Published: Thursday, June 12, 2014 - 09:28
in Health & Medicine
An international team of researchers has shown that circulating
avian influenza viruses contain all the genetic ingredients necessary to
underpin the emergence of a virus similar to the deadly 1918 influenza
virus. Searching public databases, the researchers, led by Yoshihiro
Kawaoka of the University of Wisconsin-Madison, identified eight genes
from influenza viruses isolated from wild ducks that possessed
remarkable genetic similarities to the genes that made up the 1918
pandemic flu virus.The 1918 or "Spanish flu" pandemic was one of recorded history's most devastating outbreaks of disease, resulting in an estimated 40 million deaths worldwide.
The new work was published today (June 11, 2014) in the journal Cell Host and Microbe. It shows that "there are gene pools in nature that have the potential to cause a severe pandemic in the future," says Kawaoka, an international authority on influenza and the senior author of the new report.
To assess the risk posed by a virus that could acquire all eight of the 1918-like genes, the team used reverse genetics methods to generate a virus that differed from the 1918 virus by only 3 percent of the amino acids that make the virus proteins. The resulting virus was more pathogenic in mice and ferrets that an ordinary avian flu virus, but was not as pathogenic as the 1918 virus and it did not transmit in ferrets via respiratory droplets, the primary mode of flu transmission.
Since pandemic risk escalates when a virus become transmissible, Kawaoka's group then conducted additional experiments to determine how many changes would be required for the avian 1918-like virus to become transmissible in ferrets, a well accepted model for influenza transmission studies. The researchers identified seven mutations in three viral genes that enabled the pathogen to transmit as efficiently as the 1918 virus. The resulting virus, composed of genetic factors circulating in wild a.. http://esciencenews.com/articles/2014/06/12/genes.found.nature.yield.1918.virus.with.pandemic.potential
