Emergent Viruses 4354646 202408538 2008-03-31T22:45:00Z Sabedon 2083035 /* External links */ added [[Category:Microbiology]] '''Emergent viruses''' is a concept based on the fact that through certain selection pressures, viruses can adapt and can emerge as a new disease/pathogenic strain with a new attribute facilitating its pathogenicity in a new field not normally associated with that specific virus. This includes viruses that are the cause of a [[disease]] which has notably increased in incidence; this is often a result of a wide variety of causes from both the influence of [[Human|man]] and [[nature]]. Most emergent viruses can be categorized as [[zoonotic]] (an animal disease that can be transmitted to humans), this has the advantage of possibly having several natural reservoirs for the [[disease]]. ==Overview== The most important factor in the development of an emergent disease, to [[humans]], is the ability to pass from animal host to humans. There is little to no occurrence of spontaneous new virus species development, although the possible exception commonly cited is [[Ebola virus]]. Most often the virus, due to selection pressure for an animal version of the strain of disease to [[mutate]] and therefore adapt to the infection of human hosts. ==Emergent Virus Infections Factors== - Population Movements <br> - Deforestation<br> - Irrigation<br> - Urbanization<br> - Increased long distance air travel<br> - Increased long distance air travel for livestock<br> - Migration<br> ==Examples of Emergent Diseases== ===Poliomyelitis=== Known to have existed for centuries with little [[incidence (epidemiology)|incidence]]. During the 19th century [[poliovirus]] became more prominent in populations across the world. Dense urban populations allowed the disease to propagate via close [[human]] to human contact. In addition to this, technological advances meant that traveling became more common throughout the population essentially leading to increased transmission of the [[virus]]. The situation became worse year upon year with increasing incidence of the [[disease]] worldwide. The issue was not resolved until the introduction of a poliovirus [[vaccine]] brought the situation under control. This example demonstrates how a disease can emerge in a population as a result of human influence. This examples also illustrates how an emergent virus can emerge and disappear by tackling the root cause. Poliovirus has been targeted for [[poliomyelitis eradication|eradication]] by the [[WHO]]. New emergent viruses are continually being discovered. Examples include: [[SARS]] and [[Avian influenza]] [[H5N1]]. ==External links== *[http://www.microbiologybytes.com/virology/emerging.html MicrobiologyBytes: Emerging Viruses] [[Category:Virology]] [[Category:Microbiology]]