Application of two RT-PCR methods for detection of norovirus in market-sold oysters and norovirus genetic characteristic analysis, a survey conducted in Beijing / 中华流行病学杂志

Objective: To evaluate the application of real-time RT-PCR and semi-nested RT-PCR in the detection of norovirus in oysters and analyzing the genetic characteristics of the isolates. Methods: Real-time fluorescent RT-PCR and semi-nested RT-PCR were used to detect norovirus GⅠ/GⅡ in fresh oysters collected from the markets in Beijing from November 2014 to October 2015. The detection rate of the parallel test was also analyzed. In addition, the reliability of semi-nested RT-PCR was evaluated by agreement rate and consistency test (Kappa value). The positive products of norovirus GⅠ/GⅡ capsid protein region gene by semi-nested RT-PCR were sequenced. Software BioEdit 7.0.9.0 was used for sequence alignment, and software Mega 6.0 was used to construct the evolutionary tree. Results: In 72 samples, the detection rate of norovirus was 31.94% (23/72) by real-time RT-PCR, 38.89% (28/72) by semi-nested RT-PCR and 48.61% (35/72) by parallel test. The coincidence rate of the two methods was 73.61%, a moderate degree (Kappa value =0.43). A total of 13 norovirus strains were successfully sequenced, and 11 strains (7 GⅡ.17 strains, 2 GⅡ. 4 Sydney_ 2012 strains, 1 GⅡ. 1 strain and 1 GⅡ. 21 strain) were obtained from norovirus positive samples by two RT-PCR methods, two strains (1 GⅡ. 17 strain and 1 GⅡ. 3 strain) were obtained from real-time RT-PCR negative samples which were positive for norovirus by semi-nested RT-PCR. The similarity between these strains and reference strains from diarrhea patients, environmental sewage, and shellfish products were 84.4% - 100.0%. Conclusions: The parallel test of norovirus in oysters by two RT-PCR methods can improve the detection rate and detect more genotypes. Norovirus strains in oysters were highly homologous with reference strains from diarrheal patients, environmental sewage, and shellfish products. Therefore, surveillance, prevention and control for norovirus should be carried out in people who have frequent contacts with oysters and related environments.

The two-stage interaction of Ebola virus VP40 with nucleoprotein results in a switch from viral RNA synthesis to virion assembly/budding

Ebola virus (EBOV) is an enveloped negative-sense RNA virus and a member of the filovirus family. Nucleoprotein (NP) expression alone leads to the formation of inclusion bodies (IBs), which are critical for viral RNA synthesis. The matrix protein, VP40, not only plays a critical role in virus assembly/budding, but also can regulate transcription and replication of the viral genome. However, the molecular mechanism by which VP40 regulates viral RNA synthesis and virion assembly/budding is unknown. Here, we show that within IBs the N-terminus of NP recruits VP40 and is required for VLP-containing NP release. Furthermore, we find four point mutations (L692A, P697A, P698A and W699A) within the C-terminal hydrophobic core of NP result in a stronger VP40-NP interaction within IBs, sequestering VP40 within IBs, reducing VP40-VLP egress, abolishing the incorporation of NC-like structures into VP40-VLP, and inhibiting viral RNA synthesis, suggesting that the interaction of N-terminus of NP with VP40 induces a conformational change in the C-terminus of NP. Consequently, the C-terminal hydrophobic core of NP is exposed and binds VP40, thereby inhibiting RNA synthesis and initiating virion assembly/budding.

Assessment of SARS-CoV-2 RNA shedding in semen of 36 males with symptomatic, asymptomatic, and convalescent infection during the first and second wave of COVID-19 pandemic in Italy / 亚洲男科学杂志(英文版)

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) receptor, angiotensin-converting enzyme 2 (ACE2), has been identified in the human testis, but the risk of transmission of SARS-CoV-2 through sexual intercourse still needs to be defined. The goal of our study was to determine if SARS-CoV-2 is detectable in the semen of patients suffering or recovering from coronavirus disease-19 (COVID-19), still testing positive at nasopharyngeal swabs but showing mild or no symptoms at the time of sampling. Detection of SARS-CoV-2 RNA in semen was performed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR targeting open reading frame (ORF) 1ab. Medical history of the enrolled patients was taken, including COVID-19-correlated symptoms, both at the time of diagnosis and at the time of interview. Results of real-time RT-PCR and nested PCR in semen showed no evidence of SARS-CoV-2 RNA in the 36 patients suffering or recovering from COVID-19 but still positive in a nasopharyngeal swab, from over 116 patients enrolled in the study. SARS-CoV-2 detection and persistence in semen would have an impact on both clinical practice and public health strategies, but our results would suggest that SARS-CoV-2 is not present in the semen of men recovering from COVID-19.

