A model for the SARS-CoV-2 dynamics in a population lacking herd immunity

We introduced the S-HI model, a generalized SEIR model to describe the dynamics of the SARS-CoV-2 virus in a community without herd immunity and performed simulations for six months. The S- HI model consists of eight equations corresponding to susceptible individuals, exposed, asymptomatic infected, asymptomatic recovered, symptomatic infected, quarantined, symptomatic recovered and dead. We study the dynamics of the infected, asymptomatic. Dead classes in 4 different networks: households, workplaces, agglomeration places and the general community, showing that the dynamics of the three compartments have the exact nature in each layer and that the speed of the disease considerably increases in the networks with the highest weight of contacts. The reproduction number, R0, is greater than 1 in all networks conforming to the theory. The variants of the SARS-Cov-2 virus are not taken into account, so the S-HI model would fit a situation similar to the first wave of contagion after the mandatory lockdown. Copyright: © 2022 by the authors.

Efficacy of risankizumab by baseline clinical, biochemical, and endoscopic disease severity in moderately to severely active Crohn's disease

Background: Risankizumab (RZB), a p19-anti-interleukin-23 monoclonal antibody, has demonstrated efficacy as induction and maintenance therapy in patients with moderately to severely active Crohn's disease (CD). This post hoc analysis evaluates the efficacy of induction and maintenance RZB therapy by baseline clinical, biochemical, and endoscopic disease severity. Method(s): In the ADVANCE (NCT03105128) and MOTIVATE (NCT03104413) studies, patients with moderately to severely active CD and intolerance/inadequate response to >= 1 biologic (both studies) and/or conventional therapy (ADVANCE) were randomized to receive intravenous (IV) RZB induction therapy or placebo (PBO) for 12 weeks. Patients achieving stool frequency and/or abdominal pain score clinical response to 12 weeks of induction therapy were rerandomized in the FORTIFY (NCT03105102) study to receive subcutaneous (SC) maintenance RZB (180 mg or 360 mg) or PBO (withdrawal). Clinical and endoscopic endpoints were evaluated by baseline disease characteristics (Crohn's Disease Activity Index [CDAI: <= 300, > 300], highsensitivity C-reactive protein [hs-CRP: < 10 mg/L, >= 10 mg/L], and Simple Endoscopic Score for Crohn's Disease [SES-CD: 6-15, > 15]). Induction analyses included patients who received RZB 600 mg or PBO;data from the ADVANCE and MOTIVATE studies were pooled. Nonresponder imputation incorporating multiple imputation to handle missing data due to COVID-19 was used. Result(s): The induction analysis included 527 patients who received RZB 600 mg IV and 362 patients who received PBO. Patients treated with RZB 600 mg IV achieved significantly higher response rates vs PBO at week 12, regardless of subgroup (P < .05 for all;Figure 1). In the maintenance study, patients treated with SC RZB continued to achieve higher response rates vs the PBO (withdrawal) group at week 52 regardless of subgroup (P was not < .05 for all;Figure 2). Improvements in clinical and endoscopic outcomes were generally observed from weeks 12 to 52 with RZB treatment across all subgroups. Response rates were generally similar across subgroups in both induction and maintenance studies;endoscopic remission and ulcer-free endoscopy (resolution of ulcer) rates were numerically lower for patients with increased inflammation (hs-CRP > 10 mg/mL) and higher endoscopic activity (SES-CD > 15). Conclusion(s): RZB induction therapy resulted in higher response rates for clinical and endoscopic outcomes compared with PBO at week 12, regardless of baseline clinical, biochemical, and endoscopic disease severity. RZB also showed durable efficacy with continued RZB maintenance therapy, supporting the long-term use of RZB for patients across a range of baseline disease severity and activity.

