New (H7N9) avian flu infecting people in China

[Land Mammal]

A new bird flu strain (H7N9) infecting humans has emerged in China. 3 infections were confirmed yesterday, 2 of whom died, in Shanghai.

4 new cases in a serious condition were confirmed today, in 4 different cities in the same province, north of Shanghai . Only 1 of the 4 had occupational contact with poultry. None of the contacts of the 7 confirmed cases have shown signs of the virus, so it looks as if (thus far) there's no human to human transmission.

However, two sons of one of the fatalities have been in hospital with 'serious pneumonia', one dying. It's not confirmed they were infected, but they obviously were. However, this family were butchers, so could have been infected from the same animal source. It would be much more serious if they's passed the infection on to each other.

Up to now, the main concern about an avian flu 'jumping species', and causing a global pandemic in humans, has been H5N1, which emerged about 10 years ago and has caused 360 known human infections, with a 60% mortality rate. Only a handful of H5N1 infections are believed to have been human to human. It's early days, but H7N9 seems to have a higher infectivity rate. It can't become a global pandemic until it starts passing from person to person. Even then, transmission has to occur easily, for it to have pandemic potential.

 

There have been 4 global flu pandemics in the past hundred years. By far the worst was the 1918 'Spanish flu', which may have killed 50 million people. This is believed to have been a purely avian flu, while the other, much milder flus ( Asian, Hong Kong, and the recent Mexican Swine flu) were avian/porcine/human hybrids.

 

There is no way of knowing whether this outbreak has the potential to become a global pandemic, but experts have described developments as 'worrisome'.