Alterações gastrointestinais causadas pela infecção do Sars-Cov-2 / Gastrointestinal changes caused by infection do Sars-Cov-2 / Cambios gastrointestinales causados por la infección de Sars-Cov-2

A pandemia de COVID-19 se propagou rapidamente pelo mundo, causada pela infecção do novo coronavírus (SARS-CoV-2), que surgiu na China no final de 2019. Apesar da porta de entrada mais comum do agente etiológico ser pelo trato respiratório, evidências demonstram que a doença pode apresentar sintomas extrapulmonares, como os do trato gastrointestinal. Descrever sobre possíveis alterações gastrointestinais ocasionadas em pacientes infectados pelo SARS-CoV-2. Tratou-se de uma revisão bibliográfica, que utilizou artigos científicos disponíveis na íntegra em bases de dados Medical Literature Analysis and Retrieval System Online, Google Acadêmico, Scientific Electronic Library Online, nos meses de abril a outubro de 2021, além de monografias, dissertações, teses e livros. Foram utilizados como descritores as palavras: SARS-CoV-2 e intestino, COVID-19 e intestino, alterações intestinais na COVID-19. Os distúrbios gastrointestinais mais prevalentes são náuseas, vômitos e diarreia e dor abdominal. O papel da microbiota intestinal em influenciar as doenças pulmonares foi bem articulado, devido à existência do eixo intestino-pulmão, a inflamação em um desses órgãos interfere diretamente no perfil inflamatório no outro. Embora ainda não esteja totalmente esclarecido se os sintomas gastrointestinais indicam maior viremia ou um processo fisiopatológico alternativo, observa-se que a presença destes configura um fator de risco para a maior severidade da doença.

The COVID-19 pandemic has spread rapidly around the world, caused by the infection of the new coronavirus (SARS-CoV-2), which emerged in China at the end of 2019. respiratory evidence shows that the disease can present extrapulmonary symptoms, such as those in the gastrointestinal tract. Objective: To describe possible gastrointestinal alterations caused in patients infected by SARS-CoV-2. Methodology: this was a literature review, which used scientific articles available in full in the Medical Literature Analysis and Retrieval System Online (MEDLINE), Academic Google, Scientific Electronic Library Online (SciELO) databases, as well as monographs, dissertations, theses and books. The words used as descriptors were: SARS-CoV-2 and intestine, COVID-19 and intestine, intestinal alterations in COVID-19. Development: The most prevalent gastrointestinal disorders are nausea, vomiting and diarrhea and abdominal pain. The role of the intestinal microbiota in influencing lung diseases was well articulated, due to the existence of the gut- lung axis, inflammation in one of these organs directly interfering with the inflammatory profile in the other. Conclusion: Although it is not yet fully understood whether the gastrointestinal symptoms

La pandemia COVID-19 se ha extendido rápidamente por todo el mundo, causada por la infección del nuevo coronavirus (SARS-CoV-2), que surgió en China a finales de 2019. Las evidencias respiratorias muestran que la enfermedad puede presentar síntomas extrapulmonares, como los del tracto gastrointestinal. Objetivo: Describir las posibles alteraciones gastrointestinales causadas en pacientes infectados por SARS-CoV-2. Metodología: se trató de una revisión bibliográfica, que utilizó artículos científicos disponibles en su totalidad en las bases de datos Medical Literature Analysis and Retrieval System Online (MEDLINE), Academic Google, Scientific Electronic Library Online (SciELO), así como monografías, disertaciones, tesis y libros. Las palabras utilizadas como descriptores fueron: SARS-CoV-2 e intestino, COVID-19 e intestino, alteraciones intestinales en COVID-19. Desarrollo: Las alteraciones gastrointestinales más prevalentes son náuseas, vómitos y diarrea y dolor abdominal. Se articuló bien el papel de la microbiota intestinal en la influencia de las enfermedades pulmonares, debido a la existencia del eje intestino-pulmón, la inflamación en uno de estos órganos interfiere directamente en el perfil inflamatorio del otro. Conclusiones: Aunque aún no se comprenda del todo si los síntomas gastrointestinales indican una mayor viremia o un proceso fisiopatológico alternativo, se observa que su presencia es un factor de riesgo para la mayor gravedad de la enfermedad.

