Impact of inactivated COVID-19 vaccines on lung injury in B.1.617.2 (Delta) variant-infected patients.

BACKGROUND: Chest computerized tomography (CT) scan is an important strategy that quantifies the severity of COVID-19 pneumonia. To what extent inactivated COVID-19 vaccines could impact the COVID-19 pneumonia on chest CT is not clear. METHODS: This study recruited 357 SARS-COV-2 B.1.617.2 (Delta) variant-infected patients admitted to the Second Hospital of Nanjing from July to August 2021. An artificial intelligence-assisted CT imaging system was used to quantify the severity of COVID-19 pneumonia. We compared the volume of infection (VOI), percentage of infection (POI) and chest CT scores among patients with different vaccination statuses. RESULTS: Of the 357 Delta variant-infected patients included for analysis, 105 were unvaccinated, 72 were partially vaccinated and 180 were fully vaccinated. Fully vaccination had the least lung injuries when quantified by VOI (median VOI of 222.4 cm3, 126.6 cm3 and 39.9 cm3 in unvaccinated, partially vaccinated and fully vaccinated, respectively; p < 0.001), POI (median POI of 7.60%, 3.55% and 1.20% in unvaccinated, partially vaccinated and fully vaccinated, respectively; p < 0.001) and chest CT scores (median CT score of 8.00, 6.00 and 4.00 in unvaccinated, partially vaccinated and fully vaccinated, respectively; p < 0.001). After adjustment for age, sex, comorbidity, time from illness onset to hospitalization and viral load, fully vaccination but not partial vaccination was significantly associated with less lung injuries quantified by VOI {adjust coefficient[95%CI] for "full vaccination": - 106.10(- 167.30,44.89); p < 0.001}, POI {adjust coefficient[95%CI] for "full vaccination": - 3.88(- 5.96, - 1.79); p = 0.001} and chest CT scores {adjust coefficient[95%CI] for "full vaccination": - 1.81(- 2.72, - 0.91); p < 0.001}. The extent of reduction of pulmonary injuries was more profound in fully vaccinated patients with older age, having underlying diseases, and being female sex, as demonstrated by relatively larger absolute values of adjusted coefficients. Finally, even within the non-severe COVID-19 population, fully vaccinated patients were found to have less lung injuries. CONCLUSION: Fully vaccination but not partially vaccination could significantly protect lung injury manifested on chest CT. Our study provides additional evidence to encourage a full course of vaccination.

Differences in Clinical and Imaging Features between Asymptomatic and Symptomatic COVID-19 Patients.

Objectives: The clinical and imaging features of asymptomatic carriers of severe acute respiratory syndrome coronavirus 2 and symptomatic COVID-19 patients. Methods: The clinical and chest computed tomography imaging data of 47 asymptomatic carriers and 36 symptomatic COVID-19 patients were derived. All patients underwent 4-6 CT scans over a period of 2-5 days. Results: The bulk of asymptomatic carriers who developed symptoms and most of the COVID-19 patients were older than 18 years of age with a decreased lymphocyte count, abnormal hepatic and renal function, and increased D-dimer and C-reactive protein. In the early stage, the pulmonary lesion involved mostly 1-2 lobes at the peripheral area in asymptomatic carriers but more than three lobes at both the central and peripheral areas in COVID-19 patients. In the progression stage, the lesion of asymptomatic carriers extended from the peripheral to the central area, and no significant difference was found in the lesion range compared with the symptomatic control group. In early improvement stage, the lesion was rapidly absorbed, and lesions were located primarily at the peripheral area in asymptomatic carriers; contrastingly, lesions were primarily located at both the central and peripheral areas in symptomatic patients. Asymptomatic carriers reflected a significantly shorter duration from disease onset to peak progression stage compared with the symptomatic. Conclusions: Asymptomatic carriers are a potential source of transmission and may become symptomatic COVID-19 patients despite indicating less severe pulmonary damage, earlier improvement, and better prognosis. Early isolation and intervention can eliminate such carriers as potential sources of transmission and improve their prognosis.

Clinical features and high-resolution chest computerized tomography findings of children infected by the B.1.617.2 variant of coronavirus disease 2019.

