[SARS-C0V.2/COVID-I9 in Colombia: tendencies, predictions, and tensions about health system]. / SARS-COV.2/COVID-19 en Colombia: tendencias, predicciones y tensiones sobre el sistema sanitario.

OBJECTIVE: To analyze the temporal progress in the early stage of COVID-19 in Colombia using the SIRD model. METHODS: We analyzed the temporal progress of COVID-19 based on the number of infected persons between March 6th and April 15th, 2020. The SIRD model was implemented with variation in the rate of transmission (b) in three ways. A. Quarantine until July 11. 2. B. Flexible quarantine, [b=4%]. C. Flexible quarantine2 [b=8%]. Consecutively, we aimed to predict the number of total cases and 5% of infected persons in ICU to match them with the hospital beds and ICU staff. RESULTS: The results show that the number of COVID-19 cases will increase from 54 105 to 116 081 approximately, if the quarantine is lifted on May 11. If the infection rate increase, more hospital beds and a bigger ICU staff will be mandatory. The currently 2 650 beds won't be enough in the flexible quarantine2, and five intensive care specialist and four nurses per patient will be needed. CONCLUSION: Measures like mandatory social distancing help delay the saturation of the health care system. However, it's impracticable to maintain them due to a possible economic crisis. Therefore, it's necessary to take action to enhance the ability of the health care system to avoid a collapse.

Detection of High Level of Co-Infection and the Emergence of Novel SARS CoV-2 Delta-Omicron and Omicron-Omicron Recombinants in the Epidemiological Surveillance of Andalusia.

Recombination is an evolutionary strategy to quickly acquire new viral properties inherited from the parental lineages. The systematic survey of the SARS-CoV-2 genome sequences of the Andalusian genomic surveillance strategy has allowed the detection of an unexpectedly high number of co-infections, which constitute the ideal scenario for the emergence of new recombinants. Whole genome sequence of SARS-CoV-2 has been carried out as part of the genomic surveillance programme. Sample sources included the main hospitals in the Andalusia region. In addition to the increase of co-infections and known recombinants, three novel SARS-CoV-2 delta-omicron and omicron-omicron recombinant variants with two break points have been detected. Our observations document an epidemiological scenario in which co-infection and recombination are detected more frequently. Finally, we describe a family case in which co-infection is followed by the detection of a recombinant made from the two co-infecting variants. This increased number of recombinants raises the risk of emergence of recombinant variants with increased transmissibility and pathogenicity.

The unintended consequences of confinement: Evidence from the rural area in Guatemala

Individual and social preferences have shown to be important factors in individual decision making and general economic performance. Yet, they are usually assumed as given and stable, underestimating their impact in the rhythm of economic recovery after a natural disaster or pandemic. This paper examines the effects of COVID-19 initial confinement on households' individual and social preferences across small communities in the rural area of Guatemala. We use a comprehensive panel household survey of agricultural smallholders collected during two survey rounds in 2019, prior to the pandemic, and 2020 and find that preferences generally shifted following the onset of the pandemic. We observe a significant increase in risk tolerance, deteriorated perceptions towards trust and generosity, and a higher frequency of emotional issues, while intra-household relationships remain stable. We find that experiencing a household adverse situation, a higher degree of exposure to the virus, and more stringent local confinement measures shaped several of the variations in preferences. The focus of the study on a region with high poverty and malnutrition rates offers important insights of the consequences of confinement on perceptions and attitudes in complex and vulnerable rural contexts during the wake of a public health emergency.

Common and rare variant associations with clonal haematopoiesis phenotypes.

Clonal haematopoiesis involves the expansion of certain blood cell lineages and has been associated with ageing and adverse health outcomes1-5. Here we use exome sequence data on 628,388 individuals to identify 40,208 carriers of clonal haematopoiesis of indeterminate potential (CHIP). Using genome-wide and exome-wide association analyses, we identify 24 loci (21 of which are novel) where germline genetic variation influences predisposition to CHIP, including missense variants in the lymphocytic antigen coding gene LY75, which are associated with reduced incidence of CHIP. We also identify novel rare variant associations with clonal haematopoiesis and telomere length. Analysis of 5,041 health traits from the UK Biobank (UKB) found relationships between CHIP and severe COVID-19 outcomes, cardiovascular disease, haematologic traits, malignancy, smoking, obesity, infection and all-cause mortality. Longitudinal and Mendelian randomization analyses revealed that CHIP is associated with solid cancers, including non-melanoma skin cancer and lung cancer, and that CHIP linked to DNMT3A is associated with the subsequent development of myeloid but not lymphoid leukaemias. Additionally, contrary to previous findings from the initial 50,000 UKB exomes6, our results in the full sample do not support a role for IL-6 inhibition in reducing the risk of cardiovascular disease among CHIP carriers. Our findings demonstrate that CHIP represents a complex set of heterogeneous phenotypes with shared and unique germline genetic causes and varied clinical implications.