SARS-CoV-2 with transcription regulatory sequence motif mutation poses a greater threat / 南方医科大学学报

OBJECTIVE@#To analyze the mutations in transcription regulatory sequences (TRSs) of coronaviruss (CoV) to provide the basis for exploring the patterns of SARS-CoV-2 transmission and outbreak.@*METHODS@#A combined evolutionary and molecular functional analysis of all sets of publicly available genomic data of viruses was performed.@*RESULTS@#A leader transcription regulatory sequence (TRS-L) usually comprises the first 60-70 nts of the 5' UTR in a CoV genome, and the body transcription regulatory sequences (TRS-Bs) are located immediately upstream of the genes other than ORF1a and 1b. In each CoV genome, the TRS-L and TRS-Bs share a specific consensus sequence, namely the TRS motif. Any changes of nucleotide residues in the TRS motifs are defined as TRS motif mutations. Mutations in the TRS-L or multiple TRS-Bs result in superattenuated variants. The spread of super-attenuated variants may cause an increase in asymptomatic or mild infections, prolonged incubation periods and a decreased detection rate of the viruses, thus posing new challenges to SARS-CoV-2 prevention and control. The super-attenuated variants also increase their possibility of long-term coexistence with humans. The Delta variant is significantly different from all the previous variants and may lead to a large-scale transmission. The Delta variant (B.1.617.2) with TRS motif mutation has already appeared and shown signs of spreading in Singapore, which, and even the Southeast Asia, may become the new epicenter of the next wave of SARS-CoV-2 outbreak.@*CONCLUSION@#TRS motif mutation will occur in all variants of SARS-CoV-2 and may result in super-attenuated variants. Only super-attenuated variants with TRS motif mutations will eventually lose the abilities of cross-species transmission and causing outbreaks.

Epidemiological characteristics of 17 imported patients infected with SARS-CoV-2 Omicron variant / 中南大学学报(医学版)

OBJECTIVES@#With the continuous generation of new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the pressure of epidemic prevention and control continues to increase in China. Omicron with stronger infectiousness, immune escape ability and repeated infection ability spread to many countries and regions around the world in a short period of time. China has also successively reported cases of imported Omicron infections. This study aims to understand the epidemiological characteristics of Omicron variant via analyzing the epidemiological characteristics of imported patients with Omicron in Hunan Province, and to provide reference for preventing and controlling the imported epidemics.@*METHODS@#The clinical data of imported patients with coronavirus disease 2019 admitted to Hunan Province from December 16 to December 31, 2021 were retrospectively collected. The epidemiological information, general information, clinical classification, clinical symptoms, vaccination status, and lung CT were analyzed. Nasopharyngeal swabs and blood samples were collected. Virus nucleic acid was detected by magnetic beads method using SARS-CoV-2 detection kit. Ct values of ORF1ab gene and N gene were compared between asymptomatic infected patients and confirmed patients. The specific IgM and IgG antibodies were detected by chemiluminescence assay using SARS-CoV-2 IgM test kit and SARS-CoV-2 IgG test kit, respectively. Ct values of IgM and IgG antibodies were compared between asymptomatic infected patients and confirmed patients.@*RESULTS@#Seventeen patients with Omicron variant infection were treated in Hunan, including 15 confirmed patients (5 common type and 10 mild type) and 2 asymptomatic infection patients. The 17 patients were all Chinese, they were generally young, and 16 were male. There were 9 patients with diseases. Of them 3 patients had respiratory diseases. All 17 patients had completed the whole process of vaccination, but only one person received a booster shot of SARS-CoV-2 vaccine. The clinical manifestations of the patients were mild, mainly including dry/painful/itchy throat, cough, and fatigue. The total protein and creatine in the asymptomatic infection and confirmed cases infected with Omicron variant were all within the normal range, but other biochemical indicators were abnormal. There were the significant differences in C-reactive protein and fibrinogen between asymptomatic infection and confirmed patients (both P<0.05). There were more patients with elevated C-reactive protein in confirmed patients than without confirmed ones. The detection rate of specific IgM and IgG antibodies on admission was 100%, and there was no significant difference in the specific antibody levels between asymptomatic infection and confirmed patients (P>0.05). There were no significant differences in Ct values of ORF1ab gene and N gene (21.35 and 18.39 vs 19.22 and 15.67) between the asymptomatic infection and the confirmed patients (both P>0.05). Only 3 patients had abnormal lung CT, showing a small amount of patchy and cord-like shadows. One of them had no abnormality on admission but had pulmonary lesions and migratory phenomenon after admission.@*CONCLUSIONS@#The patients with Omicron variant tend to be young people and have milder clinical symptoms, but the viral load is high and the infectiveness is strong. Therefore, the timely identification and effective isolation and control for asymptomatic infections and confirmed patients with mild symptoms are extremely important. In terms of epidemic prevention and control, the government still needs to strengthen the risk control of overseas input, adhere to normalized epidemic prevention and control measures, to effectively control the source of infection, cut off the route of transmission, and protect vulnerable people.

