Spatial-Slice Feature Learning Using Visual Transformer and Essential Slices Selection Module for COVID-19 Detection of CT Scans in the Wild

Computed tomography (CT) imaging could be convenient for diagnosing various diseases. However, the CT images could be diverse since their resolution and number of slices are determined by the machine and its settings. Conventional deep learning models are hard to tickle such diverse data since the essential requirement of the deep neural network is the consistent shape of the input data in each dimension. A way to overcome this issue is based on the slice-level classifier and aggregating the predictions for each slice to make the final result. However, it lacks slice-wise feature learning, leading to suppressed performance. This paper proposes an effective spatial-slice feature learning (SSFL) to tickle this issue for COVID-19 symptom classification. First, the semantic feature embedding of each slice for a CT scan is extracted by a conventional 2D convolutional neural network (CNN) and followed by using the visual Transformer-based sub-network to deal with feature learning between slices, leading to joint feature representation. Then, an essential slices set algorithm is proposed to automatically select a subset of the CT scan, which could effectively remove the uncertain slices as well as improve the performance of our SSFL. Comprehensive experiments reveal that the proposed SSFL method shows not only excellent performance but also achieves stable detection results. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

Exhaled Breath Aerosol Shedding by Highly Transmissible Versus Prior SARS-CoV-2 Variants.

BACKGROUND: Aerosol inhalation is recognized as the dominant mode of SARS-CoV-2 transmission. Three highly transmissible lineages evolved during the pandemic. One hypothesis to explain increased transmissibility is that natural selection favors variants with higher rates of viral aerosol shedding. However, the extent of aerosol shedding of successive SARS-CoV-2 variants is unknown. We aimed to measure the infectivity and rate of SARS-CoV-2 shedding into exhaled breath aerosol (EBA) by individuals during the Delta and Omicron waves and compared those rates with those of prior SARS-CoV-2 variants from our previously published work. METHODS: COVID-19 cases (n = 93, 32 vaccinated and 20 boosted) were recruited to give samples, including 30-minute breath samples into a Gesundheit-II exhaled breath aerosol sampler. Samples were quantified for viral RNA using RT-PCR and cultured for virus. RESULTS: Alpha (n = 4), Delta (n = 3), and Omicron (n = 29) cases shed significantly more viral RNA copies into exhaled breath aerosols than cases infected with ancestral strains and variants not associated with increased transmissibility (n = 57). All Delta and Omicron cases were fully vaccinated and most Omicron cases were boosted. We cultured virus from the EBA of one boosted and three fully vaccinated cases. CONCLUSIONS: Alpha, Delta, and Omicron independently evolved high viral aerosol shedding phenotypes, demonstrating convergent evolution. Vaccinated and boosted cases can shed infectious SARS-CoV-2 via EBA. These findings support a dominant role of infectious aerosols in transmission of SARS-CoV-2. Monitoring aerosol shedding from new variants and emerging pathogens can be an important component of future threat assessments and guide interventions to prevent transmission.

Infectious Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Exhaled Aerosols and Efficacy of Masks During Early Mild Infection.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemiology implicates airborne transmission; aerosol infectiousness and impacts of masks and variants on aerosol shedding are not well understood. METHODS: We recruited coronavirus disease 2019 (COVID-19) cases to give blood, saliva, mid-turbinate and fomite (phone) swabs, and 30-minute breath samples while vocalizing into a Gesundheit-II, with and without masks at up to 2 visits 2 days apart. We quantified and sequenced viral RNA, cultured virus, and assayed serum samples for anti-spike and anti-receptor binding domain antibodies. RESULTS: We enrolled 49 seronegative cases (mean days post onset 3.8 ±â€…2.1), May 2020 through April 2021. We detected SARS-CoV-2 RNA in 36% of fine (≤5 µm), 26% of coarse (>5 µm) aerosols, and 52% of fomite samples overall and in all samples from 4 alpha variant cases. Masks reduced viral RNA by 48% (95% confidence interval [CI], 3 to 72%) in fine and by 77% (95% CI, 51 to 89%) in coarse aerosols; cloth and surgical masks were not significantly different. The alpha variant was associated with a 43-fold (95% CI, 6.6- to 280-fold) increase in fine aerosol viral RNA, compared with earlier viruses, that remained a significant 18-fold (95% CI, 3.4- to 92-fold) increase adjusting for viral RNA in saliva, swabs, and other potential confounders. Two fine aerosol samples, collected while participants wore masks, were culture-positive. CONCLUSIONS: SARS-CoV-2 is evolving toward more efficient aerosol generation and loose-fitting masks provide significant but only modest source control. Therefore, until vaccination rates are very high, continued layered controls and tight-fitting masks and respirators will be necessary.

