Comparison of channel sampling methods and brush heads in surveillance culture of endoscope reprocessing: A propensity score matching and paired study.

BACKGROUND: Endoscopy-related infections have caused multiple outbreaks. The importance of surveillance culture is gradually recognized, but sampling techniques are not consistent in many guidelines. It is unclear whether the Flush-Brush-Flush sampling method (FBFSM) is more sensitive than the conventional flush sampling method (CFSM) and whether different sampling brushes have different effects. METHODS: The propensity score matching method was done with two matching ways, 1:1 nearest neighbor propensity score matching and full matching was used to analyze the surveillance culture data collected by FBFSM and CFSM. We fit a confounder-adjusted multiple generalized linear logistic regression model to estimate the marginal odds ratio (OR). A paired study was applied to compare the sampling effect of polyurethane foam (PU) head brush and polyamide (PA) head brush. RESULT: From 2016 to 2020, 316 reprocessed endoscope samples were collected from all 59 endoscopy centers in Tianjin. About 279 (88.3%) reprocessed endoscopes met the threshold of Chinese national standards (<20 CFU/Channel). The qualified rate of reprocessed endoscopes sampling by CFSM (91.8%) and FBFSM (81.6%) was statistically different (p < 0.05). The adjusted OR by full matching for FBFSM was 7.98 (95% confidence interval: 3.35-21.78). Forty one pairs of colonoscopes, after reprocessing from 27 centers, were tested by PA and PU brushes, and no difference was found in microbial recovery. CONCLUSION: FBFSM was confirmed to be a more sensitive sampling technique. PU and PA brushes had no significant difference in sampling effect.

Short-term effects of meteorological factors, air pollution, and sunspot on childhood hand, foot, and mouth disease in Tianjin, China: a new time series regression, 2014-2018.

This study is aimed at defining the relationship between a set of environmental factors and childhood HFMD and then at estimating the related effect. The 16 environmental factors included meteorological, air pollution, and sunspot. A traditional TSR modified by using susceptible-infectious-recovery models and distribution lag nonlinear model was applied to estimate the short-term effects of daily environmental factors on children HFMD occurrence in 2014-2018 with adjustment of potential confounding factors. A total of 70,027 children aged 0-15 years with HFMD were enrolled. No significant effect was observed for daily sunspot numbers and average visibility. We found positive effects of the ambient average temperature, with an approximately m-shaped curve of the overall cumulative relationship, peaking at 25.6 °C with a relative risk (RR) of 1.45 (95% confidence intervals 1.21-1.73). The largest RR value of hot effect was achieved on the current day and then decreased by 2 days (total group, male group, and scatter group) or 1 day (female group and nursery group), and the effect lasted about 6 to 8 days from the lag 4 or lag 6 day. A greater association of temperature with HFMD for the female group and the scattered group was observed. This study suggests that ambient average temperature might be a risk factor for children HFMD in Tianjin. Further studies are warranted to confirm these findings.

The importance of sampling technique and rinse water for assessing flexible gastrointestinal endoscope reprocessing: A 3-year study covering 59 centers.

BACKGROUND: Various guidelines recommend several sampling techniques to verify endoscope reprocessing, but a comparative study of the efficiency for recovering microorganisms was rare. Our goal was to compare different sampling techniques for the postreprocessing endoscope to assess residual bacterial contamination and analysis of the critical factors affecting the endoscope reprocessing failure. METHODS: From 2016 to 2018, 3 techniques, the conventional flushing sampling method, flush-brush-flush sampling method (FBFSM), and pump-assisted sampling method (PASM), were compared covering all 59 endoscope units in Tianjin, China. RESULTS: A total of 237 (84.64%) flushing channel samples and 110 (61.11%) final rinse water samples met the Chinese national standard. The univariate analysis showed that the qualified rates of endoscope reprocessing sampled by PASM (65.52%) and FBFSM (75%) were significantly lower than those of the conventional flushing sampling method (91.38%). Five other factors, including the final rinse water, dry, and hospital level, were potential factors besides sample technique. The multivariate logistic analysis indicated only 2 factors (sampling technique and final rinse water) remained in the model. FBFSM, PASM, and the purified water were significantly associated with the odds of endoscope reprocessing failure, with the odds ratio (95% confidence interval) of which were 4.206 (1.757-10.067), 5.326 (2.463-11.645), and 0.309 (0.137-0.695), respectively. CONCLUSIONS: The problem of residual microorganisms of the postreprocessing endoscope was severe. Sampling technique and final rinse water were critical for endoscope reprocessing verification.

Three key factors influencing the bacterial contamination of dental unit waterlines: a 6-year survey from 2012 to 2017.

