A Case Study on Rabies

Introduction

Rabies is a very interesting disease to research as it is such a complex virus. It is a zoonotic disease spread through bites or saliva of an infected animal. It is usually fatal as it does not show definitive signs of the infection until it is too late. The only diagnosis is through a series of tissue tests. The cause of Rabies virus is through a bite of an infected animal. The virus lives in the saliva, and dies when the saliva dries. It grows in the muscle, and moves to the spinal cord and into the brain. Rabies then starts from the brain and travels to the salivary glands in the final stage of the disease (U.S. Department of Health and Human Services, 2017).

Clinical Signs

The different clinical signs you will see with Rabies Virus include drooling excessively, convulsing/seizures, self-mutilation, biting or snapping, agitation and aggression, paralysis, and hydrophobia. The clinical signs in humans vary depending on how long the patient has been infected. The clinical signs are seizures, drooling excessively, delirium, hallucinations, flu-like symptoms such as weakness, discomfort, fever or headache, pain or tingling at the site of bite, insomnia, paralysis, anxiety, and agitation. Wild animals account for 92.4% of reported cases in 2015. Bats make up 30.9%, raccoons 29.4%, skunks 24.8%, and foxes 5.9% of these cases. Opossums are rarely infected due to their low body temperature, which hinders the replication of the Rabies Virus. Rodents and lagomorphs often die before they are able to transmit the virus to a human. Human rabies cases in the United States are rare, with only 1 to 3 cases reported annually (National Center for Biotechnology Information, 2013). The incidence varies depending on the country: Europe sees more cases in foxes and bats, the Middle East in wolves and dogs, Asia in dogs, Africa in dogs, mongoose, and antelope, North America in skunks, foxes, raccoons, and insectivorous bats, and South America in dogs and vampire bats (National Center for Biotechnology Information, 2013).

Diagnosis

Rabies is diagnosed with a fluorescent antibody test (DFA), which looks for the presence of rabies virus antigens in the brain tissue. To rule out rabies, two parts of the brain must be tested: the brain stem and cerebellum. This means the animal must be euthanized beforehand. Approximately 120,000 animals are tested for rabies each year in the US, but only 6% are found to be rabid (U.S. Department of Health and Human Services, 2017). Tests are similar for human diagnosis, as several tests are required to diagnose rabies before death. Tests are performed on the saliva, serum, spinal fluid, and skin biopsies of a hair follicle at the nape of the neck. After all tests are run, only then can they determine if you carry the virus; no single test is sufficient. If tested before the serious onset of the virus, you may be able to survive the disease (U.S. Department of Health and Human Services, 2017). Unfortunately, there is no treatment.

Prognosis

Once the disease develops and the patient begins to show signs, death is certain. Most public health officials recommend that the possibly infected animal be euthanized immediately. For humans who have the Rabies virus, death usually occurs within days of the onset of these symptoms. Once a person begins to exhibit signs of the disease, survival is rare (PetMD, 2018; U.S. Department of Health and Human Services, 2017). Unfortunately, for anyone who is infected with Rabies Virus, the disease has a poor prognosis. Hardly anyone who gets infected with this virus survives past the clinical signs. Once bitten, you should seek medical attention, including if you know your animal has been bitten by a wild animal (U.S. Department of Health and Human Services, 2017; Bassert, 2014).

Prevention

Preventing Rabies virus is simple: vaccinate your pet. Don’t let your animals roam unsupervised. You never know who might carry the virus, so do not let your pet near any animal you do not know. Leave strays and wild animals alone; do not touch or approach them. Keep your pets away from roadkill or carcasses. Vaccines can prevent infection. You can use the vaccine both before and after a bite. Prevention in humans is similar; primarily, leave strays and wild animals alone. Humans can also get a vaccine to prevent infection, which can be used for both bite and non-bite exposures of an infected animal (U.S. Department of Health and Human Services, 2017; Bassert, 2014; University of California, Davis, 2010). Because the disease can only be properly diagnosed from the brain stem, many animals are euthanized because of this. The clinical signs that are inevitably shown are the final signs of the disease, the days before death. If the growing disease was more presentable in the patient in the beginning stages, it would be better for diagnosis (U.S. Department of Health and Human Services, 2017). Not knowing if the animal has Rabies is dangerous for everyone, including the pet. If it was easily detectable, we would be able to save more lives. If not making the disease more visual for treatment, one would hope that there was a treatment. With that, many lives, human and animal, could be saved. That being the unknown, whether or not someone will survive the Rabies virus.

References

Bassert, J. M. (2014). McCurnin's Clinical Textbook for Veterinary Technicians. Elsevier Health Sciences.

National Center for Biotechnology Information. (2013). Rabies Virus and Rabies: A Brief Review. Retrieved from https://www.ncbi.nlm.nih.gov/

PetMD. (2018). Rabies in Humans and Animals: Symptoms, Causes, and Prevention. Retrieved from https://www.petmd.com/

U.S. Department of Health and Human Services. (2017). Rabies: Information and Prevention. Retrieved from https://www.hhs.gov/

University of California, Davis. (2010). Rabies Prevention in Humans and Animals. Retrieved from https://www.ucdavis.edu/