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1.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-324327

ABSTRACT

Background: The COVID-19 spread worldwide quickly. Exploring the epidemiological characteristics could provide a basis for responding to imported cases abroad and to formulate prevention and control strategies in areas where COVID-19 is still spreading rapidly. Methods: : The number of confirmed cases, daily growth, incidence and length of time from the first reported case to the end of the local cases (i.e., non-overseas imported cases) were compared by spatial (geographical) and temporal classification and visualization of the development and changes of the epidemic situation by layers through maps. Results: : In the first wave, a total of 539 cases were reported in Sichuan, with an incidence rate of 0.6462/100,000. The closer to Hubei the population centres were, the more pronounced the epidemic was. The peak in Sichuan Province occurred in the second week. Eight weeks after the Wuhan lockdown, the health crisis had eased. The longest epidemic length at the city level in China (except Wuhan, Taiwan, and Hong Kong) was 53 days, with a median of 23 days. Spatial autocorrelation analysis of China showed positive spatial correlation (Moran's Index >0, p<0.05). Most countries outside China began to experience a rapid rise in infection rates 4 weeks after their first case. Some European countries experienced that rise earlier than the USA. The pandemic in Germany, Spain, Italy, and China took 28, 29, 34, and 18 days, respectively, to reach the peak of daily infections, after their daily increase of up to 20 cases. During this time, countries in the African region and Southeast Asian region were at an early stage of infections, those in the Eastern Mediterranean region and region of the Americas were in a rapid growth phase. Conclusions: : After the closure of the outbreak city, appropriate isolation and control measures in the next 8 weeks were key to control the outbreak, which reduced the peak value and length of the outbreak. Some countries with improved epidemic situations need to develop a continuous "local strategy at entry checkpoints" to to fend off imported COVID-19.

2.
Nat Med ; 26(6): 845-848, 2020 06.
Article in English | MEDLINE | ID: covidwho-1641979

ABSTRACT

We report acute antibody responses to SARS-CoV-2 in 285 patients with COVID-19. Within 19 days after symptom onset, 100% of patients tested positive for antiviral immunoglobulin-G (IgG). Seroconversion for IgG and IgM occurred simultaneously or sequentially. Both IgG and IgM titers plateaued within 6 days after seroconversion. Serological testing may be helpful for the diagnosis of suspected patients with negative RT-PCR results and for the identification of asymptomatic infections.


Subject(s)
Antibodies, Viral/blood , Antibody Formation/drug effects , Betacoronavirus/pathogenicity , Coronavirus Infections/drug therapy , Pneumonia, Viral/drug therapy , Adult , Aged , Antibody Formation/immunology , Antiviral Agents/therapeutic use , Betacoronavirus/genetics , COVID-19 , Coronavirus Infections/blood , Coronavirus Infections/immunology , Coronavirus Infections/virology , Female , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Male , Middle Aged , Pandemics/prevention & control , Pneumonia, Viral/blood , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , SARS-CoV-2
3.
Clin Lab ; 68(1)2022 Jan 01.
Article in English | MEDLINE | ID: covidwho-1579898

