Risk factors associated with indoor transmission during home quarantine of COVID-19 patients.

Purpose: The study aimed to identify potential risk factors for family transmission and to provide precautionary guidelines for the general public during novel Coronavirus disease 2019 (COVID-19) waves. Methods: A retrospective cohort study with numerous COVID-19 patients recruited was conducted in Shanghai. Epidemiological data including transmission details, demographics, vaccination status, symptoms, comorbidities, antigen test, living environment, residential ventilation, disinfection and medical treatment of each participant were collected and risk factors for family transmission were determined. Results: A total of 2,334 COVID-19 patients participated. Compared with non-cohabitation infected patients, cohabitated ones were younger (p = 0.019), more commonly unvaccinated (p = 0.048) or exposed to infections (p < 0.001), and had higher rates of symptoms (p = 0.003) or shared living room (p < 0.001). Risk factors analysis showed that the 2019-nCov antigen positive (OR = 1.86, 95%CI 1.40-2.48, p < 0.001), symptoms development (OR = 1.86, 95%CI 1.34-2.58, p < 0.001), direct contact exposure (OR = 1.47, 95%CI 1.09-1.96, p = 0.010) were independent risk factors for the cohabitant transmission of COVID-19, and a separate room with a separate toilet could reduce the risk of family transmission (OR = 0.62, 95%CI 0.41-0.92, p = 0.018). Conclusion: Patients showing negative 2019-nCov antigen tests, being asymptomatic, living in a separate room with a separate toilet, or actively avoiding direct contact with cohabitants were at low risk of family transmission, and the study recommended that avoiding direct contact and residential disinfection could reduce the risk of all cohabitants within the same house being infected with COVID-19.

The irreplaceable role of medical massive open online courses in China during the COVID-19 pandemic.

BACKGROUND: Massive open online courses (MOOCs) have become innovative open-learning approach in medical education. This study aimed to evaluate the dynamic changes in the construction and application of medical MOOCs before and after the coronavirus disease 2019 (COVID-19) pandemic in China. METHODS: The dynamic changes of usages about medical MOOCs before and after 2020 were mainly searched on the Smart Education of China Higher Education platform, and the detailed learning profiles and outcome indicators were further analyzed using 40 national first-class medical MOOCs from 'zhihuishu' platform. RESULTS: A total of 2,405 medical MOOCs were exported from the Smart Education of China Higher Education platform, of which 1,313 (54.6%) were launched since 2020. The total and average numbers of participants of 141 national first-class medical MOOCs peaked during the initial spread of COVID-19 in 2020. We further analyzed the dynamic usage of MOOCs from 2018 to 2022 based on 40 national first-class medical MOOCs launched on the 'Zhihuishu' platform. The findings revealed that the number of registered learners (3,240 versus 2,654), questions and answers (27,005 versus 5,116) and students taking the final examination (2,782 versus 1,995) per semester were significantly higher since 2020 compared to these before 2020. Especially, the number of registered learners, registered schools, questions and answers, and students participating in online discussion, taking the unit quiz, taking final examinations and passing final examinations all peaked in the 2020 spring-summer semester. Pearson's correlation analysis found that the number of questions and answers and the number of learners who participated in online discussion were both positively correlated with the number of students who passed the final examination, and the correlation was especially strong since 2020. Moreover, the number of publications on medical MOOC research has soared since 2020 and has maintained a continuous upward trend. CONCLUSIONS: High-quality medical MOOCs have been launched rapidly since the COVID-19 pandemic in China. The number of participants and online interactions of medical MOOCs peaked during the initial spread of COVID-19 in 2020. MOOCs are reliable and valid digital sources that facilitate medical higher education and play irreplaceable roles in emergency management.

