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.