Chinese researchers investigating the deadly outbreak of H7N9 bird flu say people infected by the virus contracted it from poultry.
The scientists' findings confirmed what had been suspicions that bird flu virus crossed from birds to humans at live markets where chickens and other poultry are slaughtered and sold.
The Chinese team collected virus samples from 86 birds at four different poultry markets whose workers or customers had become infected with H7N9. They then compared the genetic makeup of the virus from infected birds to the virus found in human victims.
Their study, published Thursday in the Lancet medical journal
, concluded the path of infection was from birds to humans, based on similarities between the avian and human virus samples.
The researchers suggested "aggressive interventions," including suspension of live bird markets and culling of infected flocks, could help slow or stop the further spread of the virus.
H7N9 bird flu has infected at least 108 people in China and killed 22 of them since February.
Unlike other flu viruses that cause upper respiratory problems like coughing and congestion, the new virus attacks the lower part of the lungs, causing high fevers and pneumonia.