SARS: radiological features

Microbiological profile of long COVID and associated clinical and radiological findings: a prospective cross-sectional study

OBJECTIVE

To study the frequency of microbiological etiology of respiratory infections in patients with long COVID and their associated clinical and radiological findings.

METHODS

Nasopharyngeal swabs and sputum specimens were collected from 97 patients with respiratory illness stemming from long COVID. The specimens were assessed for their microbiological profile (bacteria and virus) and their association with the overall clinical and radiological picture.

RESULTS

In total, 23 (24%) patients with long COVID had viral infection (n = 12), bacterial infection (n = 9), or coinfection (n = 2). Microorganisms were detected at significantly higher rates in hospitalized patients, patients with moderate COVID-19, and patients with asthma (P < .05). Tachycardia (65%) was the most common symptom at presentation. A statistically significant number of patients with long COVID who had viral infection presented with cough and myalgia; and a statistically significant number of patients with long COVID who had bacterial infection presented with productive coughing (P < .05). Post-COVID fibrotic changes were found in 61% of cohort patients (31/51).

CONCLUSION

A decreasing trend of respiratory pathogens (enveloped viruses and bacteria) was found in long COVID. An analysis including a larger group of viral- or bacterial-infected patients with long COVID is needed to obtain high-level evidence on the presenting symptoms (cough, myalgia) and their association with the underlying comorbidities and severity.

COVID-19-associated lung weakness (CALW): Systematic review and meta-analysis

OBJECTIVES

To assess mortality and different clinical factors derived from the development of atraumatic pneumothorax (PNX) and/or pneumomediastinum (PNMD) in critically ill patients as a consequence of COVID-19-associated lung weakness (CALW).

DESIGN

Systematic review with meta-analysis.

SETTING

Intensive Care Unit (ICU).

PARTICIPANTS

Original research evaluating patients, with or without the need for protective invasive mechanical ventilation (IMV), with a diagnosis of COVID-19, who developed atraumatic PNX or PNMD on admission or during hospital stay.

INTERVENTIONS

Data of interest were obtained from each article and analyzed and assessed by the Newcastle-Ottawa Scale. The risk of the variables of interest was assessed with data derived from studies including patients who developed atraumatic PNX or PNMD.

MAIN VARIABLES OF INTEREST

Mortality, mean ICU stay and mean PaO2/FiO2 at diagnosis.

RESULTS

Information was collected from 12 longitudinal studies. Data from a total of 4901 patients were included in the meta-analysis. A total of 1629 patients had an episode of atraumatic PNX and 253 patients had an episode of atraumatic PNMD. Despite the finding of significantly strong associations, the great heterogeneity between studies implies that the interpretation of results should be made with caution.

CONCLUSIONS

Mortality among COVID-19 patients was higher in those who developed atraumatic PNX and/or PNMD compared to those who did not. The mean PaO2/FiO2 index was lower in patients who developed atraumatic PNX and/or PNMD. We propose grouping these cases under the term COVID-19-associated lung weakness (CALW).

[COVID-19-associated lung weakness (CALW): Systematic review and meta-analysis]

Objectives

To assess mortality and different clinical factors derived from the development of atraumatic pneumothorax (PNX) and/or pneumomediastinum (PNMD) in critically ill patients as a consequence of COVID-19-associated lung weakness (CALW).

Design

Systematic review with meta-analysis.

Setting

Intensive care unit (ICU).

Participants

Original research evaluating patients, with or without the need for protective invasive mechanical ventilation (IMV), with a diagnosis of COVID-19 who had developed atraumatic PNX or PNMD on admission or during their hospital stay.

Interventions

Data of interest were obtained from each article and analysed and assessed by the Newcastle-Ottawa Scale. The risk of the variables of interest was assessed by data derived from studies including patients who developed atraumatic PNX or PNMD.

Main variables of interest

Mortality, mean ICU length of stay and mean PaO₂/FiO₂ at diagnosis.

Results

Data were collected from 12 longitudinal studies. Data from a total of 4,901 patients were included in the meta-analysis. A total of 1,629 patients had an episode of atraumatic PNX and 253 patients had an episode of atraumatic PNMD. Despite finding significantly strong associations, the high heterogeneity between studies means that interpretation of the results should be made with caution.

Conclusions

Mortality of COVID-19 patients was higher in those who developed atraumatic PNX and/or PNMD compared to those who did not. The mean PaO2/FiO2 index was lower in patients who developed atraumatic PNX and/or PNMD. We propose to group these cases under the term CAPD.

Do COVID-19 CT features vary between patients from within and outside mainland China? Findings from a meta-analysis

Background

Chest computerized tomography (CT) plays an important role in detecting patients with suspected coronavirus disease 2019 (COVID-19), however, there are no systematic summaries on whether the chest CT findings of patients within mainland China are applicable to those found in patients outside.

Methods

Relevant studies were retrieved comprehensively by searching PubMed, Embase, and Cochrane Library databases before 15 April 2022. Quality assessment of diagnostic accuracy studies (QUADAS) was used to evaluate the quality of the included studies, which were divided into two groups according to whether they were in mainland China or outside. Data on diagnostic performance, unilateral or bilateral lung involvement, and typical chest CT imaging appearances were extracted, and then, meta-analyses were performed with R software to compare the CT features of COVID-19 pneumonia between patients from within and outside mainland China.

Results

Of the 8,258 studies screened, 19 studies with 3,400 patients in mainland China and 14 studies with 554 outside mainland China were included. Overall, the risk of quality assessment and publication bias was low. The diagnostic value of chest CT is similar between patients from within and outside mainland China (93, 91%). The pooled incidence of unilateral lung involvement (15, 7%), the crazy-paving sign (31, 21%), mixed ground-glass opacities (GGO) and consolidations (51, 35%), air bronchogram (44, 25%), vascular engorgement (59, 33%), bronchial wall thickening (19, 12%), and septal thickening (39, 26%) in patients from mainland China were significantly higher than those from outside; however, the incidence rates of bilateral lung involvement (75, 84%), GGO (78, 87%), consolidations (45, 58%), nodules (12, 17%), and pleural effusion (9, 15%) were significantly lower.