SARS-CoV-2 Infection and Placental Pathology Infecção por SARS-CoV-2 e patologia placentária

Abstract Placental pathophysiology in SARS-CoV-2 infection can help researchers understand more about the infection and its impact on thematernal/neonatal outcomes. This brief review provides an overview about some aspects of the placental pathology in SARSCoV- 2 infection. In total, 11 papers were included. The current literature suggests that there are no specific histopathological characteristics in the placenta related to SARSCoV- 2 infection, but placentas frominfected women aremore likely to show findings of maternal and/or fetal malperfusion. The most common findings in placentas from infected women were fibrin deposition and intense recruitment of inflammatory infiltrates. The transplacental transmission of this virus is unlikely to occur, probably due to low expression of the receptor for SARS-CoV-2 in placental cell types. Further studies are needed to improve our knowledge about the interaction between the virus and the mother-fetus dyad and the impact on maternal and neonatal/fetal outcomes.

Resumo A fisiopatologia da placenta na infecção por SARS-CoV-2 pode ajudar os pesquisadores a entender mais sobre a infecção e seu impacto nos resultados maternos/neonatais. Esta revisão breve fornece uma visão geral sobre alguns aspectos da patologia placentária na infecção por SARS-CoV-2. Ao todo, 11 artigos foram incluídos. A literatura atual sugere que não há características histopatológicas específicas nas placentas relacionadas à infecção por SARS-CoV-2, mas as placentas de mulheres infectadas têm maior probabilidade de apresentar achados de má perfusão materna e/ou fetal. Os achados mais comuns em placentas de mulheres infectadas foram deposição de fibrina e intenso recrutamento de infiltrado inflamatório. A transmissão transplacentária deste vírus é improvável, devido à baixa expressão do receptor para SARS-CoV-2 em tipos de células da placenta. Mais estudos são necessários para melhorar nosso conhecimento sobre a interação entre o vírus e a díade mãe-feto e o impacto nos resultados maternos e neonatais/fetais.

Placental Sampling for Understanding Viral Infections - A Simplified Protocol for the COVID-19 Pandemic / Coleta placentária para entender infecções virais - Um protocolo simplificado para a pandemia de COVID-19

Abstract Objective The coronavirus disease 2019 (COVID-19) is a pandemic viral disease, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The impact of the disease among the obstetric population remains unclear, and the study of the placenta can provide valuable information. Adequate sampling of the placental tissue can help characterize the pathways of viral infections. Methods A protocol of placental sampling is proposed, aiming at guaranteeing representativity of the placenta and describing the adequate conservation of samples and their integrity for future analysis. The protocol is presented in its complete and simplified versions, allowing its implementation in different complexity settings. Results Sampling with the minimum possible interval from childbirth is the key for adequate sampling and storage. This protocol has already been implemented during the Zika virus outbreak. Conclusion A protocol for adequate sampling and storage of placental tissue is fundamental for adequate evaluation of viral infections on the placenta. During the COVID-19 pandemic, implementation of this protocol may help to elucidate critical aspects of the SARS-CoV-2 infection.

