The Rabies Disease
The word “rabies” is derived from a Latin word which means “madness” or “rage” – the very characteristic of people with this disease. A person with this illness usually dies of fatal encephalitis when not diagnosed and treated early. This disease is caused by the bullet shaped rhabdovirus which is commonly called the rabies virus. The virus is transmitted to a human being when he or she is bitten by an infected animal, usually by dogs or bats. There are reports which claim that even the saliva of these infected animals could cause rabies. Rabies virus from saliva could enter skin scratches and the eyelids. In fact, aerosols of bat secretions in caves have caused rabies to some researchers. Workers who have macerated infected tissues in the laboratory for analysis have acquired the virus and developed the disease; probably aerosols from the macerated tissue entered the workers' mouth, nose, or eye linings.
Symptoms of Rabies
Preliminary symptoms differ among patients. Once the CNS is already affected, the symptoms are extreme; the patient tends to alternate between stages of disturbance and periods of silence. During this time, a regular symptom is tremors of the muscles of the pharynx and the mouth which happen when the patient senses air drafts or drinks liquids. Actually, when the patient sees water or even thinks about, he immediately shows fear followed by spasms of his oro-pharyngeal muscles. This extreme fear of water is commonly called hydrophobia. The last stages of the disease result from extensive destruction of nerve cells in the spinal cord and the brain.
Interestingly, infected animals and humans exhibit a biting behavior which is essential in transmitting the virus in the animal population. In the onset of paralysis, salivary secretion increases as swallowing becomes difficult and nervous control is gradually lost. Death occurs within a few days.
Diagnosis can be done by detecting rabies virus in the saliva, serum, or cerebrospinal liquid of the patient or the animal (suspected to have rabies) using immunofluorescence studies. If the patient or the animal (e.g. dog and cat) is already dead, rabies confirmation is done by fluorescent-antibody test performed on a brain tissue sample.
An individual bitten by an infected animal must go through post exposure prophylaxis – meaning a series of antirabies vaccination and immune globulin injections. In instances that a person has bitten by “uncatchable” animals such as bats, foxes, skunks, coyotes, raccoons, or bobcats, it is advisable that the patient should be vaccinated immediately. If rabies is prevalent in your community, it is advisable that your pets be vaccinated to secure your protections against the fatal disease.
Chick embryo-grown vaccines or the human diploid cell vaccine (HDCV) are now being administered in different countries. In this kind of treatment, the patient is injected five to six times with the vaccine at intervals during a 28-day period.
Another treatment is by collecting human rabies immune globulin (RIG) from people who are immunized against rabies (e.g. laboratory technicians) and injecting it to the patient. This procedure is medically termed “passive immunization.”
Lee, Gary. 1997. Microbiology and Infection Control for Health Professionals. Prentice-Hall.