Clinical response over 24 weeks for initial and delayed responders to induction therapy with risankizumab in Crohn's disease: Data from the ADVANCE and MOTIVATE studies

Background: The efficacy and safety of risankizumab (RZB) in patients with Crohn's disease (CD) has been demonstrated.1,2 We reported that an additional 12 weeks (ie, induction period 2) of RZB therapy could induce clinical response in patients with CD who did not achieve clinical response after an initial 12-week induction period.3 In this post hoc analysis, we report the proportion of patients who achieved clinical response over 24 weeks (initial and delayed responders to RZB induction therapy). Method(s): Data were pooled from the ADVANCE and MOTIVATE phase 3 RZB studies. Patients who had not achieved stool frequency (SF)/abdominal pain score (APS) clinical response (>= 30% decrease in average daily SF and/or >= 30% decrease in average daily APS and both not worse than baseline) after an initial 12-week induction with intravenous (IV) RZB (600 mg or 1200 mg) at weeks 0, 4, and 8 were rerandomized 1:1:1 in induction period 2 to receive IV RZB 1200 mg (at weeks 12, 16, and 20) or subcutaneous (SC) RZB (180 mg or 360 mg at weeks 12 and 20) in a double-dummy-blinded fashion. In this post hoc analysis, efficacy was analysed in patients treated with either 600 mg RZB IV or placebo (PBO) for 12 weeks in the PBO-controlled induction period and patients who did not achieve clinical response with 600 mg RZB IV for 12 weeks and were rerandomized to 360 mg RZB SC every 8 weeks during induction period 2 (currently marketed RZB doses). SF/ APS clinical response was assessed at week 12 for initial responders and at week 24 for delayed responders in induction period 2. Nonresponder imputation with no special data handling for data missing due to COVID-19 was used. No multiplicity adjustment was performed. Result(s): Of the 889 patients randomised to 600 mg IV RZB or PBO in the induction studies, 70.0% (369/527) in the RZB group compared with 45.6% (165/362) in the PBO group achieved SF/APS clinical response at week 12. Of the 47 patients who did not achieve initial clinical response to 600 mg IV RZB and received 360 mg SC in induction period 2, 32 (68.1%) achieved delayed SF/APS clinical response at week 24. The proportion of patients achieving SF/APS clinical response over 24 weeks (either initial or delayed responders) was 89.1% (401/450). The safety profile of RZB in patients with CD has been reported.1,2 Conclusion(s): In patients with moderate-to-severe CD, RZB treatment leads to approximately 9 of 10 patients achieving either initial (600 mg IV) or delayed (600 mg IV followed by 360 mg SC) clinical response over 24 weeks.

Host genetic factors involved in the susceptibility and severity of COVID-19

Background: SARS-CoV-2 infection ranges from asymptomatic forms to very serious manifestations of COVID-19 that can compromise life. The impact of the COVID-19 pandemic raises the need to identify the risk factors that determine interindividual variability in susceptibility to SARS-CoV-2 infection, pathophysiology and disease progression. Several authors suggest that the genetic component plays a key role in the complex virus-host interaction, where population differences are responsible for such heterogeneity. Method(s): A scoping review of the literature published to date was carried out in order to learn about the biological markers that seem to affect the evolution of the SARS-CoV-2 infection and the genetic polymorphisms of molecules potentially involved in the complex virus-host interaction. Result(s): Numerous evidences indicate that allelic variants of genes encoding molecules working in the early stages of virus-cell interaction or during events that define the immune response of the host, could favor the infection and/or the disease severity by SARS-CoV-2. The ABO blood group seems to play a role in immunopathogenesis, with group O individuals showing a lower risk of being infected with SARS-CoV-2, although other genetic, physiological and metabolic components of the host, such as the differential expression of toll-like receptors, HLA antigens, proinflammatory cytokines, chemokines or other effectors of the innate and acquired immune response would also be participating. Conclusion(s): The success and progression of the viral infection towards the development of clinical manifestations and the severity grade depend largely on the interaction between viral factors and the host's response, as well as seem to be conditioned by epigenetic factors and pre-existing comorbidities. The contribution of the genetic component raises the potential application of targeted preventive strategies, the identification of therapeutic targets and the development of new drugs. Copyright © 2021, Revista Salus. All rights reserved.