Resumo Objetivo A doença do novo coronavírus (COVID-19) é uma doença viral pandêmica causada pelo coronavírus da síndrome respiratória aguda 2 (SARS-CoV-2). O impacto da doença entre a população obstétrica ainda é incerto, e o estudo da placenta pode fornecer informações valiosas. Assim, a coleta adequada do tecido placentário pode ajudar a caracterizar algumas propriedades das infecções virais. Métodos Um protocolo de coleta placentária é proposto, objetivando a garantia de representatividade da placenta, descrevendo a maneira de conservação adequada das amostras, e visando garantir sua integridade para análises futuras. O protocolo é apresentado em suas versões completa e simplificada, permitindo sua implementação em diferentes configurações de infraestrutura. Resultados A amostragem com o intervalo mínimo possível do parto é essencial para coleta e armazenamento adequados. Esse protocolo já foi implementado durante a epidemia de vírus Zika. Conclusão Um protocolo para coleta e armazenamento adequados de tecido placentário é fundamental para a avaliação adequada de infecções virais na placenta. Durante a pandemia de COVID-19, a implementação deste protocolo pode ajudar a elucidar aspectos críticos da infecção por SARS-CoV-2.

El indudable beneficio de las Vacunas en la Pandemia COVID19 / The undoubted benefit of Vaccines in the COVID19 Pandemic

A finales de diciembre 2019, la Provincia de Hubei, China nos actualizaba sobre una enfermedad respiratoria que generaba insuficiencia en muy breve tiempo. Los primeros días de enero 2020, identifican al nuevo Coronavirus, y su transmisión se expande, sin respetar espacio, condición ni tradición. Una nueva pandemia se instaló desde el 11 de marzo 2020 y la búsqueda de una vacuna segura y eficaz que la detenga, congregó en una maratónica carrera a varios proyectos, de tres plataformas diferentes y esquemas de vacunación contra el COVID19

At the end of December 2019, the Hubei Province, China updated us on a respiratory disease that generated insufficiency in a very short time. The first days of January 2020, they identify the new Coronavirus, and its transmission expands, without respecting space, condition or tradition. A new pandemic was installed since March 11, 2020 and the search for a safe and effective vaccine to stop it brought together several projects from three different platforms and vaccination schemes against COVID19 in a marathon race

A case of COVID-19 with papulovesicular rash that progressed to retiform purpura, accompanied by cherry angiomas

ABSTRACT CONTEXT: Various skin manifestations have been reported in coronavirus disease. It may be difficult to determine the etiology of these lesions in view of the increased frequency of handwashing during the pandemic, along with occurrences of irritant contact dermatitis and allergic contact dermatitis due to disinfectant use; usage of herbal medicine and supplements to strengthen the immune system; and urticarial or maculopapular drug eruptions due to COVID-19 treatment. The variety of associated skin manifestations seen with COVID-19 makes it challenging to identify virus-specific skin manifestations. Petechiae, purpura, acrocyanosis and necrotic and non-necrotic purpura, which can be considered as manifestations of vascular involvement on the skin, have been reported. CASE REPORT: Here, we report a case of eruptive cherry angiomas, which was thought to have developed due to COVID-19, with a papulovesicular rash on distal extremities that progressed over time to reticular purpura. CONCLUSION: The case presented had a papulovesicular rash at the onset, which evolved to retiform purpura, and eruptive cherry angiomas were observed. It should be kept in mind that dermatological signs may vary in patients with COVID-19.

SARS-CoV-2 impact on oral health: a general view / Impacto del SARS-CoV-2 en la salud oral: una visión general

Abstract Coronavirus disease 2019 (COVID-19) is a new disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. China reported the first case of COVID-19 in December 2019, and a few months later, the World Health Organization declared it as a pandemic. Oral ulcers in adult patients have been associated with COVID-19. However, no cases have yet been documented in children. The angiotensin-converting enzyme-2 (ACE2) receptor has been identified in tissues of the oral cavity. Studies have identified the tongue as the site with the highest expression of ACE2, and the oral epithelium, gingival epithelium, and salivary glands as sites of lesser extent expression. ACE2 expression is lower in children and varies with age. SARS-CoV-2 in saliva has been identified in various studies, which suggests that this could be a useful sample for diagnosis. However, its presence in saliva would indicate the high risk of contagion of this fluid.

