Epidemiology of community-onset Clostridium difficile infection in a community in the South of England

Background and aims Clostridium difficile infection (CDI) has traditionally been considered a hospital acquired infection but there are a rising number of infections in the community. This study estimates the prevalence of community-onset CDI (CO-CDI), defined as onset of symptoms in a community setting and outside the hospital, and examines the risk factors for CO-CDI in 2–64 year-olds. Methods A standard questionnaire was used to retrospectively obtain information on the CDI risk factors of 58 cases of CO-CDI diagnosed between 1st April 2008 and 31st March 2009 in a community in the South of England. Each case was reviewed for the presence of ‘established’ risk factors for CDI, i.e., age ≥65 years, in-patient hospital stay, and recent (within ≤4 weeks) receipt of broad spectrum antibiotics, and other, ‘non-established’ risk factors for CDI, such as exposure to antibiotics more than 4 weeks preceding symptom onset, out-patient and day-surgery hospital exposure, contact with a hospitalised patient, and travel outside of the UK. Results Fifty-eight cases of CO-CDI were diagnosed among a total community population of 418,000, representing an estimated prevalence of CO-CDI of 1.29 per 10,000. All 58 cases were successfully contacted, representing a 100% response rate. Four cases were excluded from further analysis due to co-infection with Salmonella spp. and Campylobacter spp. Cases were more likely to be female, aged between 31 and 40 years, and present in the spring season (March–May), 2009. 46.3% (25/54) of cases had established risk factors for CDI, 20.4% (11/54) had non-established risk factors, 16.7% (9/54) had no risk factors and in the remaining 16.7% (9/54), available information was insufficient to classify by risk factor category. Conclusions This study suggests that CDI should be included in the differential diagnosis of community-onset diarrhea in patients with or without established risk factors for CDI