INTRODUCTION:Immunocompromised patients are at an increased risk of severe legionella infections. We present the results of an outbreak investigation initiated following a fatal case of hospital-acquired legionellosis linked to contaminated water from a toilet-flushing cistern. Additionally, we provide experimental data on the growth of Legionella spp. in flushing cisterns and propose a straightforward protocol for prevention. METHODS:We monitored the growth of Legionella spp. in the building's hot- and cold-water systems using quantitative bacterial culture on selective agar. Molecular typing of Legionella pneumophila isolates from the infected patient and the water system was conducted through core-genome multi-locus sequence typing (cgMLST). RESULTS:Legionella contamination in the hospital building's cold-water system was significantly higher than in the hot-water system and significantly higher in toilet flushing cistern's water compared with cold water from bathroom sinks and showers. Isolates from the patient and from the flushing cistern of the patient's bathroom were identical by cgMLST. In an experimental setting, daily toilet flushing for a period of 21 days resulted in a 67% reduction in the growth of Legionella spp. in the water of toilet flushing cisterns. Moreover, a one-time disinfection of cisterns with peracetic acid, followed by daily flushing, decreased legionella growth to less than 1% over a period of at least seven weeks in these setting. CONCLUSIONS:One-time disinfection of highly contaminated cisterns with peracetic acid and daily toilet flushing as short-term measure can significantly reduce legionella contamination in flushing cisterns. These measures may aid in preventing legionella infection among immunocompromised patients.

Zusammenfassung Hintergrund Die Hochfrequenz-Jetventilation (HFJV) wird in der pneumologischen Endoskopie für starre, diagnostische und therapeutische Bronchoskopien genutzt. Unklar ist hierbei, inwieweit durch den ungehinderten Atemgasstrom aus der Lunge des Patienten eine mikrobielle Belastung der Umgebungsluft entsteht. Material und Methoden Nach Beginn der HFJV (15 min) bei 16 starren Bronchoskopien wurden direkt am distalen Endoskopausgang, auf Untersucherhöhe (40 cm über dem Endoskopausgang), in 2 m Abstand vom Endoskop im Raum sowie am Zuluftauslass des Untersuchungsraums Luftkeimmessungen mit einem RCS-Luftkeimsammler vorgenommen. Anschließend erfolgten die Bestimmung der Anzahl und Art der isolierten Erreger in den Luftproben sowie eine Keimbestimmung in der bronchoalveolären Lavageflüssigkeit (BALF) aus der Patientenlunge. Ergebnisse Direkt am distalen Ende des Endoskops und auf Untersucherhöhe in 40 cm Entfernung wurde eine erhöhte Keimdichte (136 und 114 KBE/m3) nachgewiesen, die mit zunehmendem Abstand vom Bronchoskop deutlich abnahm (in 2 m Entfernung 98 KBE/m3 und am Zuluftauslass 82 KBE/m3). Die am häufigsten nachgewiesenen Bakterien waren Staphylococcus spp., Micrococcus spp. und Bacillus spp. In der BALF konnten nur in 4 von 16 Proben Erreger kultiviert werden, jedoch wurden dieselben Erreger in der BALF und der Umgebungsluft nachgewiesen. Schlussfolgerungen Bei der Durchführung einer starren Bronchoskopie, bei der die Patienten mit einem offenen HFJV-System kontrolliert mechanisch ventiliert werden, entsteht eine erhöhte Erregerbelastung der Umgebungsluft und damit eine potenzielle Gefahr für den Untersucher.

