Molecular epidemiology of invasive Group A Streptococcal infections before and after the COVID-19 pandemic in Switzerland (preprint)

Group A Streptococcus (GAS, aka Streptococcus pyogenes) poses a significant public health concern, causing a diverse spectrum of infections with high mortality rates. Following the COVID-19 pandemic, a resurgence of invasive GAS (iGAS) infections has been documented, necessitating efficient outbreak detection methods. Whole genome sequencing (WGS) serves as the gold standard for GAS molecular typing, albeit constrained by time and costs. This study aimed to characterize the postpandemic increased prevalence of iGAS on the molecular epidemiological level in order to assess whether new, more virulent variants have emerged, as well as to assess the performance of the rapid and cost-effective Fourier-transform infrared (FTIR) spectroscopy as an alternative to WGS for detecting and characterizing GAS transmission routes. A total of 66 iGAS strains isolated from nine Swiss hospitals during the COVID-19 post-pandemic increased GAS prevalence were evaluated and compared to 15 strains collected before and 12 during the COVID-19 pandemic. FT-IR measurements and WGS were conducted for network analysis. Demographic, clinical, and epidemiological data were collected. Skin and soft tissue infection was the most common diagnosis, followed by primary bacteremia and pneumonia. Viral co-infections were found in 25% of cases and were significantly associated with more severe disease requiring intensive care unit admission. WGS analysis did not reveal emerging GAS genetic distinct variants after the COVID-19 pandemic, indicating the absence of a pandemic-induced shift. FT-IR spectroscopy exhibited limitations in differentiating genetically distant GAS strains, yielding poor overlap with WGS-derived clusters. The emm1/ST28 gebotype was predominant in our cohort and was associated with five of the seven deaths recorded, in accordance with the molecular epidemiological data before the pandemic. Additionally, no notable shift in antibiotic susceptibility patterns was observed. Our data suggest that mainly non-pathogen related factors contributed to the recent increased prevalence of iGAS.

Impact of the COVID-19 Pandemic on Inpatient and Outpatient Utilization of Bariatric Surgery.

BACKGROUND: During the COVID-19 pandemic, deferral of inpatient elective surgical procedures served as a primary mechanism to increase surge inpatient capacity. Given the benefit of bariatric surgery on treating obesity and associated comorbidities, decreased access to bariatric surgery may have long-term public health consequences. Understanding the extent of the disruption of the COVID-19 pandemic to bariatric surgery will help health systems plan for appropriate access. MATERIALS AND METHODS: This is an observational cohort study using the PINC AI Healthcare Database from 1/1/2019-6/31/2021. A Poisson regression model with patient characteristics and hospital-fixed effects was used to assess the relative monthly within-hospital reduction in surgical encounters, variations by race and ethnicity, and shift from inpatient to outpatient procedures. A multivariate linear probability model was used to assess the change in 30-day readmissions from 2020 and 2021 compared to 2019. RESULTS: Among 309 hospitals, there were 46,539 bariatric procedures conducted in 2019 with a 14.8% reduction in volume to 39,641 procedures in 2020. There were 22,642 bariatric procedures observed from January to June of 2021. The most pronounced decrease in volume occurred in April with an 89.7% relative reduction from 2019. Black and Hispanic patients were more likely to receive bariatric surgery after the height of the pandemic compared to white patients. A clinically significant shift from inpatient to outpatient bariatric surgical procedures was not observed. Relative to 2019, there were no significant differences in bariatric surgical readmission rates. CONCLUSION: During the pandemic there was a sizable decrease in bariatric surgical volume. There did not appear to be disparities in access to bariatric surgery for minority patients. We did not observe a meaningful shift toward outpatient bariatric surgical procedures. Post-pandemic, monitoring is needed to assess if hospitals have been able to meet the demand for bariatric surgical procedures.

SARS-CoV-2 seroprevalence among blood donors in Uganda: 2019-2022.

