The Relation between Immunological Features and the Positive SARS-CoV-2 Nucleic Acid in Patients with Nonsevere COVID⁃19.

Objective: The novel coronavirus nucleic acid results are the core indicators of illness monitoring. This study aimed to evaluate the relationship between immunological features and positive SARS-CoV-2 nucleic acid by analyzing the clinical and immunological features in nonsevere COVID-19 cases. Methods: Data from nonsevere COVID-19 patients admitted to Haihe Hospital from May 2020 to June 2021 were retrospectively reviewed and analyzed. Results: (1) A total of 122 cases were reviewed in the present study, including 38 mild and 84 moderate cases. The average age of mild cases was significantly different from moderate cases (P < 0.001). Eight patients complained of hyposmia and it was more frequent in mild cases (P < 0.001). The nucleic acid positive duration (NPD) of nonsevere novel coronavirus was 20.49 (confidence interval (CI) 17.50-3.49) days. (2) The levels of specific IgM and IgG for COVID-19 were higher in mild cases than in moderate cases (P=0.023 and P=0.047, respectively). (3) The correlation analysis with antibodies and T-cell subtypes showed that the lymphocyte (LYM) count, T cells, CD4+T cells, and CD8+T cells had a linear correlation with NPD. (4) Among the 93 patients monitored, 62 COVID-19 cases presented a progressive rise of specific IgM and IgG. The daily increase rates of IgM and IgG were 38.42% (CI 28.22-48.61%) and 24.90% (CI 0.23-29.58%), respectively. Conclusion: The levels and daily increase rates of specific IgM and IgG against the virus can vary between cases. The NPD presented a linear correlation with the LYM, T cells, CD4+T cells, and CD8+T cells. Hence, more attention should be paid to these indicators in clinical practice.

'Dynamic zero-COVID' policy and viral clearance during an omicron wave in Tianjin, China: a city-wide retrospective observational study.

OBJECTIVE: To report how the Chinese mainland battled its first omicron wave, which happened in Tianjin, a metropolis with 14 million residents. We also sought to better understand how clinical features affected the timing of viral clearance. DESIGN: A retrospective study of the omicron wave in Tianjin between 8 January 2022 and 3 March 2022. SETTING: Except for the first cases on 8 January, all the omicron cases were identified through PCR mass testing in the residential communities. Residential quarantine and serial PCR mass testing were dynamically adjusted according to the trends of new cases. PARTICIPANTS: All the 417 consecutive PCR-positive cases identified through mass screening of the entire city's 14 million residents. 45.3% of the cases were male, and the median age was 37 (range 0.3-90). 389 (93%) cases had complete data for analysing the correlation between clinical features and the timing of viral clearance. MAIN OUTCOME AND MEASURE: Time to viral clearance. RESULTS: Tianjin initiated the 'dynamic zero-COVID' policy very early, that is, when daily new case number was ≈0.4 cases per 1 000 000 residents. Daily new cases dropped to <5 after 3 February, and the number of affected residential subdivisions dropped to ≤2 after 13 February. 64% (267/417) of the cases had no or mild symptoms. The median interval from hospital admission to viral clearance was 10 days (range 3-28). An exploratory analysis identified a feature cluster associated with earlier viral clearance, with HRs of 3.56 (95% CI 1.66 to 7.63) and 3.15 (95% CI 1.68 to 5.91) in the training and validation sets, respectively. CONCLUSIONS: The 'dynamic zero-COVID' policy can suppress an omicron wave within a month. It might be possible to predict in advance which cases will require shorter periods of isolation based on their clinical features.

Viral RNA Load in Symptomatic and Asymptomatic COVID-19 Omicron Variant-Positive Patients.

