ObjectiveTo study the current situation and influencing factors of biofilm formation of digestive endoscopy in Zhongshan Hospital, Fudan University.MethodsFrom September 1st to 13th, 2020, ATP fluorescence assay and membrane filtration method were carried out on 130 endoscopes from the Endoscopy Center of Zhongshan Hospital, Fudan University. The type, number, source, duration of use and disinfection times in the past week were collected. Positive culture samples were identified by matrix-assisted laser desorption / ionization time of flight mass spectrometry. Logistic regression analysis was used to explore the factors affecting the formation of biofilms.ResultsThe total qualified rate of ATP assay and bacterial culture was 94.62% and 92.31% respectively. The 10 positive culuture samples were mainly composed of Pseudomonas aeruginosa, Moraxella osloensis, Stenotrophomonas maltophilia, Pseudomonas putida and Micrococcus luteus. Multivariate logistic regression analysis showed that the frequency of disinfection in the past week was associated with positive biofilm culture (P=0.001). The odds ratio of disinfection frequency more than 30 times in past week compared with disinfection frequency less than 15 times was 0.040, and 95% confidence interval was (0.005, 0.295).ConclusionsThe biofilm of digestive endoscopy in the Endoscopy Center of Zhongshan Hospital, Fudan University is mainly formed by aquatic bacteria. The formation biofilm can decrease by increasing disinfection frequency, and attention should be paid to the monitoring of endoscopic biofilm in the future.
Objective To investigate the impact of different final rinsing parameters of automated endoscopic reprocessors on peracetic acid (PAA) residuals in gastrointestinal endoscope channels, and to provide scientific evidence for optimizing endoscope cleaning and disinfection processes in clinical settings and reducing patient exposure risks. Methods From January to March 2025, 86 gastroscopes and 6 automated endoscopic reprocessors regularly used in the Endoscopy Center, Zhongshan Hospital, Fudan University were selected as the research subjects. They were divided into 3 groups based on the duration and frequency of final rinsing (group A: final rinsing for 2 times, with each rinsing lasting for 2.5 minutes, and a total rinsing time of 5 minutes; group B: final rinsing for 3 times, with each rinsing lasting for 2 minutes, and a total rinsing time of 6 minutes; group C: final rinsing for 3 times, with each rinsing lasting for 2.5 minutes, and a total rinsing time of 7.5 minutes). The PAA residuals in the endoscope channels of each group before and after drying were detected, and the compliance rates of PAA residues with standards were calculated. Results During the study period, groups A, B, and C underwent 40, 52, and 43 endoscopic disinfection procedures, respectively. Before drying, there was a significant difference in the residual PAA levels among the three groups (median PAA residual levels in groups A, B, and C were 5.34, 2.51, and 0.94 mg/L, respectively; P<0.05). Further pairwise comparisons also showed statistically significant differences (P<0.05). After drying, there was a significant difference in the residual PAA levels among the three groups (median PAA residual levels in groups A, B, and C were 3.37, 0.90, and 0.75 mg/L, respectively; P<0.05). However, further pairwise comparisons revealed no significant difference in PAA residual levels between group B and group C (P>0.05), while the remaining pairwise comparisons showed statistically significant differences (P<0.05). Within-group comparisons of PAA residual levels before and after drying showed significant differences in PAA residual levels in groups A and B before and after drying (P<0.05), while there was no significant difference in PAA residual levels in group C before and after drying (P>0.05). The PAA residual compliance rates in groups A and B after drying were significantly higher than those before drying (group A: 5.00% before drying and 27.50% after drying; group B: 1.92% before drying and 57.69% after drying; P<0.05), while there was no significant difference in the PAA residual compliance rates in group C before and after drying (P>0.05). Conclusions Increasing the number of final rinsing, extending the rinsing duration, and intensifying the drying process can effectively reduce PAA residues. Clinically, it is recommended to optimize the final rinsing parameters of the automated endoscopic reprocessor, combined with intensified drying, to reduce PAA residues and ensure patient safety.