Identification of key mutations responsible for the enhancement of receptor-binding affinity and immune escape of SARS-CoV-2 Omicron variant.

The Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has raised concerns worldwide due to its enhanced transmissibility and immune escapability. The first dominant Omicron BA.1 subvariant harbors more than 30 mutations in the spike protein from the prototype virus, of which 15 mutations are located at the receptor binding domain (RBD). These mutations in the RBD region attracted significant attention, which potentially enhance the binding of the receptor human angiotensin-converting enzyme 2 (hACE2) and decrease the potency of neutralizing antibodies/nanobodies. This study applied the molecular dynamics simulations combined with the molecular mechanics-generalized Born surface area (MMGBSA) method, to investigate the molecular mechanism behind the impact of the mutations acquired by Omicron on the binding affinity between RBD and hACE2. Our results indicate that five key mutations, i.e., N440K, T478K, E484A, Q493R, and G496S, contributed significantly to the enhancement of the binding affinity by increasing the electrostatic interactions of the RBD-hACE2 complex. Moreover, fourteen neutralizing antibodies/nanobodies complexed with RBD were used to explore the effects of the mutations in Omicron RBD on their binding affinities. The calculation results indicate that the key mutations E484A and Y505H reduce the binding affinities to RBD for most of the studied neutralizing antibodies/nanobodies, mainly attributed to the elimination of the original favorable gas-phase electrostatic and hydrophobic interactions between them, respectively. Our results provide valuable information for developing effective vaccines and antibody/nanobody drugs.

American ginseng with different processing methods ameliorate immunosuppression induced by cyclophosphamide in mice via the MAPK signaling pathways.

This study aimed to clarify the effects of two processed forms of American ginseng (Panax quinquefolius L.) on immunosuppression caused by cyclophosphamide (CTX) in mice. In the CTX-induced immunosuppressive model, mice were given either steamed American ginseng (American ginseng red, AGR) or raw American ginseng (American ginseng soft branch, AGS) by intragastric administration. Serum and spleen tissues were collected, and the pathological changes in mice spleens were observed by conventional HE staining. The expression levels of cytokines were detected by ELISA, and the apoptosis of splenic cells was determined by western blotting. The results showed that AGR and AGS could relieve CTX-induced immunosuppression through the enhanced immune organ index, improved cell-mediated immune response, increased serum levels of cytokines (TNF-α, IFN-γ, and IL-2) and immunoglobulins (IgG, IgA, and IgM), as well as macrophage activities including carbon clearance and phagocytic index. AGR and AGS downregulated the expression of BAX and elevated the expression of Bcl-2, p-P38, p-JNK, and p-ERK in the spleens of CTX-injected animals. Compared to AGS, AGR significantly improved the number of CD4+CD8-T lymphocytes, the spleen index, and serum levels of IgA, IgG, TNF-α, and IFN-γ. The expression of the ERK/MAPK pathway was markedly increased. These findings support the hypothesis that AGR and AGS are effective immunomodulatory agents capable of preventing immune system hypofunction. Future research may investigate the exact mechanism to rule out any unforeseen effects of AGR and AGS.

The implementation of green supply chain management (GSCM) and environmental management system (EMS) practices and its impact on market competitiveness during COVID-19.

Despite great academic interest in global green supply chain management (GSCM) practices, its effectiveness for environmental management systems (EMS) and market competitiveness during COVID-19 remains untapped. Existing literature suggests that a fundamental link between GSCM, EMS, and market competitiveness is missing, as supply management is critical to maintain market competitiveness. To fill this gap in the literature, this study examines whether environmental management systems influence the link between GSCM practice and market competitiveness in China. We also propose the articulating role of big data analytics and artificial intelligence (BDA-AI) and environmental visibility toward these associations in the context of the COVID-19 pandemic. We evaluated the proposed model using regression-based structural equation modeling (SEM) with primary data (n = 330). This result provides empirical evidence of the impact of GSCM on EMS and market competitiveness. Moreover, the results show that the BDA-AI and the environmental visibility enhanced the positive relationship between GSCM-EMS and EMS and market competitiveness in China. Recent research shows that supply chain professionals, policymakers, managers, and researchers are turning to formal EMS, BDA-AI, and environmental visibility to help their organizations achieve the competitiveness that the market indicates they need.

