One of the first—and most fearsome—diseases humankind has had to contend with, rabies is found in almost every country in the world and is nearly always fatal, killing 55,000 people each year. In the four millennia since the first people were recorded as having gotten the disease, the number of survivors is small; indeed, of people who were exposed to rabies, did not get vaccinated, and then developed the disease, only seven are ever known to have survived.
Rabies is one of a class of viruses that can be easily transmitted between species. About 97 percent of infections are due to dog bites, but any warm-blooded animal can carry the disease, and bats are also sometimes known to be culprits. In Australia, Japan, and some other countries, rabies has been completely eliminated among land animals, and many more have been able, through comprehensive vaccination programs, reduced the incidence of the condition in dogs to nearly zero.
Nonetheless, if you have been bitten by a strange animal, it is important to get medical attention right away. In medicine as elsewhere, the best defense is a good offense, and the best thing to do after possible exposure is to get a rabies vaccine. The vaccine is effective even after infection has already occurred, but needs to be given quickly to prevent the virus, if it's present, from doing damage.
Seven people, however, have survived rabies without vaccination. They all were treated with what is called the Milwaukee protocol, after the city in which it was first used in 2004. The protocol can be administered to patients who have already started to develop rabies symptoms, such as fever and headache, difficulty swallowing and an aversion to water, insomnia, hallucinations, and the better known symptoms of agitation, anxiety, confusion, and salivation; while it is only successful in about one in 12 cases, it is the only treatment protocol shown to have any efficacy in the absence of vaccination. It entails inducing a coma to protect the brain until the infection is dealt with by the immune system. Because the Milwaukee protocol is itself dangerous, and because of its low success rate, doctors recommend getting vaccinated after any potential exposure, unless the patient is already immune, such as due to a previous vaccination.