A COMPARISON OF STREPTOCOCCUS-PYOGENES (GROUP-A STREPTOCOCCAL) BACTEREMIA AT AN URBAN AND A SUBURBAN HOSPITAL - THE IMPORTANCE OF INTRAVENOUS DRUG-USE

Background: There has been a recent resurgence of severe infections wi th streptococcus pyogenes, including bacteremias and a toxic shock-lik e syndrome. The purpose of this study was to examine the influence of intravenous drug use on the incidence, clinical epidemiology, and seve rity of S pyogenes bacteremia. Methods: We conducted a retrospective s urvey of medical records at a 500-bed tertiary care urban hospital and at a nearby 500-bed suburban university-affiliated hospital. All pati ents from each hospital with documented S pyogenes bacteremia from Jan uary 1, 1979, to December 31, 1989, were included. We examined demogra phic and clinical data from cases at the two institutions, serologic f indings from a subset of isolates from the urban hospital, and factors associated with mortality from S pyogenes bacteremia by stepwise logi stic regression analysis. Results: Ninety-five cases of S pyogenes bac teremia were identified, with 65% (62 cases) occurring at the urban ce nter. Intravenous drug use occurred more frequently at the urban cente r (P<.005); the injecting drug users were significantly younger than t he non-drug-using population (P=.001). Infection with the human immuno deficiency virus occurred in a subset of the injecting drug users at t he urban center. Cellulitis and cutaneous abscesses were the most comm on sources of bacteremia at both centers. During the study period, the numbers of S pyogenes bacteremias increased at the urban center (P=.0 07), accompanied by a significant increase in the proportion of infect ions associated with parenteral drug use (P=.003). There was no change in the prevalence of any T type throughout the study period and no cl ustering of T types among injecting drug users. The overall mortality was 23% (20/89). By logistic regression analysis, age older than 65 ye ars (relative risk [RR], 14; 95% confidence interval [CI], 3.2 to 68) and the presence of the toxic shock-like syndrome (RR, 36; 95% CI, 2.2 to 600) were significantly associated with mortality due to S pyogene s bacteremia. Conclusions: Intravenous drug use accounted for an incre ase in cases of S pyogenes bacteremia at an innercity hospital. Howeve r, advanced age and the toxic shock-like syndrome were the most import ant predictors of mortality.