Resumen La COVID-19 es una nueva enfermedad causada por el SARS-CoV-2 (coronavirus tipo 2 del síndrome respiratorio agudo grave). El primer caso de COVID-19 se reportó en China en diciembre de 2019, y unos meses después la Organización Mundial de la Salud la declaró como una pandemia. En pacientes adultos se han asociado úlceras orales a la COVID-19; en niños aún no se han documentado casos. El receptor de la enzima convertidora de la angiotensina 2 (ECA2) se ha identificado en tejidos de la cavidad oral. Los estudios han identificado que la lengua es el sitio con mayor expresión del receptor de la ECA2, y el epitelio bucal, el epitelio gingival y las glándulas salivales lo son en menor medida. La expresión de la ECA2 es menor en los niños y va aumentando con la edad. En diversos estudios se ha identificado el SARS-CoV-2 en la saliva, lo que sugiere que podría ser una muestra útil para el diagnóstico de este virus. Sin embargo, su presencia en saliva indicaría un alto riesgo de contagio de este fluido.

Renal replacement therapy by the popliteal vein in a critical patient with COVID-19 in the prone position / Terapia renal substitutiva pela veia poplítea em paciente crítico com COVID-19 na posição de pronação

Abstract This patient was a 73-year-old man who initially came to our service with acute respiratory failure secondary to COVID-19. Soon after hospitalization, he was submitted to orotracheal intubation and placed in the prone position to improve hypoxia, due to severe acute respiratory syndrome (SARS). On the third day of hospitalization, he developed acute oliguric kidney injury and volume overload. The nephrology service was activated to obtain deep venous access for renal replacement therapy (RRT). The patient could not be placed in the supine position due to significant hypoxemia. A 50-cm Permcath (MAHURKARTM, Covidien, Massachusetts, USA) was inserted through the left popliteal vein. This case report describes a possible challenging scenario that the interventional nephrologist may encounter when dealing with patients with COVID-19 with respiratory impairment in the prone position.

Resumo O paciente era um homem de 73 anos de idade que inicialmente veio ao nosso serviço com insuficiência respiratória aguda secundária à COVID-19. Logo após a internação, ele foi submetido à intubação orotraqueal e pronado para melhorar a hipóxia devido à síndrome respiratória aguda grave (SARS - do inglês "severe acute respiratory syndrome"). No terceiro dia de internação, o mesmo desenvolveu lesão renal aguda oligúrica e sobrecarga de volume. O serviço de nefrologia foi acionado para realizar acesso venoso profundo para terapia renal substitutiva (TRS). O paciente não pôde ser colocado na posição de decúbito dorsal devido a uma hipoxemia significativa. Um Permcath de 50 cm (MAHURKARTM, Covidien, Massachusetts, EUA) foi inserido através da veia poplítea esquerda. Este relato de caso descreve um possível cenário desafiador com o qual o nefrologista intervencionista pode se deparar ao lidar com pacientes com COVID-19 com problemas respiratórios e colocados em pronação.

Bilateral renal infarction in a patient with severe COVID-19 infection / Infarto renal bilateral em paciente com infecção grave por COVID-19

Abstract Thromboembolic events are frequent in patients with COVID-19 infection, and no cases of bilateral renal infarctions have been reported. We present the case of a 41-year-old female patient with diabetes mellitus and obesity who attended the emergency department for low back pain, respiratory failure associated with COVID-19 pneumonia, diabetic ketoacidosis, and shock. The patient had acute kidney injury and required hemodialysis. Contrast abdominal tomography showed bilateral renal infarction and anticoagulation was started. Kidney infarction cases require high diagnostic suspicion and possibility of starting anticoagulation.

