Pandemic fatigue impedes mitigation of COVID-19 in Hong Kong.

Hong Kong has implemented stringent public health and social measures (PHSMs) to curb each of the four COVID-19 epidemic waves since January 2020. The third wave between July and September 2020 was brought under control within 2 m, while the fourth wave starting from the end of October 2020 has taken longer to bring under control and lasted at least 5 mo. Here, we report the pandemic fatigue as one of the potential reasons for the reduced impact of PHSMs on transmission in the fourth wave. We contacted either 500 or 1,000 local residents through weekly random-digit dialing of landlines and mobile telephones from May 2020 to February 2021. We analyze the epidemiological impact of pandemic fatigue by using the large and detailed cross-sectional telephone surveys to quantify risk perception and self-reported protective behaviors and mathematical models to incorporate population protective behaviors. Our retrospective prediction suggests that an increase of 100 daily new reported cases would lead to 6.60% (95% CI: 4.03, 9.17) more people worrying about being infected, increase 3.77% (95% CI: 2.46, 5.09) more people to avoid social gatherings, and reduce the weekly mean reproduction number by 0.32 (95% CI: 0.20, 0.44). Accordingly, the fourth wave would have been 14% (95% CI%: -53%, 81%) smaller if not for pandemic fatigue. This indicates the important role of mitigating pandemic fatigue in maintaining population protective behaviors for controlling COVID-19.

Density Functional Theory Study of Bilayer Borophene-Based Anode Material for Rechargeable Lithium Ion Batteries.

The bilayer borophene has been successfully fabricated in experiments recently and possesses superior antioxidation and robust metallic properties, which holds great promise for the future anode materials of Li-ion batteries. Herein, using first-principles calculations, two bilayer borophenes including P6/mmm or P6̅m2 symmetry groups with or without vacancy defects are comprehensively explored and acted as electrode materials with high performance in Li-ion batteries. The charge density difference, adsorption energies, and Bader charge analysis are calculated and discussed for single lithium adsorbed on bilayer borophene. The results shown that with the increase of lithium concentration, the adsorption energies are rapidly decreased due to the repulsion of boron atoms except for the P6̅m2 systems with double side adsorption and corresponding energies remain the narrow range. Meanwhile, the partial density of states shows metallic character after lithium adsorption and indicates good conductivity for the charge-discharge process. Furthermore, small diffusion barriers, low average open-circuit voltage, can be achieved, and large storage capacity is up to 930.2 mA h/g at the lower lithium content of 0.375. These results propose that bilayer borophene might be a good choice for anode material applications in future Li-ion batteries with fast ion diffusion and high power density.

Structural Characterization of Boron Sheets beyond the Monolayer and Implication for Experimental Synthesis and Identification.

The successful synthesis of quasi-freestanding bilayer borophene has aroused much attention for its superior physical properties and holds great promise for future electronic devices. Herein, we comprehensively explore six boron sheets beyond the monolayer and structurally characterize them via various methods using first-principles calculations for experimental references. On the basis of atomic models of borophenes, simulated scanning tunneling microscope (STM) images show different morphologies at different bias voltages and are explained by the partial densities of states and the height differences in the vertical direction. Simulated transmission electron microscope images further probe the internal atomic arrangement of boron sheets and compensate for the shortcomings of STM images to better distinguish different phases of boron sheets. The interlayer coupling strength is stronger in bilayer borophenes than in the three-layer system via the electron localization function and Mulliken bond population. In addition, simulated X-ray diffraction and infrared spectra show different characteristic peaks and corresponding vibrational modes to further characterize these boron sheets. These theoretical results can decrease the prime cost and provide vital guidance for the experimental synthesis and identification of boron sheets beyond the monolayer.

Drinking water disinfection byproduct iodoacetic acid affects thyroid hormone synthesis in Nthy-ori 3-1 cells.