Evaluation of a complex home ventilation population before and after the advent of COVID-19 in the UK

P75 Figure 1Home ventilation delivery and dependence[Figure omitted. See PDF]ConclusionsThe apparent association between home non-invasive ventilator dependence and increased mortality in the second year of COVID-19 in the UK warrants investigation of unmet need in this patient group, compared with the invasively ventilated. Targeted review is planned in the local setting, facilitated by utilisation of home ventilation registry as a method of population surveillance.ReferencesLloyd-Owen SJ, et al. Patterns of home mechanical ventilation use in Europe: results from the Eurovent survey. ERJ 2005;25: 1025–1031.Allen M. Respiratory Medicine: GIRFT Programme National Specialty Report. London: GIRFT, 2021.

Cost analysis of chronic pain due to musculoskeletal disorders in Chile.

The magnitude of the cost of chronic pain has been a matter of concern in many countries worldwide. The high prevalence, the cost it implies for the health system, productivity, and absenteeism need to be addressed urgently. Studies have begun describing this problem in Chile, but there is still a debt in highlighting its importance and urgency on contributing to chronic pain financial coverage. This study objective is to estimate the expected cost of chronic pain and its related musculoskeletal diseases in the Chilean adult population. We conducted a mathematical decision model exercise, Markov Model, to estimate costs and consequences. Patients were classified into severe, moderate, and mild pain groups, restricted to five diseases: knee osteoarthritis, hip osteoarthritis, lower back pain, shoulder pain, and fibromyalgia. Data analysis considered a set of transition probabilities to estimate the total cost, sick leave payment, and productivity losses. Results show that the total annual cost for chronic pain in Chile is USD 943,413,490, corresponding an 80% to the five diseases studied. The highest costs are related to therapeutic management, followed by productivity losses and sick leave days. Low back pain and fibromyalgia are both the costlier chronic pain-related musculoskeletal diseases. We can conclude that the magnitude of the cost in our country's approach to chronic pain is related to increased productivity losses and sick leave payments. Incorporating actions to ensure access and financial coverage and new care strategies that reorganize care delivery to more integrated and comprehensive care could potentially impact costs in both patients and the health system. Finally, the impact of the COVID-19 pandemic will probably deepen even more this problem.

RISK OF CANNULA-SITE INFECTION FOR BEDSIDE PERCUTANEOUS CANNULATIONS PERFORMED BY INTENSIVISTS: A RETROSPECTIVE, SINGLE-INSTITUTION CASE SERIES

