Scientists say they have discovered new strains of the deadly bird flu virus in China that could pose an even more serious threat than previously feared.
A study of the evolutionary history of the H7N9 bird flu, which jumps from birds to humans and has so far killed 44 people, has led scientists to discover additional types of the H7 strain lurking in chickens in China.
While none of the new strains they detected has yet to be found in humans, some were able to infect mammals in a lab experiment, according to researchers.
The H7N7, a strain that was previously unrecognized which spreads easily in birds, has the ability to infect ferrets – considered a good human – and could potentially jump to people in the future.
“The continuing prevalence of H7 viruses in poultry could lead to the generation of highly pathogenic variants and further sporadic human infections,” a report in the weekly journal Nature said.
Scientists warned it “may pose threats beyond the current outbreak.”
“If we let this H7N7 continue circulating in chickens, I am sure that human infections cases will occur,” study co-author Yi Guan from the University of Hong Kong told AFP in an e-mail.
“This virus could cause more severe infection than… H7N9, based on our animal experiment.”
At least 135 people in China and Taiwan are known to have been infected by the H7N9 strain. Most cases have been people who had visited live poultry markets or had been in close contact with fowl. Although scientists have yet to study possible direct person-to-person transmission.
by Maesie Bertumen
Photo: Nathan Nelson/Flickr