Iodoacetic acid (IAA) is an emerging and the most genotoxic iodinated disinfection byproduct to date. IAA can disrupt the thyroid endocrine function in vivo and in vitro, but the underlying mechanisms remain unclear. In this work, transcriptome sequencing was used to investigate the effect of IAA on the cellular pathways of human thyroid follicular epithelial cell line Nthy-ori 3-1 and determine the mechanism of IAA on the synthesis and secretion of thyroid hormone (TH) in Nthy-ori 3-1 cells. Results of transcriptome sequencing indicated that IAA affected the TH synthesis pathway in Nthy-ori 3-1 cells. IAA reduced the mRNA expression of thyroid stimulating hormone receptor, sodium iodide symporter, thyroid peroxidase, thyroglobulin, paired box 8 and thyroid transcription factor-2, inhibited the cAMP/PKA pathway and Na+-K+-ATPase, and decreased the iodine intake. The results were confirmed by our previous findings in vivo. Additionally, IAA downregulated glutathione and the mRNA expression of glutathione peroxidase 1, leading to increased reactive oxygen species production. This study is the first to elucidate the mechanisms of IAA on TH synthesis in vitro. The mechanisms are associated with down-regulating the expression of genes related to TH synthesis, inhibiting iodine uptake, and inducing oxidative stress. These findings may improve future health risk assessment of IAA on thyroid in human.

Effectiveness of CoronaVac and BNT162b2 Vaccines Against Severe Acute Respiratory Syndrome Coronavirus 2 Omicron BA.2 Infections in Hong Kong.

There is limited evidence on vaccine effectiveness against asymptomatic or mild Omicron infections. We estimated that recent third doses of messenger RNA or inactivated vaccines reduced the risk of self-reported infection by 52% (95% confidence interval, 17%-73%) among randomly sampled adults during the Omicron BA.2-dominated surge in Hong Kong.

Universal Community Nucleic Acid Testing for Coronavirus Disease 2019 (COVID-19) in Hong Kong Reveals Insights Into Transmission Dynamics: A Cross-Sectional and Modeling Study.

BACKGROUND: Testing of an entire community has been used as an approach to control coronavirus disease 2019 (COVID-19). In Hong Kong, a universal community testing program (UCTP) was implemented at the fadeout phase of a community epidemic in July to September 2020. We described the utility of the UCTP in finding unrecognized infections and analyzed data from the UCTP and other sources to characterize transmission dynamics. METHODS: We described the characteristics of people participating in the UCTP and compared the clinical and epidemiological characteristics of COVID-19 cases detected by the UCTP versus those detected by clinical diagnosis and public health surveillance (CDPHS). We developed a Bayesian model to estimate the age-specific incidence of infection and the proportion of cases detected by CDPHS. RESULTS: In total, 1.77 million people, 24% of the Hong Kong population, participated in the UCTP from 1 to 14 September 2020. The UCTP identified 32 new infections (1.8 per 100000 samples tested), consisting of 29% of all local cases reported during the two-week UCTP period. Compared with the CDPHS, the UCTP detected a higher proportion of sporadic cases (62% vs 27%, P<.01) and identified 6 (out of 18) additional clusters during that period. We estimated that 27% (95% credible interval: 22%, 34%) of all infections were detected by the CDPHS in the third wave. CONCLUSIONS: We reported empirical evidence of the utility of population-wide COVID-19 testing in detecting unrecognized infections and clusters. Around three quarters of infections have not been identified through existing surveillance approaches including contact tracing.

Restaurant-Based Measures to Control Community Transmission of COVID-19, Hong Kong.

Controlling transmission in restaurants is an important component of public health and social measures for coronavirus disease. We examined the effects of restaurant measures in Hong Kong. Our findings indicate that shortening operating hours did not have an effect on time-varying effective reproduction number when capacity was already reduced.

Viral RNA and Infectious Influenza Virus on Mobile Phones of Patients With Influenza in Hong Kong and the United States.

Mobile phones are among the most highly touched personal objects. As part of a broader study on the contribution of fomites to influenza transmission, between 2017 and 2019, we swabbed mobile phones from 138 patients with influenza in 2 locations. Influenza viral RNA detection rates were 23% (23 of 99 phones) and 36% (14 of 39) in Hong Kong and Maryland, respectively. In Hong Kong, infectious influenza virus was recovered from 3 of 23 mobile phones which had influenza viral RNA detected. Mobile phone influenza contamination was positively associated with upper respiratory tract viral load and negatively associated with age. Cleaning personal objects of patients with influenza should be recommended, and individuals should avoid sharing objects with these patients.

