The exact source of infection remains unknown, though samples have tested positive in some birds in poultry markets that remain the focus of investigations by China and the UN's Food and Agriculture Organization.
Speaking in Bangkok, the FAO's Subhash Morzaria said: "This particular region is land linked and so there is a possibility that if, inadvertently or advertently, somebody moves infected poultry across borders we can anticipate the spread of this virus."
Morzaria added: "We are proactively initiating surveillance programs in neighboring countries like Myanmar, Laos and Vietnam which border China and are at particular risk and we are trying to understand how the poultry movement has taken place so we can identify more accurately where the risk is going to be."
The new virus is severe in most humans, leading to fears that if it becomes easily transmissible, it could cause a deadly influenza pandemic.
However, Morzaria said: "This new H7N9 virus hasn't been demonstrated to be transmitted between humans, so from that context we think that the H7N9 virus is not going to be a pandemic like H1N1 strains."Given what we know so far, I tend to agree that we're not looking at a pandemic. But widespread H7N9 in poultry would create enormous economic and food-security problems. The costs of testing and inspection would be high, and even birds that passed the tests would be a hard sell in many Asian markets. So the industry would falter, thousands would be out of work, and consumers would need another source of animal protein. All of which would result in more public health problems stemming from stress, unemployment, and malnutrition.