Conclusion

Considering that the chest CT features of patients in mainland China may not reflect those of the patients abroad, radiologists and clinicians should be familiar with various CT presentations suggestive of COVID-19 in different regions.

Pulmonary barotrauma in COVID-19: A systematic review and meta-analysis

BACKGROUND

An ever-increasing number of studies have reported an increased incidence of spontaneous pulmonary barotrauma such as pneumothorax, pneumomediastinum, and subcutaneous emphysema in patients with COVID-19. We conducted this systematic review and meta-analysis to assess the value and significance of the available data.

METHODS

A thorough systematic search was conducted to identify studies of barotrauma in hospitalized patients with COVID-19. Data analysis of case reports was done using a statistical package for the social sciences (SPSS) version 22, and meta-analysis was performed using CMA-3.

RESULTS

We identified a total of 4488 studies after thorough database searching.118 case reports and series, and 15 observational studies were included in the qualitative analysis. Fifteen studies were included in the quantitative analysis. The observational studies reported barotrauma in 4.2% (2.4-7.3%) among hospitalized patients; 15.6% (11-21.8%) among critically ill patients; and 18.4% (13-25.3%) in patients receiving invasive mechanical ventilation, showing a linear relationship of barotrauma with the severity of the disease. In addition, barotrauma was associated with a longer length of hospital stay, more extended ICU stay, and higher in-hospital mortality. Also, a slightly higher odds of barotrauma was seen in COVID-19 ARDS compared with non-COVID-19 ARDS.

CONCLUSION

COVID-19 pneumonia is associated with a higher incidence of barotrauma. It presents unique challenges for invasive and non-invasive ventilation management. Further studies are required to unravel the underlying pathophysiology and develop safer management strategies.

Chest radiographic score and lactate dehydrogenase are independent risk factors linked to mortality in Middle East Respiratory Syndrome Coronavirus (MERS-CoV) patients

Background

Despite the dominance of Covid-19 in the current situation, MERS-CoV is found infrequently in the Middle East. When coupled with the chest radiographic score, serum biochemical parameters may be utilized to assess serum biochemical changes in individuals with different degrees of MERS-CoV infection and to predict death. The purpose of this study was to examine the association between increased LDH levels and severe MERS-CoV outcomes utilizing ventilation days and an elevated chest radiographic score.

Results

Fifty-seven patients were included in the retrospective cohort. The mean age was 44.9 ± 13.5 years, while the range was between 12 and 73 years. With an average age of 53.3 ± 16.5 years, 18 of 57 (31.6%) patients were classified as deceased. The deceased group showed a substantially greater amount of LDH than the recovery group (280.18 ± 150.79 vs. 1241.72 ± 1327.77, p = 0.007). A cut-off value of > 512 LDH was established with a C-statistic of 0.96 (95% CI 0.92–1.00) and was 94% sensitive and 93% specific for mortality. Multivariate cox regression analysis revealed that log_e (LDH) (adjusted HR: 9.91, 95% CI: 2.44–40.3, p = 0.001) and chest radiographic score (adjusted HR: 1.24, 95% CI: 1.05–1.47, p = 0.01) were risk factors for mortality, whereas ventilation days were a protective factor (adjusted HR: 0.84, 95% CI: 0.76–0.93, p = 0.001).

Conclusion

According to our results, blood LDH levels of > 512 had a 94% sensitivity and 93% specificity for predicting in-hospital mortality in patients infected with MERS-CoV. The chest radiographic score of 11.34 ± 5.4 was the risk factor for the mortality (adjusted Hazard ratio HR: 1.24, 95% CI: 1.05–1.47, p = 0.01). Thus, threshold may aid in the identification of individuals with MERS-CoV infection who die in hospital.

Follow-up chest radiographic findings in patients with MERS-CoV after recovery

PURPOSE

To evaluate the follow-up chest radiographic findings in patients with Middle East respiratory syndrome coronavirus (MERS-CoV) who were discharged from the hospital following improved clinical symptoms.

MATERIALS AND METHODS

Thirty-six consecutive patients (9 men, 27 women; age range 21-73 years, mean ± SD 42.5 ± 14.5 years) with confirmed MERS-CoV underwent follow-up chest radiographs after recovery from MERS-CoV. The 36 chest radiographs were obtained at 32 to 230 days with a median follow-up of 43 days. The reviewers systemically evaluated the follow-up chest radiographs from 36 patients for lung parenchymal, airway, pleural, hilar and mediastinal abnormalities. Lung parenchyma and airways were assessed for consolidation, ground-glass opacity (GGO), nodular opacity and reticular opacity (i.e., fibrosis). Follow-up chest radiographs were also evaluated for pleural thickening, pleural effusion, pneumothorax and lymphadenopathy. Patients were categorized into two groups: group 1 (no evidence of lung fibrosis) and group 2 (chest radiographic evidence of lung fibrosis) for comparative analysis. Patient demographics, length of ventilations days, number of intensive care unit (ICU) admission days, chest radiographic score, chest radiographic deterioration pattern (Types 1-4) and peak lactate dehydrogenase level were compared between the two groups using the student t-test, Mann-Whitney U test and Fisher's exact test.

RESULTS

Follow-up chest radiographs were normal in 23 out of 36 (64%) patients. Among the patients with abnormal chest radiographs (13/36, 36%), the following were found: lung fibrosis in 12 (33%) patients GGO in 2 (5.5%) patients, and pleural thickening in 2 (5.5%) patients. Patients with lung fibrosis had significantly greater number of ICU admission days (19 ± 8.7 days; P value = 0.001), older age (50.6 ± 12.6 years; P value = 0.02), higher chest radiographic scores [10 (0-15.3); P value = 0.04] and higher peak lactate dehydrogenase levels (315-370 U/L; P value = 0.001) when compared to patients without lung fibrosis.

CONCLUSION

Lung fibrosis may develop in a substantial number of patients who have recovered from Middle East respiratory syndrome coronavirus (MERS-CoV). Significantly greater number of ICU admission days, older age, higher chest radiographic scores, chest radiographic deterioration patterns and peak lactate dehydrogenase levels were noted in the patients with lung fibrosis on follow-up chest radiographs after recovery from MERS-CoV.

