Metaverse in Dynamic Viral-shedding Surveillance for Emerging Infectious Disease: A Digital Twin Approach to COVID-19 Epidemic (preprint)

Metaverse in effective surveillance of outbreaks of emerging infectious diseases such as COVID-19 opens a new avenue for precision and efficient contact tracing, quarantine, and isolation. We adopted a digital twin model to generate digital threads for tracing and tracking virtual data on the cycle threshold (Ct) values of the repeated RT-PCR with parameters learned from real-world (physical) data fitted with Markov machine learning algorithms. Such a digital twin method is demonstrated with COVID-19 community-acquired outbreaks of the Alpha and Omicron Variants of Concern (VOCs) in Taiwan. The personalized dynamics of Ct-defined transitions were derived from the digital threads of the two community-acquired outbreaks to guide precision contact tracing, quarantine, and isolation of both Alpha and Omicron VOCs outbreaks. Metaverse surveillance with such a Ct-guided digital twin model is supposed to be useful for timely containing the spread of emerging infectious diseases in the future.

Healthcare utilisation in people with long COVID: an OpenSAFELY cohort study (preprint)

BackgroundLong COVID, characterised by various symptoms and complications, potentially increases healthcare utilisation and costs. However, its impact on the NHS remains to be determined. ObjectiveThis study aims to assess the healthcare utilisation of individuals with long COVID. MethodsWith the approval of NHS England, we conducted a matched cohort study using primary and secondary care data via OpenSAFELY, a platform for analysing anonymous electronic health records. The long COVID exposure group, defined by diagnostic codes, was matched with five comparators without long COVID between Nov 2020 and Jan 2023. We compared their total healthcare utilisation from GP consultations, prescriptions, hospital admissions, A&E visits, and outpatient appointments. Healthcare utilisation and costs were evaluated using a two-part model adjusting for covariates. Using a difference-in-difference model, we also compared healthcare utilisation after long COVID with pre-pandemic records. ResultsWe identified 52,988 individuals with a long COVID diagnosis, matched to 264,867 comparators without a diagnosis. In the 12 months post-diagnosis, there was strong evidence that those with long COVID were more likely to use healthcare resources (OR: 8.07, 95% CI: 7.54 - 8.64), and have 49% more healthcare utilisation (RR: 1.49, 95% CI: 1.47 - 1.50). Our model estimated that the long COVID group had 30 healthcare visits per year (predicted mean: 29.23, 95% CI: 28.58 - 29.92), compared to 16 in the comparator group (predicted mean visits: 16.04, 95% CI: 15.73 - 16.36). Individuals with long COVID were more likely to have non-zero healthcare expenditures (OR = 7.47, 95% CI = 7.02 - 7.95), with costs being 43% higher than the comparator group (cost ratio = 1.43, 95% CI: 1.38 - 1.49). The long COVID group costs approximately {pound}2,500 per person per year (predicted mean cost: {pound}2,562.50, 95% CI: {pound}2,335.60 - {pound}2,819.22), and the comparator group costs {pound}1,500 (predicted mean cost: {pound}1,527.43, 95% CI: {pound}1,404.33 - 1,664.45.) Historically, individuals with long COVID utilised healthcare resources more frequently, but their average healthcare utilisation increased more after being diagnosed with long COVID, compared to the comparator group. ConclusionLong COVID increases healthcare utilisation and costs. Public health policies should allocate more resources towards preventing, treating, and supporting individuals with long COVID.

