Spatial Interactions and the Spread of COVID-19: A Network Perspective

We use unique data on the travel history of confirmed patients at a daily frequency across 31 provinces in China to study how spatial interactions influence the geographic spread of pandemic COVID-19. We develop and simultaneously estimate a structural model of dynamic disease transmission network formation and spatial interaction. This allows us to understand what externalities the disease risk associated with a single place may create for the entire country. We find a positive and significant spatial interaction effect that strongly influences the duration and severity of pandemic COVID-19. And there exists heterogeneity in this interaction effect: the spatial spillover effect from the source province is significantly higher than from other provinces. Further counterfactual policy analysis shows that targeting the key province can improve the effectiveness of policy interventions for containing the geographic spread of pandemic COVID-19, and the effect of such targeted policy decreases with an increase in the time of delay.

The value of artificial intelligence and imaging diagnosis in the fight against COVID-19.

The outbreak of the new type of coronavirus pneumonia (COVID-19) has caused a huge impact on the world. In this case, only by adhering to the prevention and control methods of early diagnosis, early isolation, and early treatment, can the spread of the virus be prevented to the greatest extent. This article uses artificial intelligence-assisted medical imaging diagnosis as the research object, combines artificial intelligence and CT medical imaging diagnosis, introduces an intelligent COVID-19 detection system, and uses it to achieve COVID-19 disease screening and lesion evaluation. CT examination has the advantages of fast speed and high accuracy, which can provide a favorable basis for clinical diagnosis. This article collected 32 lung CT scan images of patients with confirmed COVID-19. Two professional radiologists analyzed the CT images using traditional imaging diagnostic methods and artificial intelligence-assisted imaging diagnostic methods, and the comparison showed the gap between the two methods. According to experiments, CT imaging diagnosis assisted by artificial intelligence only takes 0.744 min on average, which can save a lot of time and cost compared with the average time of 3.623 min for conventional diagnosis. In terms of comprehensive test accuracy, it can be concluded that the combination of artificial intelligence and imaging diagnosis has extremely high application value in COVID-19 diagnosis.

Reduced SARS-CoV-2 infection risk is associated with the use of Seven-Flavor Herb Tea: A multi-center observational study in Shanghai, China.

OBJECTIVE: Omicron, a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant, is responsible for numerous infections in China. This study investigates the association between the use of Seven-Flavor Herb Tea (SFHT) and the risk of SARS-CoV-2 infection to develop precise and differentiated strategies for control of the coronavirus disease 2019 (COVID-19). METHODS: This case-control study was conducted at shelter hospitals and quarantine hotels in China. A total of 5348 laboratory-confirmed COVID-19 patients were enrolled between April 1 and May 31, 2022, while 2190 uninfected individuals served as healthy controls. Structured questionnaires were used to collect data on demographics, underlying diseases, vaccination status, and use of SFHT. Patients were propensity-score-matched using 1:1 nearest-neighbor matching of the logit of the propensity score. Subsequently, a conditional logistic regression model was used for data analysis. RESULTS: Overall, 7538 eligible subjects were recruited, with an average age of [45.54 ± 16.94] years. The age of COVID-19 patients was significantly higher than that of uninfected individuals ([48.25 ± 17.48] years vs [38.92 ± 13.41] years; t = 22.437, P < 0.001). A total of 2190 COVID-19 cases were matched with uninfected individuals at a 1:1 ratio. The use of SFHT (odds ratio = 0.753, 95% confidence interval: 0.692, 0.820) was associated with a lower risk of SARS-CoV-2 infection compared to untreated individuals. CONCLUSION: Our findings suggest that taking SFHT reduces the risk of SARS-CoV-2 infection. This is a useful study in the larger picture of COVID-19 management, but data from large-sample multi-center, randomized clinical trial are warranted to confirm the finding. Please cite this article as: Zhang SX, Chen XX, Zheng Y, Cai BH, Shi W, Ru M, Li H, Zhang DD, Tian Y, Chen YL. Reduced SARS-CoV-2 infection risk is associated with the use of Seven-Flavor Herb Tea: A multi-center observational study in Shanghai, China. J Integr Med. 2023; 21(4):369-376.