Eight months follow-up study on pulmonary function, lung radiographic, and related physiological characteristics in COVID-19 survivors

To describe the long-term health outcomes of patients with COVID-19 and investigate the potential risk factors. Clinical data during hospitalization and at a mean (SD) day of 249 (15) days after discharge from 40 survivors with confirmed COVID-19 (including 25 severe cases) were collected and analyzed retrospectively. At follow-up, severe cases had higher incidences of persistent symptoms, DLCO impairment, and higher abnormal CT score as compared with mild cases. CT score at follow-up was positively correlated with age, LDH level, cumulative days of oxygen treatment, total dosage of glucocorticoids used, and CT peak score during hospitalization. DLCO% at follow-up was negatively correlated with cumulative days of oxygen treatment during hospitalization. DLCO/VA% at follow-up was positively correlated with BMI, and TNF-α level. Among the three groups categorized as survivors with normal DLCO, abnormal DLCO but normal DLCO/VA, and abnormal DLCO and DLCO/VA, survivors with abnormal DLCO and DLCO/VA had the lowest serum IL-2R, IL-8, and TNF-α level, while the survivors with abnormal DLCO but normal DLCO/VA had the highest levels of inflammatory cytokines during hospitalization. Altogether, COVID-19 had a greater long-term impact on the lung physiology of severe cases. The long-term radiological abnormality maybe relate to old age and the severity of COVID-19. Either absent or excess of inflammation during COVID-19 course would lead to the impairment of pulmonary diffusion function.

A comprehensive review of imaging findings in COVID-19 - status in early 2021

Medical imaging methods are assuming a greater role in the workup of patients with COVID-19, mainly in relation to the primary manifestation of pulmonary disease and the tissue distribution of the angiotensin-converting-enzyme 2 (ACE 2) receptor. However, the field is so new that no consensus view has emerged guiding clinical decisions to employ imaging procedures such as radiography, computer tomography (CT), positron emission tomography (PET), and magnetic resonance imaging, and in what measure the risk of exposure of staff to possible infection could be justified by the knowledge gained. The insensitivity of current RT-PCR methods for positive diagnosis is part of the rationale for resorting to imaging procedures. While CT is more sensitive than genetic testing in hospitalized patients, positive findings of ground glass opacities depend on the disease stage. There is sparse reporting on PET/CT with [18F]-FDG in COVID-19, but available results are congruent with the earlier literature on viral pneumonias. There is a high incidence of cerebral findings in COVID-19, and likewise evidence of gastrointestinal involvement. Artificial intelligence, notably machine learning is emerging as an effective method for diagnostic image analysis, with performance in the discriminative diagnosis of diagnosis of COVID-19 pneumonia comparable to that of human practitioners.

COVID-19 versus SARS: A comparative review

The two genetically similar severe acute respiratory syndrome coronaviruses, SARS-CoV-1 and SARS-CoV-2, have each been responsible for global epidemics of vastly different scales. Although both viruses arose from similar origins, they quickly diverged due to differences in their transmission dynamics and spectrum of clinical presentations. The potential involvement of multiple organs systems, including the respiratory, cardiac, gastrointestinal and neurological, during infection necessitates a comprehensive understanding of the clinical pathogenesis of each virus. The management of COVID-19, initially modelled after SARS and other respiratory illnesses, has continued to evolve as we accumulate more knowledge and experience during the pandemic, as well as develop new therapeutics and vaccines. The impact of these two coronaviruses has been profound for our health care and public health systems, and we hope that the lessons learned will not only bring the current pandemic under control, but also prevent and reduce the impact of future pandemics.

Role of Chest Imaging in Viral Lung Diseases

The infection caused by novel beta-coronavirus (SARS-CoV-2) was officially declared a pandemic by the World Health Organization in March 2020. However, in the last 20 years, this has not been the only viral infection to cause respiratory tract infections leading to hundreds of thousands of deaths worldwide, referring in particular to severe acute respiratory syndrome (SARS), influenza H1N1 and Middle East respiratory syndrome (MERS). Although in this pandemic period SARS-CoV-2 infection should be the first diagnosis to exclude, many other viruses can cause pulmonary manifestations and have to be recognized. Through the description of the main radiological patterns, radiologists can suggest the diagnosis of viral pneumonia, also combining information from clinical and laboratory data.

Radiological management and follow-up of post-COVID-19 patients

Most of the patients who overcome the SARS-CoV-2 infection do not present complications and do not require a specific follow-up, but a significant proportion (especially those with moderate / severe clinical forms of the disease) require clinicalradiological follow-up. Although there are hardly any references or clinical guidelines regarding the long-term follow-up of post-COVID-19 patients, radiological exams are being performed and monographic surveillance consultations are being set up in most of the hospitals to meet their needs. The purpose of this work is to share our experience in the management of the post-COVID-19 patient in two institutions thathave had a high incidence of COVID-19 and to propose general follow-uprecommendations from a clinical and radiological perspective.

Radiological management and follow-up of post-COVID-19 patients

Most of the patients who overcome the SARS-COV-2 infection do not present complications and do not require a specific follow-up, but a significant proportion (especially those with moderate/severe clinical forms of the disease) require clinicalradiological follow-up. Although there are hardly any references or clinical guidelines regarding the long-term follow-up of post-COVID-19 patients, radiological exams are being performed and monographic surveillance consultations are being set up in most of the hospitals to meet their needs. The purpose of this work is to share our experience in the management of the post-COVID-19 patient in two institutions thathave had a high incidence of COVID-19 and to propose general follow-uprecommendations from a clinical and radiological perspective.

Severe coronavirus disease 2019 (COVID-19) pneumonia patients treated successfully with a combination of lopinavir/ritonavir plus favipiravir: Case series

The combination therapy of Lopinavir/Ritonavir plus Favipiravir might be a treatment option for patients with COVID-19. Serum ferritin levels and lymphocytopenia are promising markers for disease severity and disease progression that are commonly available in general clinical practice.