BACKGROUND: The true burden of COVID-19 in low- and middle-income countries remains poorly characterized, especially in Africa. Even prior to the availability of SARS-CoV-2 vaccines, countries in Africa had lower numbers of reported COVID-19 related hospitalizations and deaths than other regions globally. METHODS: Ugandan blood donors were evaluated between October 2019 and April 2022 for IgG antibodies to SARS-CoV-2 nucleocapsid (N), spike (S), and five variants of the S protein using multiplexed electrochemiluminescence immunoassays (MesoScale Diagnostics, Rockville, MD). Seropositivity for N and S was assigned using manufacturer-provided cutoffs and trends in seroprevalence were estimated by quarter. Statistically significant associations between N and S antibody seropositivity and donor characteristics in November-December 2021 were assessed by chi-square tests. RESULTS: A total of 5393 blood unit samples from donors were evaluated. N and S seropositivity increased throughout the pandemic to 82.6% in January-April 2022. Among seropositive individuals, N and S antibody levels increased ≥9-fold over the study period. In November-December 2021, seropositivity to N and S antibody was higher among repeat donors (61.3%) compared with new donors (55.1%; p = .043) and among donors from Kampala (capital city of Uganda) compared with rural regions (p = .007). Seropositivity to S antibody was significantly lower among HIV-seropositive individuals (58.8% vs. 84.9%; p = .009). CONCLUSIONS: Despite previously reported low numbers of COVID-19 cases and related deaths in Uganda, high SARS-CoV-2 seroprevalence and increasing antibody levels among blood donors indicated that the country experienced high levels of infection over the course of the pandemic.

Sensitivity of rapid antigen tests for Omicron subvariants of SARS-CoV-2.

Diagnosis by rapid antigen tests (RATs) is useful for early initiation of antiviral treatment. Because RATs are easy to use, they can be adapted for self-testing. Several kinds of RATs approved for such use by the Japanese regulatory authority are available from drug stores and websites. Most RATs for COVID-19 are based on antibody detection of the SARS-CoV-2 N protein. Since Omicron and its subvariants have accumulated several amino acid substitutions in the N protein, such amino acid changes might affect the sensitivity of RATs. Here, we investigated the sensitivity of seven RATs available in Japan, six of which are approved for public use and one of which is approved for clinical use, for the detection of BA.5, BA.2.75, BF.7, XBB.1, and BQ.1.1, as well as the delta variant (B.1.627.2). All tested RATs detected the delta variant with a detection level between 7500 and 75 000 pfu per test, and all tested RATs showed similar sensitivity to the Omicron variant and its subvariants (BA.5, BA.2.75, BF.7, XBB.1, and BQ.1.1). Human saliva did not reduce the sensitivity of the RATs tested. Espline SARS-CoV-2 N showed the highest sensitivity followed by Inspecter KOWA SARS-CoV-2 and V Trust SARS-CoV-2 Ag. Since the RATs failed to detect low levels of infectious virus, individuals whose specimens contained less infectious virus than the detection limit would be considered negative. Therefore, it is important to note that RATs may miss individuals shedding low levels of infectious virus.

Development and evaluation of a virtual reality training for emergency treatment of shortness of breath based on frameworks for serious games.

Background: Virtual reality (VR) can offer an innovative approach to providing training in emergency situations, especially in times of COVID-19. There is no risk of infection, and the procedure is scalable and resource-efficient. Nevertheless, the challenges and problems that can arise in the development of VR training are often unclear or underestimated. As an example, we present the evaluation of the feasibility of development of a VR training session for the treatment of dyspnoea. This is based on frameworks for serious games, and provides lessons learned. We evaluate the VR training session with respect to usability, satisfaction, as well as perceived effectiveness and workload of participants. Methods: The VR training was developed using the established framework (Steps 1-4) for serious games of Verschueren et al. and Nicholson's RECIPE elements for meaningful gamification. Primary validation (Step 4) was performed at the University of Bern, Switzerland, in a pilot study without control group, with a convenience sample of medical students (n=16) and established measurement tools. Results: The theoretical frameworks permitted guided development of the VR training session. Validation gave a median System Usability Scale of 80 (IQR 77.5-85); for the User Satisfaction Evaluation Questionnaire, the median score was 27 (IQR 26-28). After the VR training, there was a significant gain in the participants' confidence in treating a dyspnoeic patient (median pre-training 2 (IQR 2-3) vs. post-training 3 (IQR 3-3), p=0.016).Lessons learned include the need for involving medical experts, medical educators and technical experts at an equivalent level during the entire development process. Peer-teaching guidance for VR training was feasible. Conclusion: The proposed frameworks can be valuable tools to guide the development and validation of scientifically founded VR training. The new VR training session is easy and satisfying to use and is effective - and is almost without motion sickness.