Ursodeoxycholic acid and severe COVID-19 outcomes in people with liver disease: a cohort study using the OpenSAFELY platform (preprint)

Biological evidence suggests ursodeoxycholic acid (UDCA) - a common treatment of cholestatic liver disease - may prevent severe COVID-19 outcomes. With the approval of NHS England, we conducted a population-based cohort study using primary care records, linked to death registration data and hospital records through the OpenSAFELY-TPP platform. We estimated the hazard of COVID-19 hospitalisation or death between 1 March 2020 and 31 December 2022, comparing UDCA treatment to no UDCA treatment in a population with indication. Of 11,320 eligible individuals, 642 were hospitalised or died with COVID-19 during follow-up, 402 (63%) events among UDCA users. After confounder adjustment, UDCA was associated with a 21% (95% CI 7%-33%) relative reduction in the hazard of COVID-19 hospitalisation or death, consistent with an absolute risk reduction of 1.3% (95% CI 1.0%-1.6%). Our findings support calls for clinical trials investigating UDCA as a preventative measure for severe COVID-19 outcomes.

The impact of Long COVID on Health-Related Quality-of-life using OpenPROMPT (preprint)

Background: Long COVID is a major problem affecting patient health, the health service, and the workforce. To optimise the design of future interventions against COVID-19, and to better plan and allocate health resources, it is critical to quantify the health and economic burden of this novel condition. Methods With the approval of NHS England, we developed OpenPROMPT, a UK cohort study measuring the impact of long COVID on health-related quality-of-life (HRQoL). OpenPROMPT invited responses to Patient Reported Outcome Measures (PROMs) using a smartphone application and recruited between November 2022 and October 2023. We used the validated EuroQol EQ-5D questionnaire with the UK Value Set to develop disutility scores (1-utility) for respondents with and without Long COVID using linear mixed models, and we calculated subsequent Quality-Adjusted Life-Months (QALMs) for long COVID. Results We used data from 6,070 participants where 24.7% self-reported long COVID. In multivariable regressions, long COVID had a consistent impact on HRQoL, showing a high probability of reporting loss in quality-of-life (OR: 22, 95% CI:12.35-39.29) compared with people who did not report long COVID. Reporting a disability was the largest predictor of losses of HRQoL (OR: 60.2, 95% CI: 27.79-130.57) across survey responses. Self-reported long COVID was associated with an 0.37 QALM loss. Conclusions We found substantial impacts on quality-of-life due to long COVID, representing a major burden on patients and the health service. We highlight the need for continued support and research for long COVID, as HRQoL scores compared unfavourably to patients with conditions such as multiple sclerosis, heart failure, and renal disease.

Clinical coding of long COVID in primary care 2020-2023 in a cohort of 19 million adults: an OpenSAFELY analysis (preprint)

Background Long COVID is the patient-coined term for the persistent symptoms of COVID-19 illness for weeks, months or years following the acute infection. There is a large burden of long COVID globally from self-reported data, but the epidemiology, causes and treatments remain poorly understood. Primary care is used to help identify and treat patients with long COVID and therefore Electronic Health Records (EHRs) of past COVID-19 patients could be used to help fill these knowledge gaps. We aimed to describe those with long COVID in primary care records in England. Methods With the approval of NHS England we used routine clinical data from over 19 million adults in England linked to SARS-COV-2 test result, hospitalisation and vaccination data to describe trends in the recording of 16 clinical codes related to long COVID between November 2020 and January 2023. We calculated rates per 100,000 person-years and plotted how these changed over time. We compared crude and minimally adjusted rates of recorded long COVID in patient records between different key demographic and vaccination characteristics using negative binomial models. Findings We identified a total of 55,465 people recorded to have long COVID over the study period, with incidence of new long COVID records increasing steadily over 2021, and declining over 2022. The overall rate per 100,000 person-years was 177.5 cases in women (95% CI: 175.5-179) and 100.5 men (99.5-102). In terms of vaccination against COVID-19, the lowest rates were observed in those with 3+ vaccine doses (103.5 [95% CI: 101.5-105]). Finally, the majority of those with a long COVID record did not have a recorded positive SARS-COV-2 test 12 weeks before the long COVID record. Interpretation EHR recorded long COVID remains very low compared and incident records of long COVID declined over 2022. We found the lowest rates of recorded long COVID in people with 3 or more vaccine doses. We summarised several sources of possible bias for researchers using EHRs to study long COVID. Funding This research was supported by the National Institute for Health and Care Research (NIHR) (OpenPROMPT: COV-LT2-0073))