Biology and genetic diversity of SARS-CoV-2, the causative agent of COVID-19

The infection generated by SARS-CoV-2 has caused more than 200 million cases and 4.5 million deaths worldwide. SARS-CoV-2 has accumulated mutations that allow it to be classified into different lineages. Some of these lineages have been designated variants by the WHO: under monitoring (VUM), of interest (VOI), or of concern (VOC). Methodology. Different strategies for genomic surveillance of these SARS-CoV-2 variants have been described in each country. In Venezuela, the strategies include the amplification of a fragment of the spike, PCR-RFLP, and sequencing of the complete viral genome, which has allowed us to monitor the introduction of VOCs and VOIs to the country. Results. By October 2021, in Venezuela, the circulation of three VOCs, Alpha, Gamma, and Delta, and the two VOIs (Lambda and Mu) have been described. Globally, the Delta variant predominates in practically all continents except some Latin American countries, although it is estimated that it will soon prevail in the region as well. Discussion. The circulation of variants in the countries is a very dynamic process and Venezuela does not escape from this reality;therefore, it is important to continue genomic surveillance of this virus. Copyright © 2021, Revista Salus. All rights reserved.

Efficacy of risankizumab induction and maintenance therapy by baseline Crohn's disease location: Post hoc analysis of the Phase 3 ADVANCE, MOTIVATE, and FORTIFY studies

Background and Aim: In patients with Crohn's disease (CD), disease location affects treatment outcomes.1 This post hoc analysis assessed the efficacy of risankizumab (RZB), an interleukin-23 p19 inhibitor, by disease location. Method(s): In the ADVANCE (NCT03105128) and MOTIVATE (NCT03104413) studies, patients with moderately to severely active CD and intolerance or inadequate response to conventional and/or biologic therapy (ADVANCE) or to biologic therapy (MOTIVATE) received intravenous (IV) RZB induction therapy or placebo (PBO) for 12 weeks. Patients achieving clinical response to IV RZB induction were re-randomized in a maintenance study (FORTIFY, NCT03105102) to receive subcutaneous (SC) RZB or SC PBO (i.e. withdrawal) for 52 weeks. This post hoc analysis included patients who received RZB 600 mg IV in either ADVANCE or MOTIVATE and patients who received RZB 360 mg SC in FORTIFY. Clinical and endoscopic outcomes were evaluated in patient subgroups stratified by CD location at baseline (ileal only, colonic only, ileal-colonic) using nonresponder imputation incorporating multiple imputation to handle missing data due to COVID-19. Result(s): At Week 12, significantly greater proportions of patients receiving RZB 600 mg IV achieved the co-primary endpoints of CD Activity Index (CDAI)-based clinical remission and endoscopic response compared with PBO in the colonic only (n = 190) and ileal-colonic (n = 252) subgroups (P < 0.001). At Week 12, statistically higher proportions of RZB-treated patients achieved the composite endpoint of CDAI clinical remission and endoscopic response, as well as endoscopic remission, in the colonic only and ileal-colonic subgroups compared with PBO (P < 0.001). At Week 52, significantly greater proportions of patients receiving RZB 360 mg SC achieved the co-primary endpoints of CDAI clinical remission and endoscopic response, composite CDAI clinical remission and endoscopic response, and endoscopic remission, compared with withdrawal (PBO SC) in the colonic only (n = 59) and ileal-colonic (n = 67) subgroups (P <= 0.05;Fig. 1a-1d). In patients with endoscopic remission after 12 weeks of IV RZB (Week 0 of maintenance), significantly more RZB-treated patients achieved sustained endoscopic remission at Week 52 compared with withdrawal (PBO SC) in the colonic only and ileal-colonic subgroups (P <= 0.01;Fig. 1e). At Weeks 12 and 52, efficacy rates were numerically lower in ileal-only CD relative to colonic-only and ileal-colonic CD. Results for ileal-only CD are limited by the small number of patients in this subgroup (induction, 85;maintenance, 15). Conclusion(s): RZB induction and maintenance therapy was effective in patients with moderately to severely active CD, with greater benefits observed in patients with any colonic involvement.

