Rabies Epidemiology

Rabies is a viral disease that is transmitted to humans via animal contact, known as a zoonotic disease. It has the largest impact on Asian and African populations, causing an estimated 55,000 deaths every year worldwide.

Dog bites are the most common source of rabies transmission and human deaths as a result of the disease. Young children are particularly likely to come into contact with the rabies virus as a result of contact with infected animals, accounting for up to 40% of bites from animals that may be infected with the virus.

A vaccination is available to be administered following suspected exposure to the virus, such as after an animal bite. Since the introduction of the vaccine the number of rabies death has continued to decrease each year. Throughout the world, more than 15 million people are vaccinated after being bitten by animals suspected to carry the rabies virus, which is expected to save hundreds of thousands of lives every year.

Asia and Africa

The vast majority of human deaths due to rabies occur in Asia and Africa. More than 95% of all deaths associated with rabies happen in these continents. According to recent data, India has the highest number deaths as a result of rabies each year, closely followed by Vietnam and Thailand.

This high incidence of deaths is likely to be associated with the cultural beliefs and medical treatments practiced in these regions. In particular, many of these populations do not believe in harming animals and dogs, even if they are dangerous or are known to possess the rabies virus. As a result, the stray dog population is notably higher and is more likely to effect humans in a negative way.

In addition, some cultural beliefs have an impact on the medical treatment sought. For example, it is a popular belief in India that a dog bite causes a puppy to be placed inside the human body that needs to be removed with the help of local witch doctor medicine. As a result, there is often a delay before someone potentially exposed to rabies is able to access the post-exposure vaccination, which is particularly time sensitive and only works if administered shortly after the bite. For this reason, a higher proportion people bitten do not access the vaccine in time and may die from the disease.

Americas and Europe

Rabies was once very prevalent among countries in Europe and America, and is thought to be of European origin. However, the impact that rabies has on the populations residing in these areas has greatly reduced since the introduction of public health measures to control the transmission of rabies virus.

These interventions have included wide use of vaccinations for the vast majority of domestic animals and access to post-exposure vaccinations for humans that suspect they have been in contact with the virus. As a result, in the past century the incidence of rabies deaths has dropped significantly and continues to do so.

Australia and Antarctica

Rabies is almost non-existent in Australia and Antarctica. There have been no cases of rabies reported in Antarctica from wild animal bites at any point in history.

Until recently, stray animals living in the wild in Australia did not carry the rabies virus and it was not possible, therefore for rabies to be transmitted to humans via an animal bite. However, the Australian Bat Lyssavirus (ABLA) was discovered in 1996, which carries similar symptoms and results as rabies virus and can be considered as such.

References

• http://www.who.int/mediacentre/factsheets/fs099/en/
• http://www.who.int/rabies/epidemiology/en/
• http://www.cdc.gov/rabies/location/world/index.html
• http://www.health.state.mn.us/divs/idepc/diseases/rabies/risk/animalbitesrabiesrisk.pdf
• http://www.nhs.uk/Conditions/Rabies/Pages/Introduction.aspx
• http://www.virologyj.com/content/9/1/50