Toxin-producing bacteria in infants. Lack of an association with sudden infant death syndrome.

After finding enterotoxigenic (ET) Escherichia coli in two consecutive cases of sudden infant death syndrome (SIDS), we initiated a prospective search for ET E coli in SIDS in Manitoba; in addition, we looked for toxigenic Clostridium botulinum and C difficile. In a 21-month period, small- and large-bowel contents were obtained in 33 cases of SIDS, from 32 control subjects, and in ten suspected cases of SIDS. Neither C botulinum nor ET E coli was isolated from any of these; C difficile was cultured from postmortem bowel contents of two SIDS and seven control cases. The overall isolation rate of C difficile was 17%. Despite the fact that two of these cases had toxin detectable in the bowel contents, no evidence of colitis was found in any of the cases with C difficile. We conclude that C botulinum or ET E coli have only a small role, if any, in the etiology of SIDS, and that C difficile is found relatively commonly in the gastrointestinal tract of infants without apparent local or systemic effects.