Objective To evaluate the protective efficacy of commonly used medical protective equipment against pulsed ultraviolet light at (20±0.5) Hz. Methods According to the method of Threshold Values and Biological Contact Index (2021 Edition)，the test protective equipment was placed over the light-receiving surface of the detection probe. The ultraviolet irradiance was measured at distances of 20, 50 and 100 cm from the pulsed ultraviolet disinfection device, and the effective irradiance and the maximum safe exposure time were calculated. Results At distances of 20, 50 and 100 cm from the pulsed ultraviolet disinfection device, four types of white coats can completely block pulsed ultraviolet light. At a distance of 20 cm from the pulsed ultraviolet disinfection device, the penetration rates of pulsed ultraviolet light through protective suits and isolation gowns were 1.25% and 3.75%, respectively. None of the seven key protective items can completely block pulsed ultraviolet light. At a distance of 50 cm from the pulsed ultraviolet disinfection device, N95 masks, disposable medical gloves, and curtains could completely blockpulsed ultraviolet light. At a distance of 100 cm from the pulsed ultraviolet disinfection device, N95 masks, surgical masks, boot covers, disposable medical gloves, and curtains could completely block pulsed ultraviolet light. Conclusion In practical applications, protective equipment can be correctly selected based on the penetration rate and the longest exposure time of pulsed ultraviolet light for different materials.
Objective To evaluate whether the application of a sterile cold spray after standard skin disinfection increases local microbial load or the risk of exogenous microbial contamination. Methods For contamination detection of the sterile cold spray at different times after opening, three groups were established: sterile cold spray group, air exposure group, and negative control group. Bacterial culture and counting were performed on the day of opening and 6 days after opening. For dynamic monitoring of environmental microorganisms and particles after spraying, a blank group, an airflow disturbance group, and a sterile cold spray group were established. Airborne bacteria, settling bacteria, surface microorganisms, and the number of airborne particles ≥0.5 µm were detected before spraying and at 2, 5, 10, 20, and 30 s after spraying. Additional experiments included the killing effect on indicator bacteria, inhibition of biofilm formation, ex vivo Bama pig skin model test, and a prospective self-controlled human trial. Results No bacterial growth was observed in the sterile cold spray at any time after opening. During spraying, the number of airborne particles ≥0.5 µm transiently increased but returned to baseline within 30 s. No significant differences were found in airborne bacteria, settling bacteria, or environmental surface microorganisms (P>0.05). The log kill values of the cold spray against three tested bacterial species ranged from 1.09 to 1.33, and the inhibition rates of biofilm formation ranged from 36.4% to 39.7%. No culturable microorganisms were detected in the ex vivo skin model. In the human trial, the distribution of skin microbial load in the standard skin disinfection group was equivalent to that in the group receiving standard skin disinfection followed by sterile cold spray. Conclusion The application of sterile cold spray after standard skin disinfection does not increase local microbial load nor introduce exogenous microbial contamination.
Objective To evaluate the contamination level of disinfection by-products (DBPs) from sodium hypochlorite disinfection in drinking water in Nanchong City and the potential health risks to the population. Methods From 2023 to 2024, a total of 382 drinking water samples disinfected with sodium hypochlorite were collected in Nanchong City. Seven DBPs, namely dibromochloromethane (DBCM), bromodichloromethane (BDCM), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), trichloromethane (TCM), tribromomethane (TBM), and trihalomethanes (THM), were detected in the water samples, and health risk assessments were performed. Results The qualification rate for all seven DBPs in drinking water in Nanchong City was 100%. TCM had the highest detection rate (82.46%). In the carcinogenic risk assessment, the carcinogenic risk of BDCM was higher than that of TCM (P<0.05), and the carcinogenic risk (CR) values for both exceeded 1×10-6, indicating a certain level of health risk. In the non-carcinogenic risk assessment, the hazard quotient (HQ) values for TCM and BDCM were both <1, suggesting low non-carcinogenic risk. Both carcinogenic and non-carcinogenic risks were higher in females than those in males. Stratified analysis showed that the concentrations and health risks of BDCM and DCAA in 2024 were higher than those in 2023 (P<0.05). The concentrations and health risks of DCAA and TCAA in urban drinking water were higher than those in rural areas (P<0.05). Drinking water sourced from reservoirs had higher TCM concentrations and health risks than that from rivers (P<0.05). Significant differences in the concentrations and health risks of TCM, BDCM, and DCAA were observed among different water sample types (P<0.05). Conclusion Attention should be paid to the carcinogenic risks of TCM and BDCM in drinking water disinfected with sodium hypochlorite.
