Children growing up in the 1950s who were fans of Walt Disney movies all remember "Old Yeller" and his sad demise from rabies after a grey wolf bite. Rabies, also called hydrophobia, is caused by the Rhabdoviridae virus that is present in the saliva of an infected animal. Rabies can be transmitted between animals when a rabies infected animal bites another or a rabies infected animal bites a human.
About 15,000 cases of rabies are reported annually throughout the world, although human deaths to rabies in the United States are a low two cases per one million animal bites. A rabies diagnosis is not possible immediately after an infected animal has bitten a human because the virus often lies dormant for several weeks or months. The only sign of a rabies infection immediately is a painful burning sensation around the site of the bite.
The rabies virus eventually attacks the nervous system as well as the salivary glands. Early symptoms helpful in rabies diagnosis include low grade fever, headache, nausea, diarrhea, and increasingly painful swallowing and sore throat muscles. A rabies infected individual will become very thirsty, but will actually develop a fear of water, a key symptom of the disease. Painful muscle spasms, excessive drooling and dehydration are also symptoms that signal a rabies infection.
A doctor treating a patient with the above symptoms often orders a lumbar puncture or spinal tap test in order to confirm a rabies diagnosis. This involves the insertion of a long, thin needle into a patient's back in order to obtain a sample of cerebrospinal fluid in order to rule out any other causes of the symptoms. Another effective test for rabies diagnosis is to obtain fluid from the corner of the eye for microscopic examination which can reveal the presence of the rabies virus.
Once a rabies diagnosis has been determined, proper medical treatment involves a series of rabies immunization injections given over a 28 day period.