In vitro selection of a single-strand DNA aptamer targeting the receptor-binding domain of SARS-CoV-2 spike protein.

Nucleic acid aptamers are developed from a pool of random oligonucleotide libraries with an in vitro selection through systematic evolution of ligands via exponential enrichment (SELEX) process, which are capable of specific and high-affinity molecular binding against targets. The receptor-binding domain (RBD) of spike protein from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is involved in the early stages of viral infection, is a promising target for aptamer selection. Currently, there are no effective approaches to prevent virus from spreading. In this study, a new ssDNA aptamer RBD/S-A1 binding to the RBD of spike protein from SARS-CoV-2 with high affinity (Kd=1.74 ± 0.2 nM) and low cross-binding activity was selected and evaluated. Although aptamers targeting the RBD of spike protein from SARS-CoV-2 have been described in a handful of previous studies, the RBD/S-A1 aptamer identified in this work may be considered as a potential supplementation for the current diagnosis and research of coronavirus SARS-CoV-2.

Effect of an online resourcefulness training in improving psychological well-being of front-line medical staff: a quasi-experimental study.

BACKGROUND: The global COVID-19 pandemic is still not under effective control, and strong workplace supports with comprehensive mental health interventions are urgently needed to help medical staff effectively respond to the pandemic. This study aimed to verify the effect of an online resourcefulness training program on the resourcefulness, and psychological variables of front-line medical staff working in the COVID-19 isolation ward. DESIGN: A pre-test and post-test quasi-experimental design with control group was employed. PARTICIPANTS: A total of 60 participants working in two isolation wards were recruited via convenience sampling. The two isolation wards were randomly assigned to the control group (isolation ward 1, n = 30) and the intervention group (isolation ward 2, n = 30). INTERVENTION: The participants were trained online by video conferences and WeChat. The control group received conventional training (e.g., psychological training, psychological counseling), while the intervention group received a 4-h online resourcefulness training. Both groups learned updated guidelines of COVID-19 simultaneously via video conference. The primary outcomes (resourcefulness, anxiety, depression and coping styles) and the secondary outcome (psychological resilience) were measured before intervention and three time points after intervention. RESULTS: After the intervention and one week after the intervention, the resourcefulness, resilience, and positive response scores of the participants in the intervention group were significantly higher than those of the control group. The anxiety and negative response scores in the intervention group were significantly lower than those of the control group (all p < 0.05). One month after the intervention, the scores of resourcefulness, tenacity, and positive response of the intervention group were higher than those of the control group (all p < 0.05). Repeated measures analysis of variance showed that the two groups of participants had statistically significant changes in the time-based effect and group-based effect in resourcefulness, resilience, anxiety scores and coping styles (p < 0.01). CONCLUSION: The results showed that our online resourcefulness training can significantly improve the resourcefulness, resilience, and positive response scores and effectively reduce anxiety and depression scores of front-line medical staff. This demonstrates that online resourcefulness training would be an effective tool for the psychological adjustment of front-line medical staff in fighting against COVID-19.

Efficient Transfection of In vitro Transcribed mRNA in Cultured Cells Using Peptide-Poloxamine Nanoparticles.

In vitro transcribed messenger RNA (mRNA) vaccines have displayed enormous potential in fighting against the coronavirus disease 2019 (COVID-19) pandemic. Efficient and safe delivery systems must be included in the mRNA vaccines due to the fragile properties of mRNA. A self-assembled peptide-poloxamine nanoparticle (PP-sNp) gene delivery system is specifically designed for the pulmonary delivery of nucleic acids and displays promising capabilities in mediating successful mRNA transfection. Here, an improved method for preparing PP-sNp is described to elaborate on how the PP-sNp encapsulates Metridia luciferase (MetLuc) mRNA and successfully transfects cultured cells. MetLuc-mRNA is obtained by an in vitro transcription process from a linear DNA template. A PP-sNp is produced by mixing synthetic peptide/poloxamine with mRNA solution using a microfluidic mixer, allowing for the self-assembly of PP-sNp. The charge of PP-sNp is subsequently evaluated by measuring the zeta potential. Meanwhile, the polydispersity and hydrodynamic size of PP-sNp nanoparticles are measured using dynamic light scattering. The mRNA/PP-sNp nanoparticles are transfected into cultured cells, and supernatants from the cell culture are assayed for luciferase activity. The representative results demonstrate their capacity for in vitro transfection. This protocol may shed light on developing next-generation mRNA vaccine delivery systems.

