctica. Bats in all countries are considered to be a rabies risk. Most human cases of rabies occur in Asia, Africa and South and Latin America.
The time from a rabies exposure to developing symptoms of rabies is usually between 20-60 days but may range from 5 days to 1 year. Symptoms start with headache, fever, general weakness and numbness or tingling around the wound site. The disease progresses to muscle spasms, hydrophobia (fear of water) and convulsions. Once symptoms of rabies develop, the infection is fatal.
There is no specific treatment available for rabies once symptoms develop.
Prior to travel you should check if rabies is present at your destination and determine how close you will be to reliable medical attention.
If in a rabies endemic area you should avoid contact with animals, especially dogs. This is particularly important to emphasize to children who are more likely approach animals and more likely to sustain severe bites.
After a possible exposure, basic first aid should be applied:
- Saliva should be thoroughly washed off with soap and water and the wound washed with iodine solution or alcohol.
- This is very effective in removing virus from the bite, providing it is prompt and thorough.
- Suturing of any wound should be avoided and tetanus vaccination may be needed.
It is imperative to seek medical attention as soon as possible if a bite or scratch is sustained even if pre-travel vaccination has been given (see below). The attending doctor will determine the risk of rabies and administer the appropriate treatment:
Human Rabies Specific Immunoglobulin (HRIG)
- May be required if pre-exposure vaccination has not been given and the exposure is severe.
- HRIG is produced from blood products.
- HRIG and the first dose of vaccine should ideally be started within 24 hours of the bite being inflicted.
- HRIG is known to be very difficult or impossible to obtain in many countries, so unvaccinated travellers who receive an animal bite may need to travel to another country or even come home for treatment
- Five doses over 28 days are required if pre-exposure vaccination has not been received.
Vaccination is recommended for all travellers who will be living or travelling in endemic areas and who may be exposed to rabies because of travel activities e.g. trekking, cycling/running, working or living in rural areas, being distant from medical attention or having contact with animals/bats e.g. in sanctuaries.
Prior to travel, 3 doses of rabies vaccine are given over a period of 3 – 4 weeks.
Those who have been vaccinated will develop antibodies in their blood against rabies virus.
- After any future potential rabies exposure medical attention must be sought to have 2 further booster doses of vaccine to ensure that antibody levels are sufficiently high to prevent infection developing.
The advantages of pre-exposure rabies vaccination include:
- Only 2 doses of vaccine (given 3 days apart) are required after a rabies exposure.
- Human Rabies Specific immunoglobulin (HRIG) is not required after a rabies exposure; this treatment can be hard to source in some parts of the world, particularly sub-Saharan Africa.
- If medical attention is not easily accessible, a delay in reaching treatment is less concerning than if no pre-exposure vaccine has been taken.