Acute pericarditis as a clinical manifestation in COVID-19 infection in a district hospital setting.

The global outbreak of coronavirus disease 2019(COVID-19) pandemic has heavily impacted the health service, leading to increased mortality and morbidity. Although known to manifest primarily as a respiratory illness, there are reports of cardiac involvement as extrapulmonary manifestation. We are reporting a case of pericarditis in a young patient who presented with only cardiac symptoms in COVID-19. He was admitted to the hospital for observation and treated with oral colchicine and oral ibuprofen. His conditions improved and subsequently discharged well. Acute pericarditis can present as part of the COVID-19 extrapulmonary spectrum. Therefore, it is important and challenging for clinicians to recognise the atypical presentations of COVID-19 to reduce morbidity and mortality.

Comparison of Saliva and Midturbinate Swabs for Detection of SARS-CoV-2.

Saliva is an attractive sample for detecting SARS-CoV-2. However, contradictory reports exist concerning the sensitivity of saliva versus nasal swabs. We followed close contacts of COVID-19 cases for up to 14 days from the last exposure and collected self-reported symptoms, midturbinate swabs (MTS), and saliva every 2 or 3 days. Ct values, viral load, and frequency of viral detection by MTS and saliva were compared. Fifty-eight contacts provided 200 saliva-MTS pairs, and 14 contacts (13 with symptoms) had one or more positive samples. Saliva and MTS had similar rates of viral detection (P = 0.78) and substantial agreement (κ = 0.83). However, sensitivity varied significantly with time since symptom onset. Early on (days -3 to 2), saliva had 12 times (95% CI: 1.2, 130) greater likelihood of viral detection and 3.2 times (95% CI: 2.8, 3.8) higher RNA copy numbers compared to MTS. After day 2 of symptoms, there was a nonsignificant trend toward greater sensitivity using MTS. Saliva and MTS demonstrated high agreement making saliva a suitable alternative to MTS for SARS-CoV-2 detection. Saliva was more sensitive early in the infection when the transmission was most likely to occur, suggesting that it may be a superior and cost-effective screening tool for COVID-19. IMPORTANCE The findings of this manuscript are increasingly important with new variants that appear to have shorter incubation periods emerging, which may be more prone to detection in saliva before detection in nasal swabs. Therefore, there is an urgent need to provide the science to support the use of a detection method that is highly sensitive and widely acceptable to the public to improve screening rates and early detection. The manuscript presents the first evidence that saliva-based RT-PCR is more sensitive than MTS-based RT-PCR in detecting SARS-CoV-2 during the presymptomatic period - the critical period for unwitting onward transmission. Considering other advantages of saliva samples, including the lower cost, greater acceptability within the general population, and less risk to health care workers, our findings further supported the use of saliva to identify presymptomatic infection and prevent transmission of the virus.

Similarities and Differences of CT Features between COVID-19 Pneumonia and Heart Failure

Aims: During the COVID-19 epidemic, chest computed tomography (CT) has been highly recommended for screening of patients with suspected COVID-19 because of an unclear contact history, overlapping clinical features, and an overwhelmed health system. However, there has not been a full comparison of CT for diagnosis of heart failure or COVID-19 pneumonia. Methods: Patients with heart failure (n = 23) or COVID-19 pneumonia (n = 23) and one patient with both diseases were retrospectively enrolled. Clinical information and chest CT images were obtained and analyzed. Results: There was no difference in ground-glass opacity, consolidation, crazy paving pattern, the lobes affected, and septal thickening between heart failure and COVID-19 pneumonia. However, a less rounded morphology (4% vs. 70%, P = 0.00092), more peribronchovascular thickening (70% vs. 35%, P = 0.018) and fissural thickening (43% vs. 4%, P = 0.002), and less peripheral distribution (30% vs. 87%, P = 0.00085) were found in the heart failure group than in the COVID-19 group. Importantly, there were also more patients with upper pulmonary vein enlargement (61% vs. 4%, P = 0.00087), subpleural effusion (50% vs. 0%, P = 0.00058), and cardiac enlargement (61% vs. 4%, P = 0.00075) in the heart failure group than in the COVID-19 group. Besides, more fibrous lesions were found in the COVID-19 group, although there was no statistical difference (22% vs. 4%, P = 0.080). Conclusions: Although there is some overlap of CT features between heart failure and COVID-19, CT is still a useful tool for differentiating COVID-19 pneumonia.