Impact of knowledge management capabilities on organisational performance in construction firms: the mediating role of innovation

PurposeThis study aims to investigate the mediating effect of innovation on the relationship between KM (KM) capabilities and organisational performance in the context of construction firms operating in Pakistan. Worldwide innovation predicts the performance of any firm. Today, the construction industry in Pakistan is booming, which reinforces the need for a study on innovation and KM in this sector.Design/methodology/approachThis empirical study uses a correlational research design. An online survey questionnaire was used as a data collection method. Through convenient sampling, the sample comprised 277 employees from different construction firms working under the Defence Housing Authority (a construction company operating in major cities) in Pakistan. Data were analysed through partial least squares-structural equation modelling (Smart PLS-SEM version 3) to assess the hypothesis.FindingsData analysis reveals that KM dimensions, knowledge acquisition, application and protection positively and significantly influence organisational performance;however, knowledge conversion is insignificant. Furthermore, innovation positively and substantially mediates the relationship between knowledge acquisition, application, protection, organisational performance and the insignificant terms of knowledge conversion.Research limitations/implicationsThis study is limited to the construction industry, and future research should be conducted on larger scales for better generalisation. Other mediators between KM and organisational performance (i.e. organisational complexity, workplace environment, employee knowledge-sharing attitude) should be investigated.Practical implicationsThese results are crucial and encourage managers in the construction industry, especially from a developing country like Pakistan, to understand the importance of innovation, the application of KM and the essential role it has in boosting business performance.Originality/valueThis research contributes to the scholarly debate on the mediating role of innovation in the relationship between KM and organisational performance. It also expands the literature on KM through an empirical investigation on the innovation of the construction industry in Pakistan from a management perspective.

Pathogenic characteristics of severe acute respiratory infection in adult inpatients in Yangpu District, Shanghai, 2019-2021

Objective: To understand the pathogenic spectrum and epidemiological characteristics of severe acute respiratory infection (SARI) in adult inpatients in Yangpu District, Shanghai, China, in order to explore strategies for the prevention and treatment of respiratory infectious diseases. Methods: Individual cases were from adult inpatients with SARI in Yangpu District, Shanghai, China from January 2019 to July 2021. Their respiratory samples were collected for etiological pathogen testing. Results: A total of 681 SARI cases were enrolled for sampling and lab testing. Among them, 79.00% were aged 60 years and older, and 75.48% had confirmed chronic disease history. A total of 163 infection inpatients (23.94%) were positive for at least one pathogen. The pathogens identified most frequently were influenza A virus (6.75%), followed by rhinovirus/enterovirus (3.23%), parainfluenza virus (PIV) (2.79%), Mycoplasma pneumoniae (2.35%), coronavirus (CoV) (2.06%). The positive rates of adenovirus (AdV), human metapneumovirus (hMPV), respiratory syncytial virus and bocavirus were all less than 2%. Bacterial strains were identified in eleven SARI cases, including Staphylococcus aureus and Pseudomonas aeruginosa (4 strains), Klebsiella pneumoniae (3 strains). Legionella pneumophila was detected in 9 cases (1.32%) and Bordetella pertussis in 5 cases (0.73%). Two pathogens were co-detected from 11 cases, accounting for 1.62% of 163 positive cases. The most common co-detected pathogens were influenza A virus and other pathogens, accounting for 54.55% of the mixed infection. The positive rates of pathogens were not significantly different between less than 60 years old and over 60 years old groups except for Bordetella pertussis, adenovirus and Mycoplasma pneumonia(P < 0.05). Influenza virus had epidemic peak in winter and spring, but not in summer from 2019 to 2021. Conclusion: Various respiratory pathogens are detected from adult SARI cases. It is mainly influenza virus, with co-detected pathogens and rare pathogens. This study provides helpful information for targeted prevention and control measures including vaccination.

Transmission of SARS-CoV-2 Omicron Variant under a Dynamic Clearance Strategy in Shandong, China.

