While this scenario may have been repeated in earlier years given the low seroprevelance rates noted in archived serum samples (Zheng et al., 2004) , it was the super spreader events that took place in the HZS-2 Hospital in Guangzhou that catalyzed the global severe acute respiratory syndrome (SARS) pandemic. Two brothers, working in restaurants and then a third individual were all hospitalized with severe acute respiratory symptoms (SARS) in HZS2 between the 18th and 30th of January, leading a pneumonia-related hospital outbreak on 31 January 2003. While each transmitted disease to family and health care workers, the third individual infected over 30 hospital members and patients during his 48 h stay in HZS2, 21 hospital staff after transfer to a second hospital HZS3 and about 23 relatives and friends. This key super spreader event allowed the epidemic to gain critical momentum. Another major turn of events occurred in Shanxi Province after a business woman traveled to Guangdong in late February. After returning home, she subsequently became sick. At the time, knowledge regarding the developing outbreak was not common, so she transmitted the disease to eight family members and five hospital staff in Shanxi. After being transfer to a Beijing Hospital on 1 March 2003 she became the index case for the outbreak in Beijing as well (Zhao, 2007) .