Inhaloterapia: recomendaciones para Argentina 2021 / Inhalotherapy: recommendations for Argentina 2021

Resumen En las últimas décadas ha habido un importante desarrollo de dispositivos inhalados (DI) que permiten aumentar la eficacia de las drogas y disminuir los eventos adversos. Su correcto uso es de fundamental importancia para el control de las enfermedades respiratorias obstructivas. En la Argentina no existen recomendaciones locales sobre el uso de los DI. Se revisó la base biofísica, indicación, ventajas y limitaciones, técnica de correcto uso, errores frecuentes, mantenimiento y limpieza de cada DI. El uso de nebulizaciones ha quedado restringido a la administración de drogas que no están disponibles en otros DI (ejemplo: tratamiento de fibrosis quística), o ante la falla de los otros DI. No deben ser usados durante la pandemia de SARS-CoV2. Los inhaladores de dosis medida (aerosol) deben ser indicados siempre con aerocámaras (AC), las que reducen la incidencia de eventos adversos y aumentan el depósito de la droga en el pulmón. Son los dispositivos de elección junto a los inhaladores de polvo seco. Los aerosoles se deben usar en pacientes que no generan flujos inspiratorios altos. Los inhaladores de polvo seco deben recomendarse en aquellos que pueden realizar flujos inspiratorios enérgicos. Se revisaron los diferentes DI en fibrosis quística y en pacientes con asistencia respiratoria mecánica. La elección del DI dependerá de varios factores: situación clínica, edad, experiencia previa, preferencia del paciente, disponibilidad de la droga y entrenamiento alcanzado con el correcto uso.

Abstract Last decades, a broad spectrum of inhaled devices (ID) had been developed to enhance efficacy and reduce adverse events. The correct use of IDs is a critical issue for controlling obstructive respiratory diseases. There is no recommendation on inhalation therapy in Argentina. This document aims to issue local recommendations about the prescription of IDs. Each device was reviewed regarding biophysical laws, indication, strength, limitations, correct technique of use, frequent mistakes, and device cleaning and maintenance. Nebulization should be restricted to drugs that are not available in other IDs (for example, for treatment of cystic fibrosis) or where other devices fail. Nebulization is not recommended during the SARS-CoV2 pandemic. A metered-dose inhaler must always be used with an aerochamber. Aerochambers reduce the incidence of adverse events and improve lung deposition. Metered-dose inhalers must be prescribed to patients who cannot generate a high inspiratory flow and dry powders to those who can generate an energetic inspiratory flow. We reviewed the use of different IDs in patients with cystic fibrosis and under mechanical ventilation. The individual choice of an ID will be based on several variables like clinical status, age, previous experience, patient preference, drug availability, and correct use of the device.

Vacuna Johnson & Johnson contra COVID-19: distribución mundial de la vacuna, mecanismo de acción, indicaciones, contraindicaciones y efectos secundarios. Una revisión bibliográfica / Johnson & Johnson vaccine against COVID-19: worldwide vaccine distribution, mechanism of action, indications, contraindications and side effects. A literature review