Sub-lineages of the Omicron variant of SARS-CoV-2: characteristic mutations and their relation to epidemiological behavior

By the end of 2021, the Omicron variant of SARS-CoV-2, the coronavirus responsible for COVID-19, emerges, causing immediate concern, due to the explosive increase in cases in South Africa and a large number of mutations. This study describes the characteristic mutations of the Omicron variant in the Spike protein, and the behavior of the successive epidemic waves associated to the sub-lineages throughout the world. The mutations in the Spike protein described are related to the virus ability to evade the protec-tion elicited by current vaccines, as well as with possible reduced susceptibility to host proteases for priming of the fusion process, and how this might be related to changes in tropism, a replication enhanced in nasal epithelial cells, and reduced in pulmonary tissue;traits probably associated with the apparent reduced severity of Omicron compared to other variants. © 2022, Instituto de Investigaciones Clinicas. All rights reserved.

Model applied to higher education in times of pandemic (CoVID-19)

This research analyzes the perception that students have about the use of ICT in the work and academic fields, for this the Technology Acceptance model was adopted according to the current context in which the institutions operate, the methodology is of a descriptive type, the study population was 194 students enrolled in face-to-face and distance modality of the administrative area of the UTPL. The results showed that students use ICTs at work because they conceive them as useful tools that facilitate learning, as well as increase productivity and performance. On the other hand, regarding the use of ICTs in the educational field, students relate them to the ease of interacting with those involved in the educational process, and they also agree that they are useful and flexible tools that adapt to the training needs of students. each person, finally its use increases academic performance. © 2022 IEEE Computer Society. All rights reserved.

SHORTER DISEASE DURATION IS ASSOCIATED WITH BETTER OUTCOMES IN PATIENTS WITH MODERATELY TO SEVERELY ACTIVE CROHN'S DISEASE TREATED WITH RISANKIZUMAB: RESULTS FROM THE PHASE 3 ADVANCE, MOTIVATE, AND FORTIFY STUDIES

Background: An association between shorter disease duration and improved clinical efficacy has been shown in post hoc analyses of clinical trial data with biological therapies in Crohn’s disease (CD). The efficacy and safety of risankizumab (RZB) as induction and maintenance therapy have been recently reported.1,2 Here, the efficacy of RZB stratified by baseline CD duration is reported. Methods: In ADVANCE (NCT03105128) and MOTIVATE (NCT03104413), patients with moderately to severely active CD received intravenous (IV) RZB induction therapy or placebo (PBO) for 12 weeks. Patients with clinical response to RZB IV induction were re-randomised in a 52-week maintenance study (FORTIFY NCT03105102) to receive subcutaneous (SC) RZB or PBO (ie, withdrawal). For this posthoc analysis, patient subgroups were stratified by years of CD duration at baseline (< 2, 2– 5, > 5–10, and > 10 years). Induction analyses focused on patients who received RZB 600 mg IV or PBO for 12 weeks. As all patients who entered maintenance responded to RZB IV induction, maintenance analyses were limited to those patients who responded to induction and then received RZB 360 mg SC for 52 weeks. Clinical and endoscopic outcomes were evaluated using nonresponder imputation incorporating multiple imputation to handle missing data due to impact of the COVID-19 pandemic. Safety was assessed throughout the studies. Results: The induction and maintenance analyses included 527 patients who received RZB 600 mg IV and 141 patients who received RZB 360 mg SC, respectively. At the end of induction (week 12), patients with CD duration of < 2 years achieved higher rates of endoscopic outcomes with IV RZB induction vs patients with longer durations of disease (Figure 1), and regardless of baseline CD duration, greater proportions of RZB-treated patients achieved clinical remission (defined by stool frequency and abdominal pain), endoscopic response, endoscopic remission, and ulcer-free endoscopy vs PBO (P ≤ .05). Clinical remission rates at week 12 were numerically higher in patients with CD duration of < 5 years vs > 5 years (Figure 1). Similar results for improved clinical and endoscopic outcomes associated with shorter disease duration were observed at week 52 with RZB 360 mg SC maintenance treatment (Figure 2). RZB was well tolerated with lower rates of serious adverse events and serious infections vs PBO in induction, across CD duration subgroups. Conclusions: RZB induction and maintenance therapy was effective and well tolerated with a safety profile generally similar across CD duration subgroups. Achievement of clinical and endoscopic endpoints were higher in patients with shorter duration of CD, suggesting that earlier introduction of RZB therapy may lead to improved outcomes.

