The rabies virus—which gets its name from the Latin word for rage—is arguably one of the most dreaded diseases in history, causing its victims great agony until it reaches its almost invariable conclusion of death. It is a zoonosis, most often communicated via animal bites (although there have been a very few documented cases of one human passing the virus to another), which is caused by a number of members of the genus Lyssavirus. It causes encephalitis which results in changes in behaviour; these changes manifest themselves in either the furious type or the paralytic type. Among other symptoms, the furious type causes restlessness and seemingly unfounded anger; the paralytic type causes decreased coordination, lethargy, and paralysis. Symptoms seen in both types include excessive salivation and sweating, confusion, nausea, and painful spasms in the muscles which control swallowing. These spasms often lead to a great dread and fear of water, giving rabies its other name, hydrophobia. Dogs, cats, and some other companion animals are required by law to get a preventative vaccine; there is a pre-exposure vaccine for humans, but in general it is only given to those people who work with animals and so are more likely to be bitten. Otherwise, humans are treated with a post-exposure vaccine as soon as possible; however, after the infection reaches the nervous system and symptoms begin, this treatment is no longer effective and the patient has very slim chances of survival if they have not previously received a pre-exposure vaccination. Only one person has ever survived full-blown rabies without receiving one of the vaccinations, a Wisconsin teenager named Jeanna Giese; the treatment used on her, known as the Milwaukee Protocol, has yet to be repeated successfully.

The following is a paper I have written on the virus; works cited can be found at the end of the article.

Rabies—also known as hydrophobia—is an illness of the nervous system. The zoonotic virus causes encephalitis, or swelling of the brain, and is usually contracted through being bitten by an infected animal. Thanks to modern medicine and preventative vaccines, the disease is now rare in much of the world, but the madness it induces and its unwavering conclusion of death after the onset of symptoms is enough to maintain a longstanding fear in the human community.

Rabies is caused by a few different members of the genus Lyssavirus, in the family Rhabdoveridae; there are different strains, but for the most part they are very similar. The rabies virus is an RNA virus that is bullet-shaped and has projections covering its exterior, and only affects mammals, although it can be grown in duck eggs (Melnick). The virus is transmitted through the saliva of the infected animal, which after a bite, travels through the body until it reaches the nervous system. The rabies which infects wild animals, domestic animals, and humans is referred to as the “street virus”. Strains which have been stabilised and weakened are “fixed viruses”. The “street virus” produces cytoplasmic inclusion bodies, or Negri bodies, in the nerve cells it infects (Melnick). When examining the brain of an animal or person post-mortem, the presence of Negri bodies is a positive means of diagnosing rabies. The virus has an incubation period which varies from species to species—dogs will become rabid between 10 days and six months of the virus entering the body, whereas humans will usually begin to show symptoms within 10 days to 3 months (“Rabies”, World of Microbiology…).

After the incubation period—when the virus has reached the spinal cord and infiltrated the nervous system—the first symptoms begin to appear. The initial symptoms are vague and not necessarily indicative of rabies, but they quickly become more severe. Symptoms of rabies as they appear in human beings can include sighing, nausea, vomiting, confusion, sensitivity to light and noise, lack of coordination, bouts of extreme agitation and depression, painful spasms of the throat muscles, paralysis, coma, and eventually death. The symptoms can vary, depending on the way in which the virus manifests itself. In both animals and humans, those with rabies will either have the hyperactive, “furious” type or the paralytic, “dumb” type (“Rabies”, WHO). In the hyperactive type, there is significantly greater aggression and instability of mood, while the paralytic type characteristically causes lethargy and progressive paralysis. The painful spasms in the throat which cause hydrophobia do not occur in all cases of rabies, but they are always a symptom in the hyperactive type. The infected person or animal comes to fear water because it associates drinking with the excruciating muscle contractions that it causes. Hypersalivation—the equivalent of the frothing at the mouth often seen in rabid dogs—is commonly seen, as well as intense perspiration. These, along with the fear of water, are reasons that many of those infected with rabies actually die of dehydration before the paralysis has shut down major organs.