PURPOSE: To analyse the clinical symptoms, laboratory examinations and chest CT findings of children infected by the B.1.617.2 variant of COVID-19 and to compare the differences between clinical subtypes. METHODS: Fifty-three children (28 males, 25 females; age ranging from 4 months to 17 years) were included with B.1.617.2 variant infection in Nanjing, China, from July 21 to August 12 2021. Clinical data from patients were collected and analysed in groups of mild and common types. Imaging data were divided into three stages for evaluation: early, intermediate and late stages. RESULTS: In our study, fever (53%), cough (34%) and pharyngeal discomfort (28%) were the main symptoms. There were no differences in clinical symptoms between the mild and common type. The most common laboratory test items outside the normal range were decreased mean corpuscular volume (68%), lymphocyte percentage (64% elevated and 2% decreased) and decreased serum alkaline phosphatase concentration (66%). The differences in haemoglobin and monocyte percentages between the mild and common types were statistically significant (p = .037 and .033, respectively). No influencing factor was statistically significant in the regression analysis of both symptoms and clinical subtypes. The main CT findings were ground-glass opacity and consolidation located in the periphery and bilateral multilobed involvement. The mean CT score was 1.6. CT score correlated with packet cell volume, haemoglobin, mean erythrocyte volume, mean platelet volume and platelet distribution width. CONCLUSION: The pathogenetic condition of children with B.1.617.2 variant infection is mild. Although there were intergroup differences in some blood cell analyses, T-lymphocyte counts, and comprehensive biochemical indicators, no factors had a significant effect on clinical typing and the presence or absence of symptoms. CT findings and CT scores reflect disease stage and pathological changes and correlate moderately with laboratory tests, making them of good value for disease diagnosis and monitoring.Key MessagesPaediatric patients infected with B.1.617.2 variant have a milder clinical and imaging presentation than adults and are similar to the prototype infection.CT findings and scores which reflect disease stages and pathological changes.There is a correlation between chest CT and laboratory tests, which can be useful for the diagnosis and follow-up of the disease.

Computer-Aided Diagnosis of COVID-19 CT Scans Based on Spatiotemporal Information Fusion.

Coronavirus disease (COVID-19) is highly contagious and pathogenic. Currently, the diagnosis of COVID-19 is based on nucleic acid testing, but it has false negatives and hysteresis. The use of lung CT scans can help screen and effectively monitor diagnosed cases. The application of computer-aided diagnosis technology can reduce the burden on doctors, which is conducive to rapid and large-scale diagnostic screening. In this paper, we proposed an automatic detection method for COVID-19 based on spatiotemporal information fusion. Using the segmentation network in the deep learning method to segment the lung area and the lesion area, the spatiotemporal information features of multiple CT scans are extracted to perform auxiliary diagnosis analysis. The performance of this method was verified on the collected dataset. We achieved the classification of COVID-19 CT scans and non-COVID-19 CT scans and analyzed the development of the patients' condition through the CT scans. The average accuracy rate is 96.7%, sensitivity is 95.2%, and F1 score is 95.9%. Each scan takes about 30 seconds for detection.

Prognostic Nomogram on Admission Predicting Progression for Patients with Nonsevere COVID-19

The present study aimed to establish a prognostic nomogram to stratify high-risk patients with Coronavirus Disease 2019 (COVID-19) who progressed from the nonsevere condition on admission to severe during hospitalization. This multicenter retrospective study included patients with nonsevere COVID-19 on admission from Jan 10, 2020 to Feb 7, 2020. In the training cohort, independent risk factors associated with disease progression were identified by univariate and multivariate analyses. The prognostic nomogram was established and then validated externally using C-index. The study included 351 patients (293 and 58 in the training and validation cohorts, respectively), with 27 (9.2%) and 5 (8.6%) patients progressed, respectively. In the training cohort, older age (OR 1.036, 95% CI 1.000-1.073), more lobes involved on chest CT (OR 1.841, 95% CI 1.117-3.035), comorbidity present (OR 2.478, 95% CI 1.020-6.018), and lower lymphocyte count (OR 0.081, 95% CI 0.019-0.349) were identified as independent risk factors. The prognostic nomogram was established in the training cohort with satisfied external prognostic performance (C-index 0.906, 95% CI 0.806-1.000). In conclusion, older age, comorbidity present, more lobes involved on chest CT, and lower lymphocyte count are independent risk factors associated with disease progression during hospitalization for patients with nonsevere COVID-19.

Comparison of clinical characteristics between patients with coronavirus disease 2019 (COVID-19) who retested RT-PCR positive versus negative: a retrospective study of data from Nanjing.

