The strain of the bird flu has infected 126 people, out of which 24 have died while the rest are struggling with their lives in the hospital, the BBC reports.
The director of a World Health Organization (WHO) collaborating centre in the UK, Prof John McCauley has said that the pace at which the disease is spreading and its severity is huge, adding that the relatively high number of infections since April is something unusual if the disease has only spread from a bird to a human.
McCauley also said that the global threat of H7N9 is limited only if the disease spreads from a bird to a person through direct contact, while if the threat has much more potency if the dissemination happens from one person to another, although it is not yet confirmed whether or not the disease spreads from human to human.
The report said that out of those infected, a fifth died, a fifth recovered and the rest are severely ill as the infection results in pneumonia, blood poisoning followed by organ failure.
While nearly all the H7N9 virus cases have so far been traced back to contact with poultry, which poses far less threat especially in richer countries, health experts have warned that the virus is mutating rapidly.
A leading expert in bird flu, Prof. Jeremy Farrar said that the H7N9 needs to be taken seriously as it the nastiest virus in humans in years, adding that influenza's shift across from birds into humans raises cause for concerns.
H7N9 has been termed as a pandemic in which usually older people have some immunity as they have lived longer and have been exposed to similar viruses before, but this disease has taken a toll of lives ranging from ages two to 81, indicating that there is no immunity across ages, and humans have never seen such kind of a virus before.
The H7N9 virus acquires selective adaptive mutations while moving across people, the report added.