SARS-CoV-2 Omicron caused a large wave of COVID-19 cases in China in spring 2022. Shandong was one of the most affected regions during this epidemic yet was also among those areas that were able to quickly contain the transmission. We aimed to investigate the origin, genetic diversity, and transmission patterns of the Omicron epidemic in Shandong under a dynamic clearance strategy. We generated 1,149 Omicron sequences, performed phylogenetic analysis, and interpreted results in the context of available epidemiological information. We observed that there were multiple introductions of distinct Omicron sublineages into Shandong from foreign countries and other regions in China, while a small number of introductions led to majority of local cases. We found evidence suggesting that some local clusters were potentially associated with foreign imported cases. Superspreading events and cryptic transmissions contributed to the rapid spread of this epidemic. We identified a BA.1.1 genome with the R493Q reversion mutation in the spike receptor binding domain, potentially associated with an escape from vaccine and Omicron infection elicited neutralizing immunity. Our findings illustrated how the dynamic clearance strategy constrained this epidemic's size, duration, and geographical distribution. IMPORTANCE Starting in March 2022, the Omicron epidemic caused a large wave of COVID-19 cases in China. Shandong was one of the most affected regions during this epidemic but was also among those areas that were able to quickly contain the transmission. We investigated the origin, genetic diversity, and transmission patterns of Omicron epidemic in Shandong under a dynamic clearance strategy. We found that there were multiple introductions of distinct Omicron sublineages into Shandong from foreign countries and other regions in China, while a small number of introductions led to most local cases. We found evidence suggesting that some local clusters were associated with foreign imported cases. Superspreading events and cryptic transmissions contributed to the rapid spread of this epidemic. Our study illustrated the transmission patterns of Omicron epidemic in Shandong and provided a looking glass onto this epidemic in China.

STING agonist-loaded mesoporous manganese-silica nanoparticles for vaccine applications.

Cyclic dinucleotides (CDNs), as one type of Stimulator of Interferon Genes (STING) pathway agonist, have shown promising results for eliciting immune responses against cancer and viral infection. However, the suboptimal drug-like properties of conventional CDNs, including their short in vivo half-life and poor cellular permeability, compromise their therapeutic efficacy. In this study, we have developed a manganese-silica nanoplatform (MnOx@HMSN) that enhances the adjuvant effects of CDN by achieving synergy with Mn2+ for vaccination against cancer and SARS-CoV-2. MnOx@HMSN with large mesopores were efficiently co-loaded with CDN and peptide/protein antigens. MnOx@HMSN(CDA) amplified the activation of the STING pathway and enhanced the production of type-I interferons and other proinflammatory cytokines from dendritic cells. MnOx@HMSN(CDA) carrying cancer neoantigens elicited robust antitumor T-cell immunity with therapeutic efficacy in two different murine tumor models. Furthermore, MnOx@HMSN(CDA) loaded with SARS-CoV-2 antigen achieved strong and durable (up to one year) humoral immune responses with neutralizing capability. These results demonstrate that MnOx@HMSN(CDA) is a versatile nanoplatform for vaccine applications.

Serum Neutralizing Antibody Titers 12 months after COVID-19 mRNA Vaccination: Correlation to Clinical Variables in an Adult, US-Population.