Objectives: Viral load is important when evaluating viral transmission potential, involving the use of a polymerase chain reaction (PCR) cycle threshold (Ct) value. We aimed to analyze the PCR Ct values of respiratory tract samples taken from patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant strains to evaluate these strains' viral dynamics. Methods: This study comprised 361 patients. The Ct values of SARS-CoV-2-related respiratory samples were compared between symptomatic and asymptomatic patients. Results: The median (25th percentile and 75th percentile) nasopharynx and oropharynx SARS-CoV-2 Ct values were 30.5 (24.5-35.0) and 34.5 (30.0-37.0) in the symptomatic group, respectively, and 27.8 (23.4-34.5) and 33.5 (26.0-35.0) in the asymptomatic group, respectively, without significance. In the symptomatic group, subgroup analyses according to age showed the mean nasal Ct value for patients aged >18 years was 29.0 (23.5-34.5), which was significantly lower than that of patients aged 0-4 years and 5-13 years (36.0 (30.5-38.0) and 34.5 (31.0-39.0), respectively). The nasal Ct value for asymptomatic patients aged >18 years was 25.5 (20.9-28.4), which was significantly lower than of patients aged 5-13 years (34.5 (25.6-36.4)). Conclusion: Our findings suggest that the viral loads of asymptomatic and symptomatic patients did not differ significantly. However, adults infected with SARS-CoV-2 had higher nasal viral loads that those of young children.

[Clinical study of awake prone positioning treatment in patients with common coronavirus disease 2019 caused by Omicron variant].

OBJECTIVE: To evaluate the clinical effect of awake prone positioning (APP) for common coronavirus disease 2019 (COVID-19) caused by Omicron variant. METHODS: Retrospectively analyze the clinical data of patients with COVID-19 caused by Omicron variant admitted by medical team of Tianjin Third Central Hospital during the period of supporting Tianjin COVID-19 designated hospital from January 8 to February 20, 2022. Patients who met the diagnostic criteria for common COVID-19 and had risk factors for developing severe disease or had pulse oxygen saturation (SpO2) ≤ 0.93 after exercise without supplementary oxygen were enrolled. Patients were divided into APP group and control group according to whether they completed the daily 12-hours APP in the first three days after enrollment. Demographic characteristics, clinical symptoms, COVID-19 vaccination status, laboratory examination, disease progression (progression to severe), time to nucleic acid negative conversion, length of hospital stay, and adverse reactions and tolerability [visual analog scale (VAS) score (the higher the score, the worse the tolerability] during APP were evaluated in two groups. Interleukin-6 (IL-6), C-reactive protein (CRP), SpO2/inhaled oxygen concentration (FiO2) ratio and ROX index (ROXI) were compared between two groups at enrollment, 3rd and 7th day after enrollment. RESULTS: There were no significant differences in demographic characteristics, clinical symptoms, vaccination rates of COVID-19 and laboratory tests between the two groups. There were no statistically significant differences in IL-6, CRP, SpO2/FiO2 ratio and ROXI between two groups at the time of enrollment. Compared with the group at the time of enrollment, SpO2/FiO2 ratio and ROXI in APP group increased significantly at the 3rd day after enrollment [SpO2/FiO2 ratio: 461.90 (457.10, 466.70) vs. 446.67 (437.14, 457.10), ROXI: 25.40 (23.33, 25.93) vs. 22.57 (21.86, 24.40), all P < 0.05], and the levels of IL-6 and CRP in control group were significantly increased [IL-6 (ng/L): 18.30 (6.50, 37.75) vs. 7.40 (5.10, 11.15), CRP (mg/L): 11.46 (2.11, 17.96) vs. 4.11 (1.72, 9.05), all P < 0.05]. At the 3rd day of enrollment, the levels of IL-6 and CRP in APP group were significantly lower than those in control group [IL-6 (ng/L): 7.35 (4.35, 12.80) vs. 18.30 (6.50, 37.75), CRP (mg/L): 4.52 (1.98, 9.66) vs. 11.46 (2.11, 17.96), all P < 0.05], while SpO2/FiO2 ratio and ROXI were significantly higher than those in control group [SpO2/FiO2 ratio: 461.90 (457.10, 466.70) vs. 446.67 (441.90, 459.52), ROXI: 25.40 (23.33, 25.93) vs. 23.31 (22.10, 24.66), all P < 0.05]. At the 7th day of enrollment,there were no significant differences in IL-6, CRP, SpO2/FiO2 ratio and ROXI between two groups. There were no severe cases in both groups. The time of nucleic acid negative conversion and length of hospital stay in APP group were significantly shorter than those in control group [10.0 (8.0, 12.0) days vs. 11.0 (9.0, 13.0) days, 12.0 (10.0, 14.0) days vs. 14.0 (12.0,16.0) days, respectively, all P < 0.05]. The main adverse reaction during APP was back pain, and the incidence in APP group was slightly lower than that in control group, but the difference was not statistically significant [17.9% (17/95) vs. 26.5% (27/102), P = 0.149]. VAS score in control group was significantly higher than that in APP group [score: 2.5 (2.0, 4.0) vs. 2.0 (1.0, 3.0), P = 0.004]. CONCLUSIONS: In common COVID-19 patients caused by Omicron variant with high risk factors for progression to severe disease or decreased oxygen reserve capacity, early APP can shorten the time of nucleic acid negative conversion and the length of hospital stay, but its effect on preventing disease progression cannot be determined.

