ENDOSCOPES REPROCESSING

The risk of infection associated with endoscopic procedures can be effectively controlled through an adequate reprocessing process [1].Infections related to endoscopy may be endogenous or exogenous in origin. A recent review by Kavoleva et al. [2] indicates that, in most cases, the source of infection is endogenous, meaning it originates from the patient’s own microbial flora.The microorganisms most frequently isolated include:Escherichia coliKlebsiella spp.Enterobacter spp.enterococciEndogenous infections cannot be prevented by the endoscope reprocessing process.The exogenous microorganisms most commonly associated with infections include:Pseudomonas aeruginosa and Salmonella spp. during flexible gastrointestinal endoscopyPseudomonas aeruginosa or mycobacteria during bronchoscopyContamination of endoscopes may occur during endoscopic procedures or may result from improperly maintained automated endoscope reprocessors (AERs) or contaminated processing water, facilitating the spread of microorganisms.These types of infections can be prevented through strict adherence to reprocessing and storage procedures.However, the safety margin required to ensure an effective reprocessing process is limited [3]. The internal channels of gastrointestinal endoscopes, including duodenoscopes, may harbor up to 10⁷–10¹⁰ (7–10 log) enteric microorganisms.
The cleaning phase can reduce the microbial load by approximately 4 log, while high-level disinfection provides an additional 4–5 log reduction.The incidence of infections associated with endoscopic procedures is estimated to be approximately 1 infection per 1.8 million procedures [4].Clusters of infection or colonization caused by carbapenem-resistant Enterobacteriaceae (CRE) have been associated with the use of duodenoscopes during ERCP (endoscopic retrograde cholangiopancreatography) [5].A literature review showed that between 1975 and 2010, ERCP procedures were associated with only 23 reported outbreak clusters, mainly caused by Pseudomonas aeruginosa and only rarely by enterobacteria.However, in September 2013, an outbreak occurred in a hospital in Chicago in which 10 patients were infected and 28 were colonized by carbapenemase-producing Klebsiella pneumoniae following an endoscopic procedure. The cause was attributed to structural features of the duodenoscope’s elevator channel, which made effective cleaning and disinfection difficult.Microbiological surveillance of the reprocessing process is an important strategy to:identify potential systemic errors in reprocessing procedures;detect micro-damage or defects in endoscope channels that may facilitate biofilm formation.