The duodenoscope elevator mechanism has been considered a culprit for multiple outbreaks from contaminated reusable patient-ready duodenoscopes. These outbreaks necessitated FDA to issue various Safety Communications and recommend endoscopy units to transition to duodenoscopes with innovative designs that ease or eliminate reprocessing. However, numerous studies have documented microbes in the channels of reprocessed gastrointestinal (GI) endoscopes, including duodenoscopes and linear echoendoscopes. Our aim is to estimate the channel contamination rate of patient-ready reprocessed GI endoscopes based on the currently available data.


We searched PubMed, Web of Science, and Embase from January 1, 2010, until October 10, 2020, for studies investigating contamination rates of channels of patient-ready flexible GI endoscopes by following the PRISMA guidelines. A random-effects model based on the proportion distribution was used to calculate pooled total contamination rate. A subgroup analysis was carried out for studies originating from North America (USA and Canada). We used the meta-package (metafor) in RStudio version 3.6.2 to conduct the statistical analyses. Heterogeneity between the included studies was analyzed using the inconsistency index (I2) statistics. Publication bias was assessed using funnel plots and Egger’s regression tests.


We identified 1,230 peer-reviewed studies after duplicates were removed. Finally, 20 studies fulfilled the inclusion criteria, including 1,059 positive cultures from 7,903 samples. The total weighted contamination rate was 19.98% ± 0.024 (95% Cl: 15.29%-24.68%; I2=98.6%) (figure 1a). Subgroup analysis amongst studies from North America (n=7) showed a contamination rate of 6.01% ± 0.011 (95% Cl: 3.88%-8.15%; I2=89.3%) (figure 1b). I2 indicated high heterogeneity. Egger’s regression test indicated no significant publication bias for both groups (Egger’s test of publication bias: p=0.0531 and p=0.0655).


Our analysis demonstrates that 19.98% of reprocessed patient-ready GI endoscopes may be contaminated. The contamination rate was lower amongst US studies, which may be attributed to the actions taken in the US to overcome this issue. However, our findings highlight that the elevator mechanism is not the only obstacle when reprocessing endoscopes. More studies are needed to fully determine the role of contaminated endoscope channels in the cross-transmission between the patients.

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The American Journal of Gastroenterology