Association Among Gender, Age, and Region in Taiwan's First Ten Thousand COVID-19 Cases: A Log-linear-model Analysis (preprint)

Objectives: We explore the association between age, gender, and region among Taiwan's 11290 local Covid-19 cases from January 22, 2020 to June 11, 2021. Methods: Using open data from Taiwan's CDC, we organize them into a three-dimensional contingency table. The groups are gender, age 0-29, 30-59, and 60+ years old, and two classifications for region: (1) 7 commonly-defined regions, (2) 12 groups separating Taipei, New Taipei, Keelung, Taoyuan, Hsinchu county, Miaoli county, and Hsinchu city. We adopt the log-linear model for statistical analysis and use the BIC for model selection. Results: The model with three pairwise interaction terms has the smallest BIC. In terms of interaction effects, there are more females than males among 30-59 (p<0.001), while more males than females among 60+ (p=0.028). Miaoli County has more male than female cases (p<0.001). Differences between 30-59 and 0-29 (baseline), and between 60+ and 0-29 are significant in Taipei (p=0.002 and p <0.001); similar age effects for New Taipei is observed; Miaoli County has significant difference between 60+ and 0-29 (p<0.001). All Taoyuan's interaction terms are not significant. The main effects of age, the differences between 30-59 and 0-29 (baseline), and between 60+ and 0-29, are both significant (p=0.002 and p=0.046). Conclusions: In the four regions with larger numbers of Covid-19 cases, the age and gender characteristics of the infected population are different, reflecting patterns of infection chains.

Delayed prosthetic seroma: a localized inflammatory response to COVID vaccination and infection?

We present a patient whom we believe developed a late abdominal mesh collection in response to COVID-19 mRNA vaccination booster and COVID-19 infection. A polypropylene mesh was placed during her right breast reconstruction operation 2 years ago where she underwent a right transverse abdominis rectus muscle (TRAM) free flap. She recovered uneventfully from this operation. This lady, though vaccinated, developed respiratory symptoms and tested positive for COVID-19 infection 3 days after her booster injection. She then noticed right-sided abdominal swelling 3 days after the onset of respiratory symptoms. She only presented 1 month later due to a 7-day history of pain at the site of abdominal swelling. A computed tomography scan confirmed the presence of a seroma, and she underwent ultrasound-guided percutaneous drainage. A COVID Antigen Rapid Test of the fluid returned positive, though the PCR swab returned negative. There have been no published reports of periprosthetic mesh seroma after COVID-19 vaccination or infection to date. We wanted to share our experience so that other surgeons may be aware of this potential presentation given the current ongoing pandemic. Level of evidence: Level V, risk/prognostic.

Nicotinamide n-Oxide Attenuates HSV-1-Induced Microglial Inflammation through Sirtuin-1/NF-κB Signaling.

HSV-1 is a typical neurotropic virus that infects the brain and causes keratitis, cold sores, and occasionally, acute herpes simplex encephalitis (HSE). The large amount of proinflammatory cytokines induced by HSV-1 infection is an important cause of neurotoxicity in the central nervous system (CNS). Microglia, as resident macrophages in CNS, are the first line of defense against neurotropic virus infection. Inhibiting the excessive production of inflammatory cytokines in overactivated microglia is a crucial strategy for the treatment of HSE. In the present study, we investigated the effect of nicotinamide n-oxide (NAMO), a metabolite mainly produced by gut microbe, on HSV-1-induced microglial inflammation and HSE. We found that NAMO significantly inhibits the production of cytokines induced by HSV-1 infection of microglia, such as IL-1ß, IL-6, and TNF-α. In addition, NAMO promotes the transition of microglia from the pro-inflammatory M1 type to the anti-inflammatory M2 type. More detailed studies revealed that NAMO enhances the expression of Sirtuin-1 and its deacetylase enzymatic activity, which in turn deacetylates the p65 subunit to inhibit NF-κB signaling, resulting in reduced inflammatory response and ameliorated HSE pathology. Therefore, Sirtuin-1/NF-κB axis may be promising therapeutic targets against HSV-1 infection-related diseases including HSE.