CT Quantification and Machine-learning Models for Assessment of Disease Severity and Prognosis of COVID-19 Patients

OBJECTIVE

This study was to investigate the CT quantification of COVID-19 pneumonia and its impacts on the assessment of disease severity and the prediction of clinical outcomes in the management of COVID-19 patients.

MATERIALS METHODS

Ninety-nine COVID-19 patients who were confirmed by positive nucleic acid test (NAT) of RT-PCR and hospitalized from January 19, 2020 to February 19, 2020 were collected for this retrospective study. All patients underwent arterial blood gas test, routine blood test, chest CT examination, and physical examination on admission. In addition, follow-up clinical data including the disease severity, clinical treatment, and clinical outcomes were collected for each patient. Lung volume, lesion volume, nonlesion lung volume (NLLV) (lung volume - lesion volume), and fraction of nonlesion lung volume (%NLLV) (nonlesion lung volume / lung volume) were quantified in CT images by using two U-Net models trained for segmentation of lung and COVID-19 lesions in CT images. Furthermore, we calculated 20 histogram textures for lesions volume and NLLV, respectively. To investigate the validity of CT quantification in the management of COVID-19, we built random forest (RF) models for the purpose of classification and regression to assess the disease severity (Moderate, Severe, and Critical) and to predict the need and length of ICU stay, the duration of oxygen inhalation, hospitalization, sputum NAT-positive, and patient prognosis. The performance of RF classifiers was evaluated using the area under the receiver operating characteristic curves (AUC) and that of RF regressors using the root-mean-square error.

RESULTS

Patients were classified into three groups of disease severity: moderate (n = 25), severe (n = 47) and critical (n = 27), according to the clinical staging. Of which, a total of 32 patients, 1 (1/25) moderate, 6 (6/47) severe, and 25 critical (25/27), respectively, were admitted to ICU. The median values of ICU stay were 0, 0, and 12 days, the duration of oxygen inhalation 10, 15, and 28 days, the hospitalization 12, 16, and 28 days, and the sputum NAT-positive 8, 9, and 13 days, in three severity groups, respectively. The clinical outcomes were complete recovery (n = 3), partial recovery with residual pulmonary damage (n = 80), prolonged recovery (n = 15), and death (n = 1). The %NLLV in three severity groups were 92.18 ± 9.89%, 82.94 ± 16.49%, and 66.19 ± 24.15% with p value <0.05 among each two groups. The AUCs of RF classifiers using hybrid models were 0.927 and 0.929 in classification of moderate vs (severe + critical), and severe vs critical, respectively, which were significantly higher than either radiomics models or clinical models (p < 0.05). The root-mean-square errors of RF regressors were 0.88 weeks for prediction of duration of hospitalization (mean: 2.60 ± 1.01 weeks), 0.92 weeks for duration of oxygen inhalation (mean: 2.44 ± 1.08 weeks), 0.90 weeks for duration of sputum NAT-positive (mean: 1.59 ± 0.98 weeks), and 0.69 weeks for stay of ICU (mean: 1.32 ± 0.67 weeks), respectively. The AUCs for prediction of ICU treatment and prognosis (partial recovery vs prolonged recovery) were 0.945 and 0.960, respectively.

CONCLUSION

CT quantification and machine-learning models show great potentials for assisting decision-making in the management of COVID-19 patients by assessing disease severity and predicting clinical outcomes.

Prevalence and risk factors for lung involvement on low-dose chest CT (LDCT) in a paucisymptomatic population of 247 patients affected by COVID-19

Background

Low-dose chest CT (LDCT) showed high sensitivity and ability to quantify lung involvement of COVID-19 pneumopathy. The aim of this study was to describe the prevalence and risk factors for lung involvement in 247 patients with a visual score and assess the prevalence of incidental findings.

Methods

For 12 days in March 2020, 250 patients with RT-PCR positive tests and who underwent LDCT were prospectively included. Clinical and imaging findings were recorded. The extent of lung involvement was quantified using a score ranging from 0 to 40. A logistic regression model was used to explore factors associated with a score ≥ 10.

Results

A total of 247 patients were analyzed; 138 (54%) showed lung involvement. The mean score was 4.5 ± 6.5, and the mean score for patients with lung involvement was 8.1 ± 6.8 [1–31]. The mean age was 43 ± 15 years, with 121 males (48%) and 17 asymptomatic patients (7%). Multivariate analysis showed that age > 54 years (odds ratio 4.4[2.0–9.6] p < 0.001) and diabetes (4.7[1.0–22.1] p = 0.049) were risk factors for a score ≥ 10. Multivariate analysis including symptoms showed that only age > 54 years (4.1[1.7–10.0] p = 0.002) was a risk factor for a score ≥ 10. Rhinitis (0.3[0.1–0.7] p = 0.005) and anosmia (0.3[0.1–0.9] p = 0.043) were protective against lung involvement. Incidental imaging findings were found in 19% of patients, with a need for follow-up in 0.6%.

Conclusion

The prevalence of lung involvement was 54% in a predominantly paucisymptomatic population. Age ≥ 55 years and diabetes were risk factors for significant parenchymal lung involvement. Rhinitis and anosmia were protective against LDCT abnormalities.

Immunopathogenesis of Coronavirus-Induced Acute Respiratory Distress Syndrome (ARDS): Potential Infection-Associated Hemophagocytic Lymphohistiocytosis

The outbreak of coronavirus disease 2019 (COVID-19) in December 2019 in Wuhan, China, introduced the third highly pathogenic coronavirus into humans in the 21st century. Scientific advance after the severe acute respiratory syndrome coronavirus (SARS-CoV) epidemic and Middle East respiratory syndrome coronavirus (MERS-CoV) emergence enabled clinicians to understand the epidemiology and pathophysiology of SARS-CoV-2. In this review, we summarize and discuss the epidemiology, clinical features, and virology of and host immune responses to SARS-CoV, MERS-CoV, and SARS-CoV-2 and the pathogenesis of coronavirus-induced acute respiratory distress syndrome (ARDS). We especially highlight that highly pathogenic coronaviruses might cause infection-associated hemophagocytic lymphohistiocytosis, which is involved in the immunopathogenesis of human coronavirus-induced ARDS, and also discuss the potential implication of hemophagocytic lymphohistiocytosis therapeutics for combating severe coronavirus infection.