Changing Disparities in Coronavirus Disease 2019 (COVID-19) Burden in the Ethnically Homogeneous Population of Hong Kong Through Pandemic Waves: An Observational Study.

BACKGROUND: Disparities were marked in previous pandemics, usually with higher attack rates reported for those in lower socioeconomic positions and for ethnic minorities. METHODS: We examined characteristics of laboratory-confirmed coronavirus disease 2019 (COVID-19) cases in Hong Kong, assessed associations between incidence and population-level characteristics at the level of small geographic areas, and evaluated relations between socioeconomics and work-from-home (WFH) arrangements. RESULTS: The largest source of COVID-19 importations switched from students studying overseas in the second wave to foreign domestic helpers in the third. The local cases were mostly individuals not in formal employment (retirees and homemakers) and production workers who were unable to WFH. For every 10% increase in the proportion of population employed as executives or professionals in a given geographic region, there was an 84% (95% confidence interval [CI], 1-97%) reduction in the incidence of COVID-19 during the third wave. In contrast, in the first 2 waves, the same was associated with 3.69 times (95% CI, 1.02-13.33) higher incidence. Executives and professionals were more likely to implement WFH and experienced frequent changes in WFH practice compared with production workers. CONCLUSIONS: Consistent findings on the reversed socioeconomic patterning of COVID-19 burden between infection waves in Hong Kong in both individual- and population-level analyses indicated that risks of infections may be related to occupations involving high exposure frequency and WFH flexibility. Contextual determinants should be taken into account in policy planning aiming at mitigating such disparities.

Predictive Model of Early Neurological Deterioration in Patients with Acute Ischemic Stroke: A Retrospective Cohort Study.

OBJECTIVE: This study aimed to develop a predictive model of early neurological deterioration (END) in patients with acute ischemic stroke (AIS). METHODS: The present retrospective cohort study considered patients with AIS who were admitted to a tertiary hospital in Shenzhen, China between January 2014 and December 2018. An increase of 2 points or more on the National Institute of Health Stroke Scale (NIHSS) within 7 days indicated END. We selected baseline clinical, laboratory, and neuroimaging variables to construct predictive models through multivariate logistic regression. The receiver operating characteristic curve and calibration plots were calculated. RESULTS: A total of 391 patients with AIS were enrolled in the study. END was observed in 64 (16.4%) cases. A prediction model developed from the initial NIHSS score, middle cerebral artery stenosis, and carotid stenosis of≥ 50% showed good discriminative ability: area under the receiver operating characteristic curve, 0.870 (95%CI, 0.813-0.911); threshold, -1.570; specificity, 84.40%; sensitivity, 75.00%; positive predictive value, 48.48%; and a negative predictive value, 94.52%. CONCLUSION: Our predictive model developed from the initial NIHSS score, middle cerebral artery stenosis, and carotid stenosis of ≥ 50% could identify patients with AIS who were at risk of developing END. The model requires validation by larger studies performed at other institutions.

Presence of Influenza Virus on Touch Surfaces in Kindergartens and Primary Schools.

BACKGROUNDS: Influenza virus can survive on some surfaces, facilitating indirect person-to-person transmission. METHODS: We collected swab samples weekly from commonly touched surfaces in 7 kindergartens and primary schools during the 2017/2018 winter influenza season in Hong Kong. RESULTS: We detected influenza virus ribonucleic acid (RNA) in 12 of 1352 samples (<1%) collected from 7 of 11 classrooms (5 to 2 × 106 RNA copies/mL). Viral RNA was more frequently recovered from communal items inside classrooms such as bookshelves and doorknobs. CONCLUSIONS: Surface contamination indicates the potential role of fomites in influenza virus transmission in schools. Communal items inside classrooms may cause greater potential risks of transmission during influenza epidemics.

Nonpharmaceutical Measures for Pandemic Influenza in Nonhealthcare Settings-Social Distancing Measures.

