total human cases had been reported, and mortality was assumed to be less than 10%. Details of this outbreak and a similar earlier outbreak, also in Sichuan province, were published in 2006. A smaller outbreak occurred at the same time in Hong Kong, affecting 11 people. A total of 204 human cases were documented during the Sichuan outbreak, with 38 fatalities. The human outbreak coincided with one in the local pig populations. There was no evidence of human-to-human transmission; all of the patients had been in direct contact with pigs. Many of the patients, and almost all of the fatal cases, had typical symptoms of Streptococcal toxic shock syndrome (STSS). To date, STSS has only been documented in patients infected with S. pyogenes, another member of the Streptococcus family but very different from S. suis. However, the bacteria isolates from the human and pig samples were clearly S. suis, and those isolates were able cause typical S. suis disease in piglets. The genome of S. suis isolates from the outbreak were examined to see whether its DNA sequence could explain why these particular bacteria were able to cause STSS. However, none of the genes that are present in S. pyogenes and thought to cause STSS were detected in the S. suis isolates. Comparison with other S. suis isolates from around the world, including one from an earlier smaller S. suis outbreak in Sichuan province that killed 14 out of 25 reported human cases, revealed that the two Chinese isolates were more similar to each other than to any other strains. Additional experiments are necessary to determine whether the size and high mortality of the recent outbreak is because the Chinese S. suis version is more virulent than other strains or due to the circumstances under which the Chinese patients got infected and treated. Studies are under way to characterize the bacterial isolates from the outbreak in detail. Physicians around the world should be aware of the possibility of S. suis-associated STSS when they see patients with unexplained sepsis who had been in contact with pigs. Streptococcus suis has also been identified as the most common cause of meningitis in Vietnam. The 2012 deaths of 64 of 66 children in Cambodia affected with a complex syndrome including meningitis and pneumonia has been linked to a multiple infection of the children with Dengue fever, Enterovirus 71 and S. suis The use of