Immune Response to COVID-19: Can We Benefit from the SARS-CoV and MERS-CoV Pandemic Experience?

The global range and high fatality rate of the newest human coronavirus (HCoV) pandemic has made SARS-CoV-2 the focus of the scientific world. Next-generation sequencing of the viral genome and a phylogenetic analysis have shown the high homology of SARS-CoV-2 to other HCoVs that have led to local epidemics in the past. The experience acquired in SARS and MERS epidemics may prove useful in understanding the SARS-CoV-2 pathomechanism and lead to effective treatment and potential vaccine development. This study summarizes the immune response to SARS-CoV, MERS-CoV, and SARS-CoV-2 and focuses on T cell response, humoral immunity, and complement system activation in different stages of HCoVs infections. The study also presents the quantity and frequency of T cell responses, particularly CD4+ and CD8+; the profile of cytokine production and secretion; and its relation to T cell type, disease severity, and utility in prognostics of the course of SARS, MERS, and COVID-19 outbreaks. The role of interferons in the therapy of these infections is also discussed. Moreover, the kinetics of specific antibody production, the correlation between humoral and cellular immune response and the immunogenicity of the structural HCoVs proteins and their utility in the development of a vaccine against SARS, MERS, and COVID-19 has been updated.

A comparison of COVID-19, SARS and MERS

In mid-December 2019, a novel atypical pneumonia broke out in Wuhan, Hubei Province, China and was caused by a newly identified coronavirus, initially termed 2019 Novel Coronavirus and subsequently severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As of 19 May 2020, a total of 4,731,458 individuals were reported as infected with SARS-CoV-2 among 213 countries, areas or territories with recorded cases, and the overall case-fatality rate was 6.6% (316,169 deaths among 4,731,458 recorded cases), according to the World Health Organization. Studies have shown that SARS-CoV-2 is notably similar to (severe acute respiratory syndrome coronavirus) SARS-CoV that emerged in 2002–2003 and Middle East respiratory syndrome coronavirus (MERS-CoV) that spread during 2012, and these viruses all contributed to global pandemics. The ability of SARS-CoV-2 to rapidly spread a pneumonia-like disease from Hubei Province, China, throughout the world has provoked widespread concern. The main symptoms of coronavirus disease 2019 (COVID-19) include fever, cough, myalgia, fatigue and lower respiratory signs. At present, nucleic acid tests are widely recommended as the optimal method for detecting SARS-CoV-2. However, obstacles remain, including the global shortage of testing kits and the presentation of false negatives. Experts suggest that almost everyone in China is susceptible to SARS-CoV-2 infection, and to date, there are no effective treatments. In light of the references published, this review demonstrates the biological features, spread, diagnosis and treatment of SARS-CoV-2 as a whole and aims to analyse the similarities and differences among SARS-CoV-2, SARS-CoV and MERS-CoV to provide new ideas and suggestions for prevention, diagnosis and clinical treatment.

Chest CT Evaluation of 11 Persistent Asymptomatic Patients with SARS-CoV-2 Infection

In total, 11 asymptomatic carriers who underwent nasal or oropharyngeal swab tests for SARS-CoV-2 after being in close contact with patients who developed symptomatic 2019 coronavirus disease (COVID-19) were enrolled in this study. The chest multidetector computed tomography (CT) images of the enrolled patients were qualitatively and quantitatively analyzed. The findings of the first chest CT were normal in 3 (27.3%) patients, 2 of whom were aged below 15 years. The lesions of 2 (18.2%) patients involved 1 lobe with unifocal presence. Subpleural lesions were observed in 7 (63.6%) patients. Ground glass opacity (GGO) was the most common sign observed in 7 (63.6%) patients. Crazy-paving pattern and consolidation were detected in 2 (18.2%) and 4 (36.4%) patients, respectively. Based on deep learning and quantitative analysis, the mean volume of intrapulmonary lesions in the first CT image was 85.73 ± 84.46 cm³. In patients with positive findings on CT images, the average interval between positive real-time reverse transcriptase polymerase chain reaction assay and peak volume on CT images was 5.1 ± 3.1 days. In conclusion, typical CT findings can be detected in over 70% of asymptomatic SARS-CoV-2 carriers. The initial presentation is typically GGO along the subpleural regions and bronchi, which absorbs in approximately 5 days.

CT findings of patients infected with SARS-CoV-2

Background

We aimed to describe the chest CT findings in sixty-seven patients infected by Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Methods

We retrospectively reviewed 67 patients hospitalized in Ruian People’s Hospital. All the patients received the positive diagnosis of SARS-CoV-2 infection. The CT and clinical data were collected between January 23rd, 2020 and February 10th, 2020. The CT images were analyzed by the senior radiologists.

Results

There are 54 patients with positive CT findings and 13 patients with negative CT findings. The typical CT findings in hospitalized patients with SARS-CoV-2 infection were ground glass opacities (42/54), lesions located in the peripheral area (50/54), multiple lesions (46/54), and lesions located in the lower lobes (42/54). There were less typical CT findings, including air bronchogram (18/54), pleural thickening or pleural effusion (14/54), consolidation (12/54), lesions in the upper lobes (12/54), interlobular septal thickening (11/54), reversed halo sign (9/54), single lesion (8/54), air cavities (4/54), bronchial wall thickening (3/54), and intrathoracic lymph node enlargement (2/54).

Conclusions

CT features can play an important role in the early diagnosis and follow-up of COVID-19 patients.

COVID-19: Specific and Non-Specific Clinical Manifestations and Symptoms: The Current State of Knowledge

Coronavirus disease 2019 (COVID-19), due to the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has become an epidemiological threat and a worldwide concern. SARS-CoV-2 has spread to 210 countries worldwide and more than 6,500,000 confirmed cases and 384,643 deaths have been reported, while the number of both confirmed and fatal cases is continually increasing. COVID-19 is a viral disease that can affect every age group-from infants to the elderly-resulting in a wide spectrum of various clinical manifestations. COVID-19 might present different degrees of severity-from mild or even asymptomatic carriers, even to fatal cases. The most common complications include pneumonia and acute respiratory distress syndrome. Fever, dry cough, muscle weakness, and chest pain are the most prevalent and typical symptoms of COVID-19. However, patients might also present atypical symptoms that can occur alone, which might indicate the possible SARS-CoV-2 infection. The aim of this paper is to review and summarize all of the findings regarding clinical manifestations of COVID-19 patients, which include respiratory, neurological, olfactory and gustatory, gastrointestinal, ophthalmic, dermatological, cardiac, and rheumatologic manifestations, as well as specific symptoms in pediatric patients.

