A159 emerging themes and the old tale of c. difficile infection: genetics, reservoirs, treatment and management

Clostridium difficile infection (CDI) continues to be among the top hospital associated infections affecting the elderly and trending among younger populations. Rising antibiotic resistance rates and limited treatment options often lead to recurrence of infection and frequent hospital outbreaks, imposing burden on CDI management in healthcare institutions. Here we report our experience with CDI at Health Sciences North, an acute-care large teaching hospital in Ontario, and the emerging themes important in CDI management. A collection of C. difficile was built by isolation from positive stool samples and further characterized by toxin typing, ribotyping, Multilocus Sequence Typing (MLST) and whole genome sequencing. This analysis included samples from two tandem hospital outbreaks within two major hospital wards in 2012 that involved 33 patients. Since 2008, while the CDI incidence rates among more than 220 Ontario hospitals were fluctuating with no clear trend, our hospital showed higher rates than other large hospitals in the region. From 2012 to 2017, over 3000 stool samples from symptomatic patients were analyzed for C. difficile spores using the diagnostic GeneXpert platform with over 10% positive results. It was shown that the C. difficile isolates were diverse with respect to all typing schemes and were mirrored similarly among outpatients and inpatient populations. Similar distribution patterns for genetic and phenotypic traits were observed among patients who were involved in two tandem outbreaks and within the hospital wards with no identified index strain. Patients were subjected to antibiotics and other risk factors before, during and after diagnosis. Ciprofloxacin was among the 90th percentile of the most used antibiotics, however it is the antibiotic to which most of the C. difficile isolates were resistant. Moreover, extensive survey of the vehicles and fomites involved in hospital transmission of C. difficile spores did not produce any significant spatial and temporal correlates for nosocomial transmission of C. difficile, implying the limitation of the regular outbreak management measures. We concluded that the epidemiology of CDI is more complex than that being justified by a nosocomial model of dissemination. We suggest that there are more reservoirs of C. difficile within hospitals and the communities and the status of CDI in hospitals is the result of equilibrium reached between all factors involved in persistence of C. difficile in hospitals. This has serious implications for the treatment, prevention and control measures, and might require realignment of these strategies to more proactive management. Northern Ontario Academic Medicine Association (NOAMA)