Influenza virus infections are believed to spread mostly by close contact in the community. Social distancing measures are essential components of the public health response to influenza pandemics. The objective of these mitigation measures is to reduce transmission, thereby delaying the epidemic peak, reducing the size of the epidemic peak, and spreading cases over a longer time to relieve pressure on the healthcare system. We conducted systematic reviews of the evidence base for effectiveness of multiple mitigation measures: isolating ill persons, contact tracing, quarantining exposed persons, school closures, workplace measures/closures, and avoiding crowding. Evidence supporting the effectiveness of these measures was obtained largely from observational studies and simulation studies. Voluntary isolation at home might be a more feasible social distancing measure, and pandemic plans should consider how to facilitate this measure. More drastic social distancing measures might be reserved for severe pandemics.

Nonpharmaceutical Measures for Pandemic Influenza in Nonhealthcare Settings-Personal Protective and Environmental Measures.

There were 3 influenza pandemics in the 20th century, and there has been 1 so far in the 21st century. Local, national, and international health authorities regularly update their plans for mitigating the next influenza pandemic in light of the latest available evidence on the effectiveness of various control measures in reducing transmission. Here, we review the evidence base on the effectiveness of nonpharmaceutical personal protective measures and environmental hygiene measures in nonhealthcare settings and discuss their potential inclusion in pandemic plans. Although mechanistic studies support the potential effect of hand hygiene or face masks, evidence from 14 randomized controlled trials of these measures did not support a substantial effect on transmission of laboratory-confirmed influenza. We similarly found limited evidence on the effectiveness of improved hygiene and environmental cleaning. We identified several major knowledge gaps requiring further research, most fundamentally an improved characterization of the modes of person-to-person transmission.

Nonpharmaceutical Measures for Pandemic Influenza in Nonhealthcare Settings-International Travel-Related Measures.

International travel-related nonpharmaceutical interventions (NPIs), which can include traveler screening, travel restrictions, and border closures, often are included in national influenza pandemic preparedness plans. We performed systematic reviews to identify evidence for their effectiveness. We found 15 studies in total. Some studies reported that NPIs could delay the introduction of influenza virus. However, no available evidence indicated that screening of inbound travelers would have a substantial effect on preventing spread of pandemic influenza, and no studies examining exit screening were found. Some studies reported that travel restrictions could delay the start of local transmission and slow international spread, and 1 study indicated that small Pacific islands were able to prevent importation of pandemic influenza during 1918-19 through complete border closure. This limited evidence base indicates that international travel-related NPIs would have limited effectiveness in controlling pandemic influenza and that these measures require considerable resources to implement.

Association Between the Hepatic Steatosis Index and Risk of Incident Type 2 Diabetes Mellitus in the Normoglycemic Population:A Longitudinal Prospective Study in Japan.

Purpose: The Hepatic Steatosis Index (HSI) is a reliable predictor of non-alcoholic fatty liver disease (NAFLD), which can increase the risk of type 2 diabetes mellitus (T2DM). However, limited research has directly predicted HSI's association with T2DM occurrence at normal blood glucose levels. Hence, this study aimed to assess the link between baseline HSI and T2DM development under euglycemic conditions while also exploring potential sex differences. Methods: Using data from the NAGALA cohort study, a Cox regression model analyzed the relationship between HSI and T2DM risk, calculating hazard ratios (HR) and 95% confidence intervals (CI). Subgroup analyses were conducted to investigate factors influencing HSI's prediction of incident T2DM. Results: During a mean 6.1-year follow-up, 238 individuals (1.65% of participants) developed T2DM. After adjusting for age, ethanol consumption, smoking status, SBP, DBP, TG, and TC, HSI showed a significant association with incident T2DM in individuals with normal glucose levels, consistent across sexes. Compared to the lowest quartile group (Q1), the HR and 95% CI for Q2, Q3, and Q4 were 1.09 (0.61, 1.93), 1.16 (0.68, 1.98), and 3.30 (2.04, 5.33), respectively (P for trend < 0.001). Subgroup analysis indicated that elevated HSI significantly increased the risk of incident T2DM in individuals with normal TG levels (P for interaction = 0.0170). Conclusion: This study highlights the significant association between elevated HSI levels and the likelihood of developing incident T2DM in individuals with normal glucose levels. Furthermore, it offers a simple and valuable screening tool for predicting T2DM.

