The Diagnosis and Treatment of Rabies
Sarah M. Dolitsky
Virginia Military Institute
Word Count: 1,389 words
Author Note
Help Received: References
The Diagnosis and Treatment of Rabies
The virus that causes rabies is known as lyssavirus, named after Lyssa, the Greek Goddess of rage (Evans, 2017). This is fitting considering that later symptoms of the one type of the disease are aggressiveness, hallucinations, seizures, and delirium. Initial symptoms for both types of rabies include discomfort, an itching sensation, anxiety, confusion, fear of water, difficulty swallowing, and agitation (CDC, 2011). Rabies is transmitted when the saliva of an infected animal comes into contact with another animal or human, typically through a bite. Rabies, which can be a fatal disease if left untreated, can be prevented and treated. The current paper will examine the various methods of diagnosing as well as treating the infectious disease known as rabies.
First off, diagnosing rabies is critical since, as previously states, the disease can be fatal. Since rabies, is so rare it is sometimes difficult to treat without conducting tests especially since the infected person may be unaware of a bite mark from an infected animal. This is because the incubation period of rabies typically one to three months but could be as short as a few days or as long as a year. As for diagnosing rabies, there are two clinical forms: encephalitic, known as furious, and paralytic, known as dumb. The former makes up for 80% of cases while the latter makes up the remaining 20% of rabies cases (Jackson, 2009). The symptoms for furious rabies are exactly how it sounds and how many typically stereotype rabies; aggression, madness, hallucinations, and rage. On the other hand, the symptoms for dumb rabies are less known, which are paralysis, coma, multiple organ failure, and eventual death. The laboratory tests should focus on detecting the virus antigen or RNA in tissues or fluids of the human infected. For example, Cerebrospinal fluid or CSF, often shows abnormal results for those infected with rabies. To be more specific, the white blood cell count detected in a CSF sample tends to be less than 100 cells/μL (Jackson, 2009).
Further methods for diagnosing rabies include taking a skin biopsy or a brain biopsy. A skin biopsy can be taken from the nape of the neck which contains hair follicles making it more detectable. This method is more useful than a brain biopsy since a brain biopsy can only be used to assess rabies postmortem or after the infected person has already died. However, the brain biopsy can still be used to give information on the victim’s extent and/or type of rabies. More so, the brain biopsy is specifically useful for its accuracy. Rabies cannot be excluded due to negative tests unless it’s a brain tissue test. This means that if a CSF sample or skin biopsy comes up negative for rabies, the patient could still have rabies, but if a brain biopsy comes up negative, there’s no chance the person had rabies (Jackson, 2009).
Rabies can also be diagnosed through bodily fluids such as saliva and urine, however, similar to CSF samples and skin biopsies, these may not always show up positive on initial testing. This is because the virus is not continuously shed by those infected with it, meaning it’d be a hit or miss whether a sample was collected while the infected person was shedding the virus (Nigg & Walker, 2009). The method for these kinds of bodily fluid tests are known as Direct Fluorescent Antibody Technique (DFA) and they’re applicable for almost all tissue sources in living patients (Yousaf et al., 2012).
Another method that could work for diagnosing rabies is Magnetic Resonance Imaging (MRI) of the brainstem, hippocampus, and/or hypothalamus regions. Abnormal scans can appear in these three regions when a person is infected, but the degree may vary on a wide scale depending on the stage of rabies the infected person currently has. It’s also very important to note that the reason laboratory testing is so necessary for diagnosing rabies is because there are many other medical conditions that have similar symptoms of paralytic rabies. These conditions include “Guillain Barre syndrome, Japanese encephalitis, cerebral malaria, and the West Nile Virus” (Nigg & Walker, 2009). This is important to know because a disease as fatal as rabies should be diagnosed and treated as soon as possible, which could be delayed if a misdiagnosis were to occur. To summarize diagnosing rabies, no one test is sufficient. Multiple tests should be run in congruency in order to accurately diagnose rabies (CDC, 2011).