Epidemic characteristics and spatial analysis of COVID-19 in Zhejiang Province. (Special Issue: Spatio-temporal dynamics analysis, risk assessment and emergency management for COVID-19 epidemic.) [Chinese]

Objective: To explore the temporal and spatial distribution characteristics of confirmed cases of coronavirus disease(COVID-19)in Zhejiang Province and to determine the correlation between number of confirmed cases and geographical demographic factors, so as to provide theoretical basis for the prevention and control of COVID-19.

Epidemiological characteristics and incubation period of coronavirus disease 2019 in Anhui Province. (Special Issue: Spatio-temporal dynamics analysis, risk assessment and emergency management for COVID-19 epidemic.) [Chinese]

Objective: To analyze the epidemiological characteristics and incubation of coronavirus disease 2019(COVID-19)from Jan. 22 to Mar. 8, 2020 in Anhui Province, in order to provide the basis for further understanding of the transmission pattern of COVID-19 and formulating regional control measures.

Influence factors of COVID-19 in Shandong Province based on geographically weighted generalized linear model. (Special Issue: Spatio-temporal dynamics analysis, risk assessment and emergency management for COVID-19 epidemic.) [Chinese]

Objective: To explore the related influence factors of coronavirus diseases 2019(COVID-19)in Shandong Province and understand the regional distribution characteristics of the epidemic situation, and to provide a scientific basis for guiding prevention and control strategies.

Reproduction number estimation and epidemic analysis of coronavirus disease 2019 in Shandong Province based on poisson process. (Special Issue: Spatio-temporal dynamics analysis, risk assessment and emergency management for COVID-19 epidemic.) [Chinese]

Objective: To explore the epidemic dynamics of coronavirus disease 2019(COVID-19)in Shandong Province, and to provide a scientific basis for the future prevention and control of new outbreaks of COVID-19 and other emerging infectious diseases.

Epidemic dynamics of COVID-19 in Xinyang City, Henan Province. (Special Issue: Spatio-temporal dynamics analysis, risk assessment and emergency management for COVID-19 epidemic.) [Chinese]

Objective: To explore epidemic dynamics of coronavirus disease 2019 (COVID-19) in Xinyang City so as to provide scientific basis for optimizing the prevention and control strategies and evaluating the effects of intervention.

Spatial Interactions and the Spread of COVID-19: A Network Perspective

We use unique data on the travel history of confirmed patients at a daily frequency across 31 provinces in China to study how spatial interactions influence the geographic spread of pandemic COVID-19. We develop and simultaneously estimate a structural model of dynamic disease transmission network formation and spatial interaction. This allows us to understand what externalities the disease risk associated with a single place may create for the entire country. We find a positive and significant spatial interaction effect that strongly influences the duration and severity of pandemic COVID-19. And there exists heterogeneity in this interaction effect: the spatial spillover effect from the source province is significantly higher than from other provinces. Further counterfactual policy analysis shows that targeting the key province can improve the effectiveness of policy interventions for containing the geographic spread of pandemic COVID-19, and the effect of such targeted policy decreases with an increase in the time of delay.

Pearson's patterns correlational of clinical risks at admissions with hospitalization outcomes during initial COVID-19 outbreak.

COVID-19 outbreaks have crushed our healthcare systems, which requires clinical guidance for the healthcare following the outbreaks. We conducted retrospective cohort studies with Pearson's pattern-based analysis of clinical parameters of 248 hospitalized patients with COVID-19. We found that dysregulated neutrophil densities were correlated with hospitalization duration before death (p = 0.000066, r = -0.45 for % neutrophil; p = 0.0001, r = -0.47 for neutrophil count). As such, high neutrophil densities were associated with mortality (p = 4.23 × 10-31 for % neutrophil; p = 4.14 × 10-27 for neutrophil count). These findings were further illustrated by a representative "second week crash" pattern and validated by an independent cohort (p = 5.98 × 10-11 for % neutrophil; p = 1.65 × 10-7 for neutrophil count). By contrast, low aspartate aminotransferase (AST) or lactate dehydrogenase (LDH) levels were correlated with quick recovery (p ≤ 0.00005). Collectively, these correlational at-admission findings may provide healthcare guidance for patients with COVID-19 in the absence of targeted therapy.