Resumo Fenômenos tromboembólicos são frequentes em pacientes com infecção por COVID-19 e nenhum caso de infarto renal bilateral havia sido relatado. Apresentamos o caso de uma paciente do sexo feminino, de 41 anos, com diabetes mellitus e obesidade, que deu entrada no serviço de urgência por lombalgia, insuficiência respiratória associada à pneumonia COVID-19, cetoacidose diabética e choque. A paciente apresentava lesão renal aguda e demandava hemodiálise. A tomografia abdominal contrastada mostrou infarto renal bilateral e foi iniciada anticoagulação. Os casos de infarto renal requerem alta suspeita diagnóstica e possibilidade de iniciar a anticoagulação.

Evaluación de la efectividad de las vacunas contra la COVID-19: orientación provisional / Evaluation of COVID-19 vaccine effectiveness

En este documento se presenta orientación provisional sobre las mejores prácticas para evaluar la efectividad de las vacunas contra la COVID-19 usando el diseño de estudio observacional. Se examinan las consideraciones esenciales del diseño, el análisis y la interpretación de las evaluaciones de la efectividad de las vacunas contra la COVID-19, dado que se pueden obtener resultados sesgados aun en entornos en los que la exhaustividad y la calidad de los datos son altas. Esta orientación se dirige principalmente a las evaluaciones realizadas en los países de ingresos bajos o medianos, pero la mayoría de los conceptos también son aplicables en entornos de ingresos altos.

Since its emergence in December 2019, SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), has taken a tremendous toll globally; by 28 February 2021, there have been over 110 million cases and 2.5 million deaths worldwide from COVID-19 (1). Although most COVID-19 deaths occur among older adults and persons with chronic comorbid medical conditions, deaths have occurred in persons of all ages. Moreover, the pandemic has caused widespread morbidity and necessitated control measures that have devastated economies worldwide. In response to the pandemic, the global efforts to develop multiple vaccines to protect against COVID-19 disease have been unrivalled in the history of public health. By the end of 2020, three COVID-19 vaccines have received Emergency Use Approval/Listing (EUA/EUL) by maturity level 4 regulatory authorities, based on reaching predefined criteria for safety and efficacy, and at least several dozen more are in clinical trials.

SARS-CoV-2: generalidades, origen y avances en el tratamiento / SARS-CoV-2: basic concepts, origin and treatment advances

Resumen Los primeros casos de COVID-19, causada por el virus denominado SARS-CoV-2, se registraron en Wuhan, China, en diciembre de 2019; sin embargo, su capacidad de transmisión ocasionó que seis meses después la infección prácticamente estuviera presente en todo el mundo. El origen del virus parece ser zoonótico; se propone que proviene del murciélago y podría haber tenido un hospedero intermediario que llevó a su introducción en la población humana. SARS-CoV-2 es un virus envuelto, con genoma de ARN de cadena sencilla en sentido positivo y se ancla a la enzima convertidora de angiotensina, presente en las células susceptibles para infectar el sistema respiratorio de los humanos. Aunque previamente se han conocido otros coronavirus, no han tenido el mismo impacto, por lo que la investigación en tratamientos farmacológicos no tiene el desarrollo suficiente para afrontar el reto actual. Casi desde el comienzo de la epidemia se han propuesto moléculas para el tratamiento de la infección, sin embargo, aún no se cuenta con un fármaco con suficiente efectividad terapéutica. En esta revisión se describen las características principales de SARS-CoV-2, su ciclo replicativo, su posible origen y algunos avances en el desarrollo de tratamientos antivirales.

Abstract The first cases of COVID-19, caused by the virus called SARS-CoV-2, were recorded in Wuhan, China, in December 2019; however, its transmission ability caused for the infection to be practically present throughout the world six months later. The origin of the virus appears to be zoonotic; it has been proposed that it comes from a bat and that it may have had an intermediate host that led to its introduction in the human population. SARS-CoV-2 is an enveloped virus, with a positive single-stranded RNA genome, and it binds to the angiotensin-converting enzyme, present in susceptible cells, to infect the human respiratory system. Although other coronaviruses have been previously known, they have not had the same impact, and, therefore, research on pharmacological treatments is not sufficiently developed to face the current challenge. Almost since the beginning of the epidemic, several molecules have been proposed for the treatment of infection; however, there is not yet a drug available with sufficient effectiveness for treatment. This review describes SARS-CoV-2 main characteristics, its replicative cycle, its possible origin and some advances in the development of antiviral treatments.

