Withdrawal of a novel-design duodenoscope ends outbreak of a VIM-2-producing Pseudomonas aeruginosa.

BACKGROUND AND STUDY AIMS: Infections are a recognized risk of endoscopic retrograde cholangiopancreatography (ERCP). This paper reports on a large outbreak of VIM-2-producing Pseudomonas aeruginosa that was linked to the use of a recently introduced duodenoscope with a specific modified design (Olympus TJF-Q180V). METHODS: Epidemiological investigations and molecular typing were executed in order to identify the source of the outbreak. Audits on implementation of infection control measures were performed. Additional infection control strategies were implemented to prevent further transmission. The design and the ability to clean and disinfect the duodenoscope were evaluated, and the distal tip was dismantled. RESULTS: From January to April 2012, 30 patients with a VIM-2-positive P. aeruginosa were identified, of whom 22 had undergone an ERCP using a specific duodenoscope, the TJF-Q180V. This was a significant increase compared with the hospital-wide baseline level of 2 - 3 cases per month. Clonal relatedness of the VIM-2 P. aeruginosa was confirmed for all 22 cases and for the VIM-2 strain isolated from the recess under the forceps elevator of the duodenoscope. An investigational study of the new modified design, including the dismantling of the duodenoscope tip, revealed that the fixed distal cap hampered cleaning and disinfection, and that the O-ring might not seal the forceps elevator axis sufficiently. The high monthly number of cases decreased below the pre-existing baseline level following withdrawal of the TJF-Q180V device from clinical use. CONCLUSIONS: Duodenoscope design modifications may compromise microbiological safety as illustrated by this outbreak. Extensive pre-marketing validation of the reprocessability of any new endoscope design and stringent post-marketing surveillance are therefore mandatory.

Limiting spread of VIM-positive Pseudomonas aeruginosa from colonized sink drains in a tertiary care hospital: A before-and-after study.

BACKGROUND: In healthcare environments, sinks are being increasingly recognized as reservoirs for multidrug-resistant Gram-negative bacteria. In our hospital, carbapenemase-producing, Verona Integron-encoded Metallo-beta-lactamase (VIM)-positive Pseudomonas aeruginosa (VIM-PA) was detected at low endemicity in patients, and environmental culturing revealed that sink drains were primary reservoirs. Therefore, an intervention was initiated in several wards to install sink drain plugs as physical barriers against splashing to prevent transmission of VIM-PA from drain reservoirs to the surrounding sink environment. AIM: To assess the efficacy of the intervention on limiting spread of VIM-PA. METHODS: Swabs were taken from inner sink environments (i.e. drains), and outer sink environments (i.e. wash basins, faucet aerators, and countertops) twice before and three times after the intervention. Siphon water and drain wells were also sampled before and at the moment of the intervention, respectively. All samples were screened for VIM-PA, and isolates were typed with multiple-locus variable-number tandem repeat analysis (MLVA). RESULTS: There was a significant reduction in VIM-PA positivity in both inner (P-value <0.001) and outer (P-value 0.001) sink environments after the intervention. However, VIM-PA recolonization was observed in the inner sink environments of patient rooms, and also in rooms exclusive to healthcare personnel, over time. Surfaces in the outer sink environment were rarely positive for VIM-PA after the intervention. MLVA revealed three genetic clusters, with one found in all wards and room types during the study period. CONCLUSIONS: Drain plugs are a simple and effective infection prevention and control measure to contain spread of VIM-PA from drain reservoirs.

Contact investigations for antibiotic-resistant bacteria: a mixed-methods study of patients' comprehension of and compliance with self-sampling requests post-discharge.

