Semi-continuous disinfection of sinks with UVC on a haematology-oncology department for prevention of nosocomial infections

Patients with haematological and oncological diseases face a high risk of infections due to immunosuppression. Recent studies have highlighted the role of sinks as possible reservoirs for the transmission of multi-drug-resistant microorganisms to patients. Due to biofilm formation, the sinks are difficult to clean and disinfect. This intervention study evaluated the effect of a ultraviolet-C (UVC) self-disinfecting siphon in a haematology-oncology ward on bacterial load in stagnant water in the siphon, ESBL-positive drain pipes and positive patient cultures. Thirty-one weeks of weekly water and drain samples were collected (7 weeks pre-intervention and 24 weeks post-intervention). CLARA UVC siphons were installed in 13 patient rooms (28 sinks), while two control groups had either new standard siphons installed (3 rooms, 7 sinks) or no siphon replacement (3 rooms, 7 sinks). Binary logistic regression model on high-low colony count of siphon water showed that, compared to no intervention (UVC0), there was a positive effect of sink replacement (UVC-, OR 1.65 (95% CI 1.05-2.56), but replacement by the UVC siphon had a larger effect (UVC+, OR 4.01 (95%-CI 2.23-9.23). No (positive) effect was found on ESBL positive drain pipes and patient colonization. In conclusion, our study demonstrated that UVC disinfection of stagnant water in siphons is effective in reducing the bacterial load, but no effect on drainpipes and patient colonization could be demonstrated.