Psychological Resilience to Trauma and Risk of COVID-19 Infection and Somatic Symptoms Across 2 Years.

OBJECTIVE: Exposure to trauma increases the risk of somatic symptoms, as well as acute and chronic physical diseases. However, many individuals display psychological resilience, showing positive psychological adaptation despite trauma exposure. Resilience to prior trauma may be a protective factor for physical health during subsequent stressors, including the COVID-19 pandemic. METHODS: Using data from 528 US adults in a longitudinal cohort study, we examined psychological resilience to lifetime potentially traumatic events early in the pandemic and the risk of COVID-19 infection and somatic symptoms across 2 years of follow-up. Resilience was defined as level of psychological functioning relative to lifetime trauma burden, assessed in August 2020. Outcomes included COVID-19 infection and symptom severity, long COVID, and somatic symptoms assessed every 6 months for 24 months. Using regression models, we examined associations between resilience and each outcome adjusting for covariates. RESULTS: Higher psychological resilience to trauma was associated with a lower likelihood of COVID-19 infection over time, with one standard deviation higher resilience score associated with a 31% lower likelihood of COVID-19 infection, adjusting for sociodemographics and vaccination status. Furthermore, higher resilience was associated with lower levels of somatic symptoms during the pandemic, adjusting for COVID-19 infection and long COVID status. In contrast, resilience was not associated with COVID-19 disease severity or long COVID. CONCLUSIONS: Psychological resilience to prior trauma is associated with lower risk of COVID-19 infection and lower somatic symptoms during the pandemic. Promoting psychological resilience to trauma may benefit not only mental but also physical health.

Trends in Medicare funded respiratory function testing in Australian laboratories

Introduction/Aim: Our study aimed to quantitate trends in Medicare funded respiratory function testing (RFT) in Australian laboratories over recent years, including assessing the impact of Medicare item number changes and the COVID-19 pandemic. Method(s): We interrogated the online Medicare database from July 1994 through to July 2022. All laboratory-based Medicare items related to RFTs were included, both before and after Medicare item changes that occurred in late 2018. Result(s): There was a steady increase in RFTs from ~25,000 tests in 1994 to ~114,000 prior to Medicare changes in 2018, corresponding to per-capita increase from ~140 to 450/100,000 Medicare registrants. A 16% dip in testing post 2018 Medicare item changes was followed by a small increase, then a sharp 46% decrease in testing during the early stages of the COVID-19 pandemic in 2020. Testing levels increased sharply towards the end of 2020 but have not consistently recovered to levels seen prior to COVID-19. The most recent quarter analysed represents 372 tests / 100,000 Medicare registrants. Conclusion(s): Australian Medicare funded laboratory RFTs increased steadily for 24 years before a small decline in 2018, related to Medicare item number changes, and a sharp decline in 2020 due to COVID-19. There has been a recovery since then, however numbers are more variable since the sharp COVID-19 decline.

Risk factors for SARS-CoV-2 seroprevalence following the first pandemic wave in UK healthcare workers in a large NHS Foundation Trust.

Background: We aimed to measure SARS-CoV-2 seroprevalence in a cohort of healthcare workers (HCWs) during the first UK wave of the COVID-19 pandemic, explore risk factors associated with infection, and investigate the impact of antibody titres on assay sensitivity. Methods: HCWs at Sheffield Teaching Hospitals NHS Foundation Trust were prospectively enrolled and sampled at two time points. We developed an in-house ELISA for testing participant serum for SARS-CoV-2 IgG and IgA reactivity against Spike and Nucleoprotein. Data were analysed using three statistical models: a seroprevalence model, an antibody kinetics model, and a heterogeneous sensitivity model. Results: Our in-house assay had a sensitivity of 99·47% and specificity of 99·56%. We found that 24·4% (n=311/1275) of HCWs were seropositive as of 12th June 2020. Of these, 39·2% (n=122/311) were asymptomatic. The highest adjusted seroprevalence was measured in HCWs on the Acute Medical Unit (41·1%, 95% CrI 30·0-52·9) and in Physiotherapists and Occupational Therapists (39·2%, 95% CrI 24·4-56·5). Older age groups showed overall higher median antibody titres. Further modelling suggests that, for a serological assay with an overall sensitivity of 80%, antibody titres may be markedly affected by differences in age, with sensitivity estimates of 89% in those over 60 years but 61% in those ≤30 years. Conclusions:  HCWs in acute medical units and those working closely with COVID-19 patients were at highest risk of infection, though whether these are infections acquired from patients or other staff is unknown. Current serological assays may underestimate seroprevalence in younger age groups if validated using sera from older and/or more severe COVID-19 cases.

