Two respiratory viruses in different parts of the world have captured the attention of global health officials.
Shanghai authorities are testing mislabeled mutton from a wholesaler a government website.
Professor Angus Nicoll said the H7N9 flu outbreak in humans was one that should be taken extremely seriously.
55-year-old man in central China has died from new strain, bringing number of deaths from virus to 27.
The H7N9 strain has killed 24 and infected more than 125 people.
Chinese scientists confirm for first time that new strain of bird flu is transmitted to humans from chickens.
The H7N9 virus has infected 109 people in China since it was first detected in March.
Chinese relief crews hurried food, water and other supplies into the rural hills of China's Sichuan province.
Fujian's health authority said a 65-year-old man surnamed Luo had tested positive for the virus.
An elderly man in eastern China died of bird flu on Tuesday, bringing the death toll from a strain that recently emerged in humans to 22.