Effects of Dust Event Days on Influenza: Evidence from Arid Environments in Lanzhou

Airborne aerosol is believed to be an important pathway for infectious disease transmissions like COVID-19 and influenza. However, the effects of dust event days on influenza have been rarely explored, particularly in arid environments. This study explores the effects of ambient particulate matter (PM) and dust events on laboratory-confirmed influenza in a semi-arid city. A descriptive analysis of daily laboratory-confirmed influenza (influenza) cases, PM (PM10 and PM2.5), meteorological parameters, and dust events were conducted from 2014 to 2019 in Lanzhou, China. The case-crossover design combined with conditional Poisson regression models was used to estimate the lagging effects of PM and dust events on influenza. In addition, a hierarchical model was used to quantitatively evaluate the interactive effect of PM with ambient temperature and absolute humidity on influenza. We found that PM and dust events had a significant effect on influenza. The effects of PM10 and PM2.5 on influenza became stronger as the cumulative lag days increased. The greatest estimated relative risks (RRs) were 1.018 (1.011,1.024) and 1.061 (1.034,1.087), respectively. Compared with the non-dust days, the effects of dust events with duration ≥ 1 day and with duration ≥ 2 days on influenza were the strongest at lag0 day, with the estimated RRs of 1.245 (95% CI: 1.061–1.463) and 1.483 (95% CI: 1.232–1.784), respectively. Subgroup analysis showed that pre-school children and school-aged children were more sensitive to PM and dust events exposure. Besides, we also found that low humidity and temperature had an interaction with PM to aggravate the risk of influenza. In summary, ambient PM and dust events exposure may increase the risk of influenza, and the risk of influenza increases with the dust events duration. Therefore, more efforts from the government as well as individuals should be strengthened to reduce the effect of PM on influenza, particularly in cold and dry weather.

Current status of prevention and treatment of respiratory diseases in primary care in China: a cross-sectional study.

BACKGROUND: China launched its new round of health care reform to develop primary care in 2009, establishing 954,390 primary care institutions that employed over 10 million staff by 2019. However, some studies have shown that the prevention and management of respiratory diseases is inadequate in these institutions. METHODS: We conducted a cross-sectional survey of grassroots institutions throughout China between September and December 2020 based on the standardized Prevention and Treatment System and Capacity Building Project of Respiratory Diseases in primary care settings. The operation of the respiratory department in primary health care institutions was evaluated in terms of facilities, drugs, personnel and management of chronic diseases by means of questionnaires. Descriptive analyses were performed to calculate percentages and frequencies of key parameters. RESULTS: A total of 144 primary health care institutions were surveyed, including 51 in the east, 82 in the west, 9 in the central and 2 in the northeast. Approximately 60% of institutions had spirometers and pulse oximeters. The majority had short-acting bronchodilators, theophylline, systemic corticosteroids, antibiotics, and traditional Chinese medicine. More than half had at least one respiratory physician and operator for spirometry. Half of the institutions carried out screening of chronic obstructive pulmonary disease within the jurisdiction. The institutions in the east were superior to those in the west regarding the equipment, common drugs, medical staff, and management of respiratory diseases. CONCLUSIONS: The study reveals that the overall operation of the respiratory department in primary care settings needs to be further strengthened. It is crucial to provide adequate essential equipment, medical professionals, and medicines for proper diagnosis and treatment of chronic respiratory diseases, as well as improving the management of diseases.

