Kelsey M. Lee
Castleton State College
Rabies
Definition
Rabies is a complex virus that is found in mammals and has proven to be highly fatal in humans. Deriving from the rabies virus (RV) this virus attacks its host’s central nervous system and is most commonly transmitted through the exchange of saliva through a bite (Duncan & Boulton, 2012). It has been documented however that the virus can infect an individual through contact of the virus and an open wound and some cases have shown that inhalation in bat caves is an alternative transmission route (Manning et al, 2008). There are two different types of rabies that have been identified they are furious and paralytic which is less common, however they are both equally …show more content…
After the virus is transferred into a new host it enters the unmyelinated axon terminals. The infection then spreads through a chain of neurons that are connected by synaptic junctions. After uptake into peripheral nerves, rabies virus is transported to the CNS through retrograde axoplasmic flow (Concepts in the Pathogenesis of Rabies, 2014). After infection of the brain, the virus spreads to the peripheral and autonomic nervous system. In the final stage of the infection cycle, the virus migrates to the salivary glands and is ready to be transmitted to the next host. Due to the invasion of the neurological system the virus inhibits the process of protein synthesis (Concepts in the Pathogenesis of Rabies, 2014). Along with the changes in protein synthesis, the virus impairs the release of serotonin which is a neurotransmitter responsible for controlling the sleep cycle and perception of pain and behavior. As invasive and lethal as the infection is, studies have shown that there are rarely lesions or necrosis is present in the brain despite the significant neurological changes (Concepts in the Pathogenesis of Rabies, …show more content…
As stated previously, there are four stages to being infected with RV that is seen in humans. The incubation period is the time in which the host is infected and shows no sign of symptoms (Duncan & Boulton, 2012). The prodrome stage is when the host begins to experience fever, irritability, fatigue, insomnia, anorexia, headache, sore throat, nausea and vomiting. This stage is often misdiagnosed due to its similar characteristics of influenza, Herpes simplex and Epstein-Barr virus (Duncan & Boulton, 2012). The most aggressive period of symptoms is seen during the acute neurological phase. Often this is when the diagnosis of rabies is confirmed and as the virus reaches the brain stem and moves across the whole central nervous system the more predominate the symptoms become. These signs include insomnia, anxiety, and confusion, paralysis which is complete or partial, hallucinations, hypersalivation, hydrophobia and aerophobia. Death is eminent within days of the appearance of these symptoms and many reach the coma phase prior to their final day (Duncan & Boulton,