Air pollution and CO2 emission inventory of Chinese civil aviation airport

Based on the aircraft take-off and landing data of the Civil Aviation Administration of China,fleet configuration data,and the ICAO aircraft engine emission factor database from 2017 to 2020,the air pollution and CO2 emission inventory of the landing and take-off（LTO） cycle of high-resolution aircraft of civil aviation airport of China were developed from bottom to top.On this basis,the spatial and temporal distribution characteristics of air pollutants and CO2 on air pollution of China Civil Aviation Airport LTO cycle were explored.We analyzed the 3epidemics from 2000 to 2020（SARS in 2003,MERS in 2012,and COVID-19 in 2020）on airport air pollution and CO2 emissions.The results show that the emissions of NOx,CO,HC,SO2,PM,and CO2 in the LTO cycle of civil aviation airports in China in 2020 are 10.90,8.22,0.96,0.28,0.06,1360.27 million tons respectively;The emissions of HC,CO,SO2,and CO2 are the largest in the taxiing stage,accounting for 92.80%,91.56%,41.81% and 41.81% of the total emissions respectively.The emissions of NOx and PM are the largest in the climbing stage,accounting for 47.93% and 37.39% of the total emissions respectively;Air pollutants and CO2 emissions from China's Civil Aviation Airport LTO cycle showed an increasing trend over the past 2017～2019 years,and the total emissions in 2020 were reduced by 22.39% by COVID-19.The most concentrated emission area is the economically developed East region.In the 3 epidemics of the 2000～2020 years,COVID-19 has the most significant impact on the LTO emissions from China's civil aviation airport.

COVID-19 in Genomics:A Bibliometric Analysis (preprint)

Abstract: Objective To analyze the current status, hotspots and frontier trends of genomics research on the outbreak of novel coronavirus disease (COVID-19) from 2019 to the present (March 2022). Methods Using citespace software to conduct statistical and visual analysis of data in each country, institutions, authors, journals, co-cited literature, keywords, etc. were published on the 2019-2022 Web of Science Core Collection Database (WOS) on the genomics of novel coronavirus pneumonia Results of related literature. Results A total of 9,121 English literatures were included. In 2021, the number of publications has increased significantly, and it is expected to continue to show a continuous upward trend in the future. The research hotspots of COVID-19 revolve around quarantine, biological management, angiotensin-converting enzyme-2, rna-dependent rna polymerase, etc. Research fronts and trends focus on molecular docking, messenger RNA,functional receptor, etc. Conclusion The research attention in the field of novel coronavirus pneumonia genomics has increased significantly in the past two years.

Hospitalization, interpersonal and personal factors of social anxiety among COVID-19 survivors at the six-month follow-up after hospital treatment: the minority stress model Hospitalización, factores interpersonales y personales de ansiedad social entre los sobrevivientes de COVID-19 en el seguimiento seis meses después del tratamiento hospitalario: el modelo de estrés de minoría 基于少数群体压力模型的新冠康复者住院经历, 出院后六个月人际及个人因素与社交焦虑之间的关联分析

Background As a highly infectious disease with human-to-human transmission characteristics, COVID-19 has caused panic in the general public. Those who have recovered from COVID-19 may experience discrimination and internalized stigma. They may be more likely to worry about social interaction and develop social anxiety. Objectives This study investigated the associations among hospitalization factors, social/interpersonal factors, personal factors, and social anxiety to reveal the mechanism of social anxiety in COVID-19 survivors. Methods A cross-sectional, multicenter telephone survey was conducted from July to September 2020 in five Chinese cities (i.e. Wuhan, Nanning, Shenzhen, Zhuhai, and Dongguan);adult COVID-19 survivors were recruited 6 months after they were discharged from the hospital. Linear regressions and path analysis based on the minority stress model were conducted to test the relationships among hospitalization, social/interpersonal factors, personal factors, and social anxiety. Results The response rate was 74.5% (N = 199, 55.3% females). Linear regression analyses showed that various hospitalization, social/interpersonal, and personal factors were statistically significantly associated with social anxiety. Path analysis showed that the proposed model fit the data well (χ2(df) = 3.196(3), p = .362, CFI = .999, NNFI = .996, RMSEA = .018). Internalized stigma fully mediated the association between perceived discrimination/social support and social anxiety, while it partially mediated the association between perceived affiliate stigma and social anxiety. Conclusions The results suggest that social/interpersonal and personal factors have a stronger association with social anxiety than hospitalization factors and highlight the importance of internalized stigma in understanding the mechanisms of these relationships. Clinical psychologists can refer to these modifiable psychosocial factors to develop efficient interventions for mental health promotion. HIGHLIGHTS Internalized stigma fully mediated the effects of perceived discrimination and social support on social anxiety and partially mediated the effect of perceived affiliate stigma on social anxiety.

