RESUMO
【Objective】 To analyze the SARS-CoV-2 detection results among blood donors in different periods of COVID-19 pandemic control in Shenzhen and assess the antibody levels and infection status of blood donors in different periods, so as to provide reference for subsequent blood testing strategies. 【Methods】 A total of 4 768 plasma samples of blood donors were subjected to pooled testing by nucleic acid testing(NAT) with 8 samples per pool. Additionally, these samples were subjected to a 1000-fold dilution, and the detection of SARS-CoV-2 total antibody was performed by enzyme-linked immunosorbent assay (ELISA). The 4 768 plasma samples were collected from blood donors at different time points in Shenzhen, with inquiries made to determine whether donors during the COVID-19 pandemic were in the convalescence. The antibody positive rates in blood screening samples during different periods of the pandemic and samples from individuals in the convalescence of COVID-19 infection were analyzed. Furthermore, the antibody levels were examined for differences based on gender, age, and blood type. 【Results】 All 4 768 plasma samples from blood donors were negative by NAT, while 2 342 samples were detected positive by the SARS-CoV-2 total antibody detection, with a positive rate of 49.1%. These samples from four periods (September 30 to October 3, 2022; November 3 to 6, 2022; December 27 to 31, 2022; January 6 to 18, 2023) were subjected to a 1 000-fold dilution for COVID-19 antibody detection, and the positive rates were 21.3%, 15.8%, 65.9%, and 93.9%, respectively. 【Conclusion】 The prevalence of COVID-19 antibodies among blood donors in Shenzhen during different periods of the pandemic varied significantly. There was no difference in antibody prevalence among different genders and blood types, while younger individuals exhibited a higher prevalence of antibodies. The risk of COVID-19 transmission through blood transfusion was found to be extremely low.
RESUMO
Objective:To investigate the clinical characteristics and prognostic factors of 2019 novel coronavirus (2019-nCoV) Omicron variant infected cases.Methods:A total of 987 coronavirus disease 2019 (COVID-19) adult imported cases admitted to Shanghai Public Health Clinical Center, Fudan University from July 1, 2021 to January 6, 2022 were recruited. The cases were divided into Omicron group (193 cases) and non-Omicron group (794 cases) according to the genotype of the virus. The clinical data, imaging examination and laboratory results of two groups were collected and compared. Chi-square test and Mann-Whitney U test were used as statistical methods. Multiple linear regression analysis was used for multiple linear regression analysis. Results:The majority of patients in Omicron group were 18 to 30 years old, accounting for 51.3%(99/193), which was higher than 31.4%(249/794) in non-Omicron group. The difference was statistically significant ( χ2=52.75, P<0.001). The proportion of mild cases in Omicron group was 88.6%(171/193), which was higher than 81.6%(648/794) in non-Omicron group. The difference was statistically significant ( χ2=5.37, P=0.021). Cases with symptoms were more common in Omicron group than those in non-Omicron group (60.1%(116/193) vs 29.1%(231/794)), and the difference was statistically significant ( χ2=65.49, P<0.001), with the main clinical manifestations of sore/itchy throat, fever and cough/expectoration. The proportion of cases with pulmonary computed tomography (CT) imaging manifestations at admission in Omicron group was 13.0%(25/193), which was lower than that in non-Omicron group (215/794, 27.1%). The difference was statistically significant ( χ2=16.83, P<0.001). The proportion of cases with 2019-nCoV IgG positive at admission was 47.7%(92/193) in Omicron group, which was lower than 61.1%(485/794) in non-Omicron group, and the difference was statistically significant ( χ2=11.51, P<0.001). The hospitalization time of Omicron group was 20.0 (16.0, 23.0) d, which was longer than that of non-Omicron group (14.0 (10.0, 22.0) d), and the difference was statistically significant ( Z=-7.42, P<0.001). Multiple linear regression analysis showed that the time of hospitalization of cases with 2019-nCoV IgG positive at admission was shorter, while that of the cases with fever in Omicron group was longer (both P<0.050). Conclusions:The main clinical characteristics of cases with Omicron variant are fever and upper respiratory symptoms. Their pulmonary CT imaging manifestations are less, and the time of hospitalization is slightly longer. The time of hospitalization and the virus clearance time in Omicron variant infected cases with 2019-nCoV IgG positive at admission and not presented with fever are both shorter.
RESUMO
【Objective】 To assess three severe acute respiratorysyndrome coronavirus 2 (SARS-CoV-2) enzyme linked immunosorbent assays (ELISA) and one pseudotype lentivirus-based neutralization test (ppNAT) in detecting the convalescent plasma antibody levles from COVID-19. 【Methods】 30 COVID-19 convalescent plasma samples were screened for antibodies against SARS-CoV-2 using three kinds of SARS-CoV-2 ELISA reagents and one ppNAT test in Shenzhen. The controls consisted of plasma samples from 32 healthy blood donors in February 2019. The diagnostic efficacy analysis of various SARS-CoV-2 ELISA reagents was performed using real-time fluorescent Polymerase Chain Reaction (RT-PCR). We also analyzed correlation between different immunological reagents and the age, gender, hospitalization, and severity of illness. 【Results】 The positive yielding rate of ppNAT and three kinds of IgG ELISA was higher than that of IgM ELISA. The positive yielding rates of three kinds of IgG ELISA were 100%(30/30), 93.33%(28/30), and 96.67%(29/30) respectively, while the yielding rates in control group were all 0. The positive yielding rate of three IgM ELISAs were 93.33%(28/30), 70%(21/30)and 46.67% (14/30). All the cases from negative control group were negative for IgG and IgM. Pearson correlation coefficient was calculated; there was a strong correlation between ELISA reagent 2 IgG and ELISA reagent 3 IgG (r=0.765, P0.05). 【Conclusion】 In the convalescent plasma with nucleic acid confirmed covid-19, the yielding rates of different IgM antibodies varied greatly. Antibody levels were influenced by age to some extent.
RESUMO
@#In the context of the global pandemic of COVID-19, with the epidemic epicenter located in the Wuhan City, China, patients with severe mental illness have also been deeply affected by the epidemic. In this paper, two patients with schizophrenia who recovered from COVID-19 were reported. Because of the long-term positive results of the SARS-CoV-2 serum antibody IgM test, they had to undergo medical isolation and social restrictions for a long time. After the situation was effectively identified by the medical staff and they were eliminated as a potential virus carrier and released from the medical isolation center. Since psychiatrists often lack systematic knowledge of infectious diseases, the authors hope that this paper can provide a reference to avoid unnecessary wastage of medical resources and prevent placing serious mental burden on such patients in the future.