Matching Clostridioides difficile strains obtained from shoe soles of healthcare workers epidemiologically linked to patients and confirmed by whole-genome sequencing.

BACKGROUND: The source of transmission of Clostridioides difficile in healthcare institutions is frequently unknown. The aim of this prospective cohort study was to assess the association between strains cultured from patients and shoe soles of healthcare workers (HCWs), as already shown in the operating theatre, but not on general hospital wards in an acute-care institution. METHODS: We conducted a study at a university tertiary care centre in Switzerland. From October 2019 to July 2020, shoe soles of HCWs were cultured for C. difficile twice per shift while taking care of a patient infected with toxigenic C. difficile. Additional risk factors were assessed by interviewing involved HCWs. Patients' faecal samples were processed by routine microbiological methods. Similarity of the HCWs' and patients' strains was determined by whole-genome sequencing (WGS). RESULTS: A total of 103 HCWs exposed to 42 hospitalized patients participated in the study, providing 206 samples. Contamination of shoe soles with C. difficile was detected in 37 samples (17.8%) of HCWs taking care of patients infected with C. difficile. Overall, transmission was suspected by epidemiological link and matching strains demonstrated by WGS in 74%. CONCLUSIONS: HCWs' shoe soles were positive in 17.8% with C. difficile strains linked epidemiologically and confirmed by WGS to infected patients suggesting potential transmission by HCWs' shoe soles. This pilot study provides sufficient evidence to further evaluate this potential mode of healthcare-associated transmission of C. difficile by a larger clinical trial.

Does high adherence to contact precautions lead to low in-hospital transmission of multi-drug-resistant micro-organisms in the endemic setting?

BACKGROUND: Conflicting results have been published on the impact of contact precautions (CPs) on reduction of transmission of multi-drug-resistant micro-organisms (MDROs) in the endemic setting. Ambiguous definitions coupled with low adherence partly explain these differences. AIM: We prospectively monitored the level of adherence to CPs and aimed to relate it to in-hospital transmission of MDROs. METHODS: Between January 2016 and March 2018, all patients under CPs underwent continuous monitoring of adherence to CPs by routine on-site visits on days 0, 3 and 7 after initiating CPs using a standardized checklist. The protocol included 10 interventions that were routinely checked such as CP sign at the door as well as wearing of gowns and gloves upon entry to the patient room. Patients requiring CPs were defined as colonized or infected with MDROs (meticillin-resistant Staphylococcus aureus (MRSA), non-Escherichia coli extended-spectrum beta lactamase (ESBL) Enterobacterales, vancomycin-resistant enterococci (VRE) and carbapenem-resistant Gram-negative micro-organisms (CRGN)) as well as patients infected with respiratory viruses, norovirus, scabies and hypervirulent strains of Clostridioides difficile. FINDINGS: Overall, data from 13,756 CP records from 1378 visits of 812 patients were analysed. Adherence varied between 93% and 100% for each intervention, except for "separate space for contaminated material" with an adherence of 5.3-6.1%. The incidence of in-hospital transmission during the study period was extremely low for MRSA, VRE, non-E.coli ESBL Enterobacterales and CRGN with 0.00-0.064 cases/1000 patient days. CONCLUSION: High adherence coupled with continuous monitoring of CPs correlated with a very low in-hospital transmission rate. These results indicate that CPs are highly effective if routine monitoring of adherence is implemented.

Impact of an infection control service in a university psychiatric hospital: significantly lowering healthcare-associated infections during 18 years of surveillance.

BACKGROUND: Healthcare-associated infections (HAIs) lead to high morbidity and mortality. Data for HAIs in psychiatric hospitals are scarce, and are not derived from long-term surveillance. AIM: To assess the impact of an infection control service on the prevalence of HAIs in a psychiatric hospital over an 18-year period. METHODS: In 1999, a professional infection control service was initiated at the University Psychiatric Hospital in Basel, Switzerland, with a part-time infection control nurse, a hospital epidemiologist, and administrative support. In addition to monitoring rates of multi-drug-resistant pathogens, eight prevalence studies using definitions outlined by the Centers for Disease Control and Prevention (CDC) were conducted between 2001 and 2018. For the primary outcome, a Poisson regression model was fitted to confirm cases of HAIs, standardized for patients at risk as a model offset. FINDINGS: Overall, the predicted prevalence of nosocomial infections decreased from 3.7% (95% confidence interval (CI) 2.2-5.3%) in 2001 to 1.0% (95% CI 0.2-1.8%) in 2018 after introduction of an infection control service (incidence ratio rate (IRR) for yearly decrease of 0.93, 95% CI 0.87-0.98, P=0.007). CONCLUSIONS: Implementation of an infection control service may lead to a significant long-term decrease in HAIs, even in an institution caring for patients with low risk for HAIs, such as in psychiatric hospitals. In addition, epidemics and clusters were rapidly contained. Infection control services from acute-care hospitals should be expanded to psychiatric institutions, in order to decrease the incidence of HAIs and meet new challenges in times of emergence of multi-drug-resistant pathogens.