BACKGROUND: We studied whether comorbid conditions impact strength and duration of immune responses after SARS-CoV-2 mRNA vaccination in a US-based, adult population. METHODS: Sera (pre-and-post-BNT162b2 vaccination) were tested serially up to 12 months after two doses of vaccine for SARS-CoV-2-anti-Spike neutralizing capacity by pseudotyping assay in 124 individuals; neutralizing titers were correlated to clinical variables with multivariate regression. Post-booster (third dose) effect was measured at 1 and 3 months in 72 and 88 subjects respectively. RESULTS: After completion of primary vaccine series, neutralizing antibody IC50 values were high at one month (14-fold increase from pre-vaccination), declined at six months (3.3-fold increase), and increased at one month post-booster (41.5-fold increase). Three months post-booster, IC50 decreased in COVID-naïve individuals (18-fold increase) and increased in prior COVID-19 + individuals (132-fold increase). Age >65 years (ß=-0.94, p = 0.001) and malignancy (ß=-0.88, p = 0.002) reduced strength of response at 1 month. Both neutralization strength and durability at 6 months, respectively, were negatively impacted by end-stage renal disease [(ß=-1.10, p = 0.004); (ß=-0.66, p = 0.014)], diabetes mellitus [(ß=-0.57, p = 0.032); (ß=-0.44, p = 0.028)], and systemic steroid use [(ß=-0.066, p = 0.032); (ß=-0.55, p = 0.037)]. Post-booster IC50 was robust against WA-1 and B.1.617.2. Post-booster neutralization increased with prior COVID-19 (ß = 2.9, p-value < 0.0001), and malignancy reduced neutralization response (ß=-0.68, p = 0.03), regardless of infection status. CONCLUSION: Multiple clinical factors impact the strength and duration of neutralization response post-primary series vaccination, but not the post-booster dose strength. Malignancy was associated with lower booster-dose response regardless of prior COVID infection, suggesting a need for clinically guided vaccine regimens.

Analyzing pure contagion between crude oil and agricultural futures markets

Crude oil and agricultural product prices are important factors affecting a country's economic and social stability. The pure contagion between these two markets may lead to excessive price linkage, increasing the fragility of the financial system. This paper uses the CEEMDAN method, fine-to-coarse reconstruction method, and TVP-VAR model to study the pure contagion between oil and agricultural futures markets. The empirical results show that there always is significant pure contagion between agricultural futures markets. However, pure contagion between crude oil and agricultural futures markets only exists in some specific periods. The crude oil futures market has obvious pure contagion to the agricultural futures markets in most periods. Only a few periods the agricultural futures have pure contagion to the crude oil futures. It is worth noting that the COVID-19 epidemic aggravates the pure contagion between crude oil and the agricultural futures markets. Based on the research conclusions, this paper puts forward corresponding policy recommendations, hoping to provide reference and theoretical basis for the government to formulate corresponding policies.

Changing ozone sensitivity in the South Coast Air Basin during the COVID-19 period

The South Coast Air Basin (SoCAB), which includes the city of Los Angeles and is home to more than 15 million people, frequently experiences ozone (O3) levels that exceed ambient air quality standards. While strict regulation of O3 precursors has dramatically improved air quality over the past 50 years, the region has seen limited improvement in O3 over the past decade despite continued reductions in precursor emissions. One contributing factor to the recent lack of improvement is a gradual transition of the underlying photochemical environment from a VOC-limited regime (where VOC denotes volatile organic compound) towards an NOx-limited one. The changes in human activity prompted by COVID-19-related precautions in spring and summer of 2020 exacerbated these existing changes in the O3 precursor environment. Analyses of sector-wide changes in activity indicate that emissions of NOx decreased by 15 %–20 % during spring (April–May) and by 5 %–10 % during summer (June–July) relative to expected emissions for 2020, largely due to changes in mobile-source activity. Historical trend analysis from two indicators of O3 sensitivity (the satellite HCHO/NO2 ratio and the O3 weekend/weekday ratio) revealed that spring of 2020 was the first year on record to be on averageNOx-limited, while the “transitional” character of recent summers became NOx-limited due to COVID-19-related NOx reductions in 2020. Model simulations performed with baseline and COVID-19-adjusted emissions capture this change to an NOx-limited environment and suggest that COVID-19-related emission reductions were responsible for a 0–2 ppb decrease in O3 over the study period. Reaching NOx-limited territory is an important regulatory milestone, and this study suggests that deep reductions in NOx emissions (in excess of those observed in this study) would be an effective pathway toward long-term O3 reductions.

Resurgence of Respiratory Syncytial Virus Infection During COVID-19 Pandemic Among Children in Shanghai, China.