Quantifying the Effects of Viral Load on Multistate COVID-19 Infection and Progression of Alpha and Omicron VOCs: A Bayesian Competing Markov Exponential Regression Model (preprint)

We used a Bayesian competing four-state Markov model to explore how viral shedding in terms of cycle threshold (Ct) value makes relative contribution between persistent and non-persistent asymptomatic mode, and whether it affects the subsequent progression to show symptoms. The proposed model was applied to data from two large outbreaks on Alpha and Omicron variants of concern (VOCs) in Changhua, Taiwan. A multistate Markov exponential regression model was proposed for quantifying the odds ratio (OR) of viral shedding measured by cycle threshold (Ct). A Bayesian Markov Chain Monte Carlo (MCMC) method was used for estimating the parameters of the posterior distribution. The estimated results show that developing non-persistent asymptomatic mode relative to persistent asymptomatic mode was reduced by 14% (adjusted OR = 0.86, 95% CI: 0.81–0.92) per one increasing unit of Ct for Alpha VOC, whereas these figures were shrunk to 5% (aOR = 0.95, 95% CI: 0.93–0.98) for Omicron VOC. Similar significant gradient relationships were also observed between three viral load levels. Similar, but not statistically significant, dose-response effects of viral load on the progression to symptoms for non-persistent asymptomatic mode were observed. The application of statistical model helps elucidate the pathways of SARS-CoV-2 infectious process associated with viral shedding that demonstrate viral shedding plays a crucial role in determining the path of either non-persistent or persistent asymptomatic mode in a dose-response manner, which was more pronounced for the Alpha than the Omicron. Modelling such a multistate infectious process with two competing pathways would provide a new insight into the transmissibility and the duration of insidious infection before onset of symptom and the deployment of precision containment measures with a better use of the Ct value as virologic surveillance for projecting the individual epidemic course.

Forecasting Gold Price Using a Novel Hybrid Model with MEEMD-ConvLSTM (preprint)

Gold occupies a significant position in the world economy and financial market as a precious metal. In order to forecast gold spot and futures price more accurately, this paper introduces a new prediction model called MEEMD-convLSTM. The IMF sequence of the original gold price was decomposed by using a modified ensemble empirical mode decomposition (MEEMD), and convLSTM was utilized to predict each IMF, then the predicted IMF was constructed to obtain the final forecasting results. Model confidence set test (MCS) statistically validated MEEMD-convLSTM and compared it with the traditional neural network (BP), support vector regression (SVR) and hybrid prediction models. We can draw the conclusion that MEEMD-convLSTM can improve the forecasting accuracy and be the best of all the models chosen. The results of robustness tests showed that the model had better forecasting accuracy before and after the Covid-19 outbreak. Overall, the MEEMD-convLSTM model distinguishes itself as a very promising method for gold spot and gold futures price forecasting.

Exploring the Determinants of Digital Transformation Adoption for SMEs in an Emerging Economy

In the fourth industrial revolution age, digital transformation is crucial to the sustainable development of small- and medium-sized businesses (SMEs). This study suggests a hierarchical model based on the Technology–Organization–Environment (TOE) model with three main dimensions and nine sub-dimensions for SMEs that implemented digital transformation in the emerging economy. The fuzzy analytic hierarchical process methodology (Fuzzy AHP) was used to explore and rank determinants of the digital transformation adoption for SMEs. Data were collected by the questionnaires from 72 respondents, who were the leaders of SMEs in Vietnam. The results revealed that the environmental factor was ranked the most important factor in the pairwise comparisons of the hierarchical structure, and the sub-dimension of the customer experience was at the highest ranking of the relative pairwise comparisons of the digital transformation adoption for SMEs, followed by technological compatibility, government support, organizational support, and human resources. This research makes contributions to the topic of digital transformation from both theoretical and practical implications. The result stresses the critical significance of environmental factors in the successful adoption of digital technologies in SMEs, which adds to the perspective in the context of a growing nation.

