Rabies is a viral brain disease that is almost always fatal if it is not prevented with prompt treatment. The disease, which typically spreads to humans from animals through a scratch or a bite, causes inflammation of the brain. The disease is also called hydrophobia (meaning fear of water) because it causes painful muscle spasms in the throat that prevent swallowing. In fact, this is what leads to most fatalities in untreated cases: victims become dehydrated and die. Carriers of rabies include dogs, cats, bats, skunks, raccoons, and foxes; rodents are not likely to be infected. About 70% of rabies cases develop from wild animal bites that break the skin. Though a vaccine used first in 1885 is widely used, fatalities still occur due to rabies. Most fatalities take place in Africa and Asia, but some also occur in the United States. The cost of efforts to prevent rabies in...