Practical COVID-19 Prevention Training for Obstetrics and Gynecology Residents Based on the Conceive-Design-Implement-Operate Framework.

Background: The spread of COVID-19 poses a challenge for obstetrics and gynecology (O&G) residents. In order to improve the theoretical knowledge and practical skills of residents in epidemic prevention and control, reduce work pressure and improve professional skills, effective and sound training models are required to improve the protection of O&G residents from COVID-19. Method: A total of 38 standardized training O&G residents working in Shengjing Hospital of China Medical University in March 2020 was selected. They were randomly divided into intervention and control groups. The control group underwent a protection theory exposition according to the traditional training method, while the intervention group adopted a conceive-design-implement-operate (CDIO) mode, arranged training courses in combination with the O&G specialty, and completed four modules of CDIO. After the training, the theoretical knowledge and practical operation were assessed, and the work stress and occupational identity scales were assessed. The assessment results and scores of the two groups of residents were analyzed. Results: Compared with the scores of the residents in the control group, the theoretical and technical scores of the residents in the intervention group significantly improved (P < 0.05). In the evaluation of organizational management, workload, interpersonal relationship, and doctor-patient relationship pressure, the scores of the intervention group were lower than those of the control group, with a statistical difference (P < 0.05). For the intervention group, the job stress and professional identity evaluation scores were significantly higher than those of the control group (P < 0.05). Conclusion: The CDIO model can effectively enhance the theoretical knowledge and practical skills of O&G residents in COVID-19 epidemic prevention protocols to reduce work pressure and improve professional identity. In addition, it provides new ideas, methods, and approaches for future clinical practice training.

Short- and medium-term impacts of strict anti-contagion policies on non-COVID-19 mortality in China.

The effects of coronavirus disease-19 (COVID-19) public health policies on non-COVID-19-related mortality are unclear. Here, using death registries based on 300 million Chinese people and a difference-in-differences design, we find that China's strict anti-contagion policies during the COVID-19 pandemic significantly reduced non-COVID-19 mortality outside Wuhan (by 4.6%). The health benefits persisted and became even greater after the measures were loosened: mortality was reduced by 12.5% in the medium term. Significant changes in people's behaviours (for example, wearing masks and practising social distancing) and reductions in air pollution and traffic accidents could have driven these results. We estimate that 54,000 lives could have been saved from non-COVID-19 causes during the 50 days of strict policies and 293,000 in the subsequent 115 days. The results suggest that virus countermeasures not only effectively controlled COVID-19 in China but also brought about unintended and substantial public health benefits.

Discovery and Full Genome Characterization of SARS-CoV-2 in Stool Specimen from a Recovered Patient, China.

SARS-CoV-2 was found in a recovered patient's stool specimen by combining quantitative reverse transcription PCR (qRT-PCR) and genome sequencing. The patient was virus positive in stool specimens for at least an additional 15 days after he was recovered, whereas respiratory tract specimens were negative. The discovery of the complete genome of SARS-CoV-2 in the stool sample of the recovered patient demonstrates a cautionary warning that the potential mode of the virus transmission cannot be excluded through the fecal-oral route after viral clearance in the respiratory tract.

Effect of virtual reality simulation training on the response capability of public health emergency reserve nurses in China: a quasiexperimental study.

