Epidemic streptococcal disease among Army trainees, July 1989 through June 1991.

Outbreaks of group A streptococcal infection occurred at four of seven US Army basic training installations between 1 July 1989 and 30 June 1991. Study data were collected through a respiratory disease surveillance program and on-site epidemiologic investigations. Although hospitalizations were frequent (range, 191-334) during each outbreak, average rates of hospitalization were low (2.4-4.8 hospitalizations/1000 trainees/week). Outbreak-associated morbidity included streptococcal toxic shock syndrome (2 cases, 1 fatal), acute rheumatic fever (6), acute glomerulonephritis (1), scarlet fever (1), and numerous other invasive sequelae. Four serotypes of Streptococcus pyogenes (M-1, -3, -5, and -18) were identified; M-18 caused significant disease at 2 installations. Disease control was rapidly achieved through prophylaxis programs using benzathine penicillin G in nonallergic trainees. These outbreaks extend other reports that document an evolution of the nature and severity of circulating S. pyogenes in the United States.