Primary symptomless colonisation by Clostridium difficile and decreased risk of subsequent diarrhoea

Little is known about whether patients who develop Clostridium-difficile-associated diarrhoea (CDAD) are culture-positive or culture-negative before illness. The most important risk factor is antibiotic exposure. We aimed to find out whether patients identified as primary symptom-free C difficile carriers are at higher risk of developing CDAD than patients who are culture-negative.We reviewed four longitudinal studies in which 810 patients...