Work

Ultrasound endoscopes and routine microbiological surveillance – another critical device in reprocessing

Year: 2025

Type: article

Abstract: BACKGROUND: Periodic routine microbiological surveillance of gastrointestinal endoscopes is recommended to ensure adequacy of reprocessing. AIM: To investigate whether there were differences in contamination depending on the type of endoscope. METHODS: A total of 437 microbiological surveillance samples obtained from gastrointestinal endoscopes at a tertiary-care centre in Switzerland were analysed. Sampling was performed after reprocessing in washer-disinfectors according to Standard SN EN ISO 15883-4:2018. For microbiological analysis, endoscope irrigation solution was filtered and transferred to sheep blood agar. These plates were incubated at 37 °C. If bacterial growth was detected, the species was identified using matrix-assisted laser desorption-ionization time-of-flight mass spectrometry or other microbiological identification techniques, and colony-forming units (cfu) were counted. Contamination was defined as detection of any micro-organism with ≥20 cfu/20 mL or detection of Enterobacterales, Enterococcus spp., Pseudomonas aeruginosa and other non-fermenters, Streptococcus viridans and Staphylococcus aureus, independent of cfu count. FINDINGS: In total, 204 samples were gathered from 28 gastroscopes, 146 samples from 23 colonoscopes, 45 samples from five ultrasound endoscopes, 27 from four duodenoscopes and 15 from three enteroscopes, respectively. Eleven (2.5%) samples, gathered from five endoscopes, indicated contamination. The proportion of samples indicating contamination varied largely by endoscope type: 20.0% (9/45) of ultrasound endoscope-derived, 1.4% (2/146) of colonoscope-derived, 0.5% (1/204) of gastroscope-derived, 0% (0/27) of duodenoscope-derived, and 0% (0/15) of enteroscope-derived samples were contaminated (P < 0.001). CONCLUSION: Overall, a small proportion of endoscopes were contaminated. Significant differences were observed based on the type of endoscope, with ultrasound endoscopes performing worst.

Source: Journal of Hospital Infection

DOI: 10.1016/j.jhin.2025.09.015