Occurrence of COVID-19 symptoms during SARS-CoV-2 infection defines waning of humoral immunity (preprint)

Approximately half of the SARS-CoV-2 infections occur without apparent symptoms, raising questions regarding long-term humoral immunity in asymptomatic individuals. Plasma levels of immunoglobulin G (IgG) and M (IgM) against the viral spike or nucleoprotein were determined for 25,091 individuals enrolled in a surveillance program in Wuhan, China. We compared 405 asymptomatic individuals with 459 symptomatic COVID-19 patients. The well-defined duration of the SARS-CoV-2 endemic in Wuhan allowed a side-by-side comparison of antibody responses following symptomatic and asymptomatic infections without subsequent antigen re-exposure. IgM responses rapidly declined in both groups. However, both the prevalence and durability of IgG responses and neutralizing capacities correlated positively with symptoms. Regardless of sex, age, and body weight, asymptomatic individuals lost their SARS-CoV-2-specific IgG antibodies more often and rapidly than symptomatic patients. These findings have important implications for immunity and favour immunization programs including individuals after asymptomatic infections. One-Sentence SummaryPrevalence and durability of SARS-CoV-2-specific IgG responses and neutralizing capacities correlate with COVID-19 symptoms.

Association between Use of Qingfei Paidu Tang and Mortality in Hospitalized Patients with COVID-19: A national retrospective registry study (preprint)

BackgroundQingfei Paidu Tang (QPT), a formula of traditional Chinese medicine, which was suggested to be able to ease symptoms in patients with Coronavirus Disease 2019 (COVID-19), has been recommended by clinical guidelines and widely used to treat COVID-19 in China. However, whether it decreases mortality remains unknown. PurposeWe aimed to explore the association between QPT use and in-hospital mortality among patients hospitalized for COVID-19. Study designA retrospective study based on a real-world database was conducted. MethodsWe identified patients consecutively hospitalized with COVID-19 in 15 hospitals from a national retrospective registry in China, from January through May 2020. Data on patients characteristics, treatments, and outcomes were extracted from the electronic medical records. The association of QPT use with mortality was evaluated using Cox proportional hazards models based on propensity score analysis. ResultsOf the 8939 patients included, 28.7% received QPT. The crude mortality was 1.2% (95% confidence interval [CI] 0.8% to 1.7%) among the patients receiving QPT and 4.8% (95% CI 4.3% to 5.3%) among those not receiving QPT. After adjustment for patient characteristics and concomitant treatments, QPT use was associated with a relative reduction of 50% in in-hospital mortality (hazard ratio, 0.50; 95% CI, 0.37 to 0.66 P <0.001). This association was consistent across subgroups by sex and age. Meanwhile, the incidence of acute liver injury (8.9% [95% CI, 7.8% to 10.1%]vs. 9.9% [95% CI, 9.2% to 10.7%]; odds ratio, 0.96 [95% CI, 0.81% to 1.14%], P =0.658) and acute kidney injury (1.6% [95% CI, 1.2% to 2.2%] vs. 3.0% [95% CI, 2.6% to 3.5%]; odds ratio, 0.85 [95% CI, 0.62 to 1.17], P =0.318) was comparable between patients receiving QPT and those not receiving QPT. The major study limitations included that the study was an observational study based on real-world data rather than a randomized control trial, and the quality of data could be affected by the accuracy and completeness of medical records. ConclusionsQPT was associated with a substantially lower risk of in-hospital mortality, without extra risk of acute liver injury or acute kidney injury among patients hospitalized with COVID-19.

