Scarlet fever is one of a variety of diseases caused by group A Streptococcus 
(GAS). During 2011, a scarlet fever epidemic characterized by peak monthly 
incidence rates 2.9-6.7 times higher than those in 2006-2010 occurred in 
Beijing, China. During the epidemic, hospital-based enhanced surveillance for 
scarlet fever and pharyngitis was conducted to determine characteristics of 
circulating GAS strains. The surveillance identified 3,359 clinical cases of 
scarlet fever or pharyngitis. GAS was isolated from 647 of the patients; 76.4% 
of the strains were type emm12, and 17.1% were emm1. Almost all isolates 
harbored superantigens speC and ssa. All isolates were susceptible to 
penicillin, and resistance rates were 96.1% to erythromycin, 93.7% to 
tetracycline, and 79.4% to clindamycin. Because emm12 type GAS is not the 
predominant type in other countries, wider surveillance for the possible spread 
of emm12 type GAS from China to other countries is warranted.