El SARS-CoV-2, causante de que estemos viviendo una pandemia mundial, tuvo sus orígenes en China, desde donde ha traspasado fronteras rápidamente, llegando a todos los rincones del mundo. Muchos han sido los equipos de investigación que se enfrentan el reto de conseguir una vacuna que logre combatir este mortal virus. Es por este motivo que en esta investigación se pretendió analizar la bibliografía referida a la vacuna Johnson & Johnson (J&J) contra COVID-19: distribución mundial de la vacuna, mecanismo de acción, indicaciones, contraindicaciones y efectos secundarios. Varios estudios demuestran que su eficacia varía de acuerdo con la edad y género de cada individuo; sin embargo, esta vacuna alcanzó un grado de certeza moderada. Los efectos adversos en su mayoría son leves y se resolvieron al cabo de dos días, siendo excepción algunos casos, ya que se registró un efecto adverso poco común denominado trombocitopenia prevalente en mujeres de 18 a 40 años, por este motivo, la FDA (Administración de Alimentos y Medicamentos de EE.UU.) recomienda la precaución en el uso de la vacuna con respecto a este efecto adverso que en algunos casos podría ser mortal (AU)

The SARS-CoV-2, which caused us to be experiencing a global pandemic, had its origins in China, from where it has crossed borders rapidly, reaching all corners of the world. Many research teams have faced the challenge of getting a vaccine to fight this deadly virus. For this reason, this research aimed to analyze the literature on the Johnson & Johnson COVID-19 vaccine: global distribution of the vaccine, mechanism of action, indications, contraindications and side effects. Several studies show that its effectiveness varies according to the age and gender of each individual, but this vaccine reached a moderate degree of certainty. The adverse effects are mostly mild and resolved within two days, with some exceptions being a rare adverse effect called prevalent thrombocytopenia in women aged 18 to 40 years. For this reason, the FDA recommends caution in the use of the vaccine with respect to this potentially fatal adverse effect in some cases (AU)

Comparación entre Xpert® y COBAS®-TaqMan® para la medición de carga viral de virus hepatitis B y C / Comparison between Xpert® and COBAS® TaqMan® for the measuring of viral load of hepatitis B and C viruses

INTRODUCCIÓN: La medición de carga viral (CV) de virus hepatitis B (VHB) y C (VHC) es fundamental en el seguimiento de pacientes con terapia antiviral. La metodología más utilizada para su determinación es COBAS ®-TaqMan ®. Recientemente, se desarrolló la tecnología Xpert ®, que se debe evaluar. OBJETIVO: Comparar la medición de la CV de VHB y VHC por metodología Xpert® con COBAS®-TaqMan® como método de referencia. MATERIAL Y MÉTODOS: 39 muestras de suero de pacientes con VHB y 39 con VHC, previamente cuantificadas por COBAS ®-TaqMan ®, fueron analizadas mediante Xpert® y los resultados se compararon utilizando la regresión de Deming y gráfico Bland-Altman. RESULTADOS: Hubo una alta correlación entre Xpert® y COBAS®-TaqMan®. Para VHB, la ecuación de Deming fue XpertHBV = 0,44 + 0,99xCOBASTaqManHBV, con coeficiente de correlación de 0,94 y diferencia entre medias de -0,401 log10 (IC95%: -1,985 a 1,183). Para VHC, la ecuación de Deming fue XpertHCV = 0,36 + 0,87x COBASTaqManHCV, con coeficiente de correlación de 0,98 y diferencia entre medias de 0,328 log (IC95%: -0,449 a 1,105). CONCLUSIÓN: El nuevo sistema Xpert® muestra una buena correlación con COBAS ®-TaqMan ® para la medición de la CV de VHB y VHC, siendo una buena alternativa para el seguimiento de pacientes en tratamiento.

BACKGROUND: The measurement of viral load (VL) of hepatitis B (HBV) and C (HCV) viruses is essential in the follow-up of patients with antiviral therapy. The most widely used methodology for this determination is COBAS®-TaqMan®. Recently, the Xpert® technology was developed and needs to be evaluated. AIM: To compare the measurement of the VL of HBV and HCV by Xpert® methodology with COBAS®-TaqMan® as a reference method. MATERIAL AND METHODS: 39 serum samples from patients with HBV and 39 with HCV, previously quantified by COBAS®-TaqMan®, were analyzed using Xpert® and the results were compared using Deming regression and Bland-Altman plot. RESULTS: There was a high correlation between Xpert® and COBAS®-TaqMan®. For HBV, the Deming equation was XpertHBV = 0.44 + 0.99xCOBASTaqManHBV, with a correlation coefficient of 0.94 and a difference between means of -0.401 log (95% CI: -1.985 to 1.183). For HCV, the Deming equation was XpertHCV = 0.36 + 0.87x COBASTaqManHCV, with a correlation coefficient of 0.98 and a difference between means of0.328 log10 (95% CI: -0.449 to 1.105). CONCLUSION: The new Xpert® system shows a good correlation with COBAS®-TaqMan® for the measurement of the VL of HBV and HCV, being a good alternative for the follow-up of patients under treatment.