Influence factors analysis of COVID-19 Prevention behavior of chinese Citizens: a path analysis based on the hypothetical model.

BACKGROUND: Under the outbreak of Coronavirus disease 2019 (COVID-19), a structural equation model was established to determine the causality of important factors that affect Chinese citizens' COVID-19 prevention behavior. METHODS: The survey in Qingdao covered several communities in 10 districts and used the method of cluster random sampling. The research instrument used in this study is a self-compiled Chinese version of the questionnaire. Of the 1215 questionnaires, 1188 were included in our analysis. We use the rank sum test, which is a non-parametric test, to test the influence of citizens'basic sociodemographic variables on prevention behavior, and the rank correlation test to analyze the influencing factors of prevention behavior. IBM AMOS 24.0 was used for path analysis, including estimating regression coefficients and evaluating the statistical fits of the structural model, to further explore the causal relationships between variables. RESULTS: The result showed that the score in the prevention behavior of all citizens is a median of 5 and a quartile spacing of 0.31. The final structural equation model showed that the external support for fighting the epidemic, the demand level of health information, the cognition of (COVID-19) and the negative emotions after the outbreak had direct effects on the COVID-19 prevention behavior, and that negative emotions and information needs served as mediating variables. CONCLUSIONS: The study provided a basis for relevant departments to further adopt epidemic prevention and control strategies.

RT-LAMP assay for rapid detection of the R203M mutation in SARS-CoV-2 Delta variant.

The highly infectious Delta variant strain of SARS-CoV-2 remains globally dominant and undermines COVID-19 vaccines. Rapid detection of the Delta variant is crucial for the identification and quarantine of infected individuals. In this study, our aim was to design and validate a genotyping RT-LAMP method to detect Delta variants specifically. R203M in the N gene of SARS-CoV-2 was chosen as the Delta variant-specific mutation for genotyping. To target the R203M-harboring region and the conserved sequence of the N gene, two sets of primers were designed, and a Cq (quantification cycle) ratio-based RT-LAMP for SARS-CoV-2 and R203M detection was developed by analyzing the significant discrepancy in amplification efficiency of the two sets of primers. We validated the RT-LAMP method on 498 clinical specimens in parallel with RT-qPCR, and 84 Delta variants from 198 positive samples were determined by sequencing. Compared with traditional RT-qPCR analyses, RT-LAMP appears to be 100% accurate in detecting SARS-CoV-2 clinical samples. RT-LAMP has a good ability to distinguish between Delta and non-Delta variants under a Cq ratio threshold of 1.80. Furthermore, the AUC (area under the curve) of this method was 1.00; the sensitivity, specificity and accuracy were all 100%. In summary, we have proposed a rapid, accurate and cost-effective RT-LAMP method to detect SARS-CoV-2 and Delta variants, which may facilitate the surveillance of COVID-19.

Travel changes and equitable access to urban parks in the post COVID-19 pandemic period: Evidence from Wuhan, China.

COVID-19 has spread worldwide, leading to a significant impact on daily life. Numerous studies have confirmed that people have changed their travel to urban green spaces during the COVID-19 pandemic. However, in China, where COVID-19 has been effectively controlled, how the travel behavior of visitors to urban parks has changed under different risk levels (RLs) of COVID-19 is unclear. Faced with these gaps, we took a highly developed city, Wuhan, as a case study and a questionnaire survey was conducted with 3276 respondents to analyze the changes in park visitors' travel behaviors under different COVID-19 RLs. Using a stated preference (SP) survey method, four RLs were assigned: new cases in other provinces (RL1), Hubei province (RL2), Wuhan (RL3), and in the district of the park (RL4). The results indicated that visitors reduced their willingness to visit urban parks, with 78.39%, 37.97%, and 13.34% of visitors remaining under RL2, RL3, and RL4, respectively. Furthermore, the service radius of urban parks also shrank from 4230 m under no new cases of COVID-19 to approximately 3000 m under RL3. A higher impact was found for visitors using public transport, those with a higher income and higher education, and female visitors. Based on the modified travel behaviors, the Gaussian-based two-step floating catchment area (2SFCA) method was used to evaluate the accessibility and the Gini coefficient was calculated to represent the equality of the urban parks. A higher RL led to lower accessibility and greater inequitable access. The results should help the government guide residents' travel behaviors after COVID-19.

