H7N9 virus is capable of spreading in the air

A recent Chinese study revealed that an H7N9 avian influenza virus pattern spreads easily in the air between ferrets. This is a useful finding in studying how this strain of virus can spread in humans.

The researchers tested the transmission of five H7N9 samples, all taken from people infected with the virus.

Some ferrets are directly infected with the H7N9 virus, and others are kept in a nearby cage to check if they are infected simply by breathing in an atmosphere.

As a result, all 5 H7N9 samples can spread in the air between ferrets, but there are 4 patterns that are not really transmitted easily. However, the remaining sample is capable of spreading very well when 100% of ferrets exposed to this sample in the air are infected.

Dr. Richard Webby, an avian influenza specialist from the St Jude Children's Research Hospital in Memphis, Tennessee, who is not involved in the new study, said that so far, there has been no report on H7N9 transmission from person to person is verified.

However, the new findings reinforce the evidence that the virus is capable of just undergoing a few genetic mutations that can spread from person to person.

The H7N9 strain of avian influenza virus appeared in China in February and so far there have been 132 cases of influenza infection with 43 deaths.

Dr. Webby said the researchers knew that an easy-to-pass human flu strain would easily spread among ferrets. In this new study, the H7N9 virus takes 5-7 days to spread among ferrets.

H7N9 is thought to be transmitted from poultry (especially chickens) to humans. Because the strain does not cause symptoms in chickens, it may be more difficult to detect infected birds.

"The only way we have to reduce human infections and the opportunity for human adaptation to viruses is to reduce human contact with infected birds ," Dr. Webby said.

The flu epidemic seems to have been controlled this summer, with no new reports of H7N9 infections since late May.

This new study is published in the journal Science in the middle of July.