An intensive care unit outbreak with multi-drug-resistant Pseudomonas aeruginosa - spotlight on sinks.

BACKGROUND: Pseudomonas aeruginosa and other Gram-negative bacteria have the ability to persist in moist environments in healthcare settings, but their spread from these areas can result in outbreaks of healthcare-associated infections. METHODS: This study reports the investigation and containment of a multi-drug-resistant P. aeruginosa outbreak in three intensive care units of a Swiss university hospital. In total, 255 patients and 276 environmental samples were screened for the multi-drug-resistant P. aeruginosa outbreak strain. The environmental sampling and molecular characterization of patient and environmental strains, and control strategies implemented, including waterless patient care, are described. RESULTS: Between March and November 2019, the outbreak affected 29 patients. Environmental sampling detected the outbreak strain in nine samples of sink siphons of three different intensive care units with a common water sewage system, and on one gastroscope. Three weeks after replacement of the sink siphons, the outbreak strain re-grew in siphon-derived samples and newly affected patients were identified. The outbreak ceased after removal of all sinks in the proximity of patients and in medication preparation areas, and minimization of tap water use. Multi-locus sequence typing indicated clonality (sequence type 316) in 28/29 patient isolates and all 10 environmental samples. CONCLUSIONS: Sink removal combined with the introduction of waterless patient care terminated the multi-drug-resistant P. aeruginosa outbreak. Sinks in intensive care units may pose a risk for point source outbreaks with P. aeruginosa and other bacteria persisting in moist environments.

Should International Classification of Diseases codes be used to survey hospital-acquired pneumonia?

As surveillance of hospital-acquired pneumonia (HAP) is very resource intensive, alternatives for HAP surveillance are needed urgently. This study compared HAP rates according to routine discharge diagnostic codes of the International Classification of Diseases, 10th Revision (ICD-10; ICD-HAP) with HAP rates according to the validated surveillance definitions of the Hospitals in Europe Link for Infection Control through Surveillance (HELICS/IPSE; HELICS-HAP) by manual retrospective re-evaluation of patient records. The positive predictive value of ICD-HAP for HELICS-HAP was 0.35, and sensitivity was 0.59. Therefore, the currently available ICD-10-based routine discharge data do not allow reliable identification of patients with HAP.