ABSTRACT

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a huge threat to public health. Therefore, clinical laboratories must have the ability to detect SARS-CoV-2 RNA. With the enhanced detection in Chongqing, many laboratories rapidly implemented assays for the molecular detection of SARS-CoV-2 based on real-time reverse transcription polymerase chain reaction (rRT-PCR) assays. This study aimed to improve the detection capabilities of clinical laboratories by evaluating their performance for SARS-CoV-2 RNA detection through the external quality assessment (EQA) programs of 2020 in Chongqing to contribute to the prevention of this epidemic. METHODS: The EQA panels consist of eight positive samples with concentrations within 2.7 - 5.0 log10 copies/mL quantified by digital PCR and two negative samples with other human coronaviruses clinically validated by four commercial assays. All 21 samples from four rounds were distributed to the participating laboratories through cold-chain transportation. Depending on the results from each sample, laboratories were asked to use one or two assays to detect SARS-CoV-2 RNA. Test results and raw data were also required. All data were evaluated, and the testing performance of commercial assays was compared. For the rounds, all laboratories used commercial assays. RESULTS: Four rounds of EQA programs were performed, and the percent agreements of participants were 97.5% (39/40), 97.5% (39/40), 98.9% (88/89), 100.0% (131/131). Only three false negative results and one false positive result were obtained. Statistical significance in the Ct values of the ORF region and N region of SARS-CoV-2-RNA was found by using one-step, one-step concentration, and magnetic bead methods (p < 0.05). The Ct values of the ORF region of SARS-CoV-2-RNA in P5 and P6 were significantly different in the different batches of reagent A (p < 0.05). The ORF region of SARS-CoV-2-RNA was not detected in a batch of reagent B. CONCLUSIONS: The majority of laboratories in Chongqing have reliable diagnostic ability for SARS-CoV-2 detection. Our data emphasized the importance of EQA for monitoring the performance of clinical laboratories. However, clinical laboratories must first effectively evaluate the performance of reagents prior to their use.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , RNA, Viral/genetics , Real-Time Polymerase Chain Reaction , Sensitivity and Specificity
4.
Front Public Health ; 9: 756977, 2021.
Article in English | MEDLINE | ID: covidwho-1468377

ABSTRACT

Understanding COVID-19 induced mortality risk is significant for life insurers to better analyze their financial sustainability after the outbreak of COVID-19. To capture the mortality effect caused by COVID-19 among all ages, this study proposes a temporary adverse mortality jump model to describe the dynamics of mortality in a post-COVID-19 pandemic world based on the weekly death numbers from 2015 to 2021 in the United States. As a comparative study, the Lee-Carter model is used as the base case to represent the dynamics of mortality without COVID-19. Then we compare the force of mortality, the survival probability and the liability of a life insurer by considering COVID-19 and those without COVID-19. We show that a life insurer's financial sustainability will deteriorate because of the higher mortality rates than expected in the wake of COVID-19. Our results remain unchanged when we also consider the effect of interest rate risk by adopting the Vasicek and CIR models.


Subject(s)
COVID-19 , Humans , Insurance Carriers , Pandemics , SARS-CoV-2 , United States/epidemiology
5.
Front Immunol ; 12: 748566, 2021.
Article in English | MEDLINE | ID: covidwho-1463474

ABSTRACT

Coronavirus disease 2019 (COVID-19) remains a major health challenge globally. Previous studies have suggested that changes in the glycosylation of IgG are closely associated with the severity of COVID-19. This study aimed to compare the profiles of IgG N-glycome between COVID-19 patients and healthy controls. A case-control study was conducted, in which 104 COVID-19 patients and 104 age- and sex-matched healthy individuals were recruited. Serum IgG N-glycome composition was analyzed by hydrophilic interaction liquid chromatography with the ultra-high-performance liquid chromatography (HILIC-UPLC) approach. COVID-19 patients have a decreased level of IgG fucosylation, which upregulates antibody-dependent cell cytotoxicity (ADCC) in acute immune responses. In severe cases, a low level of IgG sialylation contributes to the ADCC-regulated enhancement of inflammatory cytokines. The decreases in sialylation and galactosylation play a role in COVID-19 pathogenesis via the activation of the lectin-initiated alternative complement pathway. IgG N-glycosylation underlines the complex clinical phenotypes of SARS-CoV-2 infection.


Subject(s)
COVID-19/metabolism , Immunoglobulin G/metabolism , SARS-CoV-2/physiology , Adult , Antibody-Dependent Cell Cytotoxicity , Case-Control Studies , Chromatography, High Pressure Liquid , Complement Pathway, Mannose-Binding Lectin , Female , Glycosylation , Humans , Male , Middle Aged , Phenotype
6.
Int J Gen Med ; 14: 4073-4080, 2021.
Article in English | MEDLINE | ID: covidwho-1346355

