CHINA said it was mobilising resources nationwide to combat a new strain of deadly bird flu that has killed three people, as Japan and Hong Kong stepped up vigilance against the virus and Vietnam banned imports of Chinese poultry.
The new H7N9 bird flu strain does not appear to be transmitted from human to human but authorities in Hong Kong raised a preliminary alert and said they were taking precautions at the airport.
In Japan, airports have put up posters at entry points warning all airline passengers from China to seek medical attention if they suspect they have bird flu.
A total of 10 people in China have been confirmed to have contracted H7N9, all in the east of the country.
The latest was a 64-year-old man from Huzhou in the eastern province of Zhejiang, who state media said on Thursday was admitted to hospital on March 31.
Three infected people have died.
China "will strengthen its leadership in combating the virus ... and coordinate and deploy the entire nation's health system to combat the virus", the health ministry said in a statement late on Wednesday on its website.
In Hong Kong, authorities activated the preliminary "Alert Response Level" under a preparedness plan for an influenza pandemic, which calls for close monitoring of local chicken farms, vaccination, culling drills, and a suspension of imports of live birds from the mainland.
All passengers on flights in and out of Hong Kong were being asked to notify flight attendants or airport staff if they were feeling unwell.
Vietnam said it had banned poultry imports from China, citing the risk from H7N9.
In Beijing, the health ministry said the government will swiftly communicate details of the new strain to the outside world and its own people, following complaints it had been too slow to report on the outbreak and suspicion of a SARS-like cover-up.
Chinese internet users and some newspapers have questioned why it took so long for the government to announce the new cases, especially as two of the victims first fell ill in February. The government has said it needed time to correctly identify the virus.
In 2003, authorities initially tried to cover up an epidemic of Severe Acute Respiratory Syndrome (SARS), which emerged in China and killed about on-tenth of the 8,000 people it infected worldwide.
China "will continue to openly and transparently maintain communication and information channels with the World Health Organisation and relevant countries and regions, strengthen monitoring and preventative measures", the ministry said in a statement.
Flu experts across the world are studying samples isolated from the patients to assess H7N9'S human pandemic potential.
Other strains of bird flu, such as H5N1, have been circulating for many years and can be transmitted from bird to bird, and bird to human, but not generally from human to human.
So far, this lack of human-to-human transmission also appears to be a feature of the H7N9 strain.
However, China has yet to find any animals infected with H7N9, meaning how the humans got it remains a mystery.
"We know that it was originally a bird virus. We also know that it has taken on some genetic attributes that are not seen in bird viruses," Laurie Garrett, Senior Fellow for Global Health at the Council for Foreign Relations, told Reuters in New York.
"In other words, it seems to have adapted somehow to mammals, to humans. How that happened, we don't know," added Garrett.
While the official Xinhua news agency said it was unfair to compare SARS with H7N9, as the new bird flu virus has yet to show signs of human-to-human transmission, it did warn the government's credibility was on the line.
"If there is anything that SARS has taught China and its government, it's that one cannot be too careful or too honest when it comes to deadly pandemics. The last 10 years have taught the government a lot, but it is far from enough," it said in a commentary.