SARS-CoV-2-specific T cell memory is long-lasting in the majority of convalsecent COVID-19 individuals (preprint)

An unaddressed key question in the current coronavirus disease 2019 (COVID-19) pandemic is the duration of immunity for which specific T cell responses against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are an indispensable element. Being situated in Wuhan where the pandemic initiated enables us to conduct the longest analyses of memory T cell responses against SARS-CoV-2 in COVID-19 convalescent individuals (CIs). Magnitude and breadth of SARS-CoV-2 memory CD4 and CD8 T cell responses were heterogeneous between patients but robust responses could be detected up to 9 months post disease onset in most CIs. Loss of memory CD4 and CD8 T cell responses were observed in only 16.13% and 25.81% of CIs, respectively. Thus, the overall magnitude and breadth of memory CD4 and CD8 T cell responses were quite stable and not inversely correlated with the time from disease onset. Interestingly, the only significant decrease in the response was found for memory CD4 T cells in the first 6-month post COVID-19 disease onset. Longitudinal analyses revealed that the kinetics of SARS-CoV-2 memory CD4 and CD8 T cell responses were quite heterogenous between patients. Loss of memory CD4 T cell responses was observed more frequently in asymptomatic cases than after symptomatic COVID-19. Interestingly, the few CIs in which SARS-CoV-2-specific IgG responses disappeared showed more durable memory CD4 T cell responses than CIs who remained IgG-positive for month. Collectively, we provide the first comprehensive characterization of the long-term memory T cell response in CIs, suggesting that SARS-CoV-2-specific T cell immunity is long-lasting in the majority of individuals.

Gene Expression Meta-Analysis Identifies Molecular Changes Associated with SARS-CoV Infection in Lungs (preprint)

Background: Severe Acute Respiratory Syndrome (SARS) corona virus (SARS-CoV) infections are a serious public health threat because of their pandemic-causing potential. This work uses mRNA expression data to predict genes associated with SARS-CoV infection through an innovative meta-analysis examining gene signatures (i.e., gene lists ranked by differential gene expression between SARS and mock infection). Methods: This work defines 29 gene signatures representing SARS infection across seven strains with established mutations that vary virulence (infectious clone SARS (icSARS), Urbani, MA15, {Delta}ORF6, BAT-SRBD, {Delta}NSP16, and ExoNI) and host (human lung cultures and/or mouse lung samples) and examines them through Gene Set Enrichment Analysis (GSEA). To do this, first positive and negative icSARS gene panels were defined from GSEA-identified leading-edge genes between 500 genes from positive or negative tails of the GSE47960-derived icSARSvsmock signature and the GSE47961-derived icSARSvsmock signature, both from human cultures. GSEA then was used to assess enrichment and identify leading-edge icSARS panel genes in the other 27 signatures. Genes associated with SARS-CoV infection are predicted by examining membership in GSEA-identified leading-edges across signatures. Results: Significant enrichment (GSEA p<0.001) was observed between GSE47960-derived and GSE47961-derived signatures, and those leading-edges defined the positive (233 genes) and negative (114 genes) icSARS panels. Non-random (null distribution p<0.001) significant enrichment (p<0.001) was observed between icSARS panels and all verification icSARSvsmock signatures derived from human cultures, from which 51 over- and 22 under-expressed genes were shared across leading-edges with 10 over-expressed genes already being associated with icSARS infection. For the icSARSvsmock mouse signature, significant, non-random enrichment (both p<0.001) held for only the positive icSARS panel, from which nine genes were shared with icSARS infection in human cultures. Considering other SARS strains, significant (p<0.01), non-random (p<0.002) enrichment was observed across signatures derived from other SARS strains for the positive icSARS panel. Five positive icSARS panel genes, CXCL10, OAS3, OASL, IFIT3, and XAF1, were found in mice and human signatures. Conclusion: The GSEA-based meta-analysis approach used here identified genes with and without reported associations with SARS-CoV infections, highlighting this approachs predictability and usefulness in identifying genes that have potential as therapeutic targets to preclude or overcome SARS infections.