Effects of bamlanivimab alone or in combination with etesevimab on subsequent hospitalization and mortality in outpatients with COVID-19: a systematic review and meta-analysis.

Background: Coronavirus disease 2019 (COVID-19) has caused an enormous loss of life worldwide. The spike protein of the severe acute respiratory syndrome coronavirus 2 is the cause of its virulence. Bamlanivimab, a recombinant monoclonal antibody, has been used alone or in combination with etesevimab to provide passive immunity and improve clinical outcomes. A systematic review and meta-analysis was conducted to investigate the therapeutic effects of bamlanivimab with or without etesevimab (BAM/ETE) treatment. Methods: Our study was registered in PROSPERO (registry number CRD42021270206). We searched the following electronic databases, without language restrictions, until January 2023: PubMed, Embase, medRxiv, and the Cochrane database. A systematic review and meta-analysis was conducted based on the search results. Results: Eighteen publications with a total of 28,577 patients were identified. Non-hospitalized patients given bamlanivimab with or without etesevimab had a significantly lower risk of subsequent hospitalization (18 trials, odds ratio (OR): 0.37, 95% confidence interval (CI): [0.29-0.49], I2: 69%; p < 0.01) and mortality (15 trials, OR: 0.27, 95% CI [0.17-0.43], I2: 0%; p = 0.85). Bamlanivimab monotherapy also reduced the subsequent risk of hospitalization (16 trials, OR: 0.43, 95% CI [0.34-0.54], I2: 57%; p = 0.01) and mortality (14 trials, OR: 0.28, 95% CI [0.17-0.46], I2: 0%; p = 0.9). Adverse events from these medications were uncommon and tolerable. Conclusions: In this meta-analysis, we found the use of bamlanivimab with or without etesevimab contributed to a significantly-reduced risk of subsequent hospitalization and mortality in non-hospitalized COVID-19 patients. However, resistance to monoclonal antibodies was observed in COVID-19 variants, resulting in the halting of the clinical use of BAM/ETE. Clinicians' experiences with BAM/ETE indicate the importance of genomic surveillance. BAM/ETE may be repurposed as a potential component of a cocktail regimen in treating future COVID variants.

Cognitive appraisal of health and its influencing factors among pregnant women with gestational diabetes mellitus: A cross-sectional study.

AIM: To investigate the status quo of cognitive appraisal of health and its influencing factors among pregnant women with gestational diabetes mellitus. METHODS: A cross-sectional survey was conducted from June 2020 to November 2020. Participants were recruited from a tertiary hospital by a convenient sample method. A total of 300 pregnant women with gestational diabetes mellitus completed the survey, including self-compiled individual information questionnaire, Cognitive Appraisal of Health Scale, Pregnancy Stress Rating Scale and General Self-Efficacy Scale. RESULTS: For cognitive appraisal of health, the median score of challenge dimension was 3.75 (3.50, 4.00), benign/irrelevant was 2.75 (2.00, 3.50), harm/loss was 2.38 (2.00, 3.00) and threat was 2.40 (2.00, 2.80), respectively. Regression analyses showed that gestational age, mode of conception, history of abortion, insulin usage, pregnancy stress and self-efficacy were the predictors of cognitive appraisal of health. CONCLUSIONS: This study revealed that pregnant women with gestational diabetes mellitus tended to make positive cognitive appraisal of health. And healthcare providers need to make full use of their predictors of cognitive appraisal of health to improve cognitive appraisal to manage stress and ameliorate pregnancy outcomes.

N-Butanol Extract of Glycyrrhizae Radix et Rhizoma Inhibits Dengue Virus through Targeting Envelope Protein.

