Influence of age, sex, and diet on asymptomatic colonization of infants with Clostridium difficile.

A total of 40% of 107 stool samples from infants 1 to 52 weeks of age were found to contain Clostridium difficile antigens, detected by counterimmunoelectrophoresis. Within the group tested, there was no detectable variation by age or sex. Infants fed formula were nearly four times more likely to carry C. difficile than were those exclusively breast fed (62 versus 16%), whereas breast-fed infants also receiving formula or solids had an intermediate rate of colonization (35%). The distributions were similar when a subgroup with the highest levels of antigen was assessed separately. These data will be useful in considering potential pathogenic activities of C. difficile colonization in infancy.