Viruses: Rabies Virus
There are five general stages of rabies fully recognized by human beings researchers. The five stages include incubation, prodrome stage, the acute neurologic period, coma and death. From the different analysis done by researchers from cats, rabid dogs and ferrets, it can be argued that rabies virus is introduced to the muscle of a new host through a bite from another infected animal (Fisher, Streicker & Schnell, 2018). After infection, the virus travels from the site of the bite to the brain of the animal moving through the animal nerves. At this stage, the animal does not seem to be ill or suffering from any infection (Fisher, Streicker & Schnell, 2018). Each of the five stages of rabies in animals has its severity to the new affected animal, and as a result, the stages are explained in the following paragraphs.
- Incubation: At this stage, the animal is bitten by an infected rabid animal.
- Prodrome stage: After the biting from the saliva of an infected animal, rabies enters the wound of the animal.
- Acute neurologic period: After entering the body of a new animal, the virus travels through the nerves of the newly infected animal to the spinal cord and to the animal brain. The method of transmission lasts for an approximate of 3 to 12 weeks. At this stage, the animal does not show any form of signs.
- Coma: The virus travels through the spinal cord of the animal to the brain where it starts to multiply. After reaching the brain, the virus faster and passes to the salivary glands.
- Death: After infection of the new animal, usually dies within a period of 7 days after getting infected.
The period between when the virus is introduced in the body of a new host through a bite and the appearance of the symptoms is known as the incubation period. In most animals, the incubation period might last between weeks and months, depending on the immunity system of the animal. Any other animal which bites the infected animal during this time does not carry any risk for rabies for the virus has not yet entered and made entry to the saliva (Fisher, Streicker & Schnell, 2018). Rabies travels to the brain where it starts the body inflammation. Later after infection of the body parts, the disease travels to the brain of the animal, which is the second stage of rabies after getting into the body of the animal. The virus reaches the brain where it multiplies and causes inflammation of the brain. From the brain, rabies travels to salivary glands of the animal and the saliva (Finke & Conzelmann, 2005). After this time, when the virus has been multiple in the brain, all animals infected begin to show the first signs of rabies and can pass the virus into other animals when they bite them. In most cases, most of these signs are obvious to even untrained observers who have never witnessed an animal with rabies. Between three to five days, the virus causes enough damage to the brain of the animal up to a stage that the animal shows unmistakable signs of rabies (Menegas, Uchida & Watabe-Uchida, 2017). Not many people who at this stage can ascertain that the animal is suffering from rabies. During this stage, a bite from the animal to another animal can transmit the disease to another animal for the virus has been passed to almost every part of the animal body.
Extensive studies on dogs, ferrets and cats indicate that the virus can be excreted through the saliva of an infected animal several days before the illness is apparent in the animal. Research on these animals has been done on wild animals (Menegas, Uchida & Watabe-Uchida, 2017). However, it is known that different wildlife animals do not excrete rabies within their saliva before the onset of symptoms of the illness. Within the body, the excretion of the virus might be intermittent, and the comparative amount of the excreted virus might vary with time before and after when the clinical signs of the disease start showing off.
Rabies Virus Hoist Range
In animals, Rabies is a viral zoonosis to carnivores like raccoons and foxes and many other species of bats. Most of these animals form the wider range of rabies virus in nature. Worldwide, in terms of human disease, bats and dogs represent the most significant host reservoirs. The infection of human beings usually follows bites by the rabid animals and is mostly invariably fatal signs and symptoms of the virus when it happens (Menegas, Uchida & Watabe-Uchida, 2017). Across the globe, more than 2.5 billion persons live in regions where rabies is an endemic and where it has affected many people. It is estimated that yearly, more than 59000 persons die from rabies. More than 15 million other people receive vaccination for the problem (Menegas, Uchida & Watabe-Uchida, 2017). The virus has increased risk for children between 5-25 years. Across the globe, more than 99% of human being deaths from rabies happen in Asia continent, South America and Africa. For the last decades, India reports around 30,000 deaths yearly.
For more than 100 years, rabies vaccines to the nerve tissues origin have been used for vaccinating human beings following the exposure of rabid animals. In most states, these vaccines are considered to be inexpensive. However, they have low potency per dose and vaccines produced on sheep and goats brains have different events. Most of the poor communities across the globe highly depend on the never tissues vaccine produced through cell culture and which have been in operation and available in between 20 to 30 years (Davis et al., 2017). In treating human, the vaccines are used not only for post-exposure treatment but also can be used for pre-exposure treatment. In many nations, veterinary and rabies vaccines are widely produced and applied for immunization of different domestic animals, mostly cats and dogs. Additionally, in industrialized nations, oral vaccines are widely used for immunizing wildlife hosts of the virus rabies.
Nevertheless, different attempts of controlling rabies in animals have failed largely in most poor nations across the globe. It is rare for people to get rabies from non-bite of animals, but most of those who get it get it from animal bites (Davis et al., 2017). The animal bites through which people get rabies from include abrasions, scratches and open would expose to saliva and another potential infectious disease from a rabid animal. Other types of contacts through where people can get the virus from include having contact with body fluids of an infected animal through urine, blood and faeces of an infected animal (Schnell et al., 2010). Other modes of transmission which people should be worried about at many times include side bites and uncommon scratches. Additionally, inhalation of aerosolized rabies virus is one of the main potential non-bite method or exposure route, which some might conduct the virus from animals (Schnell et al., 2010). Bite from infected person to uninfected person might transmit the virus also.
Summary and Conclusion
Analyses have indicated that rabies is one of the most killer diseases across the globe, affecting people mostly in Asia, South America and Africa. It is a preventable viral disease, and it can be transmitted through an animal bite from a rabid animal. When it enters the animal body, it passes through nerves and the spinal cord where it reaches the brain of the animal and starts infecting it. Rabies infects the animal central nervous system where it ultimately causes the animal brain death. There are notable signs and symptoms which people and healthcare givers look at when looking for drugs to treat the virus. Most affected animals are dogs, cats and wildlife animals. Health caregivers should make sure that they master notable signs and treat animals before infecting other animals.
References
Davis, B. M., Fensterl, V., Lawrence, T. M., Hudacek, A. W., Sen, G. C., & Schnell, M. J. (2017). Ifit2 is a restriction factor in rabies virus pathogenicity. Journal of virology, 91(17).
Finke, S., & Conzelmann, K. K. (2005). Replication strategies of rabies virus. Virus research, 111(2), 120- 131.
Fisher, C. R., Streicker, D. G., & Schnell, M. J. (2018). The spread and evolution of rabies virus: conquering new frontiers. Nature Reviews Microbiology, 16(4), 241.
Menegas, W., Uchida, N., & Watabe-Uchida, M. (2017). A self-killing rabies virus that leaves a trace on the DNA. Trends in Neurosciences, 40(10), 589-591.
Schnell, M. J., McGettigan, J. P., Wirblich, C., & Papaneri, A. (2010). The cell biology of rabies virus: using stealth to reach the brain. Nature Reviews Microbiology, 8(1), 51-61.