CLINICAL AND MOLECULAR EPIDEMIOLOGY OF ENTEROCOCCAL BACTEREMIA IN A PEDIATRIC TEACHING HOSPITAL

An apparent increase in the incidence of enterococcal bacteremias from 7 to 48/1000 bacteremias during 1986 to 1991 (p < 0.01) prompted this descriptive clinical and molecular epidemiologic study of 83 episodes occurring in 80 children between 1986 and 1992. Most community-acquir ed cases were in infants, in comparison with nosocomial episodes (24/2 6 and 34/57; p < 0.01); many of them were neonates (10/26 and 6/57; p < 0.01). Nosocomial cases were associated with underlying conditions i ncluding major surgery 56%, immunosuppression 49%, organ and tissue tr ansplants 30%, and cardiac 32%, pulmonary 25%, renal 21%, and hepatic 21% disorders. Nosocomial episodes developed after a median of 32 days . There were 58 primary and 25 secondary bacteremias. Thirty-two episo des were polymicrobial and 44 organisms were involved. Twenty-six perc ent of the patients died. In 15%, death was preceded by septic shock, disseminated intravascular coagulation, and polymicrobial bacteremia ( p < 0.01). Of 75 isolates, 82% were Enterococcus faecalis and 14% were Enterococcus faecium. Fourteen E. faecalis strains produced hemolysin ; none produced beta-lactamase. Three had high-level resistance to gen tamicin and 13 to streptomycin; two E. faecium and none of the E. faec alis strains were vancomycin resistant at a low level (p < 0.01) and o ne was ampicillin resistant. Pulsed-field gel electrophoresis of whole -cell DNA digested with restriction enzymes Sma I and Eag I showed fiv e isolates with a homogeneous pattern, two with another homogeneous pa ttern, and 68 with distinct heterogeneous patterns. The increase in en terococcal bacteremias was not due to a clonal strain dissemination bu t to an increase in cases of heterogeneous enterococcal strains. We co nclude that enterococcal septicemia is now an important cause of serio us morbidity and death in critically ill children.