Analysis of SARS-CoV-2 spike glycosylation reveals shedding of a vaccine candidate (preprint)

Severe acute respiratory syndrome coronavirus 2 is the causative pathogen of the COVID-19 pandemic which as of Nov 15, 2020 has claimed 1,319,946 lives worldwide. Vaccine development focuses on the viral trimeric spike glycoprotein as the main target of the humoral immune response. Viral spikes carry glycans that facilitate immune evasion by shielding specific protein epitopes from antibody neutralisation. Immunogen integrity is therefore important for glycoprotein-based vaccine candidates. Here we show how site-specific glycosylation differs between virus-derived spikes and spike proteins derived from a viral vectored SARS-CoV-2 vaccine candidate. We show that their cellular secretion pathways are unique, resulting in different protein glycosylation and secretion, which may have implications for the resulting immune response and future vaccine design.

Intranasal Administration of ACIS KEPTIDE™ Prevents SARS-CoV2-Induced Acute Toxicity in K18-hACE2 Humanized Mouse Model of COVID-19: A Mechanistic Insight for the Prophylactic Role of KEPTIDE™ in COVID-19 (preprint)

Abstract: Previously, we have demonstrated that ACIS KEPTIDE, a chemically modified peptide, selectively binds to ACE-2 receptor and prevents the entry of SARS-CoV2 virions in vitro in primate kidney Cells. However, it is not known if ACIS KEPTIDE attenuates the entry of SARS-CoV2 virus in vivo in lung and kidney tissues, protects health, and prevent death once applied through intranasal route. In our current manuscript, we demonstrated that the intranasal administration of SARS-CoV2 (1*106) strongly induced the expression of ACE-2, promoted the entry of virions into the lung and kidney cells, caused acute histopathological toxicities, and mortality (28%). Interestingly, thirty-minutes of pre-treatment with 50 g/Kg Body weight ACIS normalized the expression of ACE-2 via receptor internalization, strongly mitigated that viral entry, and prevented mortality suggesting its prospect as a prophylactic therapy in the treatment of COVID-19. On the contrary, the peptide backbone of ACIS was unable to normalize the expression of ACE-2, failed to improve the health vital signs and histopathological abnormalities. In summary, our results suggest that ACIS is a potential vaccine-alternative, prophylactic agent that prevents entry of SARS-CoV2 in vivo, significantly improves respiratory health and also dramatically prevents acute mortality in K18-hACE2 humanized mice.

Recurrent mutations in SARS-CoV-2 genomes isolated from mink point to rapid host-adaptation (preprint)

Severe acute respiratory coronavirus 2 (SARS-CoV-2), the agent of the ongoing COVID-19 pandemic, jumped into humans from an unknown animal reservoir in late 2019. In line with other coronaviruses, SARS-CoV-2 has the potential to infect a broad range of hosts. SARS-CoV-2 genomes have now been isolated from cats, dogs, lions, tigers and minks. SARS-CoV-2 seems to transmit particularly well in mink farms with outbreaks reported in Spain, Sweden, the Netherlands, Italy, the USA and Denmark. Genomic data from SARS-CoV-2 isolated from infected minks provides a natural case study of a secondary host jump of the virus, in this case from humans to animals, and occasionally back again. We screened published SARS-CoV-2 genomes isolated from minks for the presence of recurrent mutations common in mink but infrequent in SARS-CoV-2 genomes from human infections. We identify 23 recurrent mutations including three nonsynonymous mutations in the Receptor Binding Domain of the SARS-CoV-2 spike protein that independently emerged at least four times but are only very rarely observed in strains circulating in humans. The repeat emergence of mutations across phylogenetically distinct lineages of the virus isolated from minks points to ongoing adaptation of SARS-CoV-2 to a new host. The rapid acquisition and spread of SARS-CoV-2 mutations in minks suggests that if a similar phenomenon of host adaptation had occurred upon its jump into humans, those human-specific mutations would likely have reached fixation already before the first SARS-CoV-2 genomes were generated.