Severe acute respiratory syndrome Coronavirus 2. Seroepidemiology study in Argentinian slum / Estudio seroepidemiológico de enfermedad por Coronavirus 2019 en un barrio de Argentina

Abstract Most countries in Latin America have already reported thousands of confirmed cases and vulnerable populations are the most affected by the coronavirus disease 2019 (COVID-19) pandemic. Preventive measures such as hygiene, social distancing, and isolation, essential to stop the spread of coronavirus, are difficult to accomplish for vulnerable populations due to their living conditions. Seroepidemiological surveys are assets to measure the transmission for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Until July 1st, the incidence rate of SARS-CoV-2 infection in Barrio Padre Mugica, one of the largest slums in Buenos Aires City, was 5.9%. This study aimed to establish the prevalence of SARS-CoV-2 antibodies immunoglobulin G (IgG) immediately after the outbreak, and to identify neighbourhood, household and individual factors associated with seroconversion. The prevalence based on IgG was 53.4% (95% CI 52.8% to 54.1%). For each polymerase chain reaction (RT-qPCR) confirmed case, nine people tested IgG positive, indicating a high rate of undetected (probably asymptomatic) infections. Hence, the high rate of undiagnosed people suggests that clinical criteria and epidemiological nexus should be considered. The high seroprevalence observed in the context of an intense epidemic in a vulnerable area might serve as a reference to other countries. This study contributes to future decision making by understanding population immunity against SARS-CoV2 and its relation to living conditions and foccus that comprehensive biosocial, household-level interventions are needed.

Resumen Muchos países de América Latina han informado miles de casos confirmados y las poblaciones vulnerables son las más afectadas por la pandemia de la enfermedad por coronavirus 2019 (COVID-19). Las medidas preventivas como la higiene, el distanciamiento social y el aislamiento, fundamentales para frenar la propagación del coronavirus, son difíciles de lograr en estas poblaciones debido a sus condiciones de vida. Los estudios seroepidemiológicos son de gran utilidad para medir la transmisión del síndrome respiratorio agudo severo coronavirus 2 (SARS-CoV-2). Hasta el 1 de julio, la tasa de incidencia de la infección por SARS-CoV-2 en el Barrio Padre Mugica, uno de los barrios marginales más grandes de la ciudad de Buenos Aires, era del 5.9%. Este estudio tuvo como objetivo estimar la prevalencia de anticuerpos inmunoglobulina G (IgG) para SARS-CoV-2 inmediatamente después del brote, e identificar factores del barrio, hogar e individuales asociados con la seroconversión. La prevalencia basada en IgG fue del 53.4% (IC del 95%: 52.8% a 54.1%). Para cada caso confirmado por reacción en cadena de la polimerasa (RT-qPCR), nueve personas dieron positivo en IgG, lo que indica una alta tasa de infecciones no detectadas y probablemente asintomáticas. La alta tasa de personas no diagnosticadas sugiere que se deben considerar los criterios clínicos y el nexo epidemiológico. La alta seroprevalencia observada en el contexto de una intensa epidemia en una zona vulnerable podría servir de referencia a otros países. Este estudio contribuye a la toma de decisiones futuras al comprender la inmunidad de la población contra el SARS-CoV2 en su relación con las condiciones de vida y por su enfoque en la necesidad de intervenciones integrales a nivel del hogar.