BACKGROUND: At present, about half of the world's population is at risk of being infected with dengue virus (DENV). However, there are no specific drugs to prevent or treat DENV infection. Glycyrrhizae Radix et Rhizome, a well-known traditional Chinese medicine, performs multiple pharmacological activities, including exerting antiviral effects. The aim of this study was to investigate the anti-DENV effects of n-butanol extract from Glycyrrhizae Radix et Rhizome (GRE). METHODS: Compounds analysis of GRE was conducted via ultra-performance liquid chromatography/tandem mass spectrometry (UHPLC-MS/MS). The antiviral activities of GRE were determined by the CCK-8 assay, plaque assay, qRT-PCR, Western blotting, and the immunofluorescence assay. The DENV-infected suckling mice model was constructed to explore the antiviral effects of GRE in vivo. RESULTS: Four components in GRE were analyzed by UHPLC-MS/MS, including glycyrrhizic acid, glycyrrhetnic acid, liquiritigenin, and isoliquiritigenin. GRE inhibited the attachment process of the virus replication cycle and reduced the expression of the E protein in cell models. In the in vivo study, GRE significantly relieved clinical symptoms and prolong survival duration. GRE also significantly decreased viremia, reduced the viral load in multiple organs, and inhibited the release of pro-inflammatory cytokines in DENV-infected suckling mice. CONCLUSIONS: GRE exhibited significant inhibitory activities in the adsorption stage of the DENV-2 replication cycle by targeting the envelope protein. Thus, GRE might be a promising candidate for the treatment of DENV infection.

Research progress on central mechanism of acupuncture treatment for chronic fatigue syndrome.

Chronic fatigue syndrome is a neurological disorder characterized by extreme fatigue that lasts for a long time and doesn't alleviate with rest. The number of the cases has been increasing during the era of COVID-19 pandemic. Acupuncture may have some effect on chronic fatigue syndrome, but its mechanism remains unclear. This article was to summarize the specific manifestations of abnormal central mechanism in patients with chronic fatigue syndrome through laboratory tests and neuroimaging. It was found from the laboratory evaluation that there were changes in the structure of the frontal cortex, thalamus and other brain tissues; factors, including IFN-α and IL-10 in cerebrospinal fluid were found abnormal; results of oxidative and nitrosative stress and changes in neurobiochemical substances, e.g. hypothalamus hormone levels and neurotransmitter concentrations, were observed. With magnetic resonance imaging and positron emission tomography, it was shown that the partial brain of persons with chronic fatigue syndrome had morphological changes with diminished grey matter and white; changes in cerebral blood flow velocity caused by decreased perfusion and functional activity with abnormal connectivity in brain were detected. In addition, there was significant decrease in glucose metabolism accompanied with neuroinflammatory response; metabolic disorders of serotonergic, cholinergic, glutamatergic and γ-aminobutyric acid energy neurotransmitters were also discovered. The regulatory effect of acupuncture on the above central neurological abnormalities in chronic fatigue syndrome model animals was elaborated, and the direction for further research was analyzed in order to provide ideas for further research on the central mechanism of acupuncture treatment for chronic fatigue syndrome.

Research progress on central mechanism of acupuncture treatment for chronic fatigue syndrome : 针刺调控慢性疲劳综合征中枢机制研究进展

Chronic fatigue syndrome is a neurological disorder characterized by extreme fatigue that lasts for a long time and doesn't alleviate with rest. The number of the cases has been increasing during the era of COVID-19 pandemic. Acupuncture may have some effect on chronic fatigue syndrome, but its mechanism remains unclear. This article was to summarize the specific manifestations of abnormal central mechanism in patients with chronic fatigue syndrome through laboratory tests and neuroimaging. It was found from the laboratory evaluation that there were changes in the structure of the frontal cortex, thalamus and other brain tissues;factors, including IFN-α and IL-10 in cerebrospinal fluid were found abnormal;results of oxidative and nitrosative stress and changes in neurobiochemical substances, e.g. hypothalamus hormone levels and neurotransmitter concentrations, were observed. With magnetic resonance imaging and positron emission tomography, it was shown that the partial brain of persons with chronic fatigue syndrome had morphological changes with diminished grey matter and white;changes in cerebral blood flow velocity caused by decreased perfusion and functional activity with abnormal connectivity in brain were detected. In addition, there was significant decrease in glucose metabolism accompanied with neuroinflammatory response;metabolic disorders of serotonergic, cholinergic, glutamatergic and γ-aminobutyric acid energy neurotransmitters were also discovered. The regulatory effect of acupuncture on the above central neurological abnormalities in chronic fatigue syndrome model animals was elaborated, and the direction for further research was analyzed in order to provide ideas for further research on the central mechanism of acupuncture treatment for chronic fatigue syndrome.