Impacts of p97 on Proteome Changes in Human Cells during Coronaviral Replication.

Human coronavirus (HCoV) similar to other viruses rely on host cell machinery for both replication and to spread. The p97/VCP ATPase is associated with diverse pathways that may favor HCoV replication. In this study, we assessed the role of p97 and associated host responses in human lung cell line H1299 after HCoV-229E or HCoV-OC43 infection. Inhibition of p97 function by small molecule inhibitors shows antiviral activity, particularly at early stages of the virus life cycle, during virus uncoating and viral RNA replication. Importantly, p97 activity inhibition protects human cells against HCoV-induced cytopathic effects. The p97 knockdown also inhibits viral production in infected cells. Unbiased quantitative proteomics analyses reveal that HCoV-OC43 infection resulted in proteome changes enriched in cellular senescence and DNA repair during virus replication. Further analysis of protein changes between infected cells with control and p97 shRNA identifies cell cycle pathways for both HCoV-229E and HCoV-OC43 infection. Together, our data indicate a role for the essential host protein p97 in supporting HCoV replication, suggesting that p97 is a therapeutic target to treat HCoV infection.

Inflammation/coagulopathy/fibrinolysis: Dynamic indicators of COVID-19 progression in patients with moderate COVID-19 in Wenzhou, China.

BACKGROUND: The majority of the coronavirus disease 2019 (COVID-19) non-survivors meet the criteria for disseminated intravascular coagulation (DIC). Although timely monitoring of clotting hemorrhagic development during the natural course of COVID-19 is critical for understanding pathogenesis, diagnosis, and treatment of the disease, however, limited data are available on the dynamic processes of inflammation/coagulopathy/fibrinolysis (ICF). METHODS: We monitored the dynamic progression of ICF in patients with moderate COVID-19. Out of 694 COVID-19 inpatients from 10 hospitals in Wenzhou, China, we selected 293 adult patients without comorbidities. These patients were divided into different daily cohorts according to the COVID-19 onset-time. Furthermore, data of 223 COVID-19 patients with comorbidities and 22 critical cases were analyzed. Retrospective data were extracted from electronic medical records. RESULTS: The virus-induced damages to pre-hospitalization patients triggered two ICF fluctuations during the 14-day course of the disease. C-reactive protein (CRP), fibrinogen, and D-dimer levels increased and peaked at day 5 (D) 5 and D9 during the 1st and 2nd fluctuations, respectively. The ICF activities were higher during the 2nd fluctuation. Although 12-day medication returned high CRP concentrations to normal and blocked fibrinogen increase, the D-dimer levels remained high on days 17 ±â€¯2 and 23 ±â€¯2 days of the COVID-19 course. Notably, although the oxygenation index, prothrombin time and activated partial thromboplastin time were within the normal range in critical COVID-19 patients at administration, 86% of these patients had a D-dimer level > 500 µg/L. CONCLUSION: COVID-19 is linked with chronic DIC, which could be responsible for the progression of the disease. Understanding and monitoring ICF progression during COVID-19 can help clinicians in identifying the stage of the disease quickly and accurately and administering suitable treatment.

Investigation of potential safety hazards during medical waste disposal in SARS-CoV-2 testing laboratory.