SESSION TITLE: Not the Normal Host: Infections Still Matter SESSION TYPE: Rapid Fire Original Inv PRESENTED ON: 10/17/2022 12:15 pm - 1:15 pm PURPOSE: Utilization of ECMO support for refractory cardiogenic, and respiratory failure has increased exponentially over the last 20 years. The advent of miniaturized and portable machines has led to a shift of cannulation strategies in the operating room/cath lab to the bedside. Transitioning to bedside cannulation has been previously reported as safe, with minimal risk for mortality or catheter site infections. However, bedside cannulations in the critically ill crashing patient raises concern for sterility. The aim of this study was to assess the risk of ECMO cannula site infections in bedside vs operating room/catheterization suite. METHODS: It is a retrospective single institution case series review of 52 adult and pediatric patients who were required either Veno-Venous (VV) or Veno-Arterial (VA) ECMO. Data gathering was used to quantify the rate of catheter site infections after initiation of extracorporeal support. Catheter site infections were defined as localized erythema, fluctuance, or purulence from the cannula site within 7 days of of ECMO cannula placement. RESULTS: A total of 42 (81%) pts had bedside cannulation, and the other 10 (19%), were done in IR suite/cath lab. The total number of catheter site infections was 1 (2.4%) in the bedside cannulation group. There were no infections in the non-bedside cannulation groups. 13 (30%) of the bedside cannulations, and 3 (30%) of the non-bedside cannulation group were on antibiotics during or prior to cannula insertion. CONCLUSIONS: Current literature suggests that the prevalence of infections on ECMO is 10-12%,. Traditionally, this has predisposed most cannulations to be performed in the surgical setting rather than at bedside. During the recent COVID pandemic, the frequency of bedside cannulation for ECMO had increased and was not associated with significant morbidity, and mortality. The risk of infection from the catheter site had also been determined to be minimal to none. From the data gathered above, it can be safely assumed that the risk of catheter site infection with bedside cannulation is minimal. However, the major contributing factor to decreased infection risk appears to be meticulous cannula site nursing care. The current ECMO nursing protocol utilized at our hospital required twice daily dressing changes with stringent chlorhexidine cleanses prior to redressing. The only case of catheter site infection we experienced was when this protocol was deviated. CLINICAL IMPLICATIONS: Utilizations of bedside ECMO cannulation techniques carries minimal risk for catheter site infections. It is important to state that nursing driven protocols for cannula site dressing changes, has one of the biggest implications on the risk of catheter site infections. Therefore, with the employment of appropriate nursing protocols, the concern for catheter site infections should not preclude the decision to proceed with bedside cannulation. DISCLOSURES: No relevant relationships by Ajit Alexander No relevant relationships by Melodie Blackmon Scientific Medical Advisor relationship with ALung Technologies, Inc. Please note: $5001 - $20000 by Steven Conrad, value=Consulting fee No relevant relationships by ANIBAL DOMINGUEZ no disclosure on file for Jonathan Eaton;No relevant relationships by Laurie Grier No relevant relationships by Rajkamal Hansra No relevant relationships by Prathik Krishnan No relevant relationships by Nathaniel LSUHSC-Shreveport No relevant relationships by Alex Manuel No relevant relationships by Jonathan Packer No relevant relationships by arunima sharma no disclosure on file for Chris Trosclair;No relevant relationships by Gregory Vo No relevant relationships by Robert Walter

Development of an Inter-hospital transfer network for patients requiring extracorporeal membrane oxygenation during the COVID-19 Pandemic

Extracorporeal membrane oxygenation (ECMO) is a life-saving treatment modality for patients with severe respiratory and cardiac failure. During the COVID-19 pandemic, the ability to utilize this service worldwide was limited by the number of facilities capable of providing ECMO support and their patient capacity. We describe an institution rapidly deploying an ECMO transport program to improve access to this service and optimize its capacity. As the only ELSO Center of Excellence in the state of Louisiana, and one of the few facilities that can provide this service in the state, our center had an obligation to expand our ability to provide access to ECMO support in our region. However, as we had not performed ECMO transport before the pandemic, we were faced with challenges in developing the infrastructure for a transport program. Due to limited resources and our emphasis on treating the maximum number of patients, we had to create and implement protocols simultaneously, refining them as we went. We relied on programs that had previously developed transport protocols and procedures for guidance, adapting their templates for our program's specific characteristics. Less than one month after obtaining our first CardiohelpTM system we performed our first ECMO transport by air. Over the next twelve months, we performed more than ten transports by air and ground successfully with no mortalities or complications during transport. Despite various obstacles, we succeeded in creating a transport service and improved our ability to provide ECMO support to patients throughout the state of Louisiana.

SARS-CoV-2 vaccine booster in solid organ transplant recipients previously immunised with inactivated versus mRNA vaccines: A prospective cohort study.