Respiratory syncytial virus (RSV) is the most common pathogen causing acute lower respiratory tract infection (LRTI) in children. RSV usually peaks in winter and declines by early spring in China. The outbreak of coronavirus disease 2019 (COVID-19) was reported to bring changes to the transmission pattern of respiratory pathogens including RSV. Here in this paper, we analyzed RSV-positive nasopharyngeal aspirates from inpatients in the Children's Hospital of Fudan University from October 2019 to October 2021 and compared the clinical features of the RSV-positive patients before and during COVID-19. We found an atypical upsurge of RSV infection in the late summer of 2021 after a major suppression in 2020. RSV B was the main subtype spreading among children throughout the study. Phylogenetic analysis revealed that all RSV A strains belonged to ON1 genotype and all RSV B strains were BA9 genotype. Deduced amino acid analysis displayed different substitutions in the RSV strains observed before and during COVID-19. Demographic analysis suggested that males and infants aged under 5 months were the main populations infected with RSV by gender and age, respectively. Less severe clinical outcomes were observed in patients during COVID-19 than before the pandemic, especially in RSV B-positive patients. Our findings described the epidemiological changes in RSV infection brought by COVID-19, which further underscored the importance of continuous surveillance of RSV in the shadow of COVID-19 at both local and global scales.

Comparison of Respiratory Pathogens in Children With Lower Respiratory Tract Infections Before and During the COVID-19 Pandemic in Shanghai, China

Objectives This study aimed to assess the impact of COVID-19 on the prevalence of respiratory pathogens among hospitalized children with lower respiratory tract infections (LRTIs) in Shanghai. Methods Respiratory specimens were collected from children with LRTIs in Children’s Hospital of Fudan University from February 2019 to January 2021 and common respiratory pathogens were detected using multiplex PCR. The data of 13 respiratory pathogens were analyzed and compared between the year of 2020 (from February 2020 to January 2021) and 2019 (from February 2019 to January 2020). Results A total of 1,049 patients were enrolled, including 417 patients in 2019 and 632 patients in 2020. In 2020, 27.53% of patients were tested positive for at least one pathogen, which was significantly lower than that in 2019 (78.66%). The top three pathogens were Mycoplasma pneumoniae (Mp), human adenovirus (ADV) and human rhinovirus (RV) in 2019, whereas RV, human respiratory syncytial virus (RSV) and human parainfluenza virus (PIV) were the predominant ones in 2020. The positive rates of Mp, ADV, RV, PIV, Influenza virus B (InfB), H3N2, and H1N1 were significantly decreased in 2020. RV was the most detectable respiratory pathogen in 2020, and become the most frequent pathogen in all five age groups. PIV had a high prevalence from October to December 2020 which was even higher than that in 2019. Influenza virus A (InfA) was not detected in 2020. Co-infection was significantly less frequent in 2020. Conclusion The public health interventions aiming to eliminate COVID-19 have great impact on the prevalence of common respiratory pathogens. The prevalence of RV and PIV reminds us a possible resurgence of some pathogens.

Research advances and clinical management of bronchiectasis: Chinese perspective.

Bronchiectasis is a debilitating chronic suppurative airway disease that confers a substantial burden globally. Despite the notable prevalence, research on bronchiectasis in mainland China remains in its infancy. Nevertheless, there has been a significant leap in the quantity and quality of research, which has contributed to the ever-improving clinical practice. A nationwide collaborative platform has been established to foster multicentre studies, which will help increase the level of evidence further. Here, we summarise the status quo of clinical management and consider the research priorities for bronchiectasis that have been published previously. We also highlight the efforts of the Chinese medical communities to outline the core tasks that need to be addressed within the next decade.

The changing pattern of common respiratory and enteric viruses among outpatient children in Shanghai, China: Two years of the COVID-19 pandemic.