Breath testing for SARS-CoV-2 infection

Background From a public health perspective, the identification of individuals with mild respiratory symptoms due to SARS-CoV-2 infection is important to contain the spread of the disease. The objective of this study was to identify volatile organic compounds (VOCs) in exhaled breath common to infection with different variants of the SARS-CoV-2 virus to inform the development of a point-of-care breath test to detect infected individuals with mild symptoms. Methods A prospective, real-world, observational study was conducted on mildly symptomatic out-patients presenting to community test-sites for RT-qPCR SARS-CoV-2 testing when the Alpha, Beta, and Delta variants were driving the COVID-19 pandemic. VOCs in exhaled breath were compared between PCR-positive and negative individuals using TD-GC-ToF-MS. Candidate VOCs were tested in an independent set of samples collected during the Omicron phase of the pandemic. Findings Fifty breath samples from symptomatic RT-qPCR positive and 58 breath samples from test-negative, but symptomatic participants were compared. Of the 50 RT-qPCR-positive participants, 22 had breath sampling repeated 8–12 weeks later. PCA-X model yielded 12 distinct VOCs that discriminated SARS-CoV-2 active infection compared to recovery/convalescence period, with an area under the receiver operator characteristic curve (AUROC), of 0.862 (0.747–0.977), sensitivity, and specificity of 82% and 86%, respectively. PCA-X model from 50 RT-qPCR positive and 58 negative symptomatic participants, yielded 11 VOCs, with AUROC of 0.72 (0.604–0.803) and sensitivity of 72%, specificity 65.5%. The 11 VOCs were validated in a separate group of SARS-CoV-2 Omicron positive patients' vs healthy controls demonstrating an AUROC of 0.96 (95% CI 0.827–0.993) with sensitivity of 80% specificity of 90%. Interpretation Exhaled breath analysis is a promising non-invasive, point-of-care method to detect mild COVID-19 infection. Funding Funding for this study was a competitive grant awarded from the Vancouver Coastal Research Institute as well as funding from the 10.13039/501100015803BC Cancer Foundation.

Zoonotic Animal Influenza Virus and Potential Mixing Vessel Hosts.

Influenza viruses belong to the family Orthomyxoviridae with a negative-sense, single-stranded segmented RNA genome. They infect a wide range of animals, including humans. From 1918 to 2009, there were four influenza pandemics, which caused millions of casualties. Frequent spillover of animal influenza viruses to humans with or without intermediate hosts poses a serious zoonotic and pandemic threat. The current SARS-CoV-2 pandemic overshadowed the high risk raised by animal influenza viruses, but highlighted the role of wildlife as a reservoir for pandemic viruses. In this review, we summarize the occurrence of animal influenza virus in humans and describe potential mixing vessel or intermediate hosts for zoonotic influenza viruses. While several animal influenza viruses possess a high zoonotic risk (e.g., avian and swine influenza viruses), others are of low to negligible zoonotic potential (e.g., equine, canine, bat and bovine influenza viruses). Transmission can occur directly from animals, particularly poultry and swine, to humans or through reassortant viruses in "mixing vessel" hosts. To date, there are less than 3000 confirmed human infections with avian-origin viruses and less than 7000 subclinical infections documented. Likewise, only a few hundreds of confirmed human cases caused by swine influenza viruses have been reported. Pigs are the historic mixing vessel host for the generation of zoonotic influenza viruses due to the expression of both avian-type and human-type receptors. Nevertheless, there are a number of hosts which carry both types of receptors and can act as a potential mixing vessel host. High vigilance is warranted to prevent the next pandemic caused by animal influenza viruses.

