Rabies. By: Christopher Solomon. Disease: Rabies etiologic agent: Lyssavirus (1)

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1 Rabies By: Christopher Solomon Disease: Rabies etiologic agent: Lyssavirus (1) Transmission: Transmission of this disease is most often transmitted by the bite of an infected or rabid animal (2). Reservoirs: The most common animal vehicles for transmission of this disease include but are not limited to raccoons, foxes, bats, and skunks (2). General Characteristics: Rhabdoviridae are classified due to their, Bullet shape. The genus Lyssavirus includes the Rabies virus, it also belongs to the order Monoegavirales (1). Rabies is an RNA virus approximately 12kb that encodes 5 proteins designated N, P, M, G, and L (2). The Rabies virus is also covered in approximately 400 trimeric spikes tightly arranged on the cell surface that allow for adhesion (2). All rhabdoviruses are composed of two components a helical ribonucleoprotein (RNP) and a surrounding envelope (1). When testing for the Rabies virus, the mouse neutralization test has been the standard (3). Another promising procedure is the rapid fluorescent focus inhibition test (RFFIT) (3). Testing the animal specimen for Rabies, when Rabies is suspected the animal should be euthanized, its head removed, and the head shipped under refrigerated circumstances for examination (4). Signs and Symptoms: Initial symptoms of the rabies virus could be comparable to those of the common flu including but not limited to: general weakness, discomfort, fever and headache (5). As for the site of the bite, there would be sensation, prickling and or itching (5). From here the disease progresses within days to cerebral dysfunction, anxiety, confusion and agitation (5). Later symptoms could also include delirium, abnormal behavior, hallucinations and insomnia (5). Once a person is at the stage of the disease where they start to show symptoms, survival is rare (5). It is also worth mentioning that to date only 10 people who have ever had clinical rabies have ever been reported (5). Historical Information:

2 The Latin term rabies loosely translates to madness. Rabies has been around since 2000BC, with the first record of it ever appearing occurring in the Mesopotamain society. Rabies appears to have originated in the old world, the first episode occurring in Boston in It spread from there over the next years to various other states. Rabies was considered a scourge due to its endemic nature in the 19 th century. The fear of rabies was almost irrational due to way the disease was transmitted, by other rabid animals. In modern times fear of rabies has not diminished, this is largely due to pop culture portraying rabies as having mutated into some contagious virus which turns people into zombie like ravenously hungry creatures. Virulence Factors: For the Rhabdovirus Rabies there are not to many virulence factors as its spreading is solely done through a vector (animal) biting another animal/human. However as previously stated the virus is coated with spikes all over that aid in adhesion, this would certainly help the virus spread in the new found host once it has been admitted into the new host s circulation (1). Another couple of virulence factors include G protein and cytopathic effects as these once again help the disease spread throughout the body quickly by hijacking our central nervous system and using it as a pathway to infect other organ systems within the body thus yielding the high percentage of death for this disease (4). Control/Treatment: The most prevalent way we have found to control Rabies was by vaccination of pets by the pet owners. It is recommended for pet owners to have their animal vaccinated at or around the age of 4 months, after which an annual booster shot is given to the animal to keep the animal Rabies free (7). Measures have also been taken to limit the amount of wild animals that contract and spread this disease by the use of an oral rabies vaccine that is administered to these animals in the form of bait (7). For humans the treatment is usually administered a series of shots to the first being an initial shot of antibodies against rabies that is given at or near the site of the wound this is to provide initial short term protection (7). From then the person is administered a round of shots that take place over a 28 day period (7). For a person who is expressing symptoms of rabies treatment is usually supportive care, as most of all who reach this point end in death of the host. Another way to prevent rabies is to get a pre exposure vaccine, these are often administered to people who have high risk jobs or where they come into contact with animals on a daily basis examples would include vets, or lab workers in certain cases (7). Prevention and New Vaccine Information:

3 Prevention of the disease is mainly accomplished by both being a responsible pet owner and making sure that your pets have been vaccinated, as well as keeping them in a gated or monitored location and not simply letting them run free (7). As far as new vaccinations the methods we have of treating rabies are already done substantially well as long as the disease is caught early on (prior to symptom expression)(7). Local Cases and Outbreaks: As of April 20, 2015 there were 20 cases of Rabies that had occurred in Bell County, more than half of which were attributed to the skunk population(6). Bell County is where my home town is and just the fact that there were 20 deaths from this virus alone this year is shocking to me. Similarly, here in Travis County there were 115 cases of Rabies and every single one that became infected were because of bats, makes me really rethink going to see the bats under Congress Bridge (6). In total in Texas alone there were 1132 deaths from Rabies last year (6). Global Cases and Outbreaks: The Image below depicts the location of Recent Rabies outbreaks worldwide (8). It is clear that while Rabies is a disease that is entirely preventable if action is taken quickly, in both Africa and Asia you are at the highest risk of contracting the disease. This is also where the disease is most prevalent on a yearly basis (8).

4 (8). Figure 1: shows the risk levels of contracting Rabies over a global scale in 2011 Work Cited: "Rabies." Department of Health and Human Services- Centers for Disease Control and Prevention. 6 Dec Fitzgerald E. A. et al. A collaborative study on the testing of rabies immunoglobulin by the mouse neutralization test MNT and the rapid fluorescent focus inhibition test (RFFIT). Journal of biological standardization 5 October Submission of Animals for Rabies Testing, 5. Signs and symptoms of Rabies Department of Health and Human Services: Centeres for Disease Control and Prevetion. 17 December

5 6. Rabies Outbreaks Texas Department of State health Services 20 April 2015 file:///c:/users/christopher/downloads/2014.pdf 7. Texas Department of State Health Services. Rabies Testing in Humans. Modified February 23, Accessed 12/7/ Majeski, T. We Can End Rabies Together, Disease Outbreak, Economic Burden, Infectious Disease and Vaccination. 27, September Accessed 12/7/15.