Pediatric infective endocarditis: Has Staphylococcus aureus overtaken viridans group streptococci as the predominant etiological agent?

Viridans group streptococci (VGS) have traditionally been the most common etiological agents of infective endocarditis (IE). Advances in cardiovascular surgery and the increasing use of long-term central venous catheters may have altered the epidemiology of pediatric IE. A chart review of children younger than 17 years of age with IE was completed at the Stollery Children's Hospital (Edmonton, Alberta) between 1985 and 2004. The literature was reviewed to look for changes over time in the most common etiological agents of pediatric IE. There were 31 cases of definite IE and nine cases of possible IE at the Stollery Children's Hospital, 19 of which were nosocomial. Thirty cases (75%) had congenital heart disease. The etiological agents were Staphylocccus aureus (n=16), VGS (n=5), coagulase-negative staphylococci (n=3), enterococcus (n=3), other streptococci (n=8), Enterobacter cloacae (n=1) and Stenotrophomonas maltophilia (n=1), while three cases were culture negative. Two deaths were due to S aureus IE. Review of the literature identified an increasing number of case series in which S aureus was the predominant etiological agent, but VGS still predominated in some recent series. Congenital heart disease remains the primary risk factor for pediatric IE. Prospective population-based studies are required to determine whether S aureus has become the predominant pathogen.