Cutaneous smooth muscle tumors associated with Epstein-Barr virus in an adult patient with HIV

Abstract Epstein Barr virus-associated smooth muscle tumors are an uncommon neoplasm that occurs in immunosuppressed patients of any age. Usually, it presents as multifocal tumors mainly in the spinal cord, epidural region, gastrointestinal tract and liver, upper respiratory tract and skin, the latest with few cases reported in the literature and related with human immunodeficiency virus infection and acquired immune deficiency syndrome. The authors present the first case of a Colombian adult patient with human immunodeficiency virus infection and multifocal Epstein Barr virus-associated smooth muscle tumors in the skin and epidural region, confirmed by histopathology, immunohistochemistry and in situ hybridization studies.

Grupo de Estudos da Doença Inflamatória Intestinal do Brasil sobre a vacinação para SARS-CoV2 / Brazilian ibd study group position statement on sars-cov2 vaccination

ABSTRACT Mass vaccination offers the best strategy to fight against COVID-19 pandemic, and SARS-CoV2 vaccines are being approved in several countries for emergency use. In Brazil, vaccine approval is expected in the next few days, however potential concerns exist regarding vaccine recommendations for specific populations, such as patients with inflammatory bowel disease (IBD). To address these questions, the Brazilian IBD Study Group (GEDIIB) provides this practical advice with key recommendations about the COVID-19 vaccines in IBD population.

RESUMO A vacinação em massa oferece a melhor estratégia para enfrentamento da pandemia de COVID-19, e as vacinas contra SARS-CoV2 estão sendo aprovadas em vários países para uso emergencial. No Brasil, a aprovação da vacina é esperada em breve, no entanto, existem potenciais preocupações em relação às recomendações de vacinas para populações específicas, como pacientes com doença inflamatória intestinal (DII). Para responder essas questões, o Grupo Brasileiro de Estudos IBD (GEDIIB) fornece conselhos práticos com recomendações importantes sobre as vacinas para COVID-19 na população com DII.

Vacunas SARS CoV-2, estudios en fase III / SARS CoV-2 vaccine studies currently in phase III

Resumen La enfermedad por coronavirus 2019, causada por el virus SARS-CoV2, fue declarada pandemia en marzo de 2020 por la OMS. La proteína S, de la superficie viral ha sido identificada como antígeno óptimo para el desarrollo de vacunas. En pandemia, el proceso tradicional de desarrollo de vacunas ha debido acelerarse para avanzar en una respuesta adecuada al problema, acortando los tiempos. La seguridad, inmunogenicidad, protección frente a la infección, fenómeno de "aumento dependiente de anticuerpos", duración de la protección se estudian en paralelo, a diferencia de la manera tradicional en que se llevaba a cabo en etapas sucesivas. Actualmente en Fase III hay 4 tipos vacunas: inactivadas; en base a proteínas purificadas o recombinantes, en base a ácidos nucleicos ADN/ARN y en base a vectores virales. El objetivo de esta revisión es conocer los estudios que preceden a las vacunas que actualmente están en estudios de Fase III y describir las características principales de estos estudios. Actualmente el mundo se encuentra en una situación inédita en el último siglo. Dentro las opciones para enfrentar este hecho, una vacuna o idealmente varias, seguras, eficaces e inmunogénicas, parecen ser una de las mejores alternativas para retomar en un plazo razonable la normalidad perdida.

Abstract The coronavirus disease 2019, caused by the SARS-CoV2 virus, was declared a pandemic in March 2020 by the WHO. Protein S from the viral surface has been identified as the optimal antigen for vaccine development. In a pandemic, the traditional vaccine development process has had to be accelerated to advance in an adequate response to the problem, shortening the times. Safety, immunogenicity, protection against infection, antibody dependent enhancement phenomena and duration of protection are studied in parallel, unlike the traditional way in which it was carried out in successive stages. Currently in Phase III there are 4 types of vaccines: inactivated; based on purified or recombinant proteins, based on DNA / RNA nucleic acids and based on viral vectors. The objective of this review is to understand the studies that precede the vaccines that are currently in Phase III studies and to describe the main characteristics of these studies. Currently the world is in a situation unprecedented in the last century. Among the options to face this fact, one vaccine or, ideally, several, safe, effective and immunogenic, seem to be one of the best alternatives to regain lost normality within a reasonable time.

