Transmission of multi-drug resistant Pseudomonas aeruginosa between two flexible ureteroscopes and an outbreak of urinary tract infection: the fragility of endoscope decontamination.

OBJECTIVES: Flexible endoscopes are difficult to decontaminate, and endoscope-associated infections are increasing. This report describes an outbreak of multi-drug resistant Pseudomonas aeruginosa identified following an increase in incidence of clinical infections associated with flexible ureteroscopy at a tertiary care centre in the UK. METHODS: Clinical, laboratory and central decontamination unit (CDU) records were reviewed to determine the extent of the problem, and links to the used endoscopes. Audits of the ureteroscopy procedure, endoscopy unit and CDU were performed. Endoscopes were sampled, cultured and examined for structural integrity. All available isolates were typed. RESULTS: Thirteen patients developed clinical infections linked to two flexible ureteroscopes. The first ureteroscope was likely colonized from a known infected patient and the second ureteroscope after use on another patient infected by the first. Risk factors identified include surface cuts, stretching and puckering of the outer cover in both ureteroscopes, absence of bedside cleaning, overnight delay between the ureteroscopy and decontamination, inadequate drying after decontamination and non-traceability of connector valves. CONCLUSIONS: The adequacy of flexible endoscope decontamination depends on numerous steps. With the increasing global incidence of multi-drug resistant organisms, stringent monitoring of the flexible endoscopy process by users and decontamination units is essential.

Pre-Use Ureteroscope Contamination after High Level Disinfection: Reprocessing Effectiveness and the Relation with Cumulative Ureteroscope Use.

PURPOSE: We assessed the frequency of preoperative and persistent microbial contamination of flexible ureteroscopes after reprocessing and the relation of contamination to cumulative ureteroscope use. MATERIALS AND METHODS: We evaluated the effectiveness of high level disinfection with peracetic acid as well as data on ureteroscope use for 20 new flexible ureteroscopes from December 2015 to December 2017 at a single center. In the operating room pre-use and postuse microbial samples of the ureteroscope shaft and working channel were collected to evaluate microbial contamination after reprocessing. Positive cultures were defined as 30 cfu/ml or greater of skin flora, or 10 cfu/ml or greater of uropathogenic microorganisms. A generalized estimating equation model was used to analyze whether cumulative ureteroscope use was associated with positive pre-use cultures. RESULTS: Microbial samples were collected during 389 procedures. Pre-use ureteroscope cultures were positive in 47 of 389 procedures (12.1%), of which uropathogens were found in 9 of 389 (2.3%) and skin flora in 38 of 389 (9.8%). Urinary tract infection symptoms did not develop in any of the patients who underwent surgery with a uropathogen contaminated ureteroscope. In 1 case the pre-use culture contained the same bacteria type as the prior postuse culture. Cumulative ureteroscope use was not associated with a higher probability of positive cultures. CONCLUSIONS: Microbial contamination of reprocessed ureteroscopes was found in an eighth of all procedures. Notably uropathogenic microorganisms were discovered in a small proportion of all procedures. Persistent ureteroscope contamination with uropathogens was only rarely encountered. Cumulative ureteroscope use was not associated with a higher probability of microbial contamination.

The effectiveness of sterilization for flexible ureteroscopes: A real-world study.

BACKGROUND: There are no guidelines or quality benchmarks specific to ureteroscope reprocessing, and patient injuries and infections have been linked to ureteroscopes. This prospective study evaluated ureteroscope reprocessing effectiveness. METHODS: Reprocessing practices at 2 institutions were assessed. Microbial cultures, biochemical tests, and visual inspections were conducted on sterilized ureteroscopes. RESULTS: Researchers examined 16 ureteroscopes after manual cleaning and sterilization using hydrogen peroxide gas. Every ureteroscope had visible irregularities, such as discoloration, residual fluid, foamy white residue, scratches, or debris in channels. Tests detected contamination on 100% of ureteroscopes (microbial growth 13%, adenosine triphosphate 44%, hemoglobin 63%, and protein 100%). Contamination levels exceeded benchmarks for clean gastrointestinal endoscopes for hemoglobin (6%), adenosine triphosphate (6%), and protein (100%). A new, unused ureteroscope had hemoglobin and high protein levels after initial reprocessing, although no contamination was found before reprocessing. CONCLUSIONS: Flexible ureteroscope reprocessing methods were insufficient and may have introduced contamination. The clinical implications of residual contamination and viable microbes found on sterilized ureteroscopes are unknown. Additional research is needed to evaluate the prevalence of suboptimal ureteroscope reprocessing, identify sources of contamination, and determine clinical implications of urinary tract exposure to reprocessing chemicals, organic residue, and bioburden. These findings reinforce the need for frequent audits of reprocessing practices and the routine use of cleaning verification tests and visual inspection as recommended in reprocessing guidelines.

Outbreak of ertapenem-resistant Enterobacter cloacae urinary tract infections due to a contaminated ureteroscope.

BACKGROUND: Outbreaks of urinary tract infections (UTIs) due to contaminated ureteroscopes have been rarely reported. AIM: To report such an outbreak at a regional teaching hospital in southern Taiwan. METHODS: From October to December 2010, ertapenem-resistant Enterobacter cloacae were identified from urine cultures of 15 patients who had undergone ureteroscopy prior to the infection. Three batches of surveillance cultures were obtained from the environmental objects and healthcare workers related to the procedures. Pulsed-field gel electrophoresis (PFGE) was used for bacterial typing. Antimicrobial susceptibility was assessed by disc diffusion and E-test methods. Polymerase chain reaction and sequencing were used to analyse ß-lactamase genes. FINDINGS: A total of 70 specimens were obtained during the first surveillance operation. One ertapenem-resistant E. cloacae was isolated from a ureteroscope. Although the disinfection protocols for ureteroscopes were revised and implemented, seven additional UTI cases were identified thereafter. The pathogen was identified from two subsequent surveillance cultures and was not eliminated until ethylene oxide sterilization was added to the disinfection protocol. PFGE revealed that all 15 isolates from the patients and the three isolates from the ureteroscope shared a common pattern with minor variance. Most isolates were resistant to gentamicin, levofloxacin, ceftriaxone, ceftazidime, and ertapenem. All isolates were susceptible to amikacin, imipenem, and meropenem. SHV-12 and IMP-8 genes were simultaneously identified in 16 of the 18 isolates. CONCLUSION: The outbreak of ertapenem-resistant E. cloacae was caused by a contaminated ureteroscope and was terminated by the implementation of a revised disinfection protocol for ureteroscopes.

Chaos to comprehension: cleaning, sterilization, and disinfection.

Reprocessing of endoscopic instrumentation reduces the risk of transmitting infectious organisms to patients and health care workers. Health care workers should use the Bloodborne Pathogen Standard and Standard Precautions to determine the best method to reduce and/or eliminate bioburden.