Outbreak of necrotising enterocolitis caused by Clostridium butyricum

12 hospital-born babies had necrotising enterocolitis, of varying severity, within six weeks, 5 of them within ten days. The usually described predisposing causes were absent in most, though no baby was exclusively breast -fed. Evidence of the presence of Clostridium butyricum was found in the blood of 9 out of 10 babies examined. Cl. butyricum is probably a primary, not a secondary invader.