Background: Solid-organ transplant (SOT) recipients have worse COVID-19 outcomes than general population and effective immunisation in these patients is essential but more difficult to reach. We aimed to determine the immunogenicity of an mRNA SARS-CoV-2 vaccine booster in SOT recipients previously immunised with either inactivated or homologous SARS-CoV-2 mRNA vaccine. Methods: Prospective cohort study of SOT recipients under medical care at Red de Salud UC-CHRISTUS, Chile, previously vaccinated with either CoronaVac or BNT162b2. All participants received a BNT162b2 vaccine booster. The primary study end point was anti-SARS-CoV-2 total IgG antibodies (TAb) seropositivity at 8-12 weeks (56-84 days) post booster. Secondary end points included neutralising antibodies (NAb) and specific T-cell responses. Findings: A total of 140 (50% kidney, 38% liver, 6% heart) SOT recipients (mean age 54 [13.6] years; 64 [46%] women) were included. Of them, 62 had homologous (three doses of BNT162b2) and 78 heterologous vaccine schedules (two doses of CoronaVac followed by BNT162b2 booster). Boosters were received at a median of 21.3 weeks after primary vaccination. The proportion achieving TAb seropositivity (82.3% vs 65.4%, P = 0.035) and NAb positivity (77.4% vs 55.1%, P = 0.007) were higher for the homologous versus the heterologous group. On the other hand, the number of IFN-γ and IL-2 secreting SARS-CoV-2-specific T-cells did not differ significantly between groups. Interpretation: This cohort study shows that homologous mRNA vaccine priming plus boosting in SOT recipients, reaches a significantly higher humoral immune response than inactivated SARS-CoV-2 vaccine priming followed by heterologous mRNA booster. Funding: School of Medicine, UC-Chile and ANID.ClinicalTrials.gov ID: NCT05124509.

SM-COLSARSPROT: Highly Immunogenic Supramutational Synthetic Peptides Covering the World's Population.

Fifty ~20-amino acid (aa)-long peptides were selected from functionally relevant SARS-CoV-2 S, M, and E proteins for trial B-21 and another 53 common ones, plus some new ones derived from the virus' main genetic variants for complementary trial C-21. Peptide selection was based on tremendous SARS-CoV-2 genetic variability for analysing them concerning vast human immunogenetic polymorphism for developing the first supramutational, Colombian SARS-protection (SM-COLSARSPROT), peptide mixture. Specific physicochemical rules were followed, i.e., aa predilection for polyproline type II left-handed (PPIIL) formation, replacing ß-branched, aromatic aa, short-chain backbone H-bond-forming residues, π-π interactions (n→π* and π-CH), aa interaction with π systems, and molecular fragments able to interact with them, disrupting PPIIL propensity formation. All these modified structures had PPIIL formation propensity to enable target peptide interaction with human leukocyte antigen-DRß1* (HLA-DRß1*) molecules to mediate antigen presentation and induce an appropriate immune response. Such modified peptides were designed for human use; however, they induced high antibody titres against S, M, and E parental mutant peptides and neutralising antibodies when suitably modified and chemically synthesised for immunising 61 major histocompatibility complex class II (MHCII) DNA genotyped Aotus monkeys (matched with their corresponding HLA-DRß1* molecules), predicted to cover 77.5% to 83.1% of the world's population. Such chemically synthesised peptide mixture represents an extremely pure, stable, reliable, and cheap vaccine for COVID-19 pandemic control, providing a new approach for a logical, rational, and soundly established methodology for other vaccine development.

Insights on conducting digital patient and public involvement in dementia research during the COVID-19 pandemic: supporting the development of an "E-nabling digital co-production" framework.

BACKGROUND: The rapid transition to digital working, accelerated due to the response to the COVID-19 pandemic, has impacted the involvement of patients and public in research. This paper presents experiences of engaging in digital Patient and Public Involvement (e-PPI) in dementia research since the lockdowns, offering recommendations regarding future digital and hybrid working. Furthermore, it introduces a co-produced framework for researchers, PPI coordinators and public contributors to identify and discuss challenges and opportunities provided by e-PPI. METHODS: Two online workshops and one individual interview were performed with a group of researchers and PPI coordinators with experience in PPI in dementia research, and with an existing dementia PPI group having some experience of working online during the pandemic. The project was constructed as a PPI activity, with the MindTech Involvement Team (PPI group) involved in the entire process, and a collaborative data analysis process was adopted. RESULTS: After refinement of the coding structure, the MindTech Involvement Team and Project Leaders identified four main themes, resulting in the 'E-nabling Digital Co-production' Framework. During this framework development, different positions were expressed, associated with the transition to digital working. Two main themes were shared by the participating groups regarding e-PPI: wider potential reach without geographical constraints, and the perception of more business-like sessions with reduced opportunities for social interactions and communication. Specifically for dementia research, whilst e-PPI may allow public contributors to attend more meetings, potentially mutually supportive environments provided by face-to-face meetings could be diminished, with carers experiencing a possible reduction in informal respite opportunities. CONCLUSIONS: Through involving public contributors, researchers, and PPI coordinators with a focus on digital PPI in dementia research, we were able to further refine and co-produce the 'E-nabling Digital Co-production' Framework. Demonstrating potential for analysis of benefits and limitations within e-PPI, it was possible to identify both general insights and those specific to dementia research. However, the most significant contribution of the framework is the potential to support local journeys of co-production in ongoing digital and hybrid public involvement activities.

