Clinical and epidemiologic features of group a XXXX in Ontario, Canada.

@entity1 @entity137 @entity883 @entity7706 @entity55 @entity16247 @entity39 @entity3 @entity204
BACKGROUND: Since the 1960s, group A streptococcus (GAS) has accounted for less than 1% of cases of community-acquired @entity55 . During the @entity16247 decades there has been a resurgence of @entity3 , but no large study of @entity7706 has been performed. METHODS: To determine the clinical and epidemiologic features of @entity7706 , we conducted prospective, population-based surveillance of all @entity3 in residents of Ontario from January 1, 1992, through December 31, 1999. RESULTS: Of 2079 cases of @entity3 , 222 (11%) represented @entity7706 . The incidence of @entity7706 ranged from 0.16 per 100 000 in 1992 to 0.35 per 100 000 in 1999. Most cases were community acquired (81%). Forty-four percent of nursing home-acquired cases occurred during outbreaks. The case fatality rate was 38% for @entity7706 , compared with 12% for the entire cohort with @entity3 and 26% for @entity1 with @entity39 . The presence of streptococcal @entity137 (odds ratio, 19; 95% confidence interval, 8.4-42; P =.001) and increasing age (odds ratio per decade, 1.45; 95% confidence interval, 1.2-1.7; P<.001) were associated with fatal outcome. Time to @entity204 was rapid, with a median of 2 days despite antimicrobial therapy and supportive measures. CONCLUSIONS: Group @entity883 is a common form of @entity3 but remains an uncommon cause of community-acquired @entity55 . Progression is rapid despite appropriate therapy. The incidence is similar to, and the case fatality rate higher than, that of @entity39 .