INFLUENCE OF STUDENT COMPETENCIES ON DISTANCE LEARNING IN LAW STUDENTS DURING COVID 19

The objective of this study is to determine the results of learning through the distance learning modality in the students of the law program at PUCE and their perception of the impact of student competencies on the appropriation of knowledge. The study is based on the application of interviews, documentary review and other techniques for the generation of ideas and collection of information, as well as the AHP (Analytical Hierarchy Process) multi-criteria decision method for the selection of the most relevant competencies to be analyzed according to the specific situation analyzed by the study. Based on the research conducted, the performance results of the selected sample of students were determined by establishing several indicators for the measurement of student performance. The application of the AHP multi-criteria decision method made it possible to determine the most influential student competencies for an adequate assimilation of the content of the module analyzed. It can be concluded that the majority of students make positive reference to information management as one of the most influential competencies for the mastery of the topics analyzed by the three groups of students analyzed.

Detection of the Omicron variant of SARS-CoV-2 by restriction analysis targeting the mutations K417N and N440K of the spike protein

By the end of 2021, the Omicron variant of concern (VOC) emerges in South Africa. This variant caused immediate concern, due to the explosive increase in cases associated with it and the large number of mutations it exhibits. In this study, the restriction sites that allow detecting the mutations K417N and N440K in the Spike gene are described. This analysis al-lows us to propose a rapid method for the identification of cases infected with the Omicron variant. We show that the proposed methodology can contribute to provide more information on the prevalence and rapid detection of cases of this new VOC. © 2022, Instituto de Investigaciones Clinicas. All rights reserved.

Efficacy of risankizumab induction and maintenance therapy by baseline Crohn's Disease location: Post hoc analysis of the phase 3 ADVANCE, MOTIVATE, and FORTIFY studies

Background: In Crohn's disease (CD), disease location affects treatment outcomes.1 This post hoc analysis assessed the efficacy of risankizumab (RZB), an interleukin 23 p19 inhibitor, by disease location. Methods: In ADVANCE (NCT03105128) and MOTIVATE (NCT03104413), patients with moderately to severely active CD and intolerance or inadequate response to conventional and/or biologic therapy (ADVANCE) or to biologic therapy (MOTIVATE) received intravenous (IV) RZB induction therapy or placebo (PBO) for 12 weeks. Patients achieving clinical response to IV RZB induction were re-randomised in a maintenance study (FORTIFY, NCT03105102) to receive subcutaneous (SC) RZB or SC PBO (ie, withdrawal) for 52 weeks. This post hoc analysis included patients who received RZB 600 mg IV in either ADVANCE or MOTIVATE and patients who received RZB 360 mg SC in FORTIFY. Clinical and endoscopic outcomes were evaluated in patient subgroups stratified by CD location at baseline (ileal only, colonic only, ileal-colonic) using non-responder imputation incorporating multiple imputation to handle missing data due to COVID-19. Results: At week 12, significantly greater proportions of patients receiving RZB 600 mg IV achieved the co-primary endpoints CD Activity Index (CDAI) clinical remission and endoscopic response vs PBO in the colonic only (n = 190) and ileal-colonic (n = 252) subgroups (P < .001;Figure 1A-1B). At week 12, statistically higher proportions of RZB-treated patients achieved the composite endpoint CDAI clinical remission and endoscopic response, as well as endoscopic remission in the colonic only and ileal-colonic subgroups vs PBO (P < .001;Figure 1C-1D). At week 52, significantly greater proportions of patients receiving RZB 360 mg SC achieved the co-primary endpoints CDAI clinical remission and endoscopic response, composite CDAI clinical remission and endoscopic response, and endoscopic remission vs withdrawal (PBO SC) in the colonic only (n = 59) and ileal-colonic (n = 67) subgroups (P ≤ .05;Figure 2A-2D). In patients with endoscopic remission after 12 weeks of IV RZB (week 0 of maintenance), significantly more RZB-treated patients achieved sustained endoscopic remission at week 52 vs withdrawal (PBO SC) in the colonic only and ileal-colonic subgroups (P ≤ .01;Figure 2E). At weeks 12 and 52, efficacy rates were numerically lower in ileal only CD relative to colonic only and ileal-colonic CD. Results for ileal only CD are limited by the small number of patients in the subgroup (induction, n = 85;maintenance, n = 15). Conclusion: RZB induction and maintenance therapy was effective in patients with moderately to severely active CD with greater benefits observed in patients with any colonic involvement.

