Changing Epidemiology of Streptococcus pyogenes emm Types and Associated Invasive and Noninvasive Infections

A total of 242 isolates were recovered from 76 patients with invasive diseases, 89 with scarlet fever, and 77 with pharyngitis. The most frequent emm types were types 12 (43.4%), 4 (18.2%), and 1 (16.9%). emm12 reemerged in 2005 and peaked in 2007. emm11 was recovered only from patients with invasive disease. Streptococcus pyogenes, a group A Streptococcus (GAS) spe-cies, produces many diseases, ranging from impetigo, pharyn-gitis, and scarlet fever to life-threatening sepsis, necrotizing fasciitis, and streptococcal toxic shock syndrome (STSS) (8). M protein that is encoded by the emm gene is a major virulence factor of GAS. Different M protein types are epidemiologically related to particular clinical syndromes; e.g., emm28 was iso-lated more frequently than other types among women wit