Vj. Navarro et al., A COMPARISON OF STREPTOCOCCUS-PYOGENES (GROUP-A STREPTOCOCCAL) BACTEREMIA AT AN URBAN AND A SUBURBAN HOSPITAL - THE IMPORTANCE OF INTRAVENOUS DRUG-USE, Archives of internal medicine, 153(23), 1993, pp. 2679-2684
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.