Objective To compare the resistance of phage Phi-X174 and Staphylococcus albus to ultraviolet light in aerosol state, and to explore the possibility of phage Phi-X174 as an indicator microorganism for the evaluation of the disinfection effect of air viruses. Methods The reproducibility of the killing rates of two microorganisms by a UV disinfection equipment at different disinfection times were tested, and the resistance of two types of microbial aerosols to UV light was evaluated using D value as the indicator. Results 1.5 mL of phage suspension with a concentration of 2×108 pfu/mL was atomized, and the average concentration of phage in the air disinfection chamber was 3.59×106 pfu/m3, with an inter-group error rate of 8.13%; 2 mL of Staphylococcus albus suspension with a concentration of 8×106 cfu/mL was atomized, and the average concentration of bacteria in the air disinfection chamber was 7.10×105 cfu/m3, with an inter-group error rate of 10.14%. The average killing rates of phage Phi-X174 by ultraviolet disinfection equipment at 5, 10, and 15 min were 65.30%, 86.89%, and 93.46%, respectively. The average killing rates of Staphylococcus albus at 10, 15, and 20 min were 74.87%, 85.21%, and 94.92%, respectively. Conclusion The D value of phage Phi-X174 is between 10 and 15 min, and the D value of Staphylococcus albus is between 15 and 20 min. Staphylococcus albus has a higher resistance to the UV disinfection equipment than phage Phi-X174 in aerosol state.
Objective To observe the disinfection effect of two disinfectants on the air conditioning exhaust pipe and medical cabin environment of ambulance. Methods Simulated field disinfection test was used to observe the disinfection effect of spray on the air conditioning ventilation pipe and medical cabin environment of ambulance. Results The spray of hydrogen peroxide disinfectant with a concentration of 75 g/L or hypochlorite disinfectant with available chlorine of 200 mg/L was generated by aerosol sprayer to disinfect hermetically for 30 min in the air conditioning ventilation pipe and medical cabin environment of ambulance. The killing rate of Staphylococcus aureus and Escherichia coli on stainless steel carrier by hydrogen peroxide disinfectant spray reached 99.99%; The killing rate of Staphylococcus aureus and Escherichia coli on stainless steel carrier by hypochlorite disinfectant spray was about 95%. Conclusion Hydrogen peroxide disinfectant spray has a good disinfection effect on the air conditioning pipes and medical cabin environment of ambulance, and the disinfection effect of hypochlorite disinfectant spray is lower than that of hydrogen peroxide disinfectant.
Objective To investigate the effect of erythrosine-mediated photodynamic inactivation (PDI) on influenza A virus. Methods Cell culture method was used to observe the effect of erythrosine-mediated PDI on influenza A H1N1, H3N2, and H9N2 viruses. Results 50 μmol/L erythrosine was illuminated with blue LED light for 5 min, and the average inactivation logarithmic values of influenza A H1N1, H3N2, and H9N2 were 5.44, 2.56, and 4.89 TCID50, respectively. The inactivation rates of erythrosine-mediated PDI on influenza A H1N1, H3N2, and H9N2 viruses on surfaces of different materials were ≥99.99%, ≥99.72%, and ≥99.97%, respectively. Conclusion The erythrosine-mediated PDI has a good inactivation effect on influenza A H1N1, H3N2, and H9N2 viruses.
Objective To observe the inactivation effect of an air disinfection machine on high concentration of viral aerosols in indoor air. Methods A microbial aerosol generator was used to generate high concentrations of viral aerosols of Escherichia coli phage MS2 with concentrations of 1.04×1011, 2.28×109, and 3.50×108 pfu/m3 in an aerosol chamber. A biological air sampler was used to collect the air in the room before and after disinfection to evaluate the inactivation effect of the air disinfection machine on viral aerosols. Results After the air disinfection machine running for 10 min, the killing rates of different concentrations of Escherichia coli MS2 aerosols were all >70.00%. After the air disinfector running for 30 min, the killing rates of different concentrations of Escherichia coli MS2 aerosols were all >99.99%. Conclusion This air disinfection machine has a good effect on inactivating high concentration of viral aerosols in enclosed spaces.
Objective To investigate the ultraviolet (UV) irradiation performance of a certain model of upper flat shot UV disinfector for air disinfection and its effect on the air disinfection in consulting rooms of hospital outpatient clinics. Methods From April to June 2023, consulting rooms of outpatient clinics in two hospitals in Shanghai were used as research sites, and a certain model of upper flat shot UV disinfector was installed to detect the UV irradiation intensity, indoor ozone concentration and air microorganism level at different sites during running. Results At a height of 2.6 m, the UV irradiation intensity decreased with the increase of distance; at a safe height of 2.1 m, the UV irradiation intensity was (0.2±0.2) μW/cm2. The ozone concentrations in the two consulting rooms were (0.071±0.010) mg/m3 and (0.081±0.011) mg/m3, respectively, and were not higher than that before running. The microorganism level of indoor air increased with the development of diagnosis and treatment activities, but the difference between the experimental group and the control group was not statistically significant. Conclusion The upper flat shot ultraviolet disinfector in this study is safe for human body during running, but its air disinfection effect needs to be improved.