Pose Estimation of Yoga Poses using ML Techniques

POSE ESTIMATION is a technique to identify joints in a human body from an image or video given as input to a computer. Pose estimation can be performed using Machine Learning (ML) techniques and Deep Learning techniques. Lately, it has been receiving lots of attention in the fields of Human Sensing and Artificial Intelligence. The main aim of pose estimation is to predict the poses of humans by locating key points like elbows, knees, wrists etc.In this work, we have proposed a model which uses Mediapipe, an ML framework, to obtain key point coordinates and ML algorithms like SVM, Gaussian Naive Bayes, Random Forest, Gradient Boost and K Neighbours classifier, which are compared and used to predict Yoga poses. Yoga is practised by people of all ages alike these days to fight issues caused both physically and mentally, thus improving the overall quality of life. Especially since the rise of the COVID-19 pandemic, the number of people practising yoga has only been increasing. In the model, human joint coordinates obtained are used as features. The model with the best accuracy and f score (MediaPipe+ SVM) is chosen for the final work.The yoga poses we used are Plank, Warrior 2, Downdog, Goddess, Tree and Cobra. On implementing the work, a real-time video feed from the webcam of the user's system is obtained, and pose estimation and classification of the yoga pose are done. Unlike in most current systems, suggestive measures to correct the yoga posture are also displayed in real-time alongside the webcam display of the person performing yoga along with some other basic pose information. © 2022 IEEE.

A long road to recovery? Reduced quality of life, impaired functional status and the lived experience of Long COVID patients, a cohort analysis

Introduction: One in ten people will develop symptoms of Long COVID (LC) following infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite widely reported symptomology, the impact upon quality of life (QoL) and functional status (FS) is not well documented. Accordingly, we conducted a cohort observation to determine the impact of LC on QoL and FS that also captured the lived experience. Method(s): Fifty-six patients (n=41 female, mean age 51+/-10 years) with confirmed history of COVID-19 were recruited from LC clinics in the United Kingdom and completed a 16-week cohort observation (five face-to-face visits and biweekly telephone consultations). QoL was assessed via the EQ-5D-5L and FS via the post-COVID functional status scale (PCFS) and the six-minute walk test (6MWT). Symptom profile and lived experience was captured via selfreport diaries and analysed via thematic analysis. Result(s): QoL across all domains was 2.5+/-0.6 AU at baseline and unchanged at 16-weeks (2.4+/-0.9, P=0.12). PCFS was improved at 16-weeks (2.1 +/-1.1 AU) when compared to baseline (2.7+/-0.4 AU, P=0.02) but highlighted impaired FS. 6MWT was 322+/-133 M at baseline and improved at 16 weeks (430+/-150 meters, P<0.01) but was lower than normative data for healthy age matched controls. Patients recorded 2,197 references to symptoms profile (66% coverage), highlighting broad and cyclical symptoms that impacted QoL (30% coverage) and physical and mental wellbeing. Conclusion(s): LC patients exhibit severely impacted QoL and FS that demonstrates little change over 16 weeks. Research must inform treatment and support to address symptomology and restore QoL and FS.

Clinical Team Response to the Impact of COVID-19 on Diabetes Self-Management: Findings From a Qualitative Study.

The aims of this study were to explore providers' perceptions of how COVID-19 affected patients' psychological wellbeing and diabetes self-care and discover how providers responded to sustain and improve patients' psychological health and diabetes management during the pandemic. Twenty-four semi-structured interviews were completed with primary care providers (n=14) and endocrine specialty clinicians (n=10) across sixteen clinics in North Carolina. Interview topics included: (1) current glucose monitoring approaches and diabetes management strategies for people with diabetes (2) barriers and unintended consequences encountered with respect to diabetes self-management, and (3) innovative strategies developed to overcome barriers. Interview transcripts were coded using qualitative analysis software and analyzed to identify cross-cutting themes and differences between participants. Primary care providers and endocrine specialty clinicians reported that people with diabetes experienced increased mental health symptoms, increased financial challenges and positive and negative changes in self-care routines due to COVID-19. To offer support, primary care providers and endocrine specialty providers focused discussions on lifestyle management and utilized telemedicine to connect with patients. Additionally, endocrine specialty clinicians helped patients access financial assistance programs. Findings indicate that people with diabetes experienced unique challenges to self-management during the pandemic and providers responded with targeted support strategies. Future research should explore the effectiveness of these provider interventions as the pandemic continues to evolve.

