Viruses Can Be Transferred To Non Natural Hosts
The journal article, "Cross-species virus transmission and the emergence of new epidemic diseases" by C.R. Parrish et al describes different ways viruses can be transferred to non-natural hosts and possibly cause outbreaks and epidemics in the non-natural host population. In the article, the authors discuss several viruses that have emerged and infected human from animal hosts such as HIV and SARS. The viruses described in the article have different mechanisms for switching hosts and several factors that can play a part in successful viral host switching are discussed. Several factors are studied and discussed in the article that can contribute to the transfer of viruses to non-natural hosts.
These factors include; overcoming environmental and host barriers, the host range of the virus, evolution of the virus, and adaptation of the virus within the new host species. The authors use examples of known viruses that have switched from an animal host to a human host and caused outbreaks in the new human population to study and observe how these factors affect the transmission of the virus between the species (C.R. Parrish).Virus transfer from animal species to human species can be influenced by the environment in which the virus and the humans occupy.
The authors discuss HIV, SARS, and H5N1 influenza which have emerged from animal species and caused outbreaks and epidemics in humans. Humans must come in contact with these animal species in order for the virus to switch hosts. If humans are not in contact with these animal species that the virus naturally infects, then viral transfer to another host species is rare.
However, the authors discuss how human behaviors such as population growth, population density, and intercontinental travel can influence virus transmission between species and cause outbreaks. HIV is thought to have originated from SIV(simian immunodeficiency virus) in monkeys which evolved to infect humans. Human travel, living conditions, and contact are thought to have influenced the spread of the virus to epidemic form. SARS and H5N1 are also discussed as viruses that originated in animal populations.
Domestication of animals by humans led to prolonged exposure to the virus that humans may not normally have had which may have allowed viral mutations and adaptations to infect the human species. The authors also discuss how these viruses have to overcome barriers on a cellular level in order to effectively infect a new host. The virus can accomplish this by mutating so that it can infect the new host.
In the article, the authors discuss that species that are closely related have a better chance of virus transmission. The example used for this was HIV from closely related monkey species (C.R. Parrish).The host range of a virus can also play a role in viral transfer between species.
The researchers discuss generalist viruses which can infect a range of hosts and specialist viruses which are usually species specific. Generalist viruses were originally thought to have caused more cross-species virus transmission, but the specialist viruses were also found to have infected new and different host species (C.R. Parrish).Viruses must have the ability to mutate in order to effectively switch to another host species. The viruses with RNA genomes usually generate more mutations which can lead to host switching.
However, the authors also discuss that the mutations made in the viruses can also inhibit the fitness of the virus once it is inside the new host species. The authors also discuss that recombination in viruses is important for successful infection and transfer in and between the new host species. These recombination events can be helpful adaptations for the virus to survive and thrive in the new host species. The authors observed this by studying viruses such as HIV and SARS and comparing data found related to the viruses. Viruses have to compete against cellular immunity so adaptations and mutations to protect the virus from these immune responses are imperative (C.R.
Parrish).This article is important because it describes different factors that can influence the transfer of viruses between species. Several epidemics and outbreaks have been caused by viruses that have switched species including HIV, SARS, and influenza. The authors discuss these factors because if they are known and researched, then virus species switching may be able to be better controlled. The authors discuss ways these viruses may be controlled. These include strategies such as quarantining and monitoring infected persons or animals with known viruses that are prone to host switching, vaccination of humans and animals, and possibly providing antivirals to infected individuals in hopes of controlling the virus so that a large outbreak, epidemic, or pandemic does not occur.
The authors also suggest that further research about how these viruses emerge from animal host and infect human hosts may give insight on viruses that switch species. This can aid in preemptive measures to help control virus transmission between species and possibly even eliminate or control outbreaks, epidemics, or even pandemics (C.R. Parrish).I think that the authors highlighted out some very important factors that contribute to virus transmission between species.
I definitely think that human behavior has exposed the population to these new animal viruses and that prolonged exposure to these viruses has allowed them to mutate and infect the human species which would normally not be infected under most conditions. Because we live in a society that travels frequently and to places all around the world, we are exposed to viruses in certain areas and if the animal virus is able to overcome all of the cellular obstacles it has to go through and infect a human, that virus then has an advantage. Our society is now arranged in such a way that humans live in higher density and the population is continuing to grow. Viruses can use this to their advantage because they can then be spread easier from person to person and if more people are infected, then more people are able to spread the virus. Also, the ability for humans to travel large distances in a short period of time helps spread the virus to places it may not normally have reached.
I think that the next step for research on this subject could be to further investigate if vehicles and fomites that humans come in contact with from these animal viruses may have an effect on the ability of the virus to cross species barriers and infect humans.
Article name: Viruses Can Be Transferred To Non Natural Hosts essay, research paper, dissertation