BACKGROUND: The epidemiological and clinical characteristics of patients with coronavirus disease 2019 (COVID-19) have been reported. However, the prevalence of retesting positive by RT-PCR for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the associated patient characteristics, remain unclear. METHODS: We included 90 confirmed cases of COVID-19 treated in the Nanjing Public Health Center from January 20, 2020 to February 16, 2020 in this retrospective study. All patients completed treatment for COVID-19 and were retested by RT-PCR for SARS-CoV-2 4-20 days after completion of therapy. The clinical characteristics between patients with who retested positive versus negative by RT-PCR were compared, and the factors predictive of positive retesting were analyzed. Positive retesting was modeled with the area under the receiver operating characteristic curve (AUC). RESULTS: The age range of the study population was 0.8-97 years, and all patients were cured or showed improvement. A total of 10 (11%) patients retested positive by RT-PCR 4-20 days after completion of therapy. As compared with patients who retested negative, those who retested positive had a lower percentage of pre-admission fever, a higher percentage of post-admission fever, a lower percentage of bilateral lung infection, higher white blood cell (WBC) count and creatine phosphokinase, and lower hypersensitive c-reactive protein (hs-CRP), interleukin-6 and erythrocyte sedimentation rates (all P<0.05). Logistic regression analysis of the above eight key variables showed that lower hs-CRP and higher WBC were independently associated with positive retesting by RT-PCR. A combination of hs-CRP and WBC were predictive of positive retesting, with an AUC of 0.859. CONCLUSIONS: Patients with COVID-19 who retested positive by RT-PCR for SARS-CoV-2 had mild symptoms and better blood testing results. A combination of hs-CRP and WBC may predict positive retesting by RT-PCR; however, the sensitivity and specificity should be studied further.

SARS-CoV-2 neutralizing antibody levels are correlated with severity of COVID-19 pneumonia.

The emerging coronavirus disease 2019 (COVID-19) has become a serious global public health threat. With more and more recovered patients, it is urgently needed for evaluation of the neutralizing antibody (NAb) in these patients. In this study, we collected blood samples from 49 patients recently recovered from COVID-19. Serum NAbs were measured using a novel surrogate virus neutralization test (sVNT). Factors associated with NAb titers were analyzed using Ordinary Least Squares regression model. The median age of the study participants was 37 years (IQR, 30.0-54.5) and 55.1 % (27/49) of which were male. The median time to blood collection (for NAb analysis) from illness onset, viral clearance and discharge were 43.0 days (IQR, 36.0-50.0), 27.0 days (IQR, 20.5-37) and 17.0 days (IQR, 15.0-33.0), respectively. Patients had a median NAb titer of 1: 40 (IQR, 1:15-1:120). NAbs were not detected in two asymptomatic children who quickly cleared the virus. NAb titers were higher in patients with older age (p = 0.020), symptomatic infection (p = 0.044), more profound lung involvement (p＜0.001), abnormal C-reactive protein level (p＜0.01) and elevated lactate dehydrogenase (p = 0.019). Multivariable analysis revealed that severity of pneumonia and having comorbidity positively correlated with NAb titers in recovered patients (p = 0.02), while use of corticosteroids negatively impacted NAb titers (p = 0.01). Our study suggests that some COVID-19 patients may not have detectable NAb after recovery. SARS-CoV-2 NAb titers are positively correlated with severity of COVID-19 pneumonia.

Clinical Use of Short-Course and Low-Dose Corticosteroids in Patients With Non-severe COVID-19 During Pneumonia Progression.

Background: The emerging coronavirus disease 2019 (COVID-19) has become a serious public health concern with a high number of fatalities. It is unclear whether corticosteroids could be a candidate for an early intervention strategy for patients with COVID-19. Methods: In this retrospective cohort study, we analyzed data from 28 corticosteroid-treated patients with non-severe but advanced COVID-19, in which short-course and low-dose corticosteroids were administered because of unremitting or worsening clinical conditions during hospitalization. To compare the effect of corticosteroids on viral clearance, 44 corticosteroid-untreated patients were included as controls. Results: At the time of admission, corticosteroid-treated patients (n = 28) had a more advanced baseline illness compared with corticosteroid-untreated patients (n = 44), as reflected by poorer blood laboratory parameters (lymphocytes, C-reactive protein, and lactate dehydrogenase) and more extensive chest computed tomography (CT) abnormalities. Corticosteroids were given because of radiological evidence of pneumonia progression (26/28) and/or unremitting fever (22/28) after admission. The median time from illness onset to corticosteroid treatment was 9 days (IQR, 7-10). The median duration and accumulated dose of corticosteroid treatment were 4.5 days [interquartile range (IQR), 3-5] and 140 mg of methylprednisolone (IQR, 120-200). Intravenous immunoglobulin (20 g per day for 3-5 days) was co-administered with corticosteroids. With the corticosteroid treatment, all patients achieved an abatement of fever within 1 day, and 78.6% (22/28) of the patients achieved radiological remission when evaluated about 3 days later. Only one (3.6%) patient progressed to severe COVID-19, and all patients recovered and were discharged without any sequela. The median time from illness onset to viral clearance was similar, as compared with 44 corticosteroid-untreated patients with relatively milder disease [18 (IQR 14.3-23.5) days vs. 17 (IQR, 12-20) days, p = 0.252]. When adjusted for age, sex, underlying comorbidities, baseline blood laboratory parameters, viral load, and chest radiological findings, the causal hazard ratio of corticosteroid treatment for the viral clearance was 0.79 (95%CI, 0.48-1.30, p = 0.34). Conclusion: Short-course and low-dose applications of corticosteroids, when co-administered with intravenous immunoglobulin, in non-severe COVID-19 patients during the stage of clinical deterioration may possibly prevent disease progression, while having a negligible impact on the viral clearance.