The COVID-19 pandemic has impacted the engagement of patients and the public in research. Lockdowns, social distancing, and reduced physical contact have affected the involvement of public contributors in research studies. In particular, the pandemic triggered a rapid transition to digital working, increasing the use of Information and Communication Technologies such as video conferencing on computers and mobile devices. With little time to reflect on the consequences of digital working in PPI and with a continuing legacy of hybrid or blended approaches to involvement, this project highlights the challenges and potential for e-PPI approaches (electronic/digital PPI) within the context of dementia research. In addition to examining the transition to digital working in this area, we present a co-produced framework for researchers, PPI coordinators and public contributors.

SM-COLSARSPROT: Highly Immunogenic Supramutational Synthetic Peptides Covering the World’s Population

Fifty ~20–amino acid (aa)–long peptides were selected from functionally relevant SARS-CoV-2 S, M, and E proteins for trial B-21 and another 53 common ones, plus some new ones derived from the virus’ main genetic variants for complementary trial C-21. Peptide selection was based on tremendous SARS-CoV-2 genetic variability for analysing them concerning vast human immunogenetic polymorphism for developing the first supramutational, Colombian SARS-protection (SM-COLSARSPROT), peptide mixture. Specific physicochemical rules were followed, i.e., aa predilection for polyproline type II left-handed (PPIIL) formation, replacing β-branched, aromatic aa, short-chain backbone H-bond-forming residues, π-π interactions (n→π* and π-CH), aa interaction with π systems, and molecular fragments able to interact with them, disrupting PPIIL propensity formation. All these modified structures had PPIIL formation propensity to enable target peptide interaction with human leukocyte antigen-DRβ1* (HLA-DRβ1*) molecules to mediate antigen presentation and induce an appropriate immune response. Such modified peptides were designed for human use;however, they induced high antibody titres against S, M, and E parental mutant peptides and neutralising antibodies when suitably modified and chemically synthesised for immunising 61 major histocompatibility complex class II (MHCII) DNA genotyped Aotus monkeys (matched with their corresponding HLA-DRβ1* molecules), predicted to cover 77.5% to 83.1% of the world’s population. Such chemically synthesised peptide mixture represents an extremely pure, stable, reliable, and cheap vaccine for COVID-19 pandemic control, providing a new approach for a logical, rational, and soundly established methodology for other vaccine development.

Efficacy and Safety of Sarilumab in Hospitalized Patients With Coronavirus Disease 2019: A Randomized Clinical Trial.

BACKGROUND: Open-label platform trials and a prospective meta-analysis suggest efficacy of anti-interleukin (IL)-6R therapies in hospitalized patients with coronavirus disease 2019 (COVID-19) receiving corticosteroids. This study evaluated the efficacy and safety of sarilumab, an anti-IL-6R monoclonal antibody, in the treatment of hospitalized patients with COVID-19. METHODS: In this adaptive, phase 2/3, randomized, double-blind, placebo-controlled trial, adults hospitalized with COVID-19 received intravenous sarilumab 400 mg or placebo. The phase 3 primary analysis population included patients with critical COVID-19 receiving mechanical ventilation (MV). The primary outcome was proportion of patients with ≥1-point improvement in clinical status from baseline to day 22. RESULTS: There were 457 and 1365 patients randomized and treated in phases 2 and 3, respectively. In phase 3, patients with critical COVID-19 receiving MV (n = 298; 28.2% on corticosteroids), the proportion with ≥1-point improvement in clinical status (alive, not receiving MV) at day 22 was 43.2% for sarilumab and 35.5% for placebo (risk difference, +7.5%; 95% confidence interval [CI], -7.4 to 21.3; P =.3261), a relative risk improvement of 21.7%. In post hoc analyses pooling phase 2 and 3 critical patients receiving MV, the hazard ratio for death for sarilumab vs placebo was 0.76 (95% CI, .51 to 1.13) overall and 0.49 (95% CI, .25 to .94) in patients receiving corticosteroids at baseline. CONCLUSIONS: This study did not establish the efficacy of sarilumab in hospitalized patients with severe/critical COVID-19. Post hoc analyses were consistent with other studies that found a benefit of sarilumab in patients receiving corticosteroids. CLINICAL TRIALS REGISTRATION: NCT04315298.