Molecular biology of coronaviruses: an overview of virus-host interactions and pathogenesis / Biología molecular de los coronavirus: una visión panorámica de las interacciones virus-hospedero y de la patogénesis

Abstract Coronaviruses (CoV) are enveloped, plus-strand RNA viruses that have the largest known RNA genomes and infect birds and mammals, causing various diseases. Human coronaviruses (HCoVs) were first identified in the mid-1960s and have been known to cause enteric or respiratory infections. In the last two decades, three HCoVs have emerged, including the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which initiated the ongoing pandemic. SARS-CoV-2 causes a respiratory illness that presents as a mild upper respiratory disease but may result in acute respiratory distress syndrome, multi-organ failure and can be fatal, especially when underlying comorbidities are present. Children account for a low percentage of coronavirus disease 2019 (COVID-19) cases, with seemingly less severe disease. Most pediatric patients present mild or moderate symptoms or are asymptomatic. However, some cases may be severe. Therefore, SARS-CoV-2 infection and COVID-19 in pediatric patients must be studied in detail. This review describes general features of the molecular biology of CoVs and virus-host interactions that may be implicated in the pathogenesis of SARS-CoV-2.

Resumen Los coronavirus son virus envueltos de ARN de polaridad positiva, con los genomas más grandes que se conocen. Infectan aves y mamíferos, y causan una amplia variedad de enfermedades. Los coronavirus humanos se identificaron a mediados de la década de 1960 y se sabe que causan infecciones entéricas y respiratorias. En las últimas dos décadas han emergido tres coronavirus humanos pandémicos, incluido el coronavirus 2 del síndrome agudo respiratorio grave (SARS-CoV-2) que ha causado la pandemia actual. El SARS-CoV-2 produce enfermedad respiratoria que se presenta con padecimientos moderados de las vías respiratorias altas, pero puede resultar en síndrome respiratorio agudo, falla multiorgánica y muerte, en especial en casos con morbilidad subyacente. Los casos de COVID-19 en niños representan un porcentaje bajo y con síntomas menos graves de la enfermedad. La mayoría de los pacientes pediátricos son asintomáticos o presentan enfermedad leve o moderada; sin embargo, también en niños la enfermedad puede ser grave, por lo que la infección con SARS-CoV-2 y la COVID-19 en pacientes pediátricos deben estudiarse con detalle. En esta revisión se describen las características generales de la biología molecular de los coronavirus y de las interacciones virus-hospedero que se conocen para los coronavirus humanos identificados previamente, y que podrían estar implicados en la patogénesis del SARS-CoV-2.

Progress in research of epidemiologic feature and control of SARS-CoV-2 Delta variant / 中华流行病学杂志

SARS-CoV-2 Delta variant has the characteristics of stronger infectivity, higher viral load, and shorter incubation period, posing new challenges to the prevention and control of COVID-19 pandemic. SARS-CoV-2 Delta variant was first discovered in India, then quickly spread in many countries and has gradually become one of the main epidemic strains worldwide. Local epidemics caused by SARS-CoV-2 Delta variant also occurred in several provinces in China. This article summarizes the progress in research of etiological characteristics, transmission characteristics or possible mechanism and epidemiological characteristics of SARS-CoV-2 Delta variant, and the protective effects of vaccines and control measures against SARS-CoV-2 Delta variant in order to provide references for the effective prevention and control of COVID-19 epidemic caused by SARS-CoV-2 Delta variant.

High-throughput screening identifies established drugs as SARS-CoV-2 PLpro inhibitors

A new coronavirus (SARS-CoV-2) has been identified as the etiologic agent for the COVID-19 outbreak. Currently, effective treatment options remain very limited for this disease; therefore, there is an urgent need to identify new anti-COVID-19 agents. In this study, we screened over 6,000 compounds that included approved drugs, drug candidates in clinical trials, and pharmacologically active compounds to identify leads that target the SARS-CoV-2 papain-like protease (PLpro). Together with main protease (M

No Effects of Meteorological Factors on the SARS-CoV-2 Infection Fatality Rate / 生物医学与环境科学（英文）

