Low mortality in necrotizing enterocolitis associated with coagulase-negative Staphylococcus infection

The aim of this study was to correlate the clinical course of necrotizing enterocolitis (NEC) with infection by coagulase-negative Staphylococcus at the onset of the illness. Records of all newborn infants developing NEC between January 1998 and December 2001 were reviewed. NEC was classified according to the criteria of Bell et al. Numeric variables were described by standard statistical methods. Comparisons between subgroups were performed by parametric statistical tests. Forty-four patients developed NEC stage II (n = 25) or III (n = 19). The incidence was 0.024% of live births in the hospital, and the mortality rate was 9%. The main risk factor was prematurity (84%). Only one-fourth of the patients had gastric residuals. A platelet count of <100,000 cells/mm³ occurred only in grade III NEC. Blood cultures were positive in 34% of the patients. The predominant organism (73%) was coagulase-negative Staphylococcus (CoNS). Neither Clostridium nor Bacteroides species were isolated. Stage II patients were maintained nothing per os (NPO) for 9 ± 3 days and received antibiotics for 10 ± 3 days. All of the stage III patients required an operation. In one-third of them, primary peritoneal drainage was initially performed but all required further operative procedures. We report a low incidence and mortality rate of necrotizing enterocolitis. Thrombocytopenia is confirmed as a marker of severity. Positive blood cultures for CoNS may explain, at least in part, the low mortality reported.