This study aims to investigate the potential safety hazards and provide reference for improving the medical waste disposal procedure in SARS-CoV-2 testing laboratory. Our SARS-CoV-2 testing group detected the RNA residue on the surface of medical waste with Droplet Digital PCR, and held a meeting to discuss the risks in the laboratory medical waste disposal process. After effective autoclaving, SARS-CoV-2 contaminated on the surface of medical waste bags was killed, but the average concentration of viral RNA residues was still 0.85 copies/cm2. It would not pose a health risk, but might contaminate the laboratory and affect the test results. When the sterilized medical waste bags were transferred directly by the operators without hand disinfection, re-contamination would happen, which might cause the virus to leak out of the laboratory. Furthermore, we found that sterilization effect monitoring and cooperation among operators were also very important. In summary, we investigated and analyzed the potential safety hazards during the medical waste disposal process in SARS-CoV-2 testing laboratory, and provided reasonable suggestions to ensure the safety of medical waste disposal.

Clinical Characteristics and Factors Associated with Disease Progression of Mild to Moderate COVID-19 Patients in a Makeshift (Fangcang) Hospital: A Retrospective Cohort Study.

OBJECTIVE: Information regarding the epidemiology and clinical features of mild to moderate patients caused by COVID-19 in Fangcang Hospital is scarce. Through a retrospective cohort study, the clinical characteristics of COVID-19 patients in Dongxihu Fangcang shelter hospitals were analyzed, and the factors that affected the disease progression of COVID-19 patients were explored. METHODS: The clinical characteristics of 714 patients with COVID-19 were retrospectively analyzed at Dongxihu Fangcang Hospital between February 7 and March 8, 2020. We described the clinical characteristics and distribution of discharge or transfer times for each patient. According to the disease progression of COVID-19 patients, we divided all patients into Non-Deteriorated group and Deteriorated group. Furthermore, binary logistic regression was used for a single outcome and multiple response variables. RESULTS: We treated 789 patients with mild and moderate COVID-19, of which 714 were included in this study, which included 326 (45.66%) deteriorated patients and 388 (54.34%) non-deteriorated patients. The mean age of the study population was 48.16±12.44 years. Of all patients, 319 (44.7%) were men and 395 (55.3%) were women. The average length of the patient's stay was 16.08±5.13 days. The most common clinical feature on admission was fever (593 of 714, 83.05%). It is worth noting that 80 (11.20%) of the 714 patients were asymptomatic from exposure to admission. Multivariate logistic regression analysis showed that gender, age, diabetes, respiratory system disease, fever, dyspnea, and nasal congestion were risk factors associated with deterioration in cases with COVID-19 patients, and asymptomatic (OR: 0.058; 95% CI: 0.022-0.155; P<0.001) was the protective factor for deterioration of COVID-19 patients. CONCLUSION: Accompanied by chronic diseases, old age, fever, nasal congestion, and dyspnea were factors that influenced the aggravation of COVID-19 patients, and more attention and treatment should be given to these patients.

Difficulties encountered by public health workers in COVID-19 outbreak: a cross-sectional study based on five provinces.

OBJECTIVES: The aim of this study is to address the difficulties encountered by public health workers in the early and middle stages of their efforts to combat COVID-19, compare the gaps among different types of institutions, and identify shortcomings in epidemic control. METHODS: Using multi-stage sampling, a survey of public health workers involved in the prevention and control of COVID-19 was conducted from 18 February to 1 March 2020 through a self-administered questionnaire. These public health workers were from the primary health care center (defined as "primary-urban" and "primary-rural" for those in urban and rural areas, respectively) and the center for disease control and prevention (defined as "non-primary") in five provinces including Hubei, Guangdong, Sichuan, Jiangsu and Gansu, China. RESULTS: A total of 9,475 public health workers were surveyed, of which 40.0 %, 27.0 % and 33.0 % were from the primary-rural, primary-urban and non-primary, respectively. The resources shortage were reported by 27.9 % participants, with the primary-rural being the worst affected (OR = 1.201, 95 %CI: 1.073-1.345). The difficulties in data processing were reported by 31.5 % participants, with no significant differences among institutions. The difficulties in communication and coordination were reported by 29.8 % participants, with the non-primary being the most serious (primary-rural: OR = 0.520, 95 %CI: 0.446-0.606; primary-urban: OR = 0.533, 95 %CI: 0.454-0.625). The difficulties with target audiences were reported by 20.2 % participants, with the primary-urban being the worst (OR = 1.368, 95 %CI: 1.199-1.560). The psychological distress were reported by 48.8 % participants, with no significant differences among institutions. CONCLUSIONS: Psychological distress is the most serious problem in the prevention and control of COVID-19. Resources shortage in primary-rural, difficulties in communication and coordination in non-primary, and difficulties with target audiences in the primary-urban deserve attention. This study will provide scientific evidences for improving the national public health emergency management system, especially for reducing the urban-rural differences in emergency response capacity.