Background High-frequency jet ventilation (HFJV) is used in pneumological endoscopy for rigid, diagnostic, and therapeutic bronchoscopies. It is unclear to what extent the unobstructed flow of respiratory gas from the patient's lungs causes microbial contamination of the surrounding air. Material and methods After the start of the HFJV (15 min) in 16 rigid bronchoscopies, airborne pathogen measurements were taken directly at the distal endoscope outlet, at examiner height (40 cm above the endoscope outlet), at a 2 m distance from the endoscope in the room and at the supply air outlet of the examination room using an RCS air sampler. The number and type of pathogens isolated in the air samples were then determined, as well as germs in the bronchoalveolar lavage fluid (BALF) from the patient's lungs. Results An increased bacterial density (136 and 114 CFU/m (3) ) was detected directly at the distal end of the endoscope and at examiner height at a distance of 40 cm, which decreased significantly with increasing distance from the bronchoscope (98 CFU/m (3 )at a distance of 2 m and 82 CFU/m (3) at the supply air outlet). The most frequently detected bacteria were Staphylococcus spp., Micrococcus spp. and Bacillus spp. In the BALF, pathogens could only be cultivated in four of 16 samples, but the same pathogens were detected in the BALF and the ambient air. Conclusion When performing a rigid bronchoscopy, in which patients are mechanically ventilated in a controlled manner using an open HFJV system, there is an increased pathogen load in the ambient air and therefore a potential risk for the examiner.

Abstract Objective: Investigation of the origin of a Serratia marcescens outbreak in a neonatal intensive care unit. Design: Retrospective case–control study. Setting: Regional level 3 perinatal center in Germany. Patients: This study included 4 S. marcescens–positive and 19 S. marcescens–negative neonates treated between February 1 and February 26, 2019, in the neonatal intensive care unit. Methods: A case–control study was performed to identify the source of the outbreak. The molecular investigation of S. marcescens isolates collected during the outbreak was performed using pulsed-field gel electrophoresis and next-generation sequencing. Results: The retrospective case–control study showed a significant correlation (P < .0001) between S. marcensens infection or colonization and consumption of donor milk that had tested negative for pathogenic bacteria from a single breast milk donor. Pulsed-field gel electrophoresis and next-generation sequencing retrospectively confirmed an S. marcescens strain isolated from the breast milk of this donor as the possible origin of the initial outbreak. The outbreak was controlled by the implementation of an infection control bundle including a multidisciplinary infection control team, temporary nutrition of infants with formula only and/or their mother’s own milk, repeated screening of all inpatients, strict coat and glove care, process observation, retraining of hand hygiene and continuous monitoring of environmental cleaning procedures. Conclusions: Low-level contaminated raw donor milk can be a source of infection and colonization of preterm infants with S. marcescens even if it tests negative for bacteria.

Background Here we describe a cluster of hospital-acquired Clostridium difficile infections (CDI) among 26 patients with osteoarticular infections. The aim of the study was to define the source of C. difficile and to evaluate the impact of general infection control measures and antibiotic stewardship on the incidence of CDI. Methods Epidemiological analysis included typing of C. difficile strains and analysis of possible patient to patient transmission. Infection control measures comprised strict isolation of CDI patients, additional hand washings, and intensified environmental cleaning with sporicidal disinfection. In addition an antibiotic stewardship program was implemented in order to prevent the use of CDI high risk antimicrobials such as fluoroquinolones, clindamycin, and cephalosporins. Results The majority of CDI ( n = 15) were caused by C. difficile ribotype 027 (RT027). Most RT027 isolates ( n = 9) showed high minimal inhibitory concentrations (MIC) for levofloxacin, clindamycin, and remarkably to rifampicin, which were all used for the treatment of osteoarticular infections. Epidemiological analysis, however, revealed no closer genetic relationship among the majority of RT027 isolates. The incidence of CDI was reduced only when a significant reduction in the use of fluoroquinolones ( p = 0.006), third generation cephalosporins ( p = 0.015), and clindamycin ( p = 0.001) was achieved after implementation of an intensified antibiotic stewardship program which included a systematic review of all antibiotic prescriptions. Conclusion The successful reduction of the CDI incidence demonstrates the importance of antibiotic stewardship programs focused on patients treated for osteoarticular infections.