An outbreak of bird flu has killed six and sickened at least 16 in China. The H7N9 strain has been found in live pigeons on sale in Shanghai and detected, for the first time, in humans.
New Strain
Previously, the H7N9 strain was not thought to be a threat to humans.
Chinese officials worked through Thursday night slaughtering pigeons. Over 20,000 birds have been killed since the virus was discovered last Sunday.
Avian flu can be passed from healthy pigeons -- pigeons not showing signs of illness -- unlike the last bird flu outbreak of strain H5N1.
Transmission And Containment
So far, the virus doesn't seem to be spreading from person to person, but is instead transmitted from birds to people who had direct contact with them.
People who have come into close contact with those infected are being quarantined or closely monitored, but so far none are showing symptoms.
Pigeons are commonly consumed in China, and it's thought the birds became infected through droppings of migratory birds.