Impact of health education on promoting influenza vaccination health literacy in primary school students: a cluster randomised controlled trial protocol.

INTRODUCTION: Influenza is a major public health threat, and vaccination is the most effective prevention method. However, vaccination coverage remains suboptimal. Low health literacy regarding influenza vaccination may contribute to vaccine hesitancy. This study aims to evaluate the effect of health education interventions on influenza vaccination rates and health literacy. METHODS AND ANALYSIS: This cluster randomised controlled trial will enrol 3036 students in grades 4-5 from 20 primary schools in Dongguan City, China. Schools will be randomised to an intervention group receiving influenza vaccination health education or a control group receiving routine health education. The primary outcome is the influenza vaccination rate. Secondary outcomes include health literacy levels, influenza diagnosis rate, influenza-like illness incidence and vaccine protection rate. Data will be collected through questionnaires, influenza surveillance and self-reports at baseline and study conclusion. ETHICS AND DISSEMINATION: Ethical approval has been sought from the Ethics Committee of the School of Public Health, Sun Yat-sen University. Findings from the study will be made accessible to both peer-reviewed journals and key stakeholders. TRIAL REGISTRATION NUMBER: NCT06048406.

Monitoring the dynamic changes in aroma during the whole processing of Qingzhuan tea at an industrial scale: From fresh leaves to finished tea.

Aroma is one of the most outstanding quality characteristics of Qingzhuan tea (QZT), but its formation is still unclear. Thus, the volatile organic compounds (VOCs) during the whole processing of QZT were investigated by headspace solid-phase microextraction/gas chromatography-mass spectrometry. Based on 144 identified VOCs, the results showed that de-enzyming, sun-drying, and piling fermentation were the key processes of QZT aroma formation. Furtherly, 42 differential VOCs (VIP > 1.0 and p < 0.05) and 16 key VOCs (rOAV > 1.0 and/or ROAV > 1.0) were screened. Especially, sulcatone and ß-ionone (rOAV > 100 and ROAV > 10) were considered the most important contributors to the aroma of QZT. The metabolisms of key VOCs were mainly involved in oxidative degradation of fatty acids, degradation of carotenoids, and methylation of gallic acid. This study could help to more comprehensively understand the aroma formation in QZT processing at an industrial scale.

Dahuang Zhechong Pill Alleviates Liver Fibrosis Progression by Regulating p38 MAPK/NF-κ B/TGF-ß1 Pathway.

OBJECTIVE: To explore the effect and mechanism of Dahuang Zhechong Pill (DHZCP) on liver fibrosis. METHODS: Liver fibrosis cell model was induced by transforming growth factor-ß (TGF-ß) in hepatic stellate cells (HSC-T6). DHZCP medicated serum (DMS) was prepared in rats. HSC-T6 cells were divided into the control (15% normal blank serum culture), TGF-ß (15% normal blank serum + 5 ng/mL TGF-ß), DHZCP (15% DMS + 5 ng/mL TGF-ß), DHZCP+PDTC [15% DMS + 4 mmol/L ammonium pyrrolidine dithiocarbamate (PDTC)+ 5 ng/mL TGF-ß], and PDTC groups (4 mmol/L PDTC + 5 ng/mL TGF-ß). Cell activity was detected by cell counting kit 8 and levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, IL-6, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the cell supernatant were determined by enzyme-linked immunosorbnent assay. Western blot was used to measure the expressions of p38 mitogen-activated protein kinase/nuclear factor kappa B/transforming growth factor-ß1 (p38 MAPK/NF-κ B/TGF-ß1) pathway related proteins, and the localization and expressions of these proteins were observed by immunofluorescence staining. RESULTS: DHZCP improves the viability of cells damaged by TGF-ß and reduces inflammatory cytokines and ALT and AST levels in the supernatant of HSC-T6 cells induced with TGF-ß (P<0.05 or P<0.01). Compared with the TGF-ß group, NF-κ B p65 levels in the DHZCP group were decreased (P<0.05). p38 MAPK and NF-κ B p65 levels in the DHZCP+PDTC were also reduced (P<0.01). Compared with the TGF-ß group, the protein expression of Smad2 showed a downward trend in the DHZCP, DHZCP+PDTC, and PDTC groups (all P<0.01), and the decreasing trend of Samd3 was statistically significant only in DHZCP+PDTC group (P<0.01), whereas Smad7 was increased (P<0.05 or P<0.01). CONCLUSION: DHZCP can inhibit the process of HSC-T6 cell fibrosis by down-regulating the expression of p38 MAPK/NF-κ B/TGF-ß1 pathway.