Serum microRNAs targeting ACE2 and RAB14 genes distinguish asymptomatic from critical COVID-19 patients.

Despite the extraordinary advances achieved to beat COVID-19 disease, many questions remain unsolved, including the mechanisms of action of SARS-CoV-2 and which factors determine why individuals respond so differently to the viral infection. Herein, we performed an in silico analysis to identify host microRNA targeting ACE2, TMPRSS2, and/or RAB14, all genes known to participate in viral entry and replication. Next, the levels of six microRNA candidates previously linked to viral and respiratory-related pathologies were measured in the serum of COVID-19-negative controls (n = 16), IgG-positive COVID-19 asymptomatic individuals (n = 16), and critical COVID-19 patients (n = 17). Four of the peripheral microRNAs analyzed (hsa-miR-32-5p, hsa-miR-98-3p, hsa-miR-423-3p, and hsa-miR-1246) were upregulated in COVID-19 critical patients compared with COVID-19-negative controls. Moreover, hsa-miR-32-5p and hsa-miR-1246 levels were also altered in critical versus asymptomatic individuals. Furthermore, these microRNA target genes were related to viral infection, inflammatory response, and coagulation-related processes. In conclusion, SARS-CoV-2 promotes the alteration of microRNAs targeting the expression of key proteins for viral entry and replication, and these changes are associated with disease severity. The microRNAs identified could be taken as potential biomarkers of COVID-19 progression as well as candidates for future therapeutic approaches against this disease.

Mood Disturbances Across the Continuum of Care Based on Self-Report and Clinician Rated Measures in the interRAI Suite of Assessment Instruments.

Background: Mood disturbance is a pervasive problem affecting persons of all ages in the general population and the subset of those receiving services from different health care providers. interRAI assessment instruments comprise an integrated health information system providing a common approach to comprehensive assessment of the strengths, preferences and needs of persons with complex needs across the continuum of care. Objective: Our objective was to create new mood scales for use with the full suite of interRAI assessments including a composite version with both clinician-rated and self-reported items as well as a self-report only version. Methods: We completed a cross-sectional analysis of 511,641 interRAI assessments of Canadian adults aged 18+ in community mental health, home care, community support services, nursing homes, palliative care, acute hospital, and general population surveys to develop, test, and refine new measures of mood disturbance that combined clinician and self-rated items. We examined validity and internal consistency across diverse care settings and populations. Results: The composite scale combining both clinician and self-report ratings and the self-report only variant showed different distributions across populations and settings with most severe signs of disturbed mood in community mental health settings and lowest severity in the general population prior to the COVID-19 pandemic. The self-report and composite measures were strongly correlated with each other but differed most in populations with high rates of missing values for self-report due to cognitive impairment (e.g., nursing homes). Evidence of reliability was strong across care settings, as was convergent validity with respect to depression/mood disorder diagnoses, sleep disturbance, and self-harm indicators. In a general population survey, the correlation of the self-reported mood scale with Kessler-10 was 0.73. Conclusions: The new interRAI mood scales provide reliable and valid mental health measures that can be applied across diverse populations and care settings. Incorporating a person-centered approach to assessment, the composite scale considers the person's perspective and clinician views to provide a sensitive and robust measure that considers mood disturbances related to dysphoria, anxiety, and anhedonia.

Comparison of Physical Fitness Profiles Obtained before and during COVID-19 Pandemic in Two Independent Large Samples of Children and Adolescents: DAFIS Project.

COVID-19 pandemic restrictions might have negatively affected the health-related physical fitness of children and adolescents. The aim of this study was to contrast the body composition and physical fitness data of two independent samples of children and adolescents obtained from an online database (DAFIS project) before (n = 15,287) and during (n = 2101) the first academic year of the COVID-19 pandemic. The results revealed higher values for the body mass index (p = 0.002), waist circumference (p < 0.001), and waist to hip and waist to height ratios (p < 0.001) during than before the pandemic, particularly in the case of boys. On the other hand, lower muscular fitness was observed for girls during the pandemic. Quantitative and qualitative analysis did not detect relevant changes in cardiorespiratory fitness in children or adolescents (p > 0.05). Our data suggested that pandemic constraints might have affected body composition and muscular fitness of children and adolescents. These results might be of interest for designing specific interventions oriented toward counteracting the negative effects of pandemic restrictions on health-related physical fitness.