Objective To investigate the contamination status of dental unit waterlines (DUWLs) and to compare the effects of two culture media and three inoculation methods on bacterial culture results of dental treatment water. Methods A total of 128 water samples were collected from four outlets (three-way syringe, handpiece, scaler, and cup filler) of 32 DUWLs. The samples were inoculated using three methods (membrane filtration, pour plate, and spread plate) onto R2A agar or routine nutrient agar for parallel culture. The differences in bacterial colony counts between the two media and among the three inoculation methods were compared. The contamination levels of the four outlets and the predominant bacterial species were also analyzed. Results Bacterial counts detected by all three inoculation methods using R2A agar were significantly higher than those using routine nutrient agar (P<0.01). However, no significant difference was observed among the three inoculation methods when the same medium was used. Among the four outlets, the scaler and cup filler showed higher contamination levels. The predominant contaminating bacterial species included Sphingomonas paucimobilis, Delftia acidovorans,and Brevundimonas diminuta. The consistency between using≤500 cfu/mL (R2A agar) and≤100 cfu/mL (nutrient agar) as the criteria for DUWL water quality compliance was poor. Conclusion R2A agar is more sensitive than routine nutrient agar in reflecting DUWL contamination, and the membrane filtration method offers higher accuracy for bacterial enumeration.
Objective To explore the removal effect of a new type of biofilm cleaning agent on artificial Pseudomonas aeruginosa biofilms and to provide a reference for establishing a biofilm removal method for flexible endoscopes. Methods Simulated endoscope models and flexible endoscope samples with biofilms were used as test objects. The manual cleaning tank and automatic perfusion pump cleaning method for flexible endoscopes was adopted. The experimental groupused the new biofilm cleaning agent, while the control groupused the multi-enzyme cleaning agent. The biofilm removal ability of the two cleaning agents on the simulated models and flexible endoscopes was evaluated through bacterial count and ATP bioluminescence detection. Results Compared with the multi-enzyme cleaning agent group, the biofilm removal rates in the new biofilm cleaning agent group detected by bacterial culture method and ATP bioluminescence method were significantly increased (P < 0.05), which were 50.68% vs 99.95% and 53.93% vs 99.65%, respectively. Conclusion The new biofilm cleaning agent is significantly superior to the conventional multi-enzyme cleaning agent in reducing the number of bacteria and removing the structural integrity of biofilms.
Objective To analyze the surface cleanliness of dental units and the surface of the surrounding environmental objects in the dental clinic of a hospital, and to provide theoretical basis for formulating and optimizing relevant intervention measures. Methods The ATP bioluminescence detection method was used to sample the surfaces of the dental unit and surrounding objects during before and after intervention measures. Results The overall pass rate of the pre-intervention group was 29.3%, with a median RLU value in the sputum and accessory box areas could reach 234.50. The overall pass rate of the post-intervention group (64.3%) was significantly higher than that of the pre-intervention group, and the median values of RLU detection decreased significantly. Conclusion Sufficient attention should be paid to the disinfection of dental units and surrounding surfaces in dental clinics.