Shorter disease duration is associated with better outcomes in patients with moderately to severely active Crohn's Disease treated with risankizumab: Results from the phase 3 ADVANCE, MOTIVATE, and FORTIFY studies

Background: An association between shorter disease duration and improved clinical efficacy has been shown in post hoc analyses of clinical trial data with biological therapies in Crohn's disease (CD). The efficacy and safety of risankizumab (RZB) as induction and maintenance therapy have been recently reported. Here, the efficacy of RZB stratified by baseline CD duration is reported. Methods: In ADVANCE (NCT03105128) and MOTIVATE (NCT03104413), patients with moderately to severely active CD received intravenous (IV) RZB induction therapy or placebo (PBO) for 12 weeks. Patients with clinical response to RZB IV induction were re-randomised in a 52-week maintenance study (FORTIFY, NCT03105102) to receive subcutaneous (SC) RZB or PBO (ie, withdrawal). For this post-hoc analysis, patient subgroups were stratified by years of CD duration at baseline (< 2, 2-5, > 5-10, and > 10 years). Induction analyses focused on patients who received RZB 600 mg IV or PBO for 12 weeks. As all patients who entered maintenance responded to RZB IV induction, maintenance analyses were limited to those patients who responded to induction and then received RZB 360 mg SC for 52 weeks. Clinical and endoscopic outcomes were evaluated using nonresponder imputation incorporating multiple imputation to handle missing data due to impact of the COVID-19 pandemic. Safety was assessed throughout the studies. Results: The induction and maintenance analyses included 527 patients who received RZB 600 mg IV and 141 patients who received RZB 360 mg SC, respectively. At the end of induction (week 12), patients with CD duration of < 2 years achieved higher rates of endoscopic outcomes with IV RZB induction vs patients with longer durations of disease (Figure 1), and regardless of baseline CD duration, greater proportions of RZB-treated patients achieved clinical remission (defined by stool frequency and abdominal pain), endoscopic response, endoscopic remission, and ulcer-free endoscopy vs PBO (P ≤ .05). Clinical remission rates at week 12 were numerically higher in patients with CD duration of < 5 years vs > 5 years (Figure 1). Similar results for improved clinical and endoscopic outcomes associated with shorter disease duration were observed at week 52 with RZB 360 mg SC maintenance treatment (Figure 2). RZB was well tolerated with lower rates of serious adverse events and serious infections vs PBO in induction, across CD duration subgroups. Conclusion: RZB induction and maintenance therapy was effective and well tolerated with a safety profile generally similar across CD duration subgroups. Achievement of clinical and endoscopic endpoints were higher in patients with shorter duration of CD, suggesting that earlier introduction of RZB therapy may lead to improved outcomes.

Implications of obesity in the course of covid-19

Overweight and obesity have been dominant components in the international epidemiological outlook in recent decades. Obesity is a widely recognized risk factor for the development of various chronic non-communicable diseases such as diabetes mellitus, hypertension, cardiovascular disease, and cancer, among several others. Both indi-vidually and in synergy, these factors increase infection risk. In the context of the pandemic of coronavirus disease 2019 (COVID-19), obesity has been linked with higher risk for complications and mortality. The mechanisms underlying the association between COVID-19 and obesity have not been fully elucidated;however, chronic inflammation has been identified as a central element in this scenario. Patients with obesity tend to show nutritional patterns and polypharmacy, which may significantly modify the clinical course and management of COVID-19, especially in coexistence with other comorbidities. Various hypolipemic, antihyperglycemic, and antihypertensive drugs have awakened great controversy in this context, concerning the worsening or improvement of the clinical course of COVID-19. This article explores the relationship between obesity and COVID-19 and the repercussions in its clinical management.