Polarimetric imaging for the detection of synthetic models of SARS-CoV-2: a proof of concept (preprint)

Objective: To conduct a proof-of-concept study of the detection of two synthetic models of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using polarimetric imaging. Methods: Two SARS-CoV-2 models were prepared as engineered lentiviruses pseudotyped with the G protein of the vesicular stomatitis virus, and with the characteristic Spike protein of SARS-CoV-2. Samples were preparations in two biofluids (saline solution and artificial saliva), in four concentrations, and deposited as 5-{\mu}L droplets on a supporting plate. The angles of maximal degree of linear polarization (DLP) of light diffusely scattered from dry residues were determined using Mueller polarimetry of 87 samples at 405 nm and 514 nm. A polarimetric camera was used for simultaneous imaging of several samples under 380-420 nm illumination at angles similar to those of maximal DLP. A per-pixel image analysis included quantification and combination of polarization feature descriptors in other 475 samples. Results: The angles (from sample surface) of maximal DLP were 3 degrees for 405 nm and 6 degrees for 514 nm. Similar viral particles that differ only in the characteristic spike protein of the SARS-CoV-2, their corresponding negative controls, fluids, and the sample holder were discerned from polarimetric image analysis at 10-degree and 15-degree configurations. Conclusion: Polarimetric imaging in the visible spectrum has the potential for non-contact, reagent-free detection of viruses in multiple dry fluid residues simultaneously. Further analysis including real SARS-CoV-2 in human samples -- particularly, fresh saliva -- are required. Significance: Polarimetric imaging under visible light could contribute to fast, cost-effective screening of SARS-CoV-2 and other pathogens.

The Effect of COVID-19 Lockdowns on the Air Pollution of Urban Areas of Central and Southern Chile

We present the effects of the confinement and physical distancing policies applied during the COVID-19 pandemic on the concentrations of PM10, PM2.5, NO, NO2 and O3 in 16 cities in central and southern Chile. The period between March and May in 2020 was compared with the corresponding months during 2017–2019, using surface data and satellite information. The relative percent changes in the concentration of atmospheric pollutants, and the meteorological variables observed between these two periods were used to quantify the effects of the lockdowns on the local air quality of the urban areas studied. The results showed statistically significant changes in 11 of the 16 cities. Significant relative changes between +14% and –33% were observed for PM10 in 9 cities;while statistically significant changes between –6% and –48% were evident for PM2.5 in 10 cities. Significant decreases between –27% and –55%, were observed in 4 cities in which NO2 data were available;while significant increases in O3, between 18% and 43%, were found in 4 of the 5 cities with available data. The local meteorological variables did not show significant changes between both periods. In all the cities studied, one of the main PM sources is wood burning for residential heating. Although the quarantine imposed during the health emergency could have induced an increase in residential emissions, these were compensated with the reductions in vehicular and/or industrial emissions. Therefore, these results should be carefully interpreted and should inspire new research considering the social, cultural, and economic factors that could alter the common emission patterns and air quality of urban centers.

Comparison of Physical Fitness Profiles Obtained before and during COVID-19 Pandemic in Two Independent Large Samples of Children and Adolescents: DAFIS Project

COVID-19 pandemic restrictions might have negatively affected the health-related physical fitness of children and adolescents. The aim of this study was to contrast the body composition and physical fitness data of two independent samples of children and adolescents obtained from an online database (DAFIS project) before (n = 15,287) and during (n = 2101) the first academic year of the COVID-19 pandemic. The results revealed higher values for the body mass index (p = 0.002), waist circumference (p < 0.001), and waist to hip and waist to height ratios (p < 0.001) during than before the pandemic, particularly in the case of boys. On the other hand, lower muscular fitness was observed for girls during the pandemic. Quantitative and qualitative analysis did not detect relevant changes in cardiorespiratory fitness in children or adolescents (p > 0.05). Our data suggested that pandemic constraints might have affected body composition and muscular fitness of children and adolescents. These results might be of interest for designing specific interventions oriented toward counteracting the negative effects of pandemic restrictions on health-related physical fitness.