Objective@#Previous studies have shown that meteorological factors may increase COVID-19 mortality, likely due to the increased transmission of the virus. However, this could also be related to an increased infection fatality rate (IFR). We investigated the association between meteorological factors (temperature, humidity, solar irradiance, pressure, wind, precipitation, cloud coverage) and IFR across Spanish provinces ( @*Methods@#We estimated IFR as excess deaths (the gap between observed and expected deaths, considering COVID-19-unrelated deaths prevented by lockdown measures) divided by the number of infections (SARS-CoV-2 seropositive individuals plus excess deaths) and conducted Spearman correlations between meteorological factors and IFR across the provinces.@*Results@#We estimated 2,418,250 infections and 43,237 deaths. The IFR was 0.03% in < 50-year-old, 0.22% in 50-59-year-old, 0.9% in 60-69-year-old, 3.3% in 70-79-year-old, 12.6% in 80-89-year-old, and 26.5% in ≥ 90-year-old. We did not find statistically significant relationships between meteorological factors and adjusted IFR. However, we found strong relationships between low temperature and unadjusted IFR, likely due to Spain's colder provinces' aging population.@*Conclusion@#The association between meteorological factors and adjusted COVID-19 IFR is unclear. Neglecting age differences or ignoring COVID-19-unrelated deaths may severely bias COVID-19 epidemiological analyses.

Fundamentos moleculares de la exclusión competitiva durante la coinfección de virus respiratorios: a propósito del COVID-19 / Molecular foundations of competitive exclusion during coinfection of respiratory viruses: about COVID-19

Introducción: La idea de exclusión competitiva es indiscutible cuando se trata de animales y bacterias que intentan ocupar el mismo nicho ecológico, pero su aplicación a la coinfección viral no es tan sencilla de interpretar. La interferencia viral es un fenómeno en el que un virus suprime competitivamente la replicación de otros virus coinfectantes y es el resultado más común de las coinfecciones virales. Objetivo: Comprender mejor el comportamiento de las infecciones respiratorias concomitantes en escenarios de brotes comunitarios y de forma individual en entornos hospitalarios e individuos con comorbilidades. Métodos: Se realizó una búsqueda de información en las bases de datos MEDLINE / PubMed, SciELO y LILACS. También se consideraron artículos publicados en el repositorio de preimpresión medRxiv y los informes de los Centros para el Control y Prevención de enfermedades de los Estados Unidos de América. Mediante el gestor de referencias Mendeley, se eliminaron los duplicados y aquellos que no se ajustaban al objetivo del estudio, seleccionando 48 artículos para la revisión. Análisis y síntesis de la in formación: En la literatura científica se encontró evidencia que sustenta la exclusión competitiva viral entre virus relacionados que comparten células susceptibles y permisivas. Conclusión: La exclusión competitiva impide que dos virus que comparten rutas de transmisión similares y el mismo órgano diana, infecten no sólo al mismo tiempo, sino que también se propaguen con éxito. Por lo tanto, la sindemia producida por virus que comparten estas características podría ser un evento improbable(AU)

Introduction: The idea of competitive exclusion is undisputed when it comes to animals and bacteria trying to occupy the same ecological niche, but its application to viral coinfection is not so simple to interpret. Viral interference is a phenomenon in which one virus competitively suppresses the replication of other co-infecting viruses and is the most common outcome of viral co-infections. Objective: To better understand the behavior of concomitant respiratory infections in community outbreak settings and individually in hospital settings and individuals with comorbidities. Methods: A search for information was performed in the MEDLINE / PubMed, SciELO and LILACS databases. Articles published in the preprint repository medRxiv and reports from the US Centers for Disease Control and Prevention were also considered. Using the Mendeley reference manager, duplicates and those that did not fit the study objective were eliminated, selecting 48 articles for the review. Analysis and synthesis of information: Evidence supporting viral competitive exclusion between related viruses sharing susceptible and permissive cells was found in the scientific literature. Conclusion: Competitive exclusion prevents two viruses that share similar transmission routes and the same target organ from infecting not only at the same time, but also from spreading successfully. Therefore, syndemia produced by viruses sharing these characteristics could be an unlikely event(AU)