Anytime a human is bit by any sort of animal, to include: dogs, cats, ferrets, raccoons, or bats, the animal is supposed to be captured and observed for a minimum of ten days. If any signs of rabies are shown while the animal is confined, they are supposed to be killed and beheaded, so the head could be refrigerated and transported for laboratory research examination. Then, the same methods for diagnosing rabies in humans are used to try and diagnose it in the deceased animal’s head. This is to better locate and prevent the spread of any further rabies from a certain area through more of those specific animals (Jackson, 2009).
When it comes to treating humans with rabies, the main focus is the rabies vaccine. Prior to administering the vaccine though, the wound (if found) should be thoroughly cleaned with soap and water (Yousaf et al., 2012). As for how the vaccine is used, it depends if the infected person has had their vaccine in the past two years or not. If the person infected has had their vaccine with in the past two years, they will be treated with 1 ml of the rabies vaccine on days zero and three since being diagnosed. For those infected who have not had a rabies vaccine with in the last two years, it’s recommended that they receive the same 1 ml dose of the rabies vaccine on days zero, three, seven, and fourteen. In addition to the vaccine, these people should also receive doses of human rabies immune globulin (HRIG) on days zero through seven at the dose of 20 IU/kg. The rabies vaccine is considered active immunization and should be injected into the deltoid muscle on the infected individual. The vaccine comes from a rabies strain grown on a human diploid cell culture (Nigg & Walker, 2009).
HRIG is considered passive immunization since it works by passively providing immunization by making viral antibodies neutral. HRIG is administered by injecting it into the muscle nearest the rabies bite on an infected person. The products that make HRIG come from human donors, making them effective but expensive. These should only be used on an infected person who has not had their rabies vaccine within the last two years (Nigg & Walker, 2009).
In conclusion, there are two types of rabies: encephalitic rabies, characterized my rage/madness and paralytic rabies, characterized by paralysis. These types of rabies could be initially diagnosed through their symptoms. However, to fully diagnose an infected person with rabies, multiple laboratory tests must be run congruently. Tests can be run using CSF samples, bodily fluids like saliva or urine, skin biopsies from the nape of the neck, or brain biopsies from specific locations. Since sometimes a rabies infected person’s tests will appear negative, multiple tests must be used and tested multiple times. Once diagnosed, the infected person should thoroughly clean their wound with soap and water. Once that’s been done, there are two different methods of treatment dependent upon how recently the infected person has had their rabies vaccine. If the person has had their vaccine within the last two years, they will be treated with just the active immunization of the rabies vaccine over multiple days. However, if the infected person has not had their rabies vaccine within the last two years, they will be treated with both the active immunization of the vaccine as well as the passive immunization of human rabies immune globulin (HRIG) for multiple days straight. Properly diagnosing and treating rabies is important due to how fatal the infectious disease could be. Aside from just the fatality of it, the symptoms of the infection are extreme and can be detrimental even if the infected person survives. By educating people on proper diagnosis and treatment of it, rabies can be more quickly diagnosed as well as better prevented due to education regarding keeping up to date with vaccines.
References
Evans, K. (2017, April 12). A brief history of rabies. Retrieved April 29, 2019, from https://www.labroots.com/trending/microbiology/5761/brief-history-rabies
Jackson, A.C. (2009). Update on rabies diagnosis and treatment. Current Infectious Disease Reports, 11(4), 296-301.
Nigg, A.J. & Walker, P.L. (2009). Overview, prevention, and treatment of rabies. Pharmacotherapy, 29(10), 1182-1195.
Rabies. (2011, September 20). Retrieved from https://www.cdc.gov/rabies/diagnosis/animals-humans.html
Yousaf, M.Z., Qasim, M., Zia, S., Khan, M.U., Ashfaq, U.A., & Khan, S. (2012). Rabies molecular virology, diagnosis, prevention and treatment. Virology Journal, 9(1), 1-5.