Another person died from a new strain of bird flu in China on Thursday, state media said, bringing to 10 the number of deaths from the H7N9 virus, as a U.N. body said it was concerned the virus could spread across borders in poultry.
The latest victim was in the commercial hub of Shanghai, the official Xinhua news agency reported, where several of the 38 cases to date have been found. All of the cases so far have been found in eastern China.
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 U.N.'s Food and Agriculture Organization (FAO).
Speaking in Bangkok, an FAO official said it was worried about the spread of the virus outside of China.
"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," said Subhash Morzaria, the FAO's Regional Manager of the Emergency Center for Transboundary Animal Diseases.
"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," said Morzaria.
The new virus is severe in most humans, leading to fears that if it becomes easily transmissible, it could cause a deadly influenza pandemic, though there has been no indication of that happening.
"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. These are the early indications," Morzaria added.
There is no connection between the outbreak and the thousands of dead pigs which have been found floating in Shanghai rivers in recent weeks, he said.
"The report of the floating pigs in the river, there is absolutely no relationship, it is completely not associated with this virus."
Still, the new virus has unsettled some in China.
Chinese authorities have detained a dozen people for spreading rumors about the spread of bird flu.
Yum Brands Inc, the biggest foreign fast-food chain operator in China, said the outbreak would have a "significant, negative impact" on sales at KFC stores in China in April.