Virus- H7N9 Influenza- Genesis and Evolution
Genesis and Evolution of H7N9 Influenza Virus
Aug. 21, 2013 — An international
team of influenza researchers in China, the United Kingdom and the United
States has used genetic sequencing to trace the source and evolution of the
avian H7N9 influenza virus
that emerged in humans in China earlier this year. The study, published
today in Nature, was supported by the National Institute of Allergy and
Infectious Diseases (NIAID), a component of the National Institutes of Health,
and other organizations.
Working in three Chinese provinces,
researchers led by Yi Guan, Ph.D., of the University of Hong Kong collected
samples from the throats and digestive tracts of chickens, ducks, geese,
pigeons and quail. Fecal and water samples from live poultry markets and the
natural environment were also collected. From these samples, the researchers
isolated several influenza viruses and genetically sequenced those of the H7N9
subtype as well as related H7N7 and H9N2 viruses.
These sequences were compared with
archived sequences of the same subtypes isolated in southern China between 2000
and 2013. The researchers compared the differences between the two sets of
sequences to reconstruct how the H7N9 virus evolved through various species of
birds and to determine the origin of genes.
According to their analysis,
domestic ducks and chickens played distinct roles in the genesis of the H7N9 virus infecting humans
today. Within ducks, and later within chickens, various strains of avian
H7N9, H7N7 and H9N2 influenza exchanged genes with one another in different
combinations. The resulting H7N9 virus began causing outbreaks among chickens in live poultry
markets, from which many
humans became infected. Given these results, the authors write,
continued surveillance of
influenza viruses in birds remains essential.
Share this story on Facebook
No comments:
Post a Comment