BEIJING, CHINA - SEPTEMBER 16: Health workers of Beijing Centers For Disease Control And Prevention (CDC) undergo training and exercises in dealing with public health incidents on September 16, 2006 in Beijing, China. Beijing is making preparations to tackle possible public health incidents during the 2008 Olympic Games, particularly in regard to epidemic outbreaks. China has established a nationwide electronic network for reporting epidemics, operated by at least 207,000 CDC staff, the largest of its kind in the world, according to state media.