Assessment of the impact of the vaccine pass policy on COVID-19 vaccine hesitancy and uptake among Chinese adults in Hong Kong.

BACKGROUND: Recognising the importance of attaining high vaccine coverage to mitigate the COVID-19 impact, a Vaccine Pass scheme was implemented during and after the first large Omicron wave with high mortality in older ages in Hong Kong in early 2022 requiring three doses by June 2022. We did not identify any studies evaluating the policy impact of vaccination mandates with vaccine uptake over whole policy period of time in a Chinese population. We aim to evaluate the impact of the Vaccine Pass policy on COVID-19 vaccine uptake in adults in a Chinese population in Hong Kong. METHODS: We analysed patterns in vaccine uptake and hesitancy using local data from population vaccine registry and 32 cross-sectional telephone surveys conducted from October 2021 to December 2022. The association of Vaccine Pass phases with vaccine uptake was examined using logistic regression analyses, taking into account covariates including self-risk perception, perceived self-efficacy in preventing COVID-19 and trust in government in pandemic control as well as physical distancing measures and demographics. RESULTS: The uptake of primary series and third doses was positively significantly associated with the successive stages of Vaccine Pass implementation (adjusted odds ratios ranged from 2.41 to 7.81). Other statistically significant drivers of uptake included age group, chronic condition, higher perceived personal susceptibility to COVID-19, higher trust in government, and higher educational attainment. CONCLUSION: Vaccine uptake in older adults was observed to have increased by a greater extent after the policy annoucement and implementation, under the contextual changes during and after a large Omicron wave with high mortality in Hong Kong in early 2022. Since the policy withdrawal the uptake of further booster doses has been very low in all ages. We suggest that improving voluntary booster uptake in older adults should be prioritized.

Comparison of control and transmission of COVID-19 across epidemic waves in Hong Kong: an observational study.

Background: Hong Kong contained COVID-19 for two years but experienced a large epidemic of Omicron BA.2 in early 2022 and endemic transmission of Omicron subvariants thereafter. We reflected on pandemic preparedness and responses by assessing COVID-19 transmission and associated disease burden in the context of implementation of various public health and social measures (PHSMs). Methods: We examined the use and impact of pandemic controls in Hong Kong by analysing data on more than 1.7 million confirmed COVID-19 cases and characterizing the temporal changes non-pharmaceutical and pharmaceutical interventions implemented from January 2020 through to 30 December 2022. We estimated the daily effective reproductive number (Rt) to track changes in transmissibility and effectiveness of community-based measures against infection over time. We examined the temporal changes of pharmaceutical interventions, mortality rate and case-fatality risks (CFRs), particularly among older adults. Findings: Hong Kong experienced four local epidemic waves predominated by the ancestral strain in 2020 and early 2021 and prevented multiple SARS-CoV-2 variants from spreading in the community before 2022. Strict travel-related, case-based, and community-based measures were increasingly tightened in Hong Kong over the first two years of the pandemic. However, even very stringent measures were unable to contain the spread of Omicron BA.2 in Hong Kong. Despite high overall vaccination uptake (>70% with at least two doses), high mortality was observed during the Omicron BA.2 wave due to lower vaccine coverage (42%) among adults ≥65 years of age. Increases in antiviral usage and vaccination uptake over time through 2022 was associated with decreased case fatality risks. Interpretation: Integrated strict measures were able to reduce importation risks and interrupt local transmission to contain COVID-19 transmission and disease burden while awaiting vaccine development and rollout. Increasing coverage of pharmaceutical interventions among high-risk groups reduced infection-related mortality and mitigated the adverse health impact of the pandemic. Funding: Health and Medical Research Fund.