Objective To investigate the current situation regarding the reprocessing of loaners and implants in hospital Central Sterile Supply Departments(CSSD) across hospitals in China and to provide scientific basis for the implementation of industry standards. Methods A structured questionnaire was administered to 1 688 hospitals to investigate the management system construction, informatization level and current reprocessing status of loaners and implants in their CSSDs. Results 82.29% had fully realized centralized management, 99.23% had established the management system for loaners and implants, while 63.57% included these items in their information management systems. Specialized positions with relatively fixed personnel were set up in 68.54% of hospitals, and 64.45% could deliver loaners and implants to the CSSD before 15:00 on the day prior to surgery. Suppliers provided timely instructions for cleaning, disinfection, packaging, and sterilization in 66.05% of those cases. Lists including all loaners and implants were provided by 57.17% of suppliers.59.30% of CSSDs conducted the first sterilization effectiveness tests. However, 21.74% of CSSDs did not meet the requirements specified in the instructions. 88.86% of Postoperative loaners were returned to suppliers after CSSD reprocessing.The implementation rates of information management, specialized position settings, and sterilization effectiveness tests in tertiary hospitals were significantly higher than those in secondary hospitals (P<0.05). Conclusion Central management of loaners and implants is prevalent in Chinese CSSDs. However, there are still shortcomings in information construction and the implementation of specialized positions, as well as problems such as insufficient cooperation from suppliers and non-standard sterilization operations. These issues need to be optimized from aspects such as system implementation, supplier management, and sterilization technology monitoring to ensure medical quality and surgical safety.
Objective To investigate the current situation of the cleaning, disinfection, usage and damage of digestive tract manometry catheters in tertiary medical institutions in Wuhan, and to provide a theoretical basis and data support for standardizing the decontamination process and strengthening catheter maintenance. Methods A statistical survey was conducted among 76 tertiary medical institutions in Wuhan. The survey covered the implementation status of digestive tract manometry technology, the personnel and locations for cleaning and disinfecting the catheters, the cleaning and disinfection processes and methods, whether regular biological monitoring was performed, and the forms and causes of catheter damage. Results Among the 76 surveyed hospitals, 16 (21.05%) had implemented gastrointestinal manometry. Of these, 14 institutions performed both esophageal and anorectal manometry, while 2 conducted anorectal manometry only. Regarding the usage frequency of esophageal manometry catheters, 64.29% of the hospitals reported fewer than 5 uses per catheter per month, and 21.42% reported more than 20 uses. For anorectal manometry catheters, 56.25% of hospitals reported fewer than 5 uses per catheter per month, and 31.25% reported more than 20 uses. Only 31.25% of the hospitals had established dedicated cleaning and disinfection procedures and standards for the manometry catheters. Damage to the catheters had occurred in 75% of the hospitals, with the primary forms of damage being catheter channel blockage, leakage at various connection points, balloon air leakage, and balloon detachment. Conclusion The current state of cleaning, disinfection, usage, and maintenance of digestive tract manometry catheters in tertiary medical institutions in Wuhan is suboptimal. The most common form of catheter damage is channel blockage. The main contributing factors are inadequate cleaning and disinfection protocols, as well as non-standardized procedures for catheter usage and maintenance.
Objective To investigate the spatial distribution and temporal evolution of pathogenic aerosols in indoor environments, so as to providing a basis for developing ventilation and disinfection strategies and intelligently controlling indoor air quality. Methods Taking a typical classroom as an example, a rectangular structure of 150 m3 was constructed. Considering the particle size of pathogenic aerosols and the balance between gravity and drag forces, Navier-Stokes (NS) equations for aerosol diffusion and particle transport equations were established. The diffusion processes of pathogenic aerosols under natural ventilation and air-conditioning (AC) supply modes were simulated and solved using the finite element method to deduce the spatiotemporal evolution of the aerosols. Results Under no air supply, aerosols rapidly settled under gravity within 1.5 m of the infected individual, with an adhesion rate exceeding 45%. Under natural ventilation, aerosols diffused toward doors and windows, and the adhesion rate decreased to below 25% after 17 s. Under AC supply with doors and windows open, the ventilation mode significantly influenced the diffusion trajectory. In the lower-level front-and-rear air supply mode, aerosols were expelled outdoors through directional airflow, and the adhesion rate decreased to 5% after 51 s. Conclusion The lower-level front-and-rear air supply mode is the optimal ventilation strategy for reducing aerosol infection risk in classrooms. Aerosols tend to undergo secondary adhesion on the backs of seats and human surfaces.
