Monitoring Clostridium difficile infection in an acute hospital: prevalence or incidence studies?

BACKGROUND: Surveillance of Clostridium difficile infection (CDI) is an essential component of a CDI preventative programme.

AIMS: The aim of this study was to evaluate two methods of CDI surveillance.

METHODS: Prevalence of CDI, antibiotic use and associated co-morbidity was assessed weekly on two wards over 6 weeks. In addition, CDI incidence surveillance was performed on all new CDI cases over a 13-week period. Cases were assessed for CDI risk factors, disease severity, response to treatment and outcome at 6 months.

RESULTS: Clostridium difficile infection prevalence was 3.5% (range 2.9-6.1%) on the medical ward and 1.1% (range 0-3.5%) on the surgical ward. Patients on the medical ward were older and more likely to be colonised with MRSA; however, recent antibiotic use was more prevalent among surgical patients. Sixty-one new CDI cases were audited. Patients were elderly (mean age 71 years) with significant co-morbidity (median age adjusted Charlson co-morbidity score 5). CDI ribotypes included 027 (29 cases) 078 (5) and 106 (4). Eight patients developed severe CDI, seven due to 027. Antibiotic use was common with 56% receiving three or more antibiotics in the preceding 8 weeks. Twenty-four patients had died at 6 months, five due to CDI.

CONCLUSION: Clostridium difficile infection prevalence gives a broad overview of CDI and points to areas that require more detailed surveillance and requires little time. However, patient-based CDI incidence surveillance provides a more useful analysis of CDI risk factors, disease and outcome for planning preventative programmes and focusing antibiotic stewardship efforts.