Coronavirus Disease 2019 in the Perioperative Period of Lung Resection: A Brief Report From a Single Thoracic Surgery Department in Wuhan, People's Republic of China

Coronavirus disease 2019 (COVID-19) is an emerging infectious disease that was first reported in Wuhan, People's Republic of China, and has subsequently spread worldwide. Clinical information on patients who contracted severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the perioperative period is limited. Here, we report seven cases with confirmed SARS-CoV-2 infection in the perioperative period of lung resection. Retrospective analysis suggested that one patient had been infected with the SARS-CoV-2 infection before the surgery and the other six patients contracted the infection after the lung resection. Fever, lymphopenia, and ground-glass opacities revealed on computed tomography are the most common clinical manifestations of the patients who contracted COVID-19 after the lung resection. Pathologic studies of the specimens of these seven patients were performed. Pathologic examination of patient 1, who was infected with the SARS-CoV-2 infection before the surgery, revealed that apart from the tumor, there was a wide range of interstitial inflammation with plasma cell and macrophage infiltration. High density of macrophages and foam cells in the alveolar cavities, but no obvious proliferation of pneumocyte, was found. Three of seven patients died from COVID-19 pneumonia, suggesting lung resection surgery might be a risk factor for death in patients with COVID-19 in the perioperative period.

Coronavirus Disease 2019 (COVID-19) CT Findings: A Systematic Review and Meta-analysis

PURPOSE

To date, considerable knowledge gaps remain regarding the chest CT imaging features of coronavirus disease 2019 (COVID-19). We performed a systematic review and meta-analysis of results from published studies to date to provide a summary of evidence on detection of COVID-19 by chest CT and the expected CT imaging manifestations.

METHODS

Studies were identified by searching PubMed database for articles published between December 2019 and February 2020. Pooled CT positive rate of COVID-19 and pooled incidence of CT imaging findings were estimated using a random-effect model.

RESULTS

A total of 13 studies met inclusion criteria. The pooled positive rate of the CT imaging was 89.76% and 90.35% when only including thin-section chest CT. Typical CT signs were ground glass opacities (83.31%), ground glass opacities with mixed consolidation (58.42%), adjacent pleura thickening (52.46%), interlobular septal thickening (48.46%), and air bronchograms (46.46%). Other CT signs included crazy paving pattern (14.81%), pleural effusion (5.88%), bronchiectasis (5.42%), pericardial effusion (4.55%), and lymphadenopathy (3.38%). The most anatomic distributions were bilateral lung infection (78.2%) and peripheral distribution (76.95%). The incidences were highest in the right lower lobe (87.21%), left lower lobe (81.41%), and bilateral lower lobes (65.22%). The right upper lobe (65.22%), right middle lobe (54.95%), and left upper lobe (69.43%) were also commonly involved. The incidence of bilateral upper lobes was 60.87%. A considerable proportion of patients had three or more lobes involved (70.81%).

CONCLUSIONS

The detection of COVID-19 chest CT imaging is very high among symptomatic individuals at high risk, especially using thin-section chest CT. The most common CT features in patients affected by COVID-19 included ground glass opacities and consolidation involving the bilateral lungs in a peripheral distribution.

Typical radiological progression and clinical features of patients with coronavirus disease 2019

We aimed to describe typical radiological features and progression of Coronavirus disease 2019 (COVID-19) patients. We reviewed the chest CT scans, laboratory findings, and clinical records of 66 COVID-19 patients who were admitted to affiliated hospitals of Nanchang university, Nanchang, China, from Jan 21 to Feb 2, 2020. CT was used to evaluate the radiological characteristics of COVID-19 patients. Only 4 patients (4/66, 6%) claimed their exposure to COVID-19 pneumonia patients. The major symptoms were fever (60/66, 91%) and cough (37/66, 56%). The predominant features of lesion were scattered (43/66, 65%), bilateral (50/66, 76%), ground-glass opacity (64/66, 97%), and air bronchogram sign (47/66, 71%). Forty-eight patients (48/66, 73%) had more than two lobes involved. Right lower lobe (58/66, 88%) and left lower lobe (49/66, 74%) were most likely invaded. Twelve patients (12/66, 18%) had at least one comorbid condition. Pleural traction (29/66, 44%), crazy paving (15/66, 23%), interlobular septal thickening (11/66, 17%), and consolidation (7/66, 11%) were also observed. The typical radiology features of COVID-19 patients are scattered ground-glass opacity in the bilateral lobes. Fever and cough are the major symptoms. Evaluating chest CT, clinical symptoms, and laboratory results could facilitate the early diagnosis of COVID-19, and judge disease progression.

Pediatric SARS, H1N1, MERS, EVALI, and Now Coronavirus Disease (COVID-19) Pneumonia: What Radiologists Need to Know

OBJECTIVE. The purpose of this article is to review new pediatric lung disorders-including disorders that have occurred in recent years years such as severe acute respiratory syndrome (SARS), swine-origin influenza A (H1N1), Middle East respiratory syndrome (MERS), e-cigarette or vaping product use-associated lung injury (EVALI), and coronavirus disease (COVID-19) pneumonia-to enhance understanding of the characteristic imaging findings. CONCLUSION. Although the clinical symptoms of SARS, H1N1, MERS, EVALI, and COVID-19 pneumonia in pediatric patients may be nonspecific, some characteristic imaging findings have emerged or are currently emerging. It is essential for radiologists to have a clear understanding of the characteristic imaging appearances of these lung disorders in pediatric patients to ensure optimal patient care.

