China is hoping to get swine flu virus samples from the US Center for Disease Control and Prevention (CDC) to facilitate its research on virus testing, a Chinese health expert said on Tuesday.

"We've been working around the clock on the test methods for the virus," Shu Yuelong, director of the Chinese National Influenza Center, told Xinhua.

"What makes it difficult is that this virus has never occurred in China and we don't have any samples," he said.

Shu said the Chinese Center for Disease Prevention and Control (CDC) was hoping to get some virus samples from the US CDC, but he would not comment on when they might arrive or how long it might take to develop a test for the virus.

The new virus, which carries the designation A/H1N1 and is spreading from person to person, contains DNA from avian, swine and human viruses, according to the US CDC.

The swine flu virus is suspected of killing 152 people, all in Mexico, but has caused no deaths elsewhere despite spreading to the United States, Canada and several other countries.

"The Chinese CDC and US CDC have set up an Emergency Infectious Disease Office, through which we've been working closely on the prevention and control of new infectious diseases," he said.

Dr. Hans Troedsson, WHO representative in China, said Tuesday that so far no rapid testing was available for the new virus. Health professionals need to do a virus culture and isolation to learn more about it.

The Chinese health authorities have been on full alert since the WHO warned countries around the world Saturday to monitor for any unusual flu outbreaks after the new swine flu virus was implicated in possibly dozens of human deaths in North America.

The Health Ministry has ordered all health departments to improve monitoring and reporting of suspicious pneumonia and influenza-like cases and make round-the-clock working plans.

Shu said the Chinese health authorities were in close contact with the WHO and the US CDC and they were sharing information every day.

"We (health experts) are following the situation closely, and assessing the virus and its risk to China," he said.

As of Tuesday morning, no confirmed cases of human infection of swine flu has been reported in China.

Troedsson said he believed China, and many other countries, were better placed to counter the swine flu based on the lessons learned from SARS and avian influenza.

"China is quite well prepared. They have already a quite good surveillance system in place. And they are now going to strengthen the surveillance, both centrally and at provincial level," he said.

He said the WHO had had "very good" collaboration and reporting from the Chinese government in handling avian influenza cases previously.

"So I think that was a good indication of the openness and transparency from the government," he said.

But he also said China faced challenges in the fight against infectious diseases.

One was the sheer number of its 1.3 billion people and the other was the large number of migrant people in China, both of which made perfect surveillance impossible, he said.

(Xinhua News Agency April 29, 2009)