Perineal group A streptococcal disease in a pediatric practice

Objective. This study was designed to document the frequency and define the clinical, epidemiologic, and microbiologic characteristics of perineal disease caused by group A beta-hemolytic streptococci (GAS) in a pediatric practice in which increased numbers of cases had been observed. Methods. Clinical, epidemiologic, and microbiologic data were collected on all culture-confirmed cases of perineal GAS disease during the calendar year 1997. GAS isolates from clinical cases and a comparison group of children with GAS pharyngitis were analyzed by T typing, emm gene analysis, and pulsed-field gel electrophoresis (PFGE). Results. Twenty-three cases of GAS perineal disease were diagnosed during 4530 office visits in 1997. Thirteen cases had perianal disease, 8 had vulvovaginal infection, and 2 were infected at both sites. No cases of penile disease were identified. Infections peaked in late winter and early spring and affected children with an average age of 5 years with a range of perineal, gastrointestinal, and genitourinary symptoms. Analysis of T and emm types showed the majority (82%) of perineal isolates to be T 28 emm 28, showing 2 closely related PFGE patterns. In contrast, the pharyngeal isolates were distributed among 6 different T and emm types. Conclusion. Perineal infection caused by GAS may be a relatively common diagnosis in a pediatric or family practice setting. There may be specific GAS types that have a tropism for perineal tissues but the mechanism of infection is yet to be established.