Rabies is an acute viral infection that causes encephalomyelitis (inflammation of the brain and spinal cord). The incubation period is generally between three and 12 weeks, but may range from four days to 19 years. Initial symptoms are non-specific but eventually the characteristic symptoms may appear such as hydrophobia (fear of water), hallucinations, maniacal behaviour, paralysis and coma or the less common ascending paralysis and sensory disturbance. Rabies is virtually always fatal and there is no specific treatment or cure.
Rabies occurs in warm blooded mammals. It is transmitted to humans when the saliva of an infected animal is introduced into the body, which is usually via a bite. In general, dogs are the most common source of human rabies but bats, cats, and monkeys are important sources of infection in some countries. Infection is usually the result of a bite but there have been occasions when infected saliva has entered the body via a mucous membrane, or via a wound or scratch as the result of being licked.
Rabies virus can be found in all continents except Antarctica. Most parts of the African and Asian continents and many parts of South America are endemic for rabies. Travellers to endemic areas, or on long journeys in remote parts where medical treatment is not readily available, may be at risk of the disease.
Individual countries including the UK and Australia are reported to be rabies-free. Some countries that are declared rabies-free have rabies-related viruses in their bat populations, for example in the UK, rabies-related viruses have been detected in Daubenton's bats. No cases of indigenous human rabies from animals other than bats have been reported in the UK since 1902; however, deaths from classical rabies continue to occur in people infected abroad.
According to World Health Organization (WHO) data, rabies occurs in more than 150 countries and territories, and over 3 billion people are at risk of acquiring rabies in Asia and Africa. More than 55, 000 people die from rabies every year, and over half of these deaths are in South Asia. In the UK 24 people have died from rabies since 1902.
Rabies is a fatal disease. Travellers should avoid contact with wild or domestic animals when overseas. Rabies vaccination should be given to travellers who are at risk, and their vaccination record should be carried with them.
In the event of possible exposure to rabies, urgent medical attention must be sought, even in those who have received pre-exposure vaccines. A medical evaulation will be required and additional doses of the vaccine may be needed.