BACKGROUND: Contact investigation is an important tool to identify unrecognized patients who are colonized with antibiotic-resistant bacteria. Many Dutch hospitals include already discharged contact patients by sending them a self-sampling request at home, incl. an information letter and sampling materials. Each hospital composes these information letters on their own initiative, however, whether discharged patients comprehend and comply with these requests remains unclear. Therefore, the aim was to provide insight into patients' comprehension of and self-reported compliance with self-sampling requests post-discharge. METHODS: This mixed-methods study was performed in eight Dutch hospitals. First, the Common European Framework of Reference (CEFR) language level of self-sampling request letters was established. Second, a questionnaire about patients' comprehension of the letter, self-reported compliance, and reasons for compliance or non-compliance were sent to patients that received such a request in 2018/2019. Finally, a random selection of questionnaire respondents was interviewed between January and March 2020 to gain additional insights. RESULTS: CEFR levels of 15 letters were established. Four letters were assigned level B1, four letters B1-B2, and seven letters B2. The majority of patients reported good comprehension of the letter they had received. Conversely, some respondents indicated that information about the bacterium (18.4%), the way in which results would be communicated (18.1%), and the self-sampling instructions (9.7%) were (partially) unclear. Furthermore, self-reported compliance was high (88.8%). Reasons to comply were personal health (84.3%), the health of others (71.9%), and general patient safety (96.1%). Compliant patients appeared to have a need for confirmation, wanted to protect family and/or friends, and felt they were providing the hospital the ability to control the transmission of antibiotic-resistant bacteria. Although a limited number of non-compliant patients responded to the questionnaire, it seemed that more patients did not comply with self-sampling requests when they received a letter in a higher CEFR-level (B2) compared to a lower CEFR-level (< B2) (9.8% vs. 2.5%, P = 0.049). CONCLUSIONS: This study showed an overall good comprehension of and high self-reported compliance with self-sampling requests post-discharge. Providing balanced information in self-sampling request letters has the potential to reduce patient's ambiguity and concerns, and can cause increased compliance with self-sampling requests.

Pseudomonas aeruginosa left ventricular assist device (LVAD) driveline infection acquired from the bathroom at home.

We describe a patient with a left ventricular assist device (LVAD) infection by Pseudomonas aeruginosa acquired at home. The Pseudomonas from the driveline was similar to several surface cultures of the patient's home shower. This case illustrates the potential and importance of infection prevention measures at home.

VIM-positive Pseudomonas aeruginosa in a large tertiary care hospital: matched case-control studies and a network analysis.

Background: Emergence of multidrug-resistant Pseudomonas aeruginosa is of global concern. We aimed to identify epidemiological relationships, the most common way of transmission, and risk factors for presence of Verona Integron-encoded Metallo-ß-lactamase (VIM)-positive P. aeruginosa (VIM-PA). Methods: We conducted a network analysis and matched case-control studies (1:2:2). Controls were hospital-based and matched with cases for ward, day of admission (control group 1 and 2) and time between admission and the identification of VIM-PA (control group 1). The network was visualized using Cytoscape, and risk factors were determined using conditional logistic regression. Results: Between August 2003 and April 2015, 144 case patients and 576 control patients were recruited. We identified 307 relationships in 114 out of these 144 patients, with most relationships (84.7%) identified at the same department < 3 months after a previous case patient was discharged. In the multivariable model, having undergone ≥1 gastroscopy (odds ratio [OR] = 4.40, 95% confidence interval [CI] = 2.00 to 9.65 and OR = 2.47; 95% CI = 1.12 to 5.49), > 10 day use of selective digestive tract decontamination (SDD) (OR = 2.97; 95% CI = 1.02 to 8.68 and OR = 4.61; 95% CI = 1.22 to 17.37), and use of quinolones (OR = 3.29; 95% CI = 1.34 to 8.10 and OR = 3.95; 95% CI = 1.13 to 13.83 and OR = 4.47; 95% CI = 1.75 to 11.43) were identified as risk factors when using both control groups. Conclusions: The network analysis indicated that the majority of transmissions occurred on the wards, but through unidentified and presumably persistent sources, which are most likely in the innate hospital environment. Previous use of certain antibiotic regimens made patients prone to VIM-PA carriage. Additionally, gastroscopy could be considered as a high-risk procedure in patients with risk factors. Our results add to the growing body of evidence that infection control measures targeting VIM-PA should be focused on reducing antibiotics and eliminating sources in the environment.