The rabies virus is virtually as old as recorded history, with mentions of it in medical records dating back to as early as 300 B.C. (“Rabies”, World of Microbiology…). French microbiologist Louis Pasteur developed the first rabies vaccination in 1884. He did this by drying spinal cords of rabid animals over a period of two weeks, and looking at the activity in the virus over that period of time. The longer the infected spinal cords dried, the weaker the virus became, until at the end of 14 days it was completely inactive. He inoculated a few dogs with three different suspensions of the dried out virus, beginning with the inactive version. Next he injected the dogs with the weakened, but active, 7-day-dried version. Finally, he exposed the dogs to the strong, highly active virus which had only been dried for 1 day. The dogs survived and did not contract rabies, verifying that his vaccination procedure had been a success. At first, Pasteur was very reluctant to use his new vaccine on people—he offered to vaccinate dogs, but did not want to risk giving his experimental treatment to people. However in 1885, when asked to treat a 9-year-old boy who had sustained 14 bites from a rabid dog, he agreed to administer it. This treatment undoubtedly saved young Joseph Meister’s life, as he would surely have contracted rabies otherwise. He was allowed to go home just over three weeks later, and lived a long, healthy, rabies-free life. This huge breakthrough was what allowed humankind to gain a handle on rabies and greatly reduce the number of cases in many countries.

Before Pasteur created his vaccine, a wide range of methods were employed in attempts to prevent rabies and cure those suffering it. Most of these were based on theories or guesses rather than actual medical effectiveness. Very hot baths, mercurial ointments, blistering, large doses of opium, and bloodletting were among some of the treatments used in the late 1700s (Medical Records and Researches…, 120-123). These likely did more harm than good, and were virtually always ineffective in relieving the patient of symptoms.

The treatment used today is based mainly on Pasteur’s original vaccination, and it is called post-exposure prophylaxis, or PEP. PEP is most effective when begun within 14 days of receiving a bite from an animal suspected of being rabid. Vaccination involves five injections, the latter four of which are given after 3, 7, 14, and 28 days after the initial injection (Frey, “Animal bite infections”). If the wound is serious enough to warrant it, human or horse immunoglobulin is applied locally. This treatment is only effective before the symptoms of rabies begin.

While cases of rabies in humans are rare in the United States, the situation is very different in many developing nations. In many countries in Africa and Asia, rabies in dogs is endemic, as there is not enough money to fund widescale vaccination of companion animals. In certain European countries, efforts are being to eliminate rabies in wild animal populations by dropping bait containing the vaccine in various strategic locations. While rabies is still a formidable killer in the world today, the technology exists to get it under control. With funding and initiative, it is possible that this horrible viral disease could be nearly eliminated in the future.

Frey, Rebecca J. “Animal bite infections.” Gale Encyclopedia of Medicine. Ed. Jacqueline L. Longe. 3rd ed. Detroit: Thomson Gale, 2006. Science Resource Center. Gale. Marriott Lib., Holton-Arms School, Bethesda, MD. 16 Feb. 2008 <http://galenet.galegroup.com/‌servlet/‌SciRC?ste=1&docNum=CV2642412389>.

- - -. “Rabies.” Gale Encyclopedia of Medicine. Ed. Jacqueline L. Longe. 3rd ed. Detroit: Thomson Gale, 2006. Science Resource Center. Gale. Marriott Lib., Holton-Arms School, Bethesda, MD. 16 Feb. 2008 <http://galenet.galegroup.com/‌servlet/‌SciRC?ste=1&docNum=CV2642413652>.

Medical Records and Researches, Selected from the Papers of a Private Medical Association. Comp. T. Cox, G. G. Robinson, and J. Robinson. London, 1798. Google Book Search. 12 Sept. 2007. 13 Apr. 2008 <http://books.google.com/‌books?id=4DYNAAAAYAAJ&printsec=titlepage>.

Melnick, Joseph L. “Rabies.” Encyclopedia of Science & Technology. 10th ed. AccessScience. McGraw-Hill. 13 Apr. 2008 <http://www.accessscience.com/‌server-java/‌Arknoid/‌science/‌AS/>.

“Rabies.” World Health Organization. Sept. 2006. 13 Apr. 2008 <http://www.who.int/‌mediacentre/‌factsheets/‌fs099/‌en/>.

“Rabies.” World of Microbiology and Immunology. Ed. K. Lee Lerner and Brenda Wilmoth Lerner. Detroit: Thomson Gale, 2007. Science Resource Center. Gale. Marriott Lib., Holton-Arms School, Bethesda, MD. 16 Feb. 2008 <http://galenet.galegroup.com/‌servlet/‌SciRC?ste=1&docNum=CV2644650371>.