Changes of air pollutants and simulation of a heavy pollution process during COVID-19 in Shenyang.

During COVID-19, Shenyang implemented strict household isolation measures, resulting in a sharp reduction in anthropogenic emission sources, providing an opportunity to explore the impact of human activities on air pollution. The period from January to April of 2020 was divided into normal period, blockade period and resumption period. Combined with meteorological and pollutant data, mathematical statistics and spatial analysis methods were used to compare with the same period of 2015-2019. The results showed that PM2.5, PM10, NO2 and O3 increased by 32.6%, 13.2%, 4.65% and 22.7% in the normal period, among which the western area changed significantly. During the blockade period, the concentration of pollutants decreased by 35.79%, 35.87%, 32.45% and -4.84%, of which the central area changed significantly. During the resumption period, the concentration of pollutants increased by 21.8%, 8.7%, 5.7% and -6.3%, and the area with the largest change was located in the western. During the blockade period, a heavy pollution occurred with PM2.5 as the main pollutant. The WRF-Chem model and the HYSPLIT model were used to reproduce the pollution occurrence process. The result showed that winds circulated as zonal winds during the pollution process at high altitudes. These winds were controlled by straight westerly and weak northwesterly airflows in front of the high pressure, and the ground was located behind the warm low pressure. Weather conditions were relatively stable. Thus, high temperatures (average > 10 ℃), high humidity (40%-60%) and slow wind (2 m/s) conditions prevailed for a long time in the Shenyang area. The unfavorable meteorological conditions lead to the occurrence of pollution. The backward trajectory showed that the potential source areas were concentrated in the urban agglomeration around Shenyang, and sporadic contributions came from North Korea.

Establishment and practice of grid system for prevention and control of nosocomial infection

OBJECTIVE To promote the working patterns for prevention and control of nosocomial infection in units and departments, alter the management mode from 'passive inspection' to 'active self-examination and continuous improvement', and build a network for prevention and control of nosocomial infection. METHODS The grid system for prevention and control of nosocomial infection was established based on the concept of urban management with the support of informatization in 2019 and was taken into practice. The grid system for prevention and control of nosocomial infection was established through a series of work, including division of infection control grid, settlement of grid members and optimization of quality assessment, and it was optimized and improved via practice. RESULTS The grid system for prevention and control of nosocomial infection boosted the capability of active self-examination and continuous improvement of the units and departments, consolidate the network, raise the efficiency of management of nosocomial infection and promote the supervision of nosocomial infection. CONCLUSION The grid system for prevention and control of nosocomial infection plays an important role during the prevention and control of COVID-19 epidemic. The concept of 'active self-examination and continuous improvement' is fulfilled and the prevention and control measures are rigidly implemented in the units and departments, and zero infection of healthcare workers and patients is achieved during the prevention and control of COVID-19 epidemic.

Risk assessment and control of nosocomial infection in fever clinic of general hospital

OBJECTIVE: To establish the risk assessment system of nosocomial infection in fever outpatient department of general hospital, and to realize the accurate risk control to reduce the occurrence of nosocomial infection in doctors and patients. METHODS: Based on the healthcare failure mode and effect analysis(HFMEA), the quantitative risk assessment was carried out in the fever clinic in a general hospital to establish the risk system. Regular evaluation was performed to find out the key risks that should be controlled. Accurate measures were implemented and re-evaluated were performed and then adjusted. The cycle of the process will be conducted in a row to get the improvement. RESULTS: The risk assessment system of fever clinic included the building layout and facilities whether meet the requirements of the infectious diseases prevention and control, whether the system of prevention and control of hospital infection was complete, whether the personnel management and protection was proper, whether the item management, environment cleaning and disinfection were legal compliance and whether the medical process can meet the demands of the hospital infection prevention and control, etc. At the beginning of COVID-19 epidemic, the first round of risk assessment was carried out on fever clinics, and 44 risk points were identified, among which 8 risk points needed to be controlled by key intervention measures. Targeted improvement measures were performed, then the second round of risk assessment was conducted to evaluate the control effect, which showed good risk control effect. CONCLUSION: The quantitative risk assessment system established based on HFMEA was used to regularly evaluate the risk to find out the potential nosocomial infection, to timely detect the potential nosocomial infection risk in fever outpatient clinics, to achieve accurate prevention and control of nosocomial infection in fever outpatient clinics, which can greatly reduce the risk of cross-infection of infectious diseases in hospitals and nip it in the bud.

A Semi-Quantitative Risk Assessment and Management Strategies on COVID-19 Infection to Outpatient Health Care Workers in the Post-Pandemic Period.

BACKGROUND: In the pandemic of COVID-19, due to asymptomatic patients and high personnel fluidity in outpatient clinics, health care workers (HCWs) in outpatients were facing severe threat from infection. There is an urgent need for a risk assessment to recognize and prevent infection risks. PURPOSE: To establish a semi-quantitative risk assessment model on COVID-19 infections for HCWs in outpatient departments, and apply it to practices. Further to provide infection risk management strategies to reduce infection threats in the post-pandemic of COVID-19. METHODS: We used the method of Brainstorm, Literature study and Analytic Hierarchy Process (AHP) for risk factors selection and model construction, we also created corresponding indicators for each risk factors, in order to collect data in assessment practice. RESULTS: Eighteen risk factors were recognized and selected for model construction, by scatter plot, these risk factors had been classified into four parts, spanned the scopes of diagnosis and treatment, environment, personal protection and emergency handling, with specific management suggestions provided. In the practice, outpatient clinics were divided into three risk levels, 5 clinics in high risk level, 9 in medium risk level and 11 in low risk level. CONCLUSION: A proper comprehensive risk assessment model for COVID-19 infections has been successfully established. With the model, the ability to COVID-19 prevention in outpatients can be easily evaluated. The strategies on disinfection, surveillance and personal protection were also valuable references in the post-pandemic of COVID-19.