Immunity, virus evolution, and effectiveness of SARS-CoV-2 vaccines

Phylogenetic and pathogenesis studies of the severe acute respiratory syndrome-related coronaviruses (SARS-CoVs) strains have highlighted some specific mutations that could confer the RNA genome fitness advantages and immunological resistance for their rapid spread in the human population. The analyses of 30 kb RNA SARS-CoVs genome sequences, protein structures, and functions have provided us a perspective of how host-virus protein-protein complexes act to mediate virus infection. The open reading frame (ORF)1a and ORF1b translation yields 16 non-structural (nsp1-16) and 6 accessory proteins (p6, p7a, p8ab, p9b) with multiple functional domains. Viral proteins recruit over 300 host partners forming hetero-oligomeric complexes enabling the viral RNA synthesis, packing, and virion release. Many cellular host factors and the innate immune cells through pattern-recognition receptors and intracellular RNA sensor molecules act to inhibit virus entry and intracellular replication. However, non-structural ORF proteins hijack them and suppress interferon synthesis and its antiviral effects. Pro-inflammatory chemokines and cytokines storm leads to dysfunctional inflammation, lung injury, and several clinical symptoms in patients. During the global pandemic, COVID-19 patients were identified with non-synonymous substitution of G614D in the spike protein, indicating virus co-evolution in host cells. We review findings that suggest that host RNA editing and DNA repair systems, while carrying on recombination, mutation, and repair of viral RNA intermediates, may facilitate virus evolution. Understanding how the host cell RNA replication process may be driven by SARS-CoV-2 RNA genome fitness will help the testing of vaccines effectiveness to multiple independent mutated coronavirus strains that will emerge.

Enhanced rapid commercial DNA extraction kit for the molecular detection of severe acute respiratory syndrome coronavirus 2: Easy adaptation to current protocols

Abstract INTRODUCTION Herein, the authors describe a simple enhancement to a commercial rapid DNA extraction kit based on simple viral lysis for detecting COVID-19 via RT-qPCR. METHODS After testing several different modifications, the adapted protocol with the best results in preliminary experiments was statistically evaluated in comparison with an automated robotic protocol. RESULTS Processing and testing of 119 nasopharyngeal samples ultimately yielded near-perfect agreement with the automated protocol (κ = 0.981 [95% confidence interval 0.943-1.000]). CONCLUSIONS The low cost and rapidity of the enhanced protocol makes it suitable for adoption in laboratories diagnosing COVID-19, especially those with high demand for examinations.

SARS-CoV-2 nucleic acid shedding is variable for every person

Abstract INTRODUCTION: Considering the persistent positivity on RT-qPCR tests, the results of SARS-CoV-2 were monitored to evaluate the viral RNA shedding period. METHODS: Between March and June 2020, the sequential results of 29 healthcare workers' were monitored using RT-qPCR. RESULTS: More than 50% of the individuals remained RT-qPCR positive after 14 days. Furthermore, this is the first study to describe positive RT-qPCR for SARS-CoV-2 in a healthcare worker with mild symptoms 95 days after the first positive test. CONCLUSIONS: Sequential RT-qPCR results were heterogeneous, and the viral RNA shedding period is unique for each person.

Coronavirus persistence in human respiratory tract and cell culture: An overview

ABSTRACT Emerging human coronaviruses, including the recently identified SARS-CoV-2, are relevant respiratory pathogens due to their potential to cause epidemics with high case fatality rates, although endemic coronaviruses are also important for immunocompromised patients. Long-term coronavirus infections had been described mainly in experimental models, but it is currently evident that SARS-CoV-2 genomic-RNA can persist for many weeks in the respiratory tract of some individuals clinically recovered from coronavirus infectious disease-19 (COVID-19), despite a lack of isolation of infectious virus. It is still not clear whether persistence of such viral RNA may be pathogenic for the host and related to long-term sequelae. In this review, we summarize evidence of SARS-CoV-2 RNA persistence in respiratory samples besides results obtained from cell culture and histopathology describing long-term coronavirus infection. We also comment on potential mechanisms of coronavirus persistence and relevance for pathogenesis.

