Burden of Clostridium difficile Infection (CDI) Across Whole Healthcare Economies and European Borders; COMBACTE-CDI Results
Authors: Davies Kerrie , Viprey Virginie , Ewin Duncan , Spittal William , Vernon Jon , Tkalec Valerija , Fawley Warren , Benson Anthony , Davis Georgina , Rupnik Maja , Wilcox Mark 
Published: November 2020

Background: The burden of C. difficile infection (CDI) on healthcare facilities is well recognized. However, studies focusing on inpatient settings, in addition to ascertainment bias in general, have led to a paucity of data on the true burden of CDI across whole healthcare economies. Methods: Sites testing both inpatient and community samples were recruited from 12 European countries (1 site per 3 million population). On 2 selected days, all diarrheal fecal samples (regardless of tests requested) were sent to the European Coordinating Laboratory (ECL) for C. difficile toxin testing and culture. The CDI results and tests not requested at each submitting site were compared with the ECL results to determine the number of missed CDIs. Contemporaneous C. difficile isolates from food and animal sources were collected. All isolates underwent PCR ribotyping and toxinotyping; prevalences of ribotypes among regions of Europe and reservoir settings were compared. Results: Overall, 3,163 diarrheal fecal samples were received from 119 sites. The burden of CDI varied by country (positivity rates, 0–15.8%) and by European region; the highest positivity rate in Eastern Europe was 13.1%. The testing and positivity rates in community samples were 29.6% and 1.4% vs 74.9% and 5.0% in hospital samples; 16% and 55% of samples positive for CDI at ECL were not diagnosed in hospitals and the community. The most common C. difficile ribotypes from hospital samples were 027 (11%), 181 (12%), and 014 (8%), although prevalence varied by country. The highest prevalence of toxinotype IIIb (ribotypes 027, 181, and 176) was seen in Eastern Europe (55% of all isolates), which also had the lowest testing rate. For hospital samples, the proportion of toxinotype IIIb was inversely related to the testing rate (r = −0.79) (Fig. 1). The most common ribotypes from food sources were 078 (23%) and 126 (13%) (toxinotype V), and most common ribotypes from community samples were 078 (9%) and 039 (9%). Overall, 106 different ribotypes were identified: 25 in both the hospital and community and 16 in the hospital, community, and food chain. Conclusions: The diagnosed burden of CDI varies markedly among countries in both hospital and community settings. Reduced sampling/testing in Eastern Europe is inversely related to the proportion of toxinotype IIIb strains identified, suggesting that lack of suspicion leads to underdiagnosis and outbreaks of infection. The proportion of missed CDIs in the community was ~3.5× higher than in hospitals, indicating major underrecognition in the former setting. There were marked differences in ribotypes in different reservoir settings, emphasizing the complex epidemiology of C. difficile.Funding: Proprietary organization: COMBACTE-CDI is an EU funded (Horizon2020) consortium of academic and EFPIA partners (bioMerieux, GSK, Sanofi Pasteur, Astra Zeneca, Pfizer, Da Volterra) with additional Funding: from the EFPIA partners.Disclosures: Submitter: Kerrie Davies; the work presented is funded via the EU and EFPIA (commercial) partners in a consortium.