Rabies
Rabies is a viral zoonotic disease that causes progressive and fatal inflammation of the brain and spinal cord. Clinically, it has two forms:
- Furious rabies – characterized by hyperactivity and hallucinations.
- Paralytic rabies – characterized by paralysis and coma.
Although fatal once clinical signs appear, rabies is entirely avoidable; vaccines, medicines and technologies have long been available to prevent death from rabies. Nevertheless, rabies still kills tens of thousands of people each year. Of these cases, approximately 99% are acquired from the bite of an infected dog.
Dog-mediated human rabies can be eliminated by tackling the disease at its source: infected dogs. Making people aware of how to avoid the bites of rabid dogs, to seek treatment when bitten and to vaccinate animals can successfully disrupt the rabies transmission cycle.
Rabies is estimated to cause 59 000 human deaths annually in over 150 countries, with 95% of cases occurring in Africa and Asia. Due to underreporting and uncertain estimates, this number is likely a gross underestimate. The burden of disease is disproportionally borne by rural poor populations, with approximately half of cases attributable to children under 15 years of age.
Early symptoms of a rabies infection can include a fever with pain and unusual or unexplained tingling, pricking or burning sensation (paraesthesia) at the wound site. In later states, the virus spreads to the central nervous system, causing fatal inflammation of the brain and spinal cord. The incubation period of the disease can vary from 1 week to 1 year, though it is typically 2–3 months.
The two types of rabies show different symptoms. Furious rabies causes 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, which accounts for about 20% of the total number of human cases, runs a less dramatic and usually longer course than the furious form. Muscles gradually become paralysed, 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.
Vaccinating dogs is the most cost-effective strategy for preventing rabies in people, and human rabies vaccines exist for pre-exposure immunization.
If you are bitten or scratched by an animal, particularly a dog:
- Wash the wound immediately with soap or detergent.
- Flush the wound thoroughly for about 15 minutes with copious amounts of water.
- Apply an iodine-containing or anti-viral medication to the wound 15 minutes after it has been washed and flushed.
- Avoid applying irritants to the wounds such as chili powder, plant juices, acids and alkalis.
- Avoid covering the wound with dressings or bandages.
- Seek transportation to a health care facility for further assessment and treatment by a healthcare professional.
If possible, safely confine the biting animal and collect information on it and the bite circumstance to provide to the health care professional and public health officer. Keep the biting animal confined and under observation for 10 days.
WHO continues to promote human rabies prevention through the elimination of rabies in dogs, dog bite prevention strategies, and more widespread use of the intradermal route for post-exposure prophylaxis, which reduces volume and therefore the cost of cell-cultured vaccine by 60% to 80%.