Superspreading potentials of SARS-CoV-2 Delta variants across different contact settings in eastern China: a retrospective observational study

Objectives As the genetic variants of SARS-CoV-2 continuously pose threats to global health, evaluating superspreading potentials of emerging variants is of importance for region-wide control of COVID-19 outbreaks. Methods By using detailed epidemiological contact tracing data of test-positive COVID-19 cases collected between July and August 2021 in Nanjing and Yangzhou, China, we assessed the superspreading potential of outbreaks seeded by SARS-CoV-2 Delta variants. The transmission chains and case-clusters were constructed according to the individual-based surveillance data. We modelled the disease transmission as a classic branching process with transmission heterogeneity governed by negative binomial models. Subgroup analysis was conducted by different contact settings and ages. Results We estimated an expected 14% (95% CI: 11-16%) of the most infectious cases generated 80% of the total transmission. Conclusions Delta variants demonstrated a significant potential of superspreading under strict COVID-19 control and active COVID-19 detecting measures. Enhancing the surveillance on disease transmissibility especially in high-risk settings of superspreading, along with rapid contact tracing and case isolations would be the key to mitigate the epidemic caused by the emerging variants.

Evaluation of a Quality Improvement Intervention to Improve Pediatric Palliative Care Consultation Processes.

BACKGROUND: A critical aspect of pediatric palliative care consultations is the assessment and documentation of patient and family needs. While these assessments usually include a focus on physical pain, there is less standardization of assessments of other physical symptoms and psychosocial, emotional, or spiritual needs. AIMS: To improve the breadth of assessment of psychosocial and emotional needs, screen for symptoms other than pain among pediatric patients utilizing palliative care services, and to increase documentation of assessment data from 30%-40% to 80% through practice changes implemented in 2 Plan-Do-Study-Act (PDSA) cycles. METHODS: This quality improvement project involved implementing provider education and adapting the palliative care consultation template in the electronic health record to improve breadth and consistency of assessment and documentation during consultations by the interdisciplinary pediatric palliative care team. Two PDSA cycles were performed. Chi squared tests and statistical control charts were used for data analysis. RESULTS: There was statistically significant improvement in the inclusion of documentation of a pediatric palliative care social work note from baseline (32%) to Cycle 2 (57%). Physical symptom screening declined slightly, but not significantly (p = .32) and socio-emotional discussions also declined but not significantly (p = .05). CONCLUSIONS: Screening for physical symptoms and discussions with patients and families about psychosocial/emotional needs during the initial palliative care consultations are extremely important in providing effective, holistic, patient-centered care. There is a need for development of pediatric-centric guidelines and quality measures to evaluate pediatric palliative care programs; further research is indicated to determine methods for evaluating compliance with these guidelines.

Homologous booster immunization with an inactivated vaccine induced robust antibody response in healthcare workers: A retrospective study.