Prevalence and clinical outcomes of COVID-19 in patients with pre-existing celiac disease: A systematic review and meta-analysis.

There is a scarcity of scientific evidence addressing the outcomes of COVID-19 in celiac disease (CD) patients. This systematic review and meta-analysis aimed to evaluate the correlation between pre-existing CD and COVID-19. A rigorous literature search was conducted using multiple databases. All eligible observational studies were included from around the globe. The random effect model calculated the pooled prevalence and associated 95% confidence intervals (CI). Mantel-Haenszel odds ratios were produced to report the overall effect size using random effect models for severity and mortality outcomes. Funnel plots, Egger regression tests, and Begg-Mazumdar's rank correlation test were used to appraise publication bias. Data from 11 articles consisting of 44,378 CD patients were obtained. Overall pooled random-effects estimate of SARS-CoV-2 infection in CD patients was 4.25% (95% CI, I2  = 98%). Our findings also indicated that pre-existing CD was not associated with an increased risk of hospitalisation with COVID-19 illness (OR = 1.04, 95% CI 0.87-1.24, I2  = 0%) and mortality due to illness (OR = 0.92, 95% CI 0.56-1.5, I2  = 45%) compared with patients without pre-existing CD. No significant publication bias was evident in the meta-analysis. The preliminary data from our analysis suggest that SARS-CoV-2 infection in patients with pre-existing CD is not associated with an increased risk of hospitalisation or mortality. Additional studies are required to overcome the restrictions of the limited data available at present.

Anti-PF4 antibodies associated with disease severity in COVID-19.

Severe COVID-19 is characterized by a prothrombotic state associated with thrombocytopenia, with microvascular thrombosis being almost invariably present in the lung and other organs at postmortem examination. We evaluated the presence of antibodies to platelet factor 4 (PF4)-polyanion complexes using a clinically validated immunoassay in 100 hospitalized patients with COVID-19 with moderate or severe disease (World Health Organization score, 4 to 10), 25 patients with acute COVID-19 visiting the emergency department, and 65 convalescent individuals. Anti-PF4 antibodies were detected in 95 of 100 hospitalized patients with COVID-19 (95.0%) irrespective of prior heparin treatment, with a mean optical density value of 0.871 ± 0.405 SD (range, 0.177 to 2.706). In contrast, patients hospitalized for severe acute respiratory disease unrelated to COVID-19 had markedly lower levels of the antibodies. In a high proportion of patients with COVID-19, levels of all three immunoglobulin (Ig) isotypes tested (IgG, IgM, and IgA) were simultaneously elevated. Antibody levels were higher in male than in female patients and higher in African Americans and Hispanics than in White patients. Anti-PF4 antibody levels were correlated with the maximum disease severity score and with significant reductions in circulating platelet counts during hospitalization. In individuals convalescent from COVID-19, the antibody levels returned to near-normal values. Sera from patients with COVID-19 induced higher levels of platelet activation than did sera from healthy blood donors, but the results were not correlated with the levels of anti-PF4 antibodies. These results demonstrate that the vast majority of patients with severe COVID-19 develop anti-PF4 antibodies, which may play a role in the clinical complications of COVID-19.

Toward the determination of sensitive and reliable whole-lung computed tomography features for robust standard radiomics and delta-radiomics analysis in a nonhuman primate model of coronavirus disease 2019.

Purpose: We propose a method to identify sensitive and reliable whole-lung radiomic features from computed tomography (CT) images in a nonhuman primate model of coronavirus disease 2019 (COVID-19). Criteria used for feature selection in this method may improve the performance and robustness of predictive models. Approach: Fourteen crab-eating macaques were assigned to two experimental groups and exposed to either severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or a mock inoculum. High-resolution CT scans were acquired before exposure and on several post-exposure days. Lung volumes were segmented using a deep-learning methodology, and radiomic features were extracted from the original image. The reliability of each feature was assessed by the intraclass correlation coefficient (ICC) using the mock-exposed group data. The sensitivity of each feature was assessed using the virus-exposed group data by defining a factor R that estimates the excess of variation above the maximum normal variation computed in the mock-exposed group. R and ICC were used to rank features and identify non-sensitive and unstable features. Results: Out of 111 radiomic features, 43% had excellent reliability ( ICC > 0.90 ), and 55% had either good ( ICC > 0.75 ) or moderate ( ICC > 0.50 ) reliability. Nineteen features were not sensitive to the radiological manifestations of SARS-CoV-2 exposure. The sensitivity of features showed patterns that suggested a correlation with the radiological manifestations. Conclusions: Features were quantified and ranked based on their sensitivity and reliability. Features to be excluded to create more robust models were identified. Applicability to similar viral pneumonia studies is also possible.

