(CHENGDU, China) - A highly infectious swine virus is sweeping China's pig population...... The government in Beijing acknowledged that in the past year, the virus had decimated pig stocks in southern and coastal areas. But animal virus experts said that the Chinese authorities were playing down the gravity and spread of the outbreak, and had refused to cooperate with international scientists. "They haven't really explained what this virus is," said Federico Zuckermann, a professor of immunology at the College of Veterinary Medicine of the University of Illinois. "This is like SARS. They haven't sent samples to any international body. This...