Rabies case study
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 DHHS, 2017)
The different clinical signs you will see with Rabies Virus: Drooling excessively, convulsing/Seizures, mutilating themselves, biting or snapping, agitation and aggression, paralysis and Hydrophobic. 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: 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 30.9%, Raccoon 29.4%, Skunks 24.8% and Foxes 5.9%.
Though opossum are rarely infected due to low body temperature. Low body temperature hinders replication of Rabies Virus. Rodents and lagomorphs die before in 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.(NCBI,2013) Though the incidence varies depending on the country. Europe- Foxes and Bats, Middle East- Wolves and Dogs, Asia- Dogs, Africa- Dogs, Mongoose and Antelope, N. America- Skunk, Fox, Raccoon and Insectivorous Bats, S. America- Dogs and Vampire Bats.(NCBI,2013)
Rabies is diagnosed with fluorescent antibody test (DFA), which looks for the presence of rabies virus antigens in the brain tissue. But in order to rule out rabies two parts of the brain must me tested, the brain stem and cerebellum. Of course this means the animal must be euthanized before hand. 120,000 animals are tested for rabies each year in the US, but only 6% are found to be rabid.(US DHHS, 2017) Test are similar when it comes to human diagnosis as several tests are required to diagnose rabies before death. Tests are preformed 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. Though tested before serious onset of the virus, you may be able to survive the disease.(US DHHS, 2017) Unfortunately there is no treatment.
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. With 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)(US DHHS, 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, that includes if you know your animal has been bitten by a wild animal.(US DHHS, 2017)(Bassert,2014)
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 road kill or carcasses. Vaccine can prevent infection. You can use the vaccine before and after the bite. Prevention in humans are similar, majorly leave strays and wild animals alone. Humans can also get a vaccine to prevent infection. This can be used for both bite and non bite exposures of an infected animal.(US DHHS, 2017)(Bassert,2014)(UC 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. (US DHHS, 2017) But 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.