The impact of spike mutated variants of SARS-CoV2 [Alpha, Beta, Gamma, Delta, and Lambda] on the efficacy of subunit recombinant vaccines

ABSTRACT Since the first described human infection with SARS-CoV-2 in December of 2019 many subunit protein vaccines have been proposed for use in humans. Subunit vaccines use one or more antigens suitable for eliciting a robust immune response. However, the major concern is the efficacy of subunit vaccines and elicited antibodies to neutralize the variants of SARS-CoV-2 like B.1.1.7 (Alpha), B.1.351 (Beta) and P1 (Gamma), B.1.617 (Delta) and C.37 (Lambda). The Spike protein (S) is a potential fragment for use as an antigen in vaccine development. This protein plays a crucial role in the first step of the infection process, as it binds to Angiotensin-Converting Enzyme 2 (ACE2) receptor and enters the host cell after binding. Immunization-induced specific antibodies against the receptor binding domain (RBD) may block and effectively prevent virus invasion. The focus of this review is the impact of spike mutated variants of SARS-CoV2 (Alpha, Beta, Gamma, Delta, and Lambda) on the efficacy of subunit recombinant vaccines. To date, a low or no significant impact on vaccine efficacy against Alpha and Delta variants has been reported. Such an impact on vaccine efficacy for Beta, Delta, Gamma, and Lambda variants may be even greater compared to the Alpha variant. Nonetheless, more comprehensive analyses are needed to assess the real impact on vaccine efficacy brought about by SARS-CoV-2 variants.

The impact of hepatitis E infection on hepatic fibrosis in liver transplanted patients for hepatitis C infection

ABSTRACT Hepatitis E Virus (HEV) is an infection known worldwide for its asymptomatic and self-limited course in most cases. Some cases progressing to chronicity have been described in immunosuppressed patients, especially in recipients of solid organ transplants. We evaluated laboratory parameters of HEV infection (HEV RNA, anti-HEV IgM and anti-HEV IgG) through enzyme-linked immunosorbent assay (Elisa), confirmed by immunoblotting, in a cohort of 294 patients who received liver transplants at the HCFMUSP (Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo). Laboratory and demographic data were collected from the entirety of the transplanted population. Hepatic biopsies of 122 patients transplanted due liver failure secondary to hepatitis C (HCV), with or without serological or molecular markers of HEV, were analyzed according to METAVIR score. Out of 24 (8.2%) patients tested positive for anti-HEV IgG, six (2%) were positive for anti-HEV IgM and 17 (5.8%) for HEV RNA. Of the patients transplanted because of HCV infection, 95 (77.8%) had received treatment including ribavirin for at least six months before blood sample collection. Among patients transplanted due to HCV cirrhosis who tested positive for anti-HEV IgG, only three (37.5%) showed fibrosis beyond stage 2, while five (41.7%) of the HEV RNA-positive patients had liver fibrosis beyond stage 2. Overall, the prevalence of HEV in the post-hepatic transplant scenario appears to be low, and, at least histologically, seemingly not harmful. We conclude that, although some studies reported a risk of HEV chronification, patients who had their livers transplanted due to HCV and showed serological or molecular markers of HEV did not have higher levels of fibrosis compared to patients who showed no indications of HEV infection at the time of the analysis.

Detection of coronavirus-2 by real-time reverse transcription polymerase chain reaction in conjunctival swabs from patients with severe form of Coronavirus disease 2019 in São Paulo, Brazil

OBJECTIVES: To test conjunctival swabs from patients with laboratory-confirmed severe forms of coronavirus disease 2019 (COVID-19) for the presence of SARS-CoV-2 on real-time reverse-transcription polymerase chain reaction (rRT-PCR). METHODS: Fifty conjunctival swabs were collected from 50 in-patients with laboratory-confirmed severe forms of COVID-19 at the largest teaching hospital and referral center in Brazil (HCFMUSP, São Paulo, SP). The samples were tested for SARS-CoV-2 on rRT-PCR with the primers and probes described in the CDC protocol which amplify the region of the nucleocapsid N gene (2019_nCoV_N1 and 2019_nCoV_N2) of SARS-CoV-2 RNA and compared with naso/oropharyngeal swabs collected within 24 hours of the conjunctival swabs. RESULTS: Five conjunctival samples (10%) tested positive (amplification of the N1 and N2 primer/probe sets) while two conjunctival samples (4%) yielded inconclusive results (amplification of the N1 primer/probe set only). The naso/oropharyngeal swabs were positive for SARS-CoV-2 on rRT-PCR in 34 patients (68%), negative in 14 (28%) and inconclusive in 2 (4%). The 5 patients with positive conjunctival swabs had positive (n=2), negative (n=2) or inconclusive (n=1) naso/oropharyngeal swabs on rRT-PCR. Patients with negative or inconclusive naso/oropharyngeal swabs had the diagnosis of COVID-19 confirmed by previous positive rRT-PCR results or by serology. CONCLUSION: This is the first study to present conjunctival swab rRT-PCR results for SARS-CoV-2 in a Brazilian population. In our sample of 50 patients with severe forms of COVID-19, 10% had positive conjunctival swabs, most of which were correlated with positive naso/oropharyngeal rRT-PCR results.

