A new strain of flu that has the potential to become a pandemic has been identified in China by scientists.
It emerged recently and is carried by pigs, but can infect humans, they say.
The researchers are concerned that it could mutate further so that it can spread easily from person to person, and trigger a global outbreak.
While it is not an immediate problem, they say, it has “all the hallmarks” of being highly adapted to infect humans and needs close monitoring.
So should we be worried? Is there any evidence that this new swine flu has been transmitted from human to human? The BBC’s Julian Marshall has been hearing more from Professor James Wood, head of the department of Veterinary Medicine at the University of Cambridge.
Photo shows: Pigs being fed at a pig farm near Qingdao city in eastern China’s Shandong province, 29 April 2009. Credit: EPA