An ancient coronavirus-like epidemic drove adaptation in East Asians from 25,000 to 5,000 years ago (preprint)

The current SARS-CoV-2 pandemic has emphasized the vulnerability of human populations to novel viral pressures, despite the vast array of epidemiological and biomedical tools now available. Notably, modern human genomes contain evolutionary information tracing back tens of thousands of years, which may help identify the viruses that have impacted our ancestors - pointing to which viruses have future pandemic potential. Here, we apply evolutionary analyses to human genomic datasets to recover selection events involving tens of human genes that interact with coronaviruses, including SARS-CoV-2, that started 25,000 years ago. These adaptive events were limited to ancestral East Asian populations, the geographical origin of several modern coronavirus epidemics. An arms race with an ancient corona-like virus may thus have taken place in ancestral East Asian populations. By learning more about our ancient viral foes, our study highlights the promise of evolutionary information to combat the pandemics of the future.

Examining the Persistence of Human Coronaviruses on Fresh Produce (preprint)

Human coronaviruses (HCoVs) are mainly associated with respiratory infections. However, there is evidence that highly pathogenic HCoVs, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Middle East Respiratory Syndrome (MERS-CoV), infect the gastrointestinal (GI) tract and are shed in the fecal matter of the infected individuals. These observations have raised questions regarding the possibility of fecal-oral route as well as foodborne transmission of SARS-CoV-2 and MERS-CoV. Studies regarding the survival of HCoVs on inanimate surfaces demonstrate that these viruses can remain infectious for hours to days, however, to date, there is no data regarding the viral survival on fresh produce, which is usually consumed raw or with minimal heat processing. To address this knowledge gap, we examined the persistence of HCoV-229E, as a surrogate for highly pathogenic HCoVs, on the surface of commonly consumed fresh produce, including: apples, tomatoes and cucumbers. Herein, we demonstrated that viral infectivity declines within a few hours post-inoculation (p.i) on apples and tomatoes, and no infectious virus was detected at 24h p.i, while the virus persists in infectious form for 72h p.i on cucumbers. The stability of viral RNA was examined by droplet-digital RT-PCR (ddRT-PCR), and it was observed that there is no considerable reduction in viral RNA within 72h p.i.

The analysis of the long-term impact of SARS-CoV-2 on the cellular immune system in individuals recovering from COVID-19 reveals a profound NKT cell impairment (preprint)

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) affects millions of people and killed hundred-thousands of individuals. While acute and intermediate interactions between SARS-CoV-2 and the immune system have been studied extensively, long-term impacts on the cellular immune system remained to be analyzed. Here, we comprehensively characterized immunological changes in peripheral blood mononuclear cells in 49 COVID-19 convalescent individuals (CI) in comparison to 27 matched SARS-CoV-2 unexposed individuals (UI). Despite recovery from the disease for more than 2 months, CI showed significant decreases in frequencies of invariant NKT and NKT-like cells compared to UI. Concomitant with the decrease in NKT-like cells, an increase in the percentage of Annexin V and 7-AAD double positive NKT-like cells was detected, suggesting that the reduction in NKT-like cells results from cell death months after recovery. Significant increases in regulatory T cell frequencies, TIM-3 expression on CD4 and CD8 T cells, as well as PD-L1 expression on B cells were also observed in CI, while the cytotoxic potential of T cells and NKT-like cells, defined by GzmB expression, was significantly diminished. However, both CD4 and CD8 T cells of CI showed increased Ki67 expression and were fully capable to proliferate and produce effector cytokines upon TCR stimulation. Collectively, we provide the first comprehensive characterization of immune signatures in patients recovering from SARS-CoV-2 infection, suggesting that the cellular immune system of COVID-19 patients is still under a sustained influence even months after the recovery from disease.