Objective To analyze the occurrence of occupational exposure among staff in a cardiovascular specialty hospital and to explore the risk factors for bloodborne occupational exposure. Methods A retrospective survey was conducted. All staff members working at the hospital from 2020 to 2024 were included in the occupational exposure monitoring program. The incidence of bloodborne occupational exposure was calculated, and risk factors were analyzed, including basic characteristics (occupation, gender, years of service, age, etc.), exposure location, exposure route, source of exposure, and participation in occupational exposure training/drills. Results A total of 4,263 cumulative person-times were monitored from 2020 to 2024, and 256 cases of bloodborne occupational exposure occurred, with an overall incidence of 6.01%. Univariate analysis showed that the exposure rates differed significantly among groups based on age, occupation, years of service, and participation in training and drills (P<0.05), but no significant difference was observed for gender (P>0.05). Multivariate logistic regression analysis revealed that, compared with trainees, nurses (OR=1.866), physicians (OR=1.780), and cleaning and nursing assistants (OR=2.091) had significantly higher risks of occupational exposure. Staff with <11 years of service had a higher risk than those with >20 years of service (OR=1.895). Those who did not participate in training had 1.939 times the risk of those who did (OR=1.939), and those who did not participate in drills had 2.856 times the risk of those who did (OR=2.856). Conclusion Risk factors for occupational exposure include clearly identified high-risk positions, shorter years of service, and participation in training and drills, but do not include demographic characteristics such as gender or age.
Objective To evaluate the effectiveness of failure mode and effect analysis (FMEA) in improving the cleaning quality and damage rate of medical devices based on cumulative Meta-analysis. Methods Two researchers independently searched PubMed, Web of Science, The Cochrane Library, Embase, CNKI, Wanfang Database, China Biomedical Literature Service Database, and VIP databases for published studies on FMEA in improving the quality of cleaning and damage rate of medical devices from the computer, with a timeframe of from database construction to 18 September 2024. The included studies were evaluated for quality using the Class Trial Study Quality Assessment tool, and cumulative Meta-analysis and TSA analysis of the included studies were applied with R software and trial sequential analysis (TSA) software. Results A total of 19 papers were included, with 18 papers using the rate of qualified instrument cleaning as the outcome indicator, with a total of 299 213 study subjects; there were 8 papers using the rate of damaged instruments as the outcome indicator in this 19 papers, with a total of 220 274 study subjects. The results of cumulative Meta-analysis with sample size as the cumulative factor showed that the final cumulative effect size of the rate of qualified instrument cleaning was (OR= 0.19, 95% CI 0.15-0.25), and the final cumulative effect size of the instrument damage rate was (OR=0.14, 95% CI 0.06-0.31); the results of the TSA showed that the required information size (RIS) for the instrument cleaning compliance rate was 129 096, and the RIS for the instrument damage rate was=141 767. The included sample sizes had exceeded the RIS and reached the required sample size for cumulative Meta-analysis; the results of the Egger’s test set for the qualified rate of instrument cleaning were: t=1.93, P=0.072 (P>0.05), and the funnel plots were basically symmetrical, suggesting that there was no significant publication bias. Conclusion Compared with the conventional management programme, FMEA can effectively improve the quality of medical device cleaning and damage rate, and the results of the cumulative Meta-analysis have the authenticity and reliability. There is no need for more clinical studies to confirm the effectiveness of FMEA in improving the quality of medical device cleaning and damage rate.
Objective To investigate the disinfection quality of medical institutions in Chaoyang District of Beijing, and to provide scientific basis for improving the disinfection quality. Methods According to the relevant standards, specimen sampling and lab testing were performed on the surface of the objects, hands of medical staff, hospital wastewater and other items in the medical institutions at all levels in Chaoyang District of Beijing. The results were sorted and analyzed through using SPSS 22.0. Results A total of 10 290 samples were collected from 2018 to 2024, of which 10 090 were qualified. The total qualified rate was 98.06%, and showed a linear upward trend (trend χ2 =7.404, P=0.007). Among the different monitoring items, the qualified rate of hospital wastewater (91.56%) and medical staff’s hands (94.91%) were the lowest, There was statistical difference among the qualified rates of disinfection of different monitoring items (χ2=330.849, P<0.001). Among the different quarters, the qualified rate in the third quarter was the lowest (97.32%). Conclusion The qualified rates of disinfection in medical institutions are generally increasing in Chaoyang District of Beijing. In addition, attention should be paid to the disinfection quality of wastewater and hands of medical staff, as well as the disinfection quality in the third quarter.
