Cumulative exposure to healthcare is associated with C. difficile colonisation and infection. However, studies using whole-genome sequencing have shown in endemic settings with routine infection control only the minority of C. difficile infections are acquired from other known cases. Together this raises the possibility that there are other sources of infection in hospitals.

Data on the role of colonised patients in C. difficile transmission will be presented, including studies of patients with C. difficile colonisation and diarrhoea of another cause. These patients typically have evidence of C. difficile in faecal samples, but not detectable toxin. These patients may be as infectious as infected patients on a per patient basis. Where possible colonised patients with diarrhoea of another cause should be managed for infection control purposes in a similar way to cases.

Studies presenting data on the role of asymptomatically colonised patients will also be discussed. There is preliminary data in this area, but further studies are needed before making a firm recommendation for infection control around such patients.

Dr David Eyre, Oxford University Hospitals