The H7N9 bird flu virus has the potential to spread easily through the air between ferrets, suggesting that it may spread easily in humans too, new findings suggest.
For now, the deadly H7N9 bird flu virus does not transfer well from human to human and the spread usually occurs through infected birds.
“We now know H7N9 can spread human-to-human,” said Dr. Marc Siegel, an associate professor of medicine at NYU Langone Medical Center in New York City. “So far, however, we are not seeing large outbreaks. That’s not an accident. You can see something in a test tube or in a ferret that doesn’t reproduce in real life.”
For the purpose of the study, researchers at the National Avian Influenza Reference Laboratory at Harbin Veterinary Research Institute, China looked at dozens of H7N9 strains picked from over 10,000 samples taken from poultry markets, poultry farms, wild bird habitats and slaughterhouses across the country.
The researchers looked at the genetic makeup of these strains and compared them with the genetic makeup of five strains of H7N9, all taken from people who got sick with the virus.
To check transmission was possible by simply breathing the same air, some ferrets were directly infected with the virus; others were placed in cages nearby.
Ferrets are mammals often used to study possible virus transmission between humans.
All five strains of H7N9 virus were able to spread through the air between ferrets.
While four viral strains did not transmit very well, one strain was able to spread completely and infected 100 percent of the ferrets who were exposed to it through the air, researchers highlighted.
“The situation raises many urgent questions and global public health concerns,” study’s co-author Hualan Chen, director of the National Avian Influenza Reference Laboratory at Harbin Veterinary Research Institute said.
“Our results suggest that the H7N9 virus is likely to transmit among humans, and immediate action is needed to prevent an influenza pandemic caused by this virus,” Chen highlighted.
However, Dr. Richard Webby, a bird flu expert at St. Jude Children’s Research Hospital in Memphis, Tenn., who was not involved in the new study did not agree with the findings of the study.
According to the findings the ‘flu virus that transmits well between humans will transmit well between ferrets,’ Webby said. “But ferrets aren’t a perfect model. For example, they don’t take into account pre-existing immunity in the human population,” Webby averred.
The findings of the new report were published July 18 in the online edition of the journal Science.