BACKGROUND: The contaminated output water from dental unit waterlines (DUWLs) is a potential risk to both patients and dental personnel who are frequently exposed to this water or aerosols. AIM: The purpose was to evaluate the contamination level and prevalence of bacteria in the output water of DUWLs, and to identify key factors to provide technical support for formulating relevant policies. METHODS: We developed a special sampling connector designed for collecting dental handpiece output water and a measurement device to assess retraction of a dental chair unit (DCU). Output water from dental handpieces and air/water syringes were collected as representative of DUWLs. Water samples were tested with reference to China's national standard. FINDINGS: From 2012 to 2017, 318 DCUs were randomly selected from 64 hospitals in Tianjin, China. Of these DCUs, 78.93% had no disinfection to prevent DUWL contamination. Three-hundred and forty-three (56.14%) samples complied with the guidelines on DUWL output water. The highest concentration of bacteria was 1.8 × 106  colony-forming units (CFUs)/mL. The three key factors of influence were as follows: daily or weekly disinfection of DUWLs; water supply source being hospital self-made purified water or purchased purified bottled water; and DCU with a valid anti-retraction valve. Potential infectious agents, including Bacillus cereus, Burkholderia cepacia and Pseudomonas aeruginosa, were isolated. CONCLUSION: There was a high rate of contamination in DUWLs. This highlights the need to develop national standards. There is a need to disinfect the DUWLs periodically and use a cleaner source of water; more attention should be paid to the efficacy of DCU anti-retraction valves.

Microbiologic assessment of flexible gastrointestinal endoscope reprocessing using a pump-assisted sampling technique: an investigation involving all endoscopy units in Tianjin, China.

BACKGROUND: Microbiologic surveillance of flexible gastrointestinal endoscopes is recommended in several guidelines as the primary means of identifying reprocessing failures. This study aimed to evaluate the contamination level and prevalence of bacteria of post-reprocessing endoscopes and to access whether using a pump-assisted sampling method (PASM) improves the sensitivity of culture. METHODS: All 59 endoscopy units in Tianjin, China, were investigated. The PASM and the conventional flushing sampling method (CFSM) were used to compare the results of the microbial culture. Logistic regression analysis was used to identify the influencing factors. RESULTS: One hundred four (56.52%) flushing channel samples of gastrointestinal endoscopes were positive for culture, and the maximum bacterial concentration was 14,100 colony-forming units (CFU)/channel. One hundred fifty-one (82.07%) flushing samples were qualified according to the national standard of China (≤ 20 CFU/channel). The qualified rate of the samples collected by PASM was significantly lower than the qualified rate by CFSM (65.52% vs 89.68%). Using PASM (odds ratio [OR]: 4.257; 95% confidence interval [CI]: 1.870-9.690) would increase the sensitivity of culture. The use of purified water (OR: 0.288; 95% CI: 0.102-0.814) could reduce the risk of endoscope reprocessing failure. CONCLUSION: Many endoscopes fail to meet the national standard for microbial culture after reprocessing. Our results suggest that using a pump-assisted method could increase the sensitivity of the test.

Evaluation of bacterial contamination of dental unit waterlines and use of a newly designed measurement device to assess retraction of a dental chair unit.

INTRODUCTION: Dental unit waterline (DUWL) output water is delivered through instruments of a dental chair unit (DCU) to irrigate and cool teeth. However, these waterlines can be heavily contaminated with bacteria. AIM: The purpose of the present study was to assess retraction and investigate the contamination level and prevalence of bacteria in DUWL output water. METHODS: Fifty-eight DCUs were randomly selected from 30 hospitals in 10 districts of Tianjin, one of the four special municipalities of China. A unique sampling connector was used in place of the dental handpiece to collect water samples. Evaluation of retraction was accomplished using a retraction measurement device designed in accordance with the International Standard ISO 7494-2:2015(E). RESULTS: A total of 263 water samples were collected, and the highest concentration of bacteria [1.8 × 10(6) colony-forming units (CFU)/mL] was found in the handpiece group. Thirty (51.72%) water samples in the handpiece group and 21 (36.21%) in the air/water syringe groups were cultured, yielding colony counts of > 500 CFU/mL. Potential infectious agents, such as Bacillus cereus, Kocuria kristinae and Pseudomonas fluorescens, were isolated from the water samples. Thirty (51.72%) DCUs failed the retraction evaluation. There was a significant, positive correlation (P < 0.05) between the concentration of bacteria in the water sample and the retracted volume. CONCLUSION: It is of paramount importance to increase compliance with the standards for controlling DUWL contamination. Routine microbial monitoring and evaluation of retraction are necessary to provide high-quality water for use in dental treatment.