Objective To observe the effect of three different disinfection methods on sustained contamination control of dental unit waterlines (DUWL). Methods Site sampling and quantitative bacterial detection were used to observe the effect of three disinfection methods on sustained contamination control of DUWL. Results Using chlorine-containing disinfectant with 500 mg/L of available chlorine once a week or with 20 mg/L of available chlorine once a day, it could maintain a total bacterial count of less than 100 cfu/mL in water from triple syringes and high-speed handpieces for 24 consecutive weeks. Using iodinated resin with 6 mg/L of available iodine for continuous exposure, it could maintain a total bacterial count of less than 100 cfu/mL for 1 to 24 weeks in water from triple syringes and 4 to 24 weeks in water from high-speed handpieces. Conclusion All three disinfection methods can make the water quality of DUWL meet the drinking water standard, and iodinated resin has more superiority.
Objective To understand the performance of Class II biological safety cabinets and its influencing factors in medical and health institutions in Beijing, and to provide reference for implementing refined management. Methods The instrument testing method was used to detect and analyze the performance indicators of Class Ⅱ biological safety cabinets in 39 medical and health institutions in Beijing. Results A total of 309 domestic and imported biological safety cabinets were tested, with a comprehensive qualified rate of 61.2%. The performance indicators of domestic and imported products were basically the same. The comprehensive qualified rate of A2 type biological safety cabinets with a service life of less than 10 years was relatively high. The main factors affecting the qualified rate of biological safety cabinets were the lack of performance testing equipment, insufficient professional personnel inspections, and the absence of professional testing institutions for annual inspections. Conclusions The comprehensive qualified rate of domestic and imported biological safety cabinets in medical and health institutions in Beijing is comparable, and the configuration of domestic biological safety cabinets should be increased. Therefore, it is necessary to strengthen the supervision and monitoring of biological safety cabinets and improve their safety protection performance.
Objective To evaluate the effect of wearing portable hand sanitizer on the hand hygiene compliance of medical staff in intensive care unit (ICU). Methods A before-after control intervention study was conducted, in which 32 medical staff in ICU were equipped with 60 mL vial of portable hand sanitizer. The concealed observation method was used to observe the surveillance video of ICU, random hand sampling method was used to determine the total number of bacterial colonies and ATP bioluminescence in hands, and questionnaire survey was used to evaluate the hand hygiene compliance and satisfaction before and after the intervention. Results The survey found that the overall compliance rate of hand hygiene increased from 54.26% before the intervention to 78.91% after the intervention, and the difference was statistically significant (P<0.05). The consumption of hand hygiene products also increased significantly after the intervention, with the estimated number of hand hygiene times per bed-day increased from 28.71 times before the intervention to 45.94 times after the intervention. The qualified rates of colony count and ATP bioluminescence detection in medical staff’s hands in random sampling were high, indicating that there was no significant change in the correctness of hand hygiene compared to that before the intervention (P>0.05). The questionnaire survey showed that medical staff were satisfied with the portable hand sanitizer and believed that using the portable hand sanitizer could increase hand hygiene compliance. Conclusion Portable hand sanitizer can effectively improve the hand hygiene compliance of medical staff in ICU.
Objective To analyze the distribution characteristics of pathogens and the changes of drug resistance rate, and to provide references for rational clinical use of drug and treatment. Methods Non-repetitive strains of bacterial culture were collected in department of pediatric surgery from 2019 to 2023 and analyzed retrospectively. Results A total of 2 188 pathogens were detected, including 1 527 gram-negative bacteria(69.78%) and 609 Gram-positive bacteria(27.83%). The top four pathogens were Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella pneumoniae. Peritoneal and soft tissue pus accounted for 79.52% and 5.90% respectively among all specimens. The resistance rate of E. coli to ceftriaxone showed an increasing trend(P<0.05). The resistance rate of S. aureus to penicillin ranged from 81.8% to 100%, that of erythromycin and clindamycin fluctuated between 51.0% and 70.8%. Conclusion Gram negative bacilli were the main strains isolated from pediatric surgery in our hospital, which are mainly detected in abdominal pus and urine samples, while S. aureus is mainly detected in soft tissue pus, orthopedic pus, and venous blood. The drug resistance of pathogens should be monitored and analyzed regularly, and the indication of antibiotic application should be strictly enforced to prevent and slow down the generation of drug-resistant bacteria.