Rapid Progression to Acute Respiratory Distress Syndrome: Review of Current Understanding of Critical Illness from Coronavirus Disease 2019 (COVID-19) Infection

The outbreak of coronavirus disease 2019 (COVID-19) in December 2019 in the city of Wuhan in Mainland China has spread across the globe with >100,000 infected individuals and 3000 deaths reported in 93 countries as of 7 March 2020. We report a case of COVID-19 infection in a 64-year-old man who developed rapidly worsening respiratory failure and acute respiratory distress syndrome (ARDS) that required intubation. As the clinical spectrum of COVID-19 infection ranges from mild illness to ARDS with high mortality risk, there is need for research that identifies early markers of disease severity. Current evidence suggests that patients with advanced age, dyspnoea or pre-existing comorbidities should be monitored closely, especially at 1–2 weeks after symptom onset. It remains to be seen whether laboratory findings such as lymphopaenia or elevated lactate dehydrogenase may serve as early surrogates for critical illness or markers of disease recovery. Management of ARDS in COVID-19 patients remains supportive while we await results of drug trials. More studies are needed to understand the incidence and outcomes of ARDS and critical illness from COVID-19 infection which are important for critical care management of patients and resource planning. Key words: Intensive Care, Mortality, Pneumonia, Risk factors

Imaging and clinical features of patients with 2019 novel coronavirus SARS-CoV-2

BACKGROUND

The pneumonia caused by the 2019 novel coronavirus (SARS-CoV-2, also called 2019-nCoV) recently break out in Wuhan, China, and was named as COVID-19. With the spread of the disease, similar cases have also been confirmed in other regions of China. We aimed to report the imaging and clinical characteristics of these patients infected with SARS-CoV-2 in Guangzhou, China.

METHODS

All patients with laboratory-identified SARS-CoV-2 infection by real-time polymerase chain reaction (PCR) were collected between January 23, 2020, and February 4, 2020, in a designated hospital (Guangzhou Eighth People's Hospital). This analysis included 90 patients (39 men and 51 women; median age, 50 years (age range, 18-86 years). All the included SARS-CoV-2-infected patients underwent non-contrast enhanced chest computed tomography (CT). We analyzed the clinical characteristics of the patients, as well as the distribution characteristics, pattern, morphology, and accompanying manifestations of lung lesions. In addition, after 1-6 days (mean 3.5 days), follow-up chest CT images were evaluated to assess radiological evolution.

FINDINGS

The majority of infected patients had a history of exposure in Wuhan or to infected patients and mostly presented with fever and cough. More than half of the patients presented bilateral, multifocal lung lesions, with peripheral distribution, and 53 (59%) patients had more than two lobes involved. Of all included patients, COVID-19 pneumonia presented with ground glass opacities in 65 (72%), consolidation in 12 (13%), crazy paving pattern in 11 (12%), interlobular thickening in 33 (37%), adjacent pleura thickening in 50 (56%), and linear opacities combined in 55 (61%). Pleural effusion, pericardial effusion, and lymphadenopathy were uncommon findings. In addition, baseline chest CT did not show any abnormalities in 21 patients (23%), but 3 patients presented bilateral ground glass opacities on the second CT after 3-4 days.

CONCLUSION

SARS-CoV-2 infection can be confirmed based on the patient's history, clinical manifestations, imaging characteristics, and laboratory tests. Chest CT examination plays an important role in the initial diagnosis of the novel coronavirus pneumonia. Multiple patchy ground glass opacities in bilateral multiple lobular with periphery distribution are typical chest CT imaging features of the COVID-19 pneumonia.

[Dynamic changes of chest CT imaging in patients with COVID-19]

OBJECTIVE

To analyze the dynamic changes of chest CT images of patients with coronavirus disease 2019 (COVID-19).

METHODS

Fifty-two cases of COVID-19 were admitted in the First Affiliated Hospital of Zhejiang University School of Medicine. The consecutive chest CT scans were followed up for all patients with an average of 4 scans performed per patient during the hospitalization. The shortest interval between each scan was 2 days and the longest was 7 days. The shape, number and distribution of lung shadows, as well as the characteristics of the lesions on the CT images were reviewed.

RESULTS

The obvious shadows infiltrating the lungs were shown on CT images in 50 cases, for other 2 cases there was no abnormal changes in the lungs during the first CT examination. Ground-glass opacities (GGO) were found in 48 cases (92.3%), and 19 cases (36.5%) had patchy consolidation and sub-consolidation, which were accompanied with air bronchi sign in 17 cases (32.7%). Forty one cases (78.8%) showed a thickened leaflet interval, 4 cases (7.6%) had a small number of fibrous stripes. During hospitalization, GGO lesions in COVID-19 patients gradually became rare,the fibrous strip shadows increased and it became the most common imaging manifestation. The lesions rapidly progressed in 39 cases (75.0%) within 6-9 days after admission. On days 10-14 of admission, the lesions distinctly resolved in 40 cases (76.9%).

CONCLUSIONS

The chest CT images of patients with COVID-19 have certain characteristics with dynamic changes, which are of value for monitoring disease progress and clinical treatment.

Dynamic CT assessment of disease change and prognosis of patients with moderate COVID-19 pneumonia

OBJECTIVES

To assess prognosis or dynamic change from initial diagnosis until recovery of the patients with moderate coronavirus disease (COVID-19) pneumonia using chest CT images.

MATERIALS AND METHODS

In this retrospective study, 33 patients (18 men, 15 women; median age, 49.0 years) with confirmed with moderate COVID-19 pneumonia in a multicenter hospital were included. The patients underwent at least four chest non-contrast-enhanced computed tomography (CT) scans at approximately 5-day intervals. We analyzed the clinical and CT characteristics of the patients. Moreover, the total CT score and the sum of lung involvement were determined for every CT scan.