Impaired cytotoxic CD8+ T cell response in elderly COVID-19 patients (preprint)

SARS-CoV-2 infection induces a T cell response that most likely contributes to virus control in COVID-19 patients, but may also induce immunopathology. Until now, the cytotoxic T cell response has not been very well characterized in COVID-19 patients. Here, we analyzed the differentiation and cytotoxic profile of T cells in 30 cases of mild COVID-19 during acute infection. SARS-CoV-2 infection induced a cytotoxic response of CD8+ T cells, but not CD4+ T cells, characterized by the simultaneous production of granzyme A and B, as well as perforin within different effector CD8+ T cell subsets. PD-1 expressing CD8+ T cells also produced cytotoxic molecules during acute infection indicating that they were not functionally exhausted. However, in COVID-19 patients over the age of 80 years the cytotoxic T cell potential was diminished, especially in effector memory and terminally differentiated effector CD8+ cells, showing that elderly patients have impaired cellular immunity against SARS-CoV-2. Our data provides valuable information about T cell responses in COVID-19 patients that may also have important implications for vaccine development. ImportanceCytotoxic T cells are responsible for the elimination of infected cells and are key players for the control of viruses. CD8+ T cells with an effector phenotype express cytotoxic molecules and are able to perform target cell killing. COVID-19 patients with a mild disease course were analyzed for the differentiation status and cytotoxic profile of CD8+ T cells. SARS-CoV-2 infection induced a vigorous cytotoxic CD8+ T cell response. However, this cytotoxic profile of T cells was not detected in COVID-19 patients over the age of 80 years. Thus, the absence of a cytotoxic response in elderly patients might be a possible reason for the more frequent severity of COVID-19 in this age group in comparison to younger patients.

Antiviral activity of lambda-carrageenan against influenza viruses in mice and severe acute respiratory syndrome coronavirus 2 in vitro (preprint)

Influenza virus and coronavirus, belonging to enveloped RNA viruses, are major causes of human respiratory diseases. The aim of this study was to investigate the broad spectrum antiviral activity of a naturally existing sulfated polysaccharide, lambda-carrageenan ({lambda}-CGN), purified from marine red algae. Cell culture-based assays revealed that the macromolecule efficiently inhibited both influenza A and B viruses, as well as currently circulating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with EC50 values ranging from 0.3-1.4 g/ml. No toxicity to host cells was observed at concentrations up to 300 g/ml. Plaque titration and western blot analysis verified that {lambda}-CGN reduced expression of viral proteins in cell lysates and suppressed progeny virus production in culture supernatants in a dose-dependent manner. This polyanionic compound exerts antiviral activity by targeting viral attachment to cell surface receptors and preventing entry. Moreover, intranasal administration to mice during influenza A viral challenge not only alleviated infection-mediated reductions in body weight but also protected 60% of mice from virus-induced mortality. Thus, {lambda}-CGN could be a promising antiviral agent for preventing infection by several respiratory viruses.

Case report: one case of coronavirus disease 2019 (COVID-19) in a patient co-infected by HIV with a normal CD4+ T cell count.

BACKGROUND: The COVID-19 has been a severe pandemic all around the world. Nowadays the patient with co-infection of HIV and SARS-CoV-2 was rarely reported. Here we reported a special case with HIV and SARS-CoV-2 co-infection, which showed a prolonged viral shedding duration. CASE PRESENTATION: The patient was infected with HIV 8 years ago through sexual transmission and had the normal CD4+T cell count. She was found SARS-CoV-2 positive using real-time Polymerase Chain Reaction (RT-PCR) during the epidemic. Most importantly, the patient had a prolonged viral shedding duration of SARS-CoV-2 about 28 days. CONCLUSION: The viral shedding duration may be prolonged in people living with HIV. The 14 days isolation strategy might not be long enough for them. The isolation or discharge of these patients needs further confirmation for preventing epidemics.