Objective To understand the current situation of occupational exposure protection for hospital nursing staff and to provide a basis for formulating occupational exposure protection measures. Methods A questionnaire survey was conducted to investigate and analyze the current status of occupational exposure protection among nursing staff in 9 tertiary hospitals in Beijing. Results A total of 958 on-the-job nursing staff were surveyed, and 385 nursing staff who had experienced occupational exposure accounted for 40.19% of the total surveyed population. The awareness and implementation rates of standard prevention among nursing staff were 92.28% and 88.41%, respectively. 23.38% of hospitals did not have safe injection equipment. 96.36% of nursing staff had received occupational exposure training, and most respondents believed that it was necessary to strengthen occupational exposure training for newly hired nursing staff. Conclusion Nursing staff in large hospitals in Beijing have a high awareness of standard prevention measures. However, some hospitals lack safe injection equipment and should establish compensation mechanisms for occupational exposure.
Objective To investigate the disinfection quality of a level-A tertiary hospital in Tongling city, in order to provide a basis for better control of nosocomial infection. Methods A retrospective study was conducted to analyze the disinfection quality monitoring data of a level-A tertiary hospital in Tongling City from 2019 to 2022. Results A total of 2 153 samples were collected from 2019 to 2022, of which 2 093 samples were qualified, with a qualified rate of 97.21%, and there was a statistically significant difference in the qualified rate of disinfection effect among difference years (χ2=10.84, P<0.05); The lowest qualified rate was hands of medical staff, with statistically significant difference between different items (χ2=115.87, P<0.001); There were statistically significant differences in hand hygiene and indoor air monitoring between different years (χ2=15.48, P<0.001; χ2=22.06, P<0.001). Conclusion From 2019 to 2022, the disinfection quality monitoring effect of a level-A tertiary hospital in Tongling was good, and targeted measures should be taken for hands of medical staff with low qualified rate.
Objective To predict the incidence of nosocomial infection in hospital intensive care unit (ICU) of tropical region, and to provide scientific basis for the prevention and control of nosocomial infection. Methods Multivariate analysis method was used to construct a prediction model for nosocomial infection in ICU of a comprehensive hospital in Haikou City, and the fitting and predictive performances were evaluated. Results The average absolute errors for predicted values of ARIMA model and grey prediction model were 14.56% and 16.39%, respectively. The fitting and predictive performance of ARIMA model was better than that of grey prediction model. Conclusion The ARIMA model can better predict the risk of nosocomial infections in ICU, and can provide reference for overall monitoring and management of nosocomial infections.
Objective To understand the characteristics and drug resistance of Salmonella typhimurium infection in children. Methods Through retrospective analysis and drug sensitivity testing, the clinical data and drug sensitivity test results of hospitalized children with Salmonella typhimurium infection in pediatric department of a hospital were statistically analyzed. Results Among the 105 pediatric patients with Salmonella typhimurium infection included in the analysis, there were 30 cases, 24 cases, 26 cases, 10 cases and 15 cases respectively from 2017 to 2021, showing a decreasing trend year by year. The affected population was mainly children under 3 years old, with 96 cases, accounting for 91.43% of the total number of cases. The Salmonella typhimurium detected in the submitted samples from pediatric patients was sensitive to imipenem and ertapenem, with low resistance rates to levofloxacin, ceftriaxone, piperacillin/tazobactam, and amoxicillin/clavulanate potassium. It had a high resistance rate to compound sulfamethoxazole, amikacin, cefuroxime, etc. Conclusion Children infected with Salmonella typhimurium in Lishui district are mostly infants and young children aged 0 to 3 years old. Clinically isolated strains are sensitive to most commonly used antibiotics, and antibiotics can be selected based on drug sensitivity tests.
Objective To understand the current situation of newly built nucleic acid testing laboratories in Shaanxi province, and to analyze the existing problems and propose improvement measures. Methods Through on-site inspection and testing methods, 37 nucleic acid testing laboratories in Shaanxi province were surveyed and analyzed. Results The layout of the newly built nucleic acid testing laboratories in this survey was reasonable and could meet the basic requirements of nucleic acid testing experiments. The investigation found that construction companies and low-level hospitals had some problems, such as lack of understanding of the requirements for nucleic acid testing laboratories, insufficient exhaust air volume, unreasonable static pressure gradient, and blind selection of Class Ⅱ B2 biosafety cabinets. Conclusion It is recommended that nucleic acid testing laboratories should implement regionalized management, install dedicated exhaust fans in each work area, maintain a reasonable static pressure gradient, and choose Class Ⅱ A2 biosafety cabinets.
