Hong Kong confirmed its first case of H7N9, the newest form of avian influenza that first emerged in February 2013.
As of today, World Health Organization (WHO) has confirmed 137 infections and 45 deaths (a concerning 33% mortality rate) and has described the new strain as "unusually dangerous" and "one of the most lethal" viruses they have faced in recent years.
Fortunately, we've yet to see a highly contagious version of the virus, and Asia has done an excellent job containing it so far. Hong Kong officials were able to isolate the latest incident by tracking down even going to origin in China and clearing 17 people who came in contact with the infected patient.
Genetic mutations are primarily random so the chances of increased transmission are low. While anything is possible, the most likely scenario is that a vaccine will be created before H7N9 is able to have a significant impact on the human population.
So That is why WHO assigned name of this H7N9 was because that time the Director General Dr. Margret Chan Who is from HK said in the meeting this is a serious virus and very difficult to tackle!!!
In Cantonese she said, "好七難攪" that was how this terms "H7N9" came from!...