SARS-CoV-2 infection induces sustained humoral immune responses in convalescent patients following symptomatic COVID-19 (preprint)

Long-term antibody responses and neutralizing activities following SARS-CoV-2 infections have not yet been elucidated. We quantified immunoglobulin M (IgM) and G (IgG) antibodies recognizing the SARS-CoV-2 receptor-binding domain (RBD) of the spike (S) or the nucleocapsid (N) protein, and neutralizing antibodies during a period of six months following COVID-19 disease onset in 349 symptomatic COVID-19 patients, which were among the first world-wide being infected. The positivity rate and magnitude of IgM-S and IgG-N responses increased rapidly. High levels of IgM-S/N and IgG-S/N at 2-3 weeks after disease onset were associated with virus control and IgG-S titers correlated closely with the capacity to neutralize SARS-CoV-2. While specific IgM-S/N became undetectable 12 weeks after disease onset in most patients, IgG-S/N titers showed an intermediate contraction phase, but stabilized at relatively high levels over the six months observation period. At late time points the positivity rates for binding and neutralizing SARS-CoV-2-specific antibodies was still over 70%. Taken together, our data indicate sustained humoral immunity in recovered patients who suffer from symptomatic COVID-19, suggesting prolonged immunity.

The prevalence of antibodies to SARS-CoV-2 in asymptomatic healthcare workers with intensive exposure to COVID-19 (preprint)

The prevalence of asymptomatic SARS-CoV-2 infection in healthcare workers with intensive exposure to COVID-19 is unclear. In this study, we investigated the seroprevalence of SARS-CoV-2 in 797 asymptomatic healthcare workers with intensive exposure to COVID-19 patients in Wuhan, China. Positive IgG was detected from 35 asymptomatic healthcare workers, and the prevalence of antibodies to SARS-CoV-2 in asymptomatic healthcare workers was 4.39% (35/797). None of them developed COVID-19 until May 15. 33 of them have performed at least one chest CT scan showing no viral pneumonia features, and 16 have finished at least one-time SARS-CoV-2 RNA detection with negative results. When contacting with the patients, 15 of them dressed with full personal protective equipment (PPE), and 16 worn N95 mask and gown. To the best of our knowledge, this is the first investigation reported that the seroprevalence of SARS-CoV-2 was 4.39% in asymptomatic healthcare workers with applied PPE in a high epidemic area, which may provide useful information of estimating asymptomatic infection rate in general population.

ANDC: an early warning score to predict mortality risk for patients with Coronavirus Disease 2019 (preprint)

Background: Patients with severe Coronavirus Disease 2019 (COVID-19) will progress rapidly to acute respiratory failure or death. We aimed to develop a quantitative tool for early predicting mortality risk of patients with COVID-19.Methods: 301 patients with confirmed COVID-19 admitted to Main District and Tumor Center of the Union Hospital of Huazhong University of Science and Technology (Wuhan, China) between January 1, 2020 to February 15, 2020 were enrolled in this retrospective two-centers study. Data on patient demographic characteristics, laboratory findings and clinical outcomes was analyzed. A nomogram was constructed to predict the death probability of COVID-19 patients.Results: Age, neutrophil-to-lymphocyte ratio, D-dimer and C-reactive protein obtained on admission were identified by LASSO regression as predictors of mortality for COVID-19 patients. The nomogram demonstrated good calibration and discrimination with the area under the curve (AUC) of 0.921 and 0.975 for the derivation and validation cohort, respectively. An integrated score (named ANDC) with its corresponding death probability was derived. Using ANDC cut-off values of 59 and 101, COVID-19 patients were classified into three subgroups. The death probability of low risk group (ANDC < 59) was less than 5%, moderate risk group (59 ≤ ANDC ≤ 101) was 5% to 50%, and high risk group (ANDC > 101) was more than 50%, respectively.Conclusion: The prognostic nomogram exhibited good discrimination power in early identification of COVID-19 patients with high mortality risk, and ANDC score may help physicians to optimize patient stratification management.