Mental Health Help-Seeking and Associated Factors Among Public Health Workers During the COVID-19 Outbreak in China.

Background: The COVID-19 outbreak in China has created multiple stressors that threaten individuals' mental health, especially among public health workers (PHW) who are devoted to COVID-19 control and prevention work. This study aimed to investigate the prevalence of mental help-seeking and associated factors among PHW using Andersen's Behavioral Model of Health Services Use (BMHSU). Methods: A cross-sectional survey was conducted among 9,475 PHW in five provinces across China between February 18 and March 1, 2020. The subsample data of those who reported probable mental health problems were analyzed for this report (n = 3,417). Logistic and hierarchical regression analyses were conducted to examine the associations of predisposing, enabling, need, and COVID-19 contextual factors with mental health help-seeking. Results: Only 12.7% of PHW reported professional mental help-seeking during the COVID-19 outbreak. PHW who were older, had more days of overnight work, received psychological training, perceived a higher level of support from the society, had depression and anxiety were more likely to report mental help-seeking (ORm range: 1.02-1.73, all p < 0.05) while those worked in Centers for Disease Control and Prevention were less likely to seek help (ORm = 0.57, p < 0.01). The belief that mental health issues were not the priority (64.4%), lack of time (56.4%), and shortage of psychologists (32.7%) were the most frequently endorsed reasons for not seeking help. Conclusions: The application of BMHSU confirmed associations between some factors and PHW's mental health help-seeking. Effective interventions are warranted to promote mental health help-seeking of PHW to ameliorate the negative impact of mental illness and facilitate personal recovery and routine work.

Prevalence of mental health problems and associated factors among front-line public health workers during the COVID-19 pandemic in China: an effort-reward imbalance model-informed study.

BACKGROUND: Poor mental health status and associated risk factors of public health workers have been overlooked during the COVID-19 pandemic. This study used the effort-reward imbalance model to investigate the association between work-stress characteristics (effort, over-commitment, reward) and mental health problems (anxiety and depression) among front-line public health workers during the COVID-19 pandemic in China. METHODS: A total of 4850 valid online questionnaires were collected through a self- constructed sociodemographic questionnaire, the adapted ERI questionnaire, the 9-item Patient Health Questionnaire (PHQ-9) and the 7-item General Anxiety Disorder Scale (GAD-7). Hierarchical logistic regression analysis was conducted to investigate the association between ERI factors and mental health problems (i.e., depression and anxiety), with reward treated as a potential moderator in such associations. RESULTS: The data showed that effort and over-commitment were positively associated with depression and anxiety, while reward was negatively associated with depression and anxiety. Development and job acceptance were the two dimensions of reward buffered the harmful effect of effort/over-commitment on depression and anxiety, whereas esteem was non-significant. CONCLUSIONS: This study confirmed the harmful effects of effort and over-commitment on mental health among public health workers during the COVID-19 pandemic in China. Such effects could be alleviated through an appropriate reward system, especially the development and job acceptance dimensions of such a system. These findings highlight the importance of establishing an emergency reward system, comprising reasonable work-allocation mechanism, bonuses and honorary titles, a continuous education system and better career-development opportunities.