Case Report of China/Tianjin's First Novel Coronavirus Variant Omicron.

COVID-19 is a new acute respiratory infectious disease caused by a novel Coronavirus (2019-COV-2) infection. On November 26, 2021, the World Health Organization announced a new 2019-COV-2 variant strain Omicron (B.1.1.529). Omicron's emergence added further uncertainty to the outbreak. Here we report the first case infected with Omicron in China, a 17-year-old female student. In this paper, the clinical symptoms, laboratory and imaging examinations and treatment of the first Omicron-infected patient in China were analyzed. This report might provide a reference for the diagnosis and treatment of patients infected with Omicron strain across the world. The novel Coronavirus antibody tests were performed on the day of admission: IgM level was normal, novel Coronavirus antibody IgG was 132.666s /CO and IgG was 148.47s /CO on the 7th day of admission. IgG showed an increasing trend, which is consistent with the results of multiple novel Coronavirus non-Omicron strain infections.

[Analysis of clinical characteristics of 362 vaccinated or unvaccinated patients infected by novel coronavirus Omicron variant].

OBJECTIVE: To analyze the epidemiological and clinical characteristics of patients infected by novel coronavirus Omicron variant, and also to analyze whether vaccination against novel coronavirus has an impact on the severity and prognosis of Omicron patients. METHODS: A prospective, single-center observational study was conducted to collect data of consecutive patients with Omicron variant infection admitted to the designated hospital for coronavirus disease 2019 (COVID-19) charged by Tianjin COVID-19 rescue medical team of Tianjin Third Central Hospital, from January 8 to February 2, 2022. The clinical characteristics of the patients were analyzed, and the influence of whether the patients were inoculated with booster vaccination on the condition and outcome was analyzed. Data were collected including epidemiological, clinical features, laboratory and imaging examination, treatment measures and clinical outcomes, and difference between groups was analyzed. RESULTS: A total of 362 patients were included, including 136 cases (37.57%) in the booster group, 190 cases (52.49%) in the routine vaccination group, and 36 cases (9.94%) in the unvaccinated group. There was a trend of concentrated distribution of patients, of which 171 cases (47.24%) patients showed family clustering, involving 69 families. Seventy-four cases (20.44%) of the 362 patients had one or more underlying diseases, mainly hypertension (64 cases, 17.68%), diabetes mellitus (23 cases, 6.35%), and coronary heart disease (18 cases, 4.97%); 215 patients (59.39%) had one or more discomfort symptoms, mainly cough (158 cases, 43.65%), pharyngeal discomfort (154 cases, 42.54%) and fever (136 cases, 37.57%). The diagnostic typing was mild type in 194 cases (53.59%), moderate type in 165 cases (45.58%) and severe type in 3 cases (0.83%). The patients had elevated immunoglobulin G (IgG) antibody titers to the novel coronavirus on admission [23.17 (3.08, 60.77)]. Patients were medically isolated and the main treatment measures included traditional Chinese medicine identification (Chinese medicine or tonics) in 265 cases (73.20%), prone treatment in 188 cases (51.93%), anticoagulation with low-molecular heparin in 106 cases (29.28%), immunomodulatory therapy with thymofacine in 21 cases (5.80%), antimicrobial drugs in 20 cases (5.52%), transnasal high-flow oxygen therapy in 12 cases (3.31%), glucocorticoids