OBJECTIVE: To develop a virtual reality simulation training programme, and further verify the effect of the programme on improving the response capacity of emergency reserve nurses confronting public health emergencies. DESIGN: A prospective quasiexperimental design with a control group. PARTICIPANTS: A total of 120 nurses were recruited and randomly divided into the control group and the intervention group. INTERVENTION: Participants underwent a 3-month training. The control group received the conventional training of emergency response (eg, theoretical lectures, technical skills and psychological training), while the intervention group underwent the virtual reality simulation training in combination with skills training. The COVID-19 cases were incorporated into the intervention group training, and the psychological training was identical to both groups. At the end of the training, each group conducted emergency drills twice. Before and after the intervention, the two groups were assessed for the knowledge and technical skills regarding responses to fulminate respiratory infectious diseases, as well as the capacity of emergency care. Furthermore, their pandemic preparedness was assessed with a disaster preparedness questionnaire. RESULTS: After the intervention, the scores of the relevant knowledge, the capacity of emergency care and disaster preparedness in the intervention group significantly increased (p<0.01). The score of technical skills in the control group increased more significantly than that of the intervention group (p<0.01). No significant difference was identified in the scores of postdisaster management in two groups (p>0.05). CONCLUSION: The virtual reality simulation training in combination with technical skills training can improve the response capacity of emergency reserve nurses as compared with the conventional training. The findings of the study provide some evidence for the emergency training of reserve nurses in better response to public health emergencies and suggest this methodology is worthy of further research and popularisation.

Estimating the Prevalence of Asymptomatic COVID-19 Cases and Their Contribution in Transmission - Using Henan Province, China, as an Example.

Background: Novel coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), is now sweeping across the world. A substantial proportion of infections only lead to mild symptoms or are asymptomatic, but the proportion and infectivity of asymptomatic infections remains unknown. In this paper, we proposed a model to estimate the proportion and infectivity of asymptomatic cases, using COVID-19 in Henan Province, China, as an example. Methods: We extended the conventional susceptible-exposed-infectious-recovered model by including asymptomatic, unconfirmed symptomatic, and quarantined cases. Based on this model, we used daily reported COVID-19 cases from January 21 to February 26, 2020, in Henan Province to estimate the proportion and infectivity of asymptomatic cases, as well as the change of effective reproductive number, R t . Results: The proportion of asymptomatic cases among COVID-19 infected individuals was 42% and the infectivity was 10% that of symptomatic ones. The basic reproductive number R 0 = 2.73, and R t dropped below 1 on January 31 under a series of measures. Conclusion: The spread of the COVID-19 epidemic was rapid in the early stage, with a large number of asymptomatic infected individuals having relatively low infectivity. However, it was quickly brought under control with national measures.

Progress in robotics for combating infectious diseases.

The world was unprepared for the COVID-19 pandemic, and recovery is likely to be a long process. Robots have long been heralded to take on dangerous, dull, and dirty jobs, often in environments that are unsuitable for humans. Could robots be used to fight future pandemics? We review the fundamental requirements for robotics for infectious disease management and outline how robotic technologies can be used in different scenarios, including disease prevention and monitoring, clinical care, laboratory automation, logistics, and maintenance of socioeconomic activities. We also address some of the open challenges for developing advanced robots that are application oriented, reliable, safe, and rapidly deployable when needed. Last, we look at the ethical use of robots and call for globally sustained efforts in order for robots to be ready for future outbreaks.

Clinical characteristics and risk factors of mild-to-moderate COVID-19 patients with false-negative SARS-CoV-2 nucleic acid.

This study investigates the clinical and imaging characteristics of coronavirus disease 2019 (COVID-19) patients with false-negative nucleic acids. Mild-to-moderate COVID-19 patients, including 19 cases of nucleic acid false-negative patients and 31 cases of nucleic acid positive patients, were enrolled. Their epidemiological, clinical, and laboratory examination data and imaging characteristics were analyzed. Risk factors for false negatives were discussed. Compared with the nucleic acid positive group, the false-negative group had less epidemiological exposure (52.6% vs 83.9%; P = .025), less chest discomfort (5.3% vs 32.3%; P = .035), and faster recovery (10 [8, 13] vs 15 [11, 18.5] days; P = .005). The number of involved lung lobes was (2 [1, 2.5] vs 3 [2, 4] days; P = .004), and the lung damage severity score was (3 [2.5, 4.5] vs 5 [4, 9] days; P = .007), which was lighter in the nucleic acid false-negative group. Thus, the absence of epidemiological exposure may be a potential risk factor for false-negative nucleic acids. The false-negative cases of COVID-19 are worth noting because they have a risk of viral transmission without positive test results, lighter clinical manifestations, and less history of epidemiological exposure.