VIRUSES: EMERING AND RE-EMERGING
Lisa Do
MBIO 3320
February 18, 2008
Viruses: Emerging and Re-emerging
What is an emerging virus? Based on medterms.com, an emerging infectious disease is one “that has newly appeared in a population”, or one “that has been known for some time, but is rapidly increasing in incidence or geographic range”. Therefore, an emerging virus would one example of what might have caused that emerging infectious disease. According to Sir Peter Medawar, a zoologist who developed and proved the theory of acquired immunological tolerance, “A virus is a piece of bad news wrapped in protein”. Viruses are microorganisms that are solely dependent on hosts’ cells in order to survive and continue replicating. Being that viruses are so versatile, they are known to infect a wide range of species. Different types of viruses are capable of infecting different species such as bacteria, plants, or animals. Some examples of each are the tobacco mosaic virus for plants, the bacteriophage for bacteria, and chickenpox for humans. In most cases, viruses cause diseases that are either endemic or epidemic. Most importantly, because viruses cause such a wide range of diseases, it is important to know the disease they cause, what or who is affected, symptoms that arise, diagnosis, and treatment and prevention where possible. In this technical essay the main focus will be on animal viruses rather than plant viruses or bacteriophages. More specifically, there will be emphasis made on the Japanese encephalitis virus (JEV), Coxsackie B virus, Herpes B virus, and Respiratory syncytial virus.
JEV is an emerging virus from family Flaviviridae and genus Flavivirus. Its genome is positive-sense and single-stranded RNA. JEV is specifically known to cause Japanese encephalitis, which is also known as Japanese B encephalitis, or Japanese epidemic encephalitis. JEV is considered the most common causative agent of viral encephalitis in humans. This virus...