in 5 cases (1.38%), non-invasive mechanical ventilation in 1 case (0.28%), and invasive mechanical ventilation in 1 case (0.28%). A total of 362 patients were discharged with no deaths, of which 12 patients (3.31%) were admitted to the intensive care unit (ICU). The median duration of illness was 13 (10, 15) days, the median length of hospitalization was 13 (11, 15) days, and the median time to nucleic acid conversion was 13 (10, 15) days. Compared with the unvaccinated group, the IgG antibody titers of patients in the booster and routine vaccination groups [41.49 (20.32, 81.38), 19.94 (2.33, 49.25) vs. 0.16 (0.07, 1.94)] and the proportion of mild patients [66.91% (91/136), 48.94% (93/190) vs. 27.28% (10/36)] were higher, which were also higher in the booster vaccination group than in the conventional vaccination group (all P < 0.05). Compared to the conventional and booster vaccination groups, the unvaccinated group had a higher proportion of severe patients [5.56% (2/36) vs. 0.53% (1/190), 0 (1/136)], longer time to nucleic acid conversion [days: 15 (11, 16) vs.12 (10, 15), 13 (11, 15)], and longer disease duration [days: 15 (11, 16) vs. 12 (10, 15), 13 (11, 15)], and a higher percentage of ICU admissions [16.67% (6/36) vs. 2.63% (5/190), 0.74% (1/136)], with statistically significant differences among the three groups (all P < 0.05). CONCLUSIONS: Omicron variant is extremely infectious with aggregated onset, but its clinical symptoms are mild. The vaccine, especially the booster vaccination, remains effective in preventing severe-stage progression and improving prognosis in patients with Omicron variant infection.

The effect of the systemic immune-inflammation index on conversion time of virus nucleic acid turning negative in COVID-19 patients

Objective: To investigate the effect of the systemic immune-inflammation index(SII) on the conversion time of virus nucleic acid turning negative in patients with coronavirus disease 2019(COVID-19).

Analysis of risk factors for subsequent infection in patients with COVID-19

Objective: To explore the risk factors of subsequent bacterial infection in patients with novel coronavirus disease 2019 (COVID-19).

Analysis of factors affecting the prognosis of COVID-19 patients and viral shedding duration.

The clinical characteristics of patients with COVID-19 were analysed to determine the factors influencing the prognosis and virus shedding time to facilitate early detection of disease progression. Logistic regression analysis was used to explore the relationships among prognosis, clinical characteristics and laboratory indexes. The predictive value of this model was assessed with receiver operating characteristic curve analysis, calibration and internal validation. The viral shedding duration was calculated using the Kaplan-Meier method, and the prognostic factors were analysed by univariate log-rank analysis and the Cox proportional hazards model. A retrospective study was carried out with patients with COVID-19 in Tianjin, China. A total of 185 patients were included, 27 (14.59%) of whom were severely ill at the time of discharge and three (1.6%) of whom died. Our findings demonstrate that patients with an advanced age, diabetes, a low PaO2/FiO2 value and delayed treatment should be carefully monitored for disease progression to reduce the incidence of severe disease. Hypoproteinaemia and the fever duration warrant special attention. Timely interventions in symptomatic patients and a time from symptom onset to treatment <4 days can shorten the duration of viral shedding.