469. Validation and Characterization of Community-Acquired Clostridium difficile Infections from the Quebec C. difficile Infection Surveillance Program (QCISP)

BACKGROUND: Community-acquired Clostridium difficile infections (CA-CDI) are under a mandatory reporting program starting in August 2004 across 95 healthcare institutions from the QCISP. There has been a slow and continuous increase in the incidence rate of hospitalized CA-CDI since 2007 without any known obvious explanation. The objectives of this study were to characterize cases of CA-CDI and investigate the potential causes of this increase. METHODS: A retrospective study was carried out using a survey sent to eligible healthcare institutions. Hospitals participating in QCISP that reported ≥3 cases of CA-CDI in 2016–2017 were invited to participate. To identify potential causes of the apparent increase in CA-CDI incidence, they were asked to provide clinical information regarding up to three cases of CA-CDI for two distinct surveillance years (2011–2012 and 2016–2017). To characterize each CA-CDI cases, a broad range of demographic, clinical, and laboratory variables were collected, including medical history, history of contact with primary and secondary healthcare institutions, previous antibiotics use as well as laboratory diagnostic test. A χ(2) test have been used to test year differences in indicator distributions. RESULTS: A total of 49 healthcare institutions provided data on 172 cases of CA-CDI. Overall, 92% (n = 159) of them meet the QCISP CA-CDI criteria definition. Among them, most patients (67%) were female, and average age was 66.7 ± 20.5 year old. Seventy-four percent had received antibiotic in the previous year. Between the two years, there was no significant change in the socio-demographic and clinical variables of CA-CDI cases. The proportion of patients receiving immunosuppressive drugs and proton pump inhibitors at the time of diagnosis was 11% and 45%, respectively. The proportion of cases visiting ambulatory healthcare settings during the year previous to patient admission increased from 61% (2011–2012) to 69% (2016–2017) (P = 0.18). Moreover, there was a significant increase in the proportion of CA-CDI diagnosed by laboratory PCR test (from 8% to 55%; P < 0.0001). CONCLUSION: This study provided important data to characterize CA-CDI using the QCISP. The increase in the use of PCR is associated with the incidence of CA-CDI but may not be the cause of it. DISCLOSURES: Y. Longtin, Merck: Grant Investigator, Research grant. Becton Dickinson: Grant Investigator, Grant recipient.