Spatiotemporal analysis of SARS-CoV-2 infection reveals an expansive wave of monocyte-derived macrophages associated with vascular damage and virus clearance in hamster lungs (preprint)

Factors of the innate immune response to SARS-CoV-2 in the lungs are pivotal for the ability of the host to deal with the infection. In humans, excessive macrophage infiltration is associated with disease severity. Using 3D spatiotemporal analysis of optically cleared hamster lung slices in combination with virological, immunohistochemical and RNA sequence analyses, we visualized the spread of SARS-CoV-2 through the lungs and the rapid anti-viral response in infected lung epithelial cells, followed by a wave of monocyte-derived macrophage (MDM) infiltration and virus elimination from the tissue. These SARS-CoV-2 induced innate immune processes are closely related to the onset of necrotizing inflammatory and consecutive remodelling responses in the lungs, which manifests as extensive cell death, vascular damage, thrombosis, and cell proliferation. Here we show that MDM are directly linked to virus clearance, and appear in connection with tissue injury and blood vessel damage. Rapid initiation of prothrombotic factor upregulation, tissue repair and alveolar cell proliferation results in tissue remodelling, which is followed by fibrosis development despite a decrease in inflammatory and anti-viral activities. Thus, although the hamsters are able to resolve the infection following the MDM influx and repair lung tissue integrity, longer-term alterations of the lung tissues arise as a result of concurrent tissue damage and regeneration processes.

Telehealth use by walk-in patients who subsequently visited an academic emergency department: a repeated cross-sectional study during the COVID-19 summer 2021.

AIM OF THE STUDY: During the COVID-19 pandemic, telehealth use increased worldwide in a variety of medical specialities and reached new population groups. A baseline survey of telehealth use prior to admission to the emergency department (ED) conducted before COVID-19 concluded that predominantly well-educated men used telehealth. It is unclear how COVID-19 changed the use of telehealth in Swiss emergency patients. We therefore aimed to investigate (i) the frequency of telehealth use during the pandemic, and (ii) how the pandemic has influenced telehealth use and users. MATERIALS AND METHODS: A repeated cross-sectional study was conducted among ED walk-in patients at a tertiary university hospital in Switzerland. The study took place one and a half years after the first confirmed COVID-19 case, during 30 shifts from 8 to 29 July 2021 and compared with the baseline survey conducted in 2019. Eligible patients were questioned about their use of, and attitudes to telehealth. RESULTS: A total of 1020 patients were screened for the COVID survey and 443 complete questionnaires were evaluated. A trend towards a general increase (+6.4%) in telehealth use was demonstrated (50.3%, n = 223 COVID survey vs 43.9%, n = 183 baseline survey; p = 0.058), with a shift to more female patients using telehealth in the COVID survey (female 54.9%, n = 124 vs 45.1%, n = 102; p = 0.052). During the pandemic, first use of telehealth was reported by 12.2% (n = 54) of patients, with a significant increase among patients with low educational status, and the latter patients often indicated that they did not plan to use telehealth after the pandemic. The perceived usefulness of telehealth and adherence to recommendations increased in the COVID survey compared with the baseline survey (adherence 90.3%, n = 149, vs 78.0%, n = 131; p = 0.002). CONCLUSION: We found a trend towards increased use of telehealth among Swiss ED patients. First-time users of telehealth were predominantly less educated and inclusion of these user groups may not be sustainable, as was indicated by the patients. COVID-19 led to greater adherence to telehealth recommendations and higher perceived usefulness. This could be due to the limited access to healthcare providers due to pandemic precautions. When offering telehealth, the needs of all patient groups must be considered, in order to ensure that telehealth provides the greatest benefit with lower barriers to use.