CYBERBULLYING BOSSAL THROUGH DIGITAL DEVICES IN TIMES OF COVID-19

The present research aims to analyze the causes of cyberbullying caused by teleworking in times of Covid-19, for this it is necessary to rethink the definition of mobbing since, in a health emergency, many known terms have been reformulated. The research was developed under the quali-quantitative modality since, in addition to discussing the positions of the different authors mentioned in it, statistics issued by the Ministry of Labor concerning the complaints received during 2020 are taken as a reference, in addition to taking the referential form data from datareportal.com concerning the people of Ecuador, who connect to mobile devices 2020. The type of research is documentary and transversal since it focused on discussing elements and consequences generated within the time in which the health emergency.

SARS-CoV-2 genetic diversity in Venezuela: predominance of D614G variants and analysis of one outbreak

SARS-CoV-2 is the new coronavirus responsible for COVID-19 disease. The first two cases of COVID-19 were detected in Venezuela on March 13, 2020. The aim of this study was the genetic characterization of Venezuelan SARS-CoV-2 isolates. A total of 7 full SARS-CoV-2 genome sequences were obtained by Sanger sequencing, from patients of different regions of Venezuela, mainly from the beginning of the epidemic. Ten out of 11 isolates (6 complete genomes and 4 partial spike genomic regions) belonged to lineage B, bearing the D614G mutation in the Spike protein. Isolates from the first outbreak that occurred in the Margarita Island harbored an in-frame deletion in its sequence, without amino acids 83-85 of the NSP1 of the ORF1. The search for deletions in 48,635 sequences showed that the NSP1 gene exhibit the highest frequency of deletions along the whole genome. Structural analysis suggests a change in the N-terminal domain with the presence of this deletion. In contrast, isolates circulating later in this island lacked the deletion, suggesting new introductions to the island after this first outbreak. In conclusion, a high diversity of SARS-CoV-2 isolates were found circulating in Venezuela, with predominance of the D614G mutation. The first small outbreak in Margarita Island seemed to be associated with a strain carrying a small deletion in the NSP1 protein, but these isolates do not seem to be responsible for the larger outbreak which started in July.

EVALUATION OF DISTANCE LEARNING APPROACHES IN THE CONTEXT OF THE COVID-19 EPIDEMIC

The Covid-19 pandemic and its devastating consequences have been unprecedented in human history. Its high level of contagion has imposed confinement and isolation in countless countries, affecting both the economy and education. In this area, distance education has been promoted through the use of Information and Communication Technologies (ICTs) at all educational levels. This is why several institutions adopt different approaches to distance education. Given the above, there is concern with its relevance and its evaluation is considered opportune, which is the objective of the present work. Two multi-criteria methods (MC) were used: Saaty's AHP and Topsis for their versatility in decision making and expert criteria. For which the work presented by Garcia Aretio is taken as a basis. It is concluded that, for the case of confinement, distance education is chosen, where technologies play a primordial role due to the remote synchrony approach (100%), and for post-confinement, the Synchrony and Asynchrony modality is preferred.

Biology and evolution of the coronavirus that causes COVID-19

The new coronavirus that causes COVID-19 is called SARS-CoV-2 and belongs to the subgenus Sarbecovirus, like its predecessor SARS-CoV. Bats appear to be the hosts of the ancestral viruses that originated these viruses, through recombination with the virus of an intermediate animal, which might be the pangolin. The virus interacts with the ACE2 receptor (angiotensin converting enzyme 2) and enters the cell by the endocytic pathway, through an early or late endosome. Viral RNA serves as messenger RNA for the translation of the first reading frame and the rest of the messenger RNAs are produced by discontinuous transcription. This peculiarity confers to this viral family a high frequency of recombination, which is associated to the high frequency of species jumping. Viruses belonging to the order Nidovirales are the only known RNA viruses with a polymerase with proof correction capacity;therefore their mutation rate is reduced. However, these genomes appear to be susceptible to be deaminated by cellular enzymes. All these mechanisms of generation of diversity leads to the existence of lineages, including those with the D614G mutation in the spike associated with a higher transmissibility. However, mutations associated with greater severity are not known to date. Just as there are different viral variants, the clinical manifestation of the disease is also highly variable. Some genetic, physiological and metabolic factors are being known that could be determining a more severe clinical presentations, often associated with the immunopathology of this disease.