ABSTRACT

PURPOSE: To analyze the clinical characteristics of patients with coronavirus disease 19 (COVID-19) in Chongqing, and identify the potential hematological markers for reference. PATIENTS AND METHODS: 78 COVID-19-infected patients in Chongqing were recruited and divided into the non-severe and the severe group. The clinical characteristics and hematological features of the patients of the two groups were compared. Receiver-operating characteristic curves (ROC) were calculated to evaluate the diagnostic performance of potential markers, and the dynamic changes of blood routine analyzing items were compared between the non-severe and severe groups. RESULTS: 78 patients (median age of 45 years, 41 females and 37 males) were enrolled. The patients in the severe group exhibited significantly lower lymphocyte (P<0.05) but higher neutrophil to lymphocyte ratio (NLR) (P<0.05) than the patients in the non-severe group. The highest area under the ROC curve (AUC) was lymphocyte (0.74). The patients in the severe group had a lower level of lymphocyte during hospitalization (P<0.01) and lymphocyte-monocyte ratio (LMR) in the progressive and convalescent phases (P<0.05) than the patients in the non-severe group. However, the level of neutrophil of the patients in the severe group was higher in the progressive phase (P<0.05), and so was NLR in the acute, progressive, and convalescent-phase (P<0.05). CONCLUSION: Infected with COVID-19 changed the levels of lymphocyte, neutrophil, LMR, and NLR in the blood, and these analyzing items were significantly different between the non-severe and severe groups. Furthermore, the dynamic changes of lymphocyte and NLR levels may help discriminate the severe group from the non-severe group.

7.
Int J Gen Med ; 14: 2785-2797, 2021.
Article in English | MEDLINE | ID: covidwho-1292123

ABSTRACT

BACKGROUND: COVID-19 infections are still at pandemic levels globally and there are currently no specific drugs to treat these infections. Previous studies have demonstrated that serum albumin levels were abnormally low in COVID-19 patients and might be used as a prognosis biomarker. Supplemental albumin has been used as an experimental therapeutic method. However, dynamic evaluation of albumin in patients with COVID-19 was limited and whether serum albumin could predict the prognosis of these patients is unknown. METHODS: We enrolled 79 COVID-19 patients in the present study and reviewed electronic medical laboratory records. Data was processed using SPSS software (Version 20.0) and correlation analysis was performed between serum albumin and other clinical and laboratory findings. RESULTS: Serum albumin levels were gradually decreased both in severe and non-severe COVID-19 patients. Moreover, 17.7% of the patients presented with hypoalbuminemia at least one time during 3 consecutive weekly time points. The hypoalbuminemia group displayed more severe disease and comorbidity that included fever, fatigue, headache, and dizziness on admission. Moreover, serum albumin levels were positively correlated with lymphocyte and RBC numbers, Hb and prealbumin levels as well as with total T cell numbers and the presence of CD4+ and CD8+ T cells. In contrast, there was a negative correlation with C-reactive protein levels and this was an indicator of patient recovery. CONCLUSION: Our results demonstrated that hypoalbuminemia was common in COVID-19 patients and its levels were linked to disease severity. Patients with fever, fatigue and headache or dizziness on admission were more likely to experience hypoalbuminemia. Dynamic monitoring of serum albumin is therefore necessary and should be performed during COVID-19 patient treatments as a tool for evaluating the prognosis of COVID-19 infections.

8.
Anal Chem ; 93(11): 4782-4787, 2021 03 23.
Article in English | MEDLINE | ID: covidwho-1114675

ABSTRACT

The outbreak of coronavirus disease 2019 (COVID-19) caused by SARS CoV-2 is ongoing and a serious threat to global public health. It is essential to detect the disease quickly and immediately to isolate the infected individuals. Nevertheless, the current widely used PCR and immunoassay-based methods suffer from false negative results and delays in diagnosis. Herein, a high-throughput serum peptidome profiling method based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is developed for efficient detection of COVID-19. We analyzed the serum samples from 146 COVID-19 patients and 152 control cases (including 73 non-COVID-19 patients with similar clinical symptoms, 33 tuberculosis patients, and 46 healthy individuals). After MS data processing and feature selection, eight machine learning methods were used to build classification models. A logistic regression machine learning model with 25 feature peaks achieved the highest accuracy (99%), with sensitivity of 98% and specificity of 100%, for the detection of COVID-19. This result demonstrated a great potential of the method for screening, routine surveillance, and diagnosis of COVID-19 in large populations, which is an important part of the pandemic control.


