The Hong Kong government ordered all chickens at the territory's only wholesale poultry market to be destroyed, and has banned the import of live chickens from the mainland for three weeks. The Cheung Sha Wan market will be closed for 21 days for disinfection and local farms would suspend sending chickens to the wholesale market. Shanghai will also halt live poultry trading from 31 January for three months.
The virus H7N9 made the jump from domestic chickens and ducks to infecting Chinese people in April, 2013, after which 2 people died.
According to the World Health Organization, cases of human H7N9 infection have been reported so far in China, Hong Kong and Taiwan. Most of those infected reported contact with live poultry, and information so far did not support sustained human-to-human transmission, the WHO said.
What does this mean to people living in the UK or USA? Unfortunately, flu, along with any unwanted disease, can travel via an airplane from overseas visitors. We have to rely on the authorities catching the virus before it slips into our society.
In humans, symptoms include fever sore throats, aching limbs and coughing. This sounds like a regular flu or bad cold.
There are many questions about bird flu that remain unanswered and are under investigation. It is known that some forms of bird flu viruses, such as H5N1, are more highly pathogenic (cause more serious illness) than others, yet the reasons for these differences are unclear. Human and bird influenza viruses have a similar structure but differ in the composition of proteins on their external surfaces. Because influenza viruses have the capacity to mutate, or undergo changes in their surface proteins, scientists are concerned that the bird flu viruses may eventually change into forms of the virus that are able to infect humans more easily.