Study on glacial tourism exploitation in the dagu glacier scenic spot based on the ahp–aseb method

Due to the impact of COVID-19, people’s demand for non-contact tourism is increasing. The development of Internet technologies such as the Internet of Things, virtual reality (VR), and augmented reality (AR) can meet this demand. Internet technology makes non-contact tourism grow. However, these new technologies are emerging only within application cases, which cannot provide comprehensive methodological guidance for tourism suppliers. Despite the booming development of winter tourism in China, there are still many problems, especially affecting the tourist experience.rarchy process (AHP) and activity, setting, experience and benefit (ASEB) grid analysis were used to analyze the activities, settings, experiences and benefits of the scenic spot from the tourist perspective taking the Dagu Glacier Scenic Spot (DGSS) as an example. The research aims to increase the attraction of the scenic zone, and promote the coordinated and sustainable development of business in West China under the goal of improving tourists’ experiences. The results show that: subgoals of experience (E) and benefit (B) are the main directions of the development of ice and snow tourism in the DGSS. Furthermore, the threat of benefits (TB), the threat of setting (TS), the threat of experience (TE), the opportunities of benefits (OB), the opportunities of setting (OS), and the opportunities of experience (OE) are the main concerns. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

[Comparison of heart failure and COVID-19 in chest CT features and clinical characteristics].

Objective: To identify the characteristics including clinical features and pulmonary computed tomography (CT) features of heart failure and COVID-19. Methods: This study was a retrospective study. A total of 7 patients with heart failure and 12 patients with COVID-19 in the Second Xiangya Hospital of Central South University between December 1, 2019 and February 15, 2020 were enrolled. The baseline clinical and imaging features of the two groups were statistically analyzed. Results: There was no significant difference in age and sex between the two groups(both P>0.05), but the incidence of epidemiological contact history, fever or respiratory symptoms in the COVID-19 group was significantly higher than that in the heart failure group (12/12 vs. 0, P<0.001; 12/12 vs. 4/7, P=0.013). While the proportion of cardiovascular diseases and impaired cardiac function was significantly less than that of the heart failure group(2/12 vs.7/7, P<0.001；0 vs.7/7, P<0.001). For imaging features, both groups had ground-glass opacity and thickening of interlobular septum, but the ratio of central and gradient distribution was higher in patients with heart failure than that in patients with COVID-19 (4/7 vs. 1/12, P=0.04). In heart failure group, the ratio of the expansion of pulmonary veins was also higher (3/7 vs. 0，P=0.013), and the lung lesions can be significantly improved after effective anti-heart failure treatment. Besides, there were more cases with rounded morphology in COVID-19 group（9/12 vs. 2/7, P=0.048）. Conclusions: More patients with COVID-19 have epidemiological history and fever or respiratory symptoms. There are significant differences in chest CT features, such as enlargement of pulmonary veins, lesions distribution and morphology between heart failure and COVID-19.

Initial CT scanning in patients with COVID-19 pneumonia in the Peruvian Central Air Force Hospital: A case series

We present nine cases of COVID-19 patients that developed pneumonia caused by SARSCov-2 who were seen in the Peruvian Central Air Force Hospital and showed different clinical features, risk factors, and outcomes. Findings of their thorax CT scans are described using a tomographic score that was applied on admission. Points assigned were based on the percentage of involvement on each pulmonary lobe and this allowed us to determine a clinical diagnosis of pneumonia according to its severity, even before having positive results in molecular and serological tests for some of these patients.

First deceased by covid-19 in Peru

The case of the first deceased in Peru is presented. 78-year-old man, with a history of hypertension, who presented a characteristic clinical picture of the disease caused by the new coronavirus (COVID-19), which had fundamental epidemiological data, the positive confirmatory test together with some laboratory parameters and radiological image also characteristic;that followed a fatal evolution, despite receiving the recommended therapy at that time. This case highlighted the need to quickly identify those patients who could have an unfavorable evolution, in order to provide the earliest and most adequate treatment.