Subject(s)
COVID-19/diagnosis , Peptides/blood , SARS-CoV-2/metabolism , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Area Under Curve , COVID-19/metabolism , COVID-19/virology , Case-Control Studies , Discriminant Analysis , High-Throughput Screening Assays , Humans , Least-Squares Analysis , Machine Learning , Principal Component Analysis , ROC Curve , SARS-CoV-2/isolation & purification , Sensitivity and Specificity , Tuberculosis/metabolism , Tuberculosis/pathology
9.
Ann Clin Biochem ; 57(6): 429-434, 2020 11.
Article in English | MEDLINE | ID: covidwho-982712

ABSTRACT

OBJECTIVES: The purpose of the current study was to evaluate the analytical performance of seven kits for detecting IgM/IgG antibodies against coronavirus (SARS-CoV-2) by using four chemiluminescence immunoassay systems. METHODS: Fifty patients diagnosed with SARS-CoV-2 infection and 130 controls without coronavirus infection from the General Hospital of Chongqing were enrolled in the current retrospective study. Four chemiluminescence immunoassay systems, including seven IgM/IgG antibody detection kits for SARS-CoV-2 (A_IgM, A_IgG, B_IgM, B_IgG, C_IgM, C_IgG and D_Ab), were employed to detect antibody concentrations. The chi-square test, the receiver operating characteristic (ROC) curve and Youden's index were determined to verify the cut-off value of each detection system. RESULTS: The repeatability verification results of the A, B, C and D systems are all qualified. D_Ab performed best (92% sensitivity and 99.23% specificity), and B_IgM performed worse than the other systems. Except for the A_IgM and C_IgG systems, the optimal diagnostic thresholds and cut-off values of the other kits and their recommendations are inconsistent with each other. B_IgM had the worst AUC, and C_IgG had the best diagnostic accuracy. More importantly, the B_IgG system had the highest false-positive rate for testing patients with AIDS, tumours and pregnancies. The A_IgM system test showed the highest false-positive rates among elderly individuals over 90 years old. COVID-2019 IgM/IgG antibody test systems exhibit performance differences. CONCLUSIONS: The Innodx Biotech Total Antibody serum diagnosis kit is the most reliable detection system for anti-SARS-CoV-2 antibodies, which can be used together with nucleic acid tests as an alternative method for SARS-CoV-2 detecting.


Subject(s)
Antibodies, Viral/analysis , Antibody Specificity , Betacoronavirus/immunology , Immunoassay/methods , Luminescence , Antibodies, Viral/blood , Antibodies, Viral/immunology , Female , Humans , Limit of Detection , Male , Middle Aged , SARS-CoV-2
10.
J Infect Dis ; 222(2): 189-193, 2020 06 29.
Article in English | MEDLINE | ID: covidwho-643587

ABSTRACT

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel ß-coronavirus, causes severe pneumonia and has spread throughout the globe rapidly. The disease associated with SARS-CoV-2 infection is named coronavirus disease 2019 (COVID-19). To date, real-time reverse-transcription polymerase chain reaction (RT-PCR) is the only test able to confirm this infection. However, the accuracy of RT-PCR depends on several factors; variations in these factors might significantly lower the sensitivity of detection. METHODS: In this study, we developed a peptide-based luminescent immunoassay that detected immunoglobulin (Ig)G and IgM. The assay cutoff value was determined by evaluating the sera from healthy and infected patients for pathogens other than SARS-CoV-2. RESULTS: To evaluate assay performance, we detected IgG and IgM in the sera from confirmed patients. The positive rate of IgG and IgM was 71.4% and 57.2%, respectively. CONCLUSIONS: Therefore, combining our immunoassay with real-time RT-PCR might enhance the diagnostic accuracy of COVID-19.


Subject(s)
Antibodies, Viral/blood , Betacoronavirus/immunology , Clinical Laboratory Techniques/methods , Coronavirus Infections/diagnosis , Immunoenzyme Techniques/methods , Pneumonia, Viral/diagnosis , Serologic Tests/methods , Adult , COVID-19 , COVID-19 Testing , COVID-19 Vaccines , Coronavirus Infections/immunology , Female , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Luminescent Measurements , Male , Middle Aged , Pandemics , Peptides/immunology , Pneumonia, Viral/immunology , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2 , Sensitivity and Specificity , Viral Proteins/immunology
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