Nonpharmaceutical interventions (NPIs) taken to combat the coronavirus disease 2019 (COVID-19) pandemic have not only decreased the spread of severe acute respiratory syndrome coronavirus 2 but also have had an impact on the prevalence of other common viruses. This study aimed to investigate the long-term impact of NPIs on common respiratory and enteric viruses among children in Shanghai, China, as NPIs were relaxed after June 2020. The laboratory results and clinical data of outpatient children with acute respiratory tract infections (ARTI) and acute gastroenteritis (AGE) were analyzed and compared between the post-COVID-19 period (from June 2020 to January 2022) and pre-COVID-19 period (from June 2018 to January 2020). A total of 107 453 patients were enrolled from June 2018 to January 2022, including 43 190 patients with ARTI and 64 263 patients with AGE. The positive rates of most viruses decreased during the post-COVID-19 period, with the greatest decrease for influenza A (-0.94%), followed by adenoviruses (AdV) (-61.54%), rotaviruses (-48.17%), and influenza B (-40%). However, the positive rates of respiratory syncytial virus (RSV) and enteric AdV increased during the post-COVID-19 period as the NPIs were relaxed. Besides this, in the summer of 2021, an unexpected out-of-season resurgence of RSV activity was observed, and the resurgence was more prominent among children older than 5 years. The effectiveness of the current relaxed NPIs in control of common respiratory and enteric viruses was variable. Relaxation of NPIs might lead to the resurgence of common viruses.

Development of a multiplex droplet digital PCR assay for detection of enterovirus, parechovirus, herpes simplex virus 1 and 2 simultaneously for diagnosis of viral CNS infections.

BACKGROUND: Enterovirus (EV), parechovirus (HPeV), herpes simplex virus 1 and 2 (HSV1/2) are common viruses leading to viral central nervous system (CNS) infections which are increasingly predominant but exhibit deficiency in definite pathogen diagnosis with gold-standard quantitative PCR method. Previous studies have shown that droplet digital PCR (ddPCR) has great potential in pathogen detection and quantification, especially in low concentration samples. METHODS: Targeting four common viruses of EV, HPeV, HSV1, and HSV2 in cerebrospinal fluid (CSF), we developed a multiplex ddPCR assay using probe ratio-based multiplexing strategy, analyzed the performance, and evaluated it in 97 CSF samples collected from patients with suspected viral CNS infections on a two-channel ddPCR detection system. RESULTS: The four viruses were clearly distinguished by their corresponding fluorescence amplitude. The limits of detection for EV, HPeV, HSV1, and HSV2 were 5, 10, 5, and 10 copies per reaction, respectively. The dynamic range was at least four orders of magnitude spanning from 2000 to 2 copies per reaction. The results of 97 tested clinical CSF specimens were identical to those deduced from qPCR/qRT-PCR assays using commercial kits. CONCLUSION: The multiplex ddPCR assay was demonstrated to be an accurate and robust method which could detect EV, HPeV, HSV1, and HSV2 simultaneously. It provides a useful tool for clinical diagnosis and disease monitoring of viral CNS infections.

COVID-19 induces new-onset insulin resistance and lipid metabolic dysregulation via regulation of secreted metabolic factors.

Abnormal glucose and lipid metabolism in COVID-19 patients were recently reported with unclear mechanism. In this study, we retrospectively investigated a cohort of COVID-19 patients without pre-existing metabolic-related diseases, and found new-onset insulin resistance, hyperglycemia, and decreased HDL-C in these patients. Mechanistically, SARS-CoV-2 infection increased the expression of RE1-silencing transcription factor (REST), which modulated the expression of secreted metabolic factors including myeloperoxidase, apelin, and myostatin at the transcriptional level, resulting in the perturbation of glucose and lipid metabolism. Furthermore, several lipids, including (±)5-HETE, (±)12-HETE, propionic acid, and isobutyric acid were identified as the potential biomarkers of COVID-19-induced metabolic dysregulation, especially in insulin resistance. Taken together, our study revealed insulin resistance as the direct cause of hyperglycemia upon COVID-19, and further illustrated the underlying mechanisms, providing potential therapeutic targets for COVID-19-induced metabolic complications.