Coronavirus Disease 2019 (Covid-19) severely impacted the health, society, and economy around the world. With declining protective efficacy of primary vaccination and the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, a Covid-19 booster vaccination is being fully implemented globally. Many people received three doses of BBIBP-CorV inactivated vaccine in China and other developing countries. However, the antibody response and immune persistence of the homologous BBIBP-CorV booster vaccination is yet to be thoroughly evaluated, as previous studies focused within one month after the third dose. In this study, 97 participants were enrolled to analyze the antibody response and immune persistence within 6 months as well as the safety within 7 days after the third-dose of homologous BBIBP-CorV inactivated vaccine. The seroconversion rate for total antibody against the receptor binding domain (RBD) of the SARS-CoV-2 spike (S) protein were both 100% at month 1 and month 6 after the third dose. The IgG against the RBD of the SARS-CoV-2 S protein seroconversion rate increased from 42.27% before the third dose to 100% 1 month after the third dose and then slightly decreased to 98.97% 5 months later. Positive IgM against the RBD of the SARS-CoV-2 S protein was rare and was observed in only one participant at month 1 after the third dose. The neutralizing antibody levels at month 1 and month 6 after the third dose increased 63.32-fold and 13.16-fold compared with those before the third dose, and the positive rate for neutralizing antibody was still 100% at month 6 after the third dose. Importantly, the antibody responses induced by the vaccine and immune persistence were not affected by sex or age. No serious adverse reactions were reported. Total antibody and IgG against the RBD of the SARS-CoV-2 S protein were highly correlated with neutralizing antibody, suggesting that total antibody and IgG against the RBD of the SARS-CoV-2 S protein could be used as predictors for neutralizing antibody. In conclusion, the third dose of homologous BBIBP-CorV inactivated vaccine induced a robust antibody response and moderate immune persistence. These finding are of great significance for development future vaccination strategies.

Superspreading potentials of SARS-CoV-2 Delta variants across different contact settings in Eastern China: A retrospective observational study.

OBJECTIVES: As the genetic variants of SARS-CoV-2 continuously pose threats to global health, evaluating superspreading potentials of emerging genetic variants is of importance for region-wide control of COVID-19 outbreaks. METHODS: By using detailed epidemiological contact tracing data of test-positive COVID-19 cases collected between July and August 2021 in Nanjing and Yangzhou, China, we assessed the superspreading potential of outbreaks seeded by SARS-CoV-2 Delta variants. The transmission chains and case-clusters were constructed according to the individual-based surveillance data. We modelled the disease transmission as a classic branching process with transmission heterogeneity governed by negative binomial models. Subgroup analysis was conducted by different contact settings and age groups. RESULTS: We reported a considerable heterogeneity in the contact patterns and transmissibility of Delta variants in eastern China. We estimated an expected 14% (95% CI: 11-16%) of the most infectious cases generated 80% of the total transmission. CONCLUSIONS: Delta variants demonstrated a significant potential of superspreading under strict control measures and active COVID-19 detecting efforts. Enhancing the surveillance on disease transmissibility especially in high-risk settings, along with rapid contact tracing and case isolations would be one of the key factors to mitigate the epidemic caused by the emerging genetic variants of SARS-CoV-2.

Challenges for medical students in applying ethical principles to allocate life-saving medical devices during the COVID-19 pandemic (preprint)

Background: The COVID-19 pandemic has sparked a widespread ethical dilemma of distributing scarce life-saving medical devices to critically ill patients and created a huge opportunity for virtual learning for medical students to exercise the principles of medical ethics. Methods: We arranged for medical students to interact with virtual patients with respiratory failure and asked them to apply ethical principles to justify their prioritization of who should receive life-saving facilities. We analyzed the reports and investigated the ethical principles chosen and the factors that may play important roles in making critical medical decisions. Results: A total of 67 medical students were recruited. Overall, 73% of them made decisions based on principles of justice. However, 66% of the participants applied multiple ethical principles to justify their clinical decisions. While facing conflicting choices regarding different ethical principles, 48% used the principle of justice to justify their final decisions. However, they had diverse interpretations of the principle of justice. Most students requested additional medical knowledge, laws, or guidelines from institutions to help them make decisions, and 43% of them were able to proposed a strategy to address this ethical dilemma. Conclusions: Justice is the first priority for medical students while allocating medical facilities to critically ill patients. Clear guidelines may help them make ethical decisions when facing this dilemma.