BEIJING - A group of medical, veterinary and avian experts recently gathered in Beijing to see if there is a relation between the current outbreak of the H7N9 bird flu virus and migratory birds.

Having failed to remove the birds from a list of possible carriers, the experts suggested monitoring not only east China, where the first H7N9 cases were reported, but also northern and northeastern provinces, which lie along the birds' migratory routes.

The new virus is closely related to Eurasian migratory birds, although it is difficult for those birds to transfer the virus to humans, the experts concluded, adding that the spread of the virus may have occurred through an intermediary organism.

Since the new virus had completed its evolution prior to the outbreak and stayed in the bodies of the intermediaries, it would've been impossible to detect the virus at an early stage, the experts said at their meeting, which was held by the State Bureau of Forestry.

The bureau said poultry and birds living on the coast may be the most likely intermediaries.

Participants attending the meeting came from the Chinese Center for Disease Control and Prevention, the Academy of Military Medical Sciences, the Chinese Academy of Sciences, Zhejiang University, Northeast Forestry University and the Chinese Academy of Forestry.