Influenza Epidemics Due To Hybrid Viruses
A recent article published in the open-access journal PLoS Pathogens maintains that over its evolutionary history, reassortment of the influenza A poison happens often.
Genetic reassortment is when genetic material mixes from two similar viruses that are infecting the same cell. Influenza virus A is a species of virus that causes influenza in birds, humans, pigs, and horses; it has often given rise to human influenza pandemics.
A team of researchers from both Pennsylvania State University and the National Institutes of Health (NIH) looked at influenza viruses from 1918 to 2005. They focused on viruses that cause seasonal epidemics in humans, especially ones that were associated with high mortality.
The severe influenza epidemics of 1947 and 1951, according to the researchers, were the result of genetic reassortment events. Two of man influenza viruses from the same H1N1 strained switched genetic material, and thus produced two new hybrid viruses.
It has been unknown while to exactly why very severe influenza epidemics occur periodically and lead to unusually high-toned illness and mortality levels - like the ones in 1947 and 1951. The ordinary model of human influenza virus evolution argues that major pandemics (of which 1918 was the largest) are due to genetic reassortment of human and avian (bird) influenza viruses. However, the seasonal influenza epidemics that occur each winter in the United States are thought to arise without genetic reassortment.
The new research findings add a layer of complexity to the descent by continuous differentiation of seasonal influenza than was previously believed. That is, within a single population, multiple forms of the same strain co-circulate and re-assort. These quickly-generating, story viruses are capable of starting greater epidemics.
The authors believe that vaccine design can be helped grant that intensive surveillance can capture the full extent of in what plight genetically diverse the influenza virus is that is co-circulating at a given proper time.
Multiple Reassortment Events in the Evolutionary History of H1N1 Influenza A Virus Since 1918
Nelson MI, Viboud C, Simonsen L, Bennett RT, Griesemer SB, et al.
PLoS Pathogens 4(2): e1000012. (2008).
doi:10.1371/journal.ppat.1000012
Click Here to View Journal Website
Written by: Peter M Crosta
Copyright: Medical News Today
Not to have being reproduced without permission of Medical News Today
April 7th, 2008 at 2:07 am
Fortunately, it’s still funny.
April 9th, 2008 at 5:08 pm
stop saying grose things about this! It’s your terrible way of thinking! Normal people don’t care about stuff like that