Rabies is a more serious threat to humans worldwide than previously thought. A new study estimates that 59,000 people a year-or more than 160 a day-die of rabies, primarily in poorer countries where most dogs are not vaccinated.
This figure is based on mathematical modeling and is much higher than previous estimates of deaths due to rabies, which are based on officially reported cases. The previous estimates may be low due to under-reporting of cases of rabies and because of misdiagnoses. Many people who contract rabies in poorer countries die at home, which is one reason the number of official cases is low.
Although any mammal can be infected by the rabies virus and can transmit it, almost all cases of rabies in humans in poorer countries are from dogs. In most developed countries, dogs are routinely vaccinated against rabies. Mass vaccinations of dogs are more cost effective than vaccine treatments for someone who has been bitten. Dog vaccine costs between 20 cents and a few dollars, but human vaccine costs up to $150 a dose. Human vaccine is often not available in very poor countries.
Rabies is a viral disease that can be spread through a bite or scratch from an infected animal. It has an extremely high fatality rate unless it is treated promptly, before symptoms start. The disease causes an acute inflammation of the brain in mammals that in turn causes violent movements, uncontrolled excitement, and later, paralysis and loss of consciousness.
A person who is bitten by a rabid animal can survive if they are treated with rabies vaccine, which is called post-exposure prophylaxis. The fatality rate for rabies is so high in people who have not received rabies vaccine or immunoglobulin before symptoms appear that there are few recorded cases of someone surviving.
The mathematical modeling was performed by the Global Alliance for Rabies Control and published in the online journal PLoS Neglected Tropical Diseases.
You can read the study online at http://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0003709.