Clinical characteristics of 24 asymptomatic infections with COVID-19 screened among close contacts in Nanjing, China.

Previous studies have showed clinical characteristics of patients with the 2019 novel coronavirus disease (COVID-19) and the evidence of person-to-person transmission. Limited data are available for asymptomatic infections. This study aims to present the clinical characteristics of 24 cases with asymptomatic infection screened from close contacts and to show the transmission potential of asymptomatic COVID-19 virus carriers. Epidemiological investigations were conducted among all close contacts of COVID-19 patients (or suspected patients) in Nanjing, Jiangsu Province, China, from Jan 28 to Feb 9, 2020, both in clinic and in community. Asymptomatic carriers were laboratory-confirmed positive for the COVID-19 virus by testing the nucleic acid of the pharyngeal swab samples. Their clinical records, laboratory assessments, and chest CT scans were reviewed. As a result, none of the 24 asymptomatic cases presented any obvious symptoms while nucleic acid screening. Five cases (20.8%) developed symptoms (fever, cough, fatigue, etc.) during hospitalization. Twelve (50.0%) cases showed typical CT images of ground-glass chest and 5 (20.8%) presented stripe shadowing in the lungs. The remaining 7 (29.2%) cases showed normal CT image and had no symptoms during hospitalization. These 7 cases were younger (median age: 14.0 years; P=0.012) than the rest. None of the 24 cases developed severe COVID-19 pneumonia or died. The median communicable period, defined as the interval from the first day of positive nucleic acid tests to the first day of continuous negative tests, was 9.5 days (up to 21 days among the 24 asymptomatic cases). Through epidemiological investigation, we observed a typical asymptomatic transmission to the cohabiting family members, which even caused severe COVID-19 pneumonia. Overall, the asymptomatic carriers identified from close contacts were prone to be mildly ill during hospitalization. However, the communicable period could be up to three weeks and the communicated patients could develop severe illness. These results highlighted the importance of close contact tracing and longitudinally surveillance via virus nucleic acid tests. Further isolation recommendation and continuous nucleic acid tests may also be recommended to the patients discharged.

Clinical characteristics and changes of chest CT features in 307 patients with common COVID-19 pneumonia infected SARS-CoV-2: A multicenter study in Jiangsu, China

Objective The study was aimed to describe the clinical characteristics and evaluate the dynamic changes of chest CT features in the first three weeks in the common type fo COVID-19 pneumonia patients in Jiangsu Province. Methods 307 patients infected SARS-CoV-2 classified as common type were enrolled in the study. 628 chest CT scans were divided into three groups based on the time interval between symptoms and chest CT scan. The clinical characteristics were descriptively analyzed.The chest CT features were quantitatively evaluated. Mann-Whitney U test was used to test the differences in three groups and between men and women. Spearman rank correlation was used to test the association between the arterial blood gas(ABG) analysis results and chest CT scores. Results Fever (69.1%) and cough (62.8%) were common symptoms. 111(36.2%) patients were anorexia. GGO was the most common manifestation of COVID-19 pneumonia, which could be followed by consolidation and fibrosis. Lower lobe or subpleural region was the most common distribution form of lesion. More lung lobes were involved in the third week. Total chest CT scores in the second week were higher than the first week. Fibrosis Scores increased in the second and third week. Total CT score, GGO score and fibrosis score of male patients were significantly higher than female in the second week. Male patients had higher consolidation score and fibrosis score than female in the third week. Total CT score and GGO score had weak to moderate correlation with arterial blood gas indices. Conclusion Changes in chest CT were difficult to assess quantitatively in the first third weeks. Male patients recovered slower than female in the second week. Although CT score had correlations with arterial blood gas indices, long-term follow-up of pulmonary function test is needed to determine the recovery of lung.