RESULTS

The most widespread presenting symptoms were fever (32/33, 97.0%) and cough (17/33, 51.5%), which were often accompanied by decreased lymphocyte count (15/33, 45.5%) and increased C-reactive protein levels (18/33, 54.6%). Bilateral, multifocal ground glass opacities (32/33, 97.0%), consolidation (25/33, 75.8%), vascular thickening (23/33, 69.7%), and bronchial wall thickening (21/33, 63.6%) with peripheral distribution were the most frequent CT findings during moderate COVID-19 pneumonia. In patients recovering from moderate COVID-19 pneumonia, four stages (stages 1-4) of evolution were identified on chest CT with average CT scores of 3.4±2.3, 6.0±4.4, 5.6±3.8, and 4.9±3.2, respectively, from the onset of symptoms. For most patients, the peak of average total CT score increased for approximately 8 days after the onset of symptoms, after which it decreased gradually. The mean CT score of all patients was 4.7 at the time of discharge.

CONCLUSION

The moderate COVID-19 pneumonia CT score increased rapidly in a short period of time initially, followed by a slow decline over a relatively long time. The peak of the course occurred in stage 2. Complete recovery of patients with moderate COVID-19 pneumonia with high mean CT score at the time of discharge requires longer time.

Chest imaging of H7N9 subtype of human avian influenza

Background

Human infection with avian influenza A H7N9 virus is an acute respiratory infectious disease, which usually causes severe pneumonia with a high mortality. Chest radiographs and Computed Tomography (CT) are principal radiological modalities to assess the lung abnormalities.

Objectives

The goal of this study was to investigate the chest images characteristic of H7N9 subtype of human avian influenza.

Materials and methods

The clinical and imaging data of 11 cases diagnosed as H7N9 subtype of human avian influenza were collected from 4 cities in the southern region of the Yangtze River, China. The chest imaging manifestations were analyzed by the assigned expert group. The analyzed cases include 7 males and 4 females aged from 20 to 84 years, with a mean of 55.6 years. The clinical symptoms were mainly fever (100%, 11/11) and cough (72.7%, 8/11).

Results

Segmental or lobar ground-glass opacity (GGO) or consolidation was shown in 8 cases (72.7% or 8/11). Air bronchogram was found in 7 cases (63.6% or 7/11). The lesions developed into multiple or diffuse in both lungs rapidly at the progressive stage. The reticulation shadows were shown after some lesions absorbed at the stable stage.

Conclusions

The characteristic imaging demonstrations of H7N9 subtype of human avian influenza are segmental or lobar exudative lesions at lungs at the initial stage, which rapidly progress into bilateral distribution at lungs at the progressive stage.

Inhibition of infection caused by severe acute respiratory syndrome-associated coronavirus by equine neutralizing antibody in aged mice

The high susceptibility of elderly to severe acute respiratory syndrome-associated coronavirus (SARS-CoV) indicates how crucial it is to protect the elderly by various strategies. Aged BALB/c mice displayed a high susceptibility to SARS-CoV and have been a valuable platform for evaluation of strategies against SARS-CoV infection. In this study, we confirmed the validity of this model using various methods, and verified that equine anti-SARS-CoV F(ab')₂ can prevent aged animals from SARS-CoV infection. In a therapeutic setting, treatment with anti-SARS-CoV F(ab')₂ decreased viral load more than several thousand folds in the lungs. Thus, this antibody should be a potential candidate for treatment of elderly patients suffering from SARS.

Recombinant modified vaccinia virus Ankara expressing the spike glycoprotein of severe acute respiratory syndrome coronavirus induces protective neutralizing antibodies primarily targeting the receptor binding region

Immunization with a killed or inactivated viral vaccine provides significant protection in animals against challenge with certain corresponding pathogenic coronaviruses (CoVs). However, the promise of this approach in humans is hampered by serious concerns over the risk of leaking live severe acute respiratory syndrome (SARS) viruses. In this study, we generated a SARS vaccine candidate by using the live-attenuated modified vaccinia virus Ankara (MVA) as a vector. The full-length SARS-CoV envelope Spike (S) glycoprotein gene was introduced into the deletion III region of the MVA genome. The newly generated recombinant MVA, ADS-MVA, is replication incompetent in mammalian cells and highly immunogenic in terms of inducing potent neutralizing antibodies in mice, rabbits, and monkeys. After two intramuscular vaccinations with ADS-MVA alone, the 50% inhibitory concentration in serum was achieved with reciprocal sera dilutions of more than 1,000- to 10,000-fold in these animals. Using fragmented S genes as immunogens, we also mapped a neutralizing epitope in the region of N-terminal 400 to 600 amino acids of the S glycoprotein (S400-600), which overlaps with the angiotensin-converting enzyme 2 (ACE2) receptor-binding region (RBR; S318-510). Moreover, using a recombinant soluble RBR-Fc protein, we were able to absorb and remove the majority of the neutralizing antibodies despite observing that the full S protein tends to induce a broader spectrum of neutralizing activities in comparison with fragmented S proteins. Our data suggest that a major mechanism for neutralizing SARS-CoV likely occurs through blocking the interaction between virus and the cellular receptor ACE2. In addition, ADS-MVA induced potent immune responses which very likely protected Chinese rhesus monkeys from pathogenic SARS-CoV challenge.

Management of Critically Ill Patients with Severe Acute Respiratory Syndrome (SARS)

Severe acute respiratory syndrome (SARS) is frequently complicated with acute respiratory failure. In this article, we aim to focus on the management of the subgroup of SARS patients who are critically ill. Most SARS patients would require high flow oxygen supplementation, 20-30% required intensive care unit (ICU) or high dependency care, and 13-26% developed acute respiratory distress syndrome (ARDS). In some of these patients, the clinical course can progress relentlessly to septic shock and/or multiple organ dysfunction syndrome (MODS). The management of critically ill SARS patients requires timely institution of pharmacotherapy where applicable and supportive treatment (oxygen therapy, noninvasive and invasive ventilation). Superimposed bacterial and other opportunistic infections are common, especially in those treated with mechanical ventilation. Subcutaneous emphysema, pneumothoraces and pneumomediastinum may arise spontaneously or as a result of positive ventilatory assistance. Older age is a consistently a poor prognostic factor. Appropriate use of personal protection equipment and adherence to infection control measures is mandatory for effective infection control. Much of the knowledge about the clinical aspects of SARS is based on retrospective observational data and randomized-controlled trials are required for confirmation. Physicians and scientists all over the world should collaborate to study this condition which may potentially threaten human existence.