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An outbreak of OXA-23-producing carbapenem-resistant Acinetobacter baumannii amongst ICU-patients with COVID-19 likely occurred by transmission through inanimate surfaces, potentially facilitated by a contaminated positioning pillow shared between patients. Subsequent rapid spread may have been caused by exposure to respiratory secretions contaminating healthcare worker's gloves and gowns during prone positioning., (© 2024. The Author(s).)

Background: We sought to decipher transmission pathways in healthcare-associated infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within our hospital by epidemiological work-up and complementary whole genome sequencing (WGS). We report the findings of the four largest epidemiologic clusters of SARS-CoV-2 transmission occurring during the second wave of the pandemic from 11/2020 to 12/2020., Methods: At the University Hospital Basel, Switzerland, systematic outbreak investigation is initiated at detection of any nosocomial case of SARS-CoV-2 infection, as confirmed by polymerase chain reaction, occurring more than five days after admission. Clusters of nosocomial infections, defined as the detection of at least two positive patients and/or healthcare workers (HCWs) within one week with an epidemiological link, were further investigated by WGS on respective strains., Results: The four epidemiologic clusters included 40 patients and 60 HCWs. Sequencing data was available for 70% of all involved cases (28 patients and 42 HCWs), confirmed epidemiologically suspected in house transmission in 33 cases (47.1% of sequenced cases) and excluded transmission in the remaining 37 cases (52.9%). Among cases with identical strains, epidemiologic work-up suggested transmission mainly through a ward-based exposure (24/33, 72.7%), more commonly affecting HCWs (16/24, 66.7%) than patients (8/24, 33.3%), followed by transmission between patients (6/33, 18.2%), and among HCWs and patients (3/33, 9.1%, respectively two HCWs and one patient)., Conclusions: Phylogenetic analyses revealed important insights into transmission pathways supporting less than 50% of epidemiologically suspected SARS-CoV-2 transmissions. The remainder of cases most likely reflect community-acquired infection randomly detected by outbreak investigation. Notably, most transmissions occurred between HCWs, possibly indicating lower perception of the risk of infection during contacts among HCWs., (© 2023. The Author(s).)

Background: The optimal extent of screening of contact patients (CoPat) after exposure to patients infected or colonized with vancomycin-resistant enterococci (VRE) remains controversial., Methods: We retrospectively developed a new risk stratification for screening patients exposed to VRE, based on data from three outbreaks-two with Enterococcus faecium vanB and one with Enterococcus faecium vanA involving 1096 CoPat-in a low endemic setting. We classified them into four risk groups: three on environmental exposure, one by healthcare exposure: high (sharing the same room/bathroom with a VRE-colonized patient), medium (hospitalization in the same room after a VRE-colonized patient's discharge until terminal disinfection including ultraviolet C (UVc)-disinfection), low (hospitalized in the same room within three weeks before the VRE-colonized patient), and "staff" (screening of patients having the same medical care team)., Results: VRE-transmission occurred in 7.9% in the high-risk group compared to 0.6% and 0% in the medium and low risk groups. There was a significant trend to higher rates of transmission by risk level of exposure (p < 0.001). In the "staff" group, VRE transmission rate was 2.3%., Conclusion: Based on this stratification, we recommend to focus screening of exposed CoPat on the high-risk and "staff" group, saving resources and costs, but larger studies will allow to further improve the yield of VRE screening in the outbreak setting., (© 2022. The Author(s).)

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., (Copyright © 2021 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

Background: A number of episodes of nosocomial Agrobacterium spp . bacteremia (two cases per year) were observed at Bern University Hospital, Switzerland, from 2015 to 2017. This triggered an outbreak investigation., Methods: Cases of Agrobacterium spp . bacteremias that occurred between August 2011 and February 2017 were investigated employing line lists, environmental sampling, rapid protein- (MALDI-TOF MS), and genome-based typing (pulsed field gel electrophoresis and whole genome sequencing) of the clinical isolates., Results: We describe a total of eight bacteremia episodes due to A. radiobacter ( n  = 2), Agrobacterium genomovar G3 ( n  = 5) and A. pusense ( n  = 1). Two tight clusters were observed by WGS typing, representing the two A. radiobacter isolates (cluster I, isolated in 2015) and four of the Agrobacterium genomovar G3 isolates (cluster II, isolated in 2016 and 2017), suggesting two different point sources. The epidemiological investigations revealed two computer tomography (CT) rooms as common patient locations, which correlated with the two outbreak clusters. MALDI-TOF MS permitted faster evaluation of strain relatedness than DNA-based methods. High resolution WGS-based typing confirmed the MALDI-TOF MS clustering., Conclusions: We report clinical and epidemiological characteristics of two outbreak clusters with Agrobacterium. spp. bacteremia likely acquired during CT contrast medium injection and highlight the use of MALDI-TOF MS as a rapid tool to assess relatedness of rare gram-negative pathogens in an outbreak investigation., Competing Interests: Competing interestsThe authors declare that they have no competing interests., (© The Author(s). 2019.)