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BackgroundThe Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), designated as a variant of concern by the World Health Organization, spreads globally and was confirmed as the cause of the Omicron wave of the coronavirus disease 2019 (COVID-19) pandemic in Shanghai, China. The viral shedding duration of Omicron variants needs to be determined. MethodsWe retrospectively analyzed 382 patients admitted to a shelter hospital for COVID-19. Of the patients, 8 patients were referred to a designated hospital, 100 were infected asymptomatic patients, and 274 patients had mild COVID-19. ResultsThe vaccination rates (including fully and boosted) in the asymptomatic and mild COVID-19 patients were 92.00% and 94.16%, respectively. Majority of the studied population showed a first reverse transcription-polymerase chain reaction cycle threshold (Ct) value of 20. For 2565 nasopharyngeal swabs from close or sub-close contacts, the Ct value gradually increased to 35 for 8 days, and the median duration of viral shedding time was 10 days after the first positive detection of the SARS-CoV-2 nuclei acid. ConclusionsQuantitative viral RNA load assays in COVID-19 (BA.2.2.1) close or sub-closed contacts could be used to prevent transmissions and control precautions.
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ObjectivesNo data were available about in-flight transmission of SARS-CoV-2. Here, we report an in-flight transmission cluster of COVID-19 and describe the clinical characteristics of these patients. MethodsAfter a flight, laboratory-confirmed COVID-19 was reported in 12 patients. Ten patients were admitted to the designated hospital. Data were collected from 25th January to 28th February 2020. Clinical information was retrospectively collected. ResultsAll patients are passengers without flight attendants. The median age was 33 years, and 70% were females. None was admitted to intensive care unit, and no patients succumbed through 28th February. The median incubation period was 3.0 days and from illness onset to hospital admission was 2 days. The most common symptom was fever. Two patients were asymptomatic and negative for chest CT scan throughout the disease courses. On admission, initial RT-PCR were positive in 9 patients, however initial chest CT were positive in only half patients. The median lung "total severity score" of chest CT was 6. Notably, "Crazy-Paving" pattern, pleural effusion, and ground-glass nodules were also seen. ConclusionIt is potential for COVID-19 transmission by airplane, but the symptoms are mild. Passengers and attendants must be protected during the flight.
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Objective This study aimed to investigate the effect of splenic CD11clow CD45RBhigh dendritic cell (DC)derived from endotoxin tolerance (ET)mice on the expression of zinc finger protein A20 in acute liver failure (ALF)and to clarify the possible mechanism.Methods ET mice were modeled. CD11clow CD45RBhigh DC were isolated from spleen by magnetic activated cell sorting (MACS).One hundred and twenty-six healthy male BALB/c mice were randomly divided into four groups:control group (group A,n=6),ALF group (group B,n =40),normal CD11clow CD45RBhigh DC-treated group (group C,n=40),ET-CD11clow CD45RBhigh DC-treated group (group D,n=40).Mice in group B,C and D were injected with D-galactosamine (D-GalN)600 mg/kg and lipopolysaccharides (LPS)10 μg/mouse.Mice in group A were given the same volume of normal saline (NS).Half an hour after the D-GalN/LPS injection,mice in group C were treated with splenic CD11clow CD45RBhigh DC derived from normal mice (1 ×10 6/mouse,0.2 mL/mouse).Mice in group D were treated with splenic CD11clow CD45RBhigh DC derived from ET mice (1 × 10 6/mouse,0.2 mL/mouse).Mice in group A and B were given the same volume of 0.9% NaCl solution (0.2 mL/mouse).Alanine aminotransferase (ALT)and aspartate aminotransferase (AST)levels were measured at each time point.Liver histopathological changes were confirmed by hematoxglin and eosin methods.Expressions of tumor necrosis factor-α (TNF-α),nuclear factor-kappa B (NF-κB),and zinc finger protein A20 were measured by reverse transcriptase polymerase chain reaction(RT-PCR)and Western blot.One-way analysis of variance was used to compare means between groups.Normal distribution and homogeneity of variance were tested.LSD test was conducted in patients accorded with homogeneity of variance.Results ALT and AST levels increased 2 h after modeling in group B and peaked at 24 h,which were significantly higher than groups A (t = 31 .00, 11 .52,both P <0.05).ALT and AST levels also increased after 2 h after modeling and peaked at 24 h in group C and group D,which were both significantly higher than group B (t =14.60,26.43,both P <0.05).The mRNA levels and protein expressions of TNF-αand NF-κB in group B increased gradually and peaked at 12 h after D-GalN/LPS injection.Compared to that of group A,the differences were both statistically significant (t = 427.58,122.42,179.35 ,165 .98,all P < 0.05 ).The mRNA level and protein expression of zinc finger protein A20 in group B decreased gradually and reached the minimum at 12 h after D-GalN/LPS injection,which was statistically different compared to group A (t = 90.80, 160.43,both P <0.05).On the contrary,the levels of zinc finger protein A20 in group C and D increased gradually and peaked at 12 h after D-GalN/LPS injection.The expression level of zinc finger protein A20 in group D was significantly higher than group C (t = 11 .21 ,24.80,both P < 0.05 ).Conclusion Treatment of splenic CD11clow CD45RBhigh DC derived from ET mice contributes to liver protection against D-GalN/LPS-induced ALF.
