Japanese researchers say they have determined that the H7N9 avian influenza virus can be transmitted via respiratory droplets. It's the first time researchers have confirmed that a bird flu virus can be spread by airborne droplets.
The researchers say a new type of influenza comes about when a bird flu virus accumulates genetic mutations and becomes transmissible to humans.
In 2013, cases of humans infected with the H7N9 strain were first reported in China. More than 1,500 people, many of them in China, have contracted the virus, mainly from birds.
A research group, headed by Professor Yoshihiro Kawaoka at the University of Tokyo, conducted a study using ferrets. The team says they discovered that the virus exits through an infected animal's droplets.
They placed 2 ferrets---one healthy and one with the virus---in 2 separate cages that were 7 centimeters apart. Four days later, they confirmed that the previously healthy ferret was infected.
The researchers also found droplets containing the virus 80 centimeters away from the sick animal.
Previously, it was believed that avian flu viruses were not present in the droplets of infected mammals.
Professor Kawaoka warns that the H7N9 strain has the potential to cause a global pandemic.