Hepatitis E virus infection increases the risk of diabetes and severity of liver disease in patients with chronic hepatitis C virus infection

OBJECTIVES: Co-infection with hepatitis A or B viruses may aggravate liver injury in patients infected with hepatitis C virus (HCV). However, few studies have assessed co-infection with hepatitis E virus (HEV) and HCV. Therefore, this study aimed to assess the prevalence and impact of HEV infection among Brazilian patients with chronic HCV infection. METHODS: This observational study included adult patients with chronic HCV infection who were naive to antiviral therapy from January 2013 to March 2016. A total of 181 patients were enrolled, and HEV serology and PCR were performed for all patients. RESULTS: Seropositivity for anti-HEV IgG was detected in 22 (12.0%) patients and anti-HEV immunoglobulin M in 3 (1.6%). HEV RNA showed inconclusive results in nine (4.9%) patients and was undetectable in the remaining patients. HEV serology positive patients had more severe liver disease, characterized by liver fibrosis ≥3 versus ≤2 (p<0.001), Aspartate Aminotransferase-to-Platelet Ratio Index of ≥1.45 (p=0.003), and Fibrosis-4 score of ≥3.25 (p=0.001). Additionally, the odds of HEV-positive patients developing diabetes mellitus were 3.65 (95% CI 1.40-9.52) times the corresponding odds of HEV-negative patients. A case-control-based histological analysis (n=11 HEV-HCV-positive patients and n=22 HCV-positive patients) showed no significant differences between the groups. CONCLUSIONS: This prevalence is higher than that reported in previous studies of the general population in Brazil. Thus, HEV infection may influence the severity of liver disease and may represent an additional risk of developing diabetes mellitus in patients with HCV infection.

Improving Diagnosis of Hepatitis C Virus Infection Using Hepatitis C Core Antigen Testing in a Resource-Poor Setting

Abstract INTRODUCTION: We compared the hepatitis C virus (HCV) core antigen test with the HCV RNA assay to confirm anti-HCV results to determine whether the HCV core antigen test could be used as an alternative confirmatory test to the HCV RNA test. METHODS: Sera from 156 patients were analyzed for anti-HCV and HCV core antigen using a chemiluminescent microparticle immunoassay (Architect i2000SR) and for HCV RNA using the artus HCV RG RT-PCR Kit (QIAGEN) in a Rotor-Gene Q instrument. RESULTS: The diagnostic sensitivity, specificity, and positive and negative predictive values of the HCV core antigen assay compared to the HCV RNA test were 77.35%, 100%, 100%, and 89.38%, respectively. HCV core antigen levels showed a good correlation with those from HCV RNA quantification (r =0.872). However, 13 samples with a viral load of less than 4000 IU/mL were negative in the HCV core antigen assay. All gray-zone reactive samples were also RNA positive and were positive on repeat testing. CONCLUSIONS: The Architect HCV core antigen assay is highly specific and has an excellent positive predictive value. At the present level of sensitivity (77%), the study is still relevant in a low-income setting in which most of the HCV-positive patients would go undiagnosed, since HCV RNA testing is not available and/or not affordable. HCV core antigen testing can also help determine the true burden of infection in a population, considering the fact that almost 50% of the anti-HCV positive cases are negative for HCV RNA.