Long-term outcomes for epidemic viral pneumonia survivors after discharge from the intensive care unit: a systematic review

ABSTRACT Objective To review the long-term outcomes (functional status and psychological sequelae) of survivors of critical illnesses due to epidemic viral pneumonia before the COVID-19 pandemic and to establish a benchmark for comparison of the COVID-19 long-term outcomes. Methods This systematic review of clinical studies reported the long-term outcomes in adults admitted to intensive care units who were diagnosed with viral epidemic pneumonia. An electronic search was performed using databases: MEDLINE®, Web of Science™, LILACS/IBECS, and EMBASE. Additionally, complementary searches were conducted on the reference lists of eligible studies. The quality of the studies was assessed using the Newcastle-Ottawa Scale. The results were grouped into tables and textual descriptions. Results The final analysis included 15 studies from a total of 243 studies. This review included 771 patients with Influenza A, Middle East Respiratory Syndrome, and Severe Acute Respiratory Syndrome. It analyzed the quality of life, functionality, lung function, mortality, rate of return to work, rehospitalization, and psychiatric symptoms. The follow-up periods ranged from 1 to 144 months. We found that the quality of life, functional capacity, and pulmonary function were below expected standards. Conclusion This review revealed great heterogeneity between studies attributed to different scales, follow-up time points, and methodologies. However, this systematic review identified negative long-term effects on patient outcomes. Given the possibility of future pandemics, it is essential to identify the long-term effects of viral pneumonia outbreaks. This review was not funded. Prospero database registration: (www.crd.york.ac.uk/prospero) under registration ID CRD42021190296.

Directrices en torno a las epidemias en México. Perspectiva histórica / Guidelines on epidemics in Mexico. Historical perspective

Resumen Se ofrece una perspectiva de las epidemias y pandemias en México en tres periodos: fines del siglo XVIII y siglos XX y XXI, con el fin de analizar cómo las autoridades sanitarias y gubernamentales abordaron estos problemas, así como los desafíos que han representado. Se consultaron fuentes históricas documentales y, en los casos actuales, la participación en ellos. Se combinó metodología epidemiológica e histórica social. La presencia de las epidemias en México es una constante, lo cual evidencia la necesidad de actualizar el sistema de vigilancia epidemiológica, de estar preparados para enfrentar una epidemia y de elaborar un plan de contingencia.

Abstract A perspective of epidemics and pandemics in Mexico is offered, focusing on three time periods, namely, end of the 18th century, the 20th century, and the 21st century, in order to analyze how they were approached by health and government authorities, as well as the challenges they have represented. Historical documentary sources were consulted and, in current cases, participation in them was analyzed. Epidemiological and social historical methodologies were combined. The presence of epidemics in Mexico is a constant on its evolution, which highlights the need for the epidemiological surveillance system to be updated, the importance of being prepared to face an epidemic and to develop a contingency plan.

Genetic variation characteristics of HA gene of influenza A virus (H3N2) in Guizhou province from 2017 to 2019 / 中国基层医药

Objective:To analyze the genetic variation characteristics of the HA gene of influenza A virus (H3N2) in Guizhou province from 2017 to 2019. Methods:Twenty strains of influenza A virus (H3N2) were randomly selected from 10 network laboratories in Guizhou province for RNA extraction. Reverse transcriptase-polymerase chain reaction and sequencing were performed. The products were analyzed using bioinformatics software.Results:The nucleotide homology of the HA gene of the 20 strains was 97.7%-100%, which was highly homologous to the vaccine strains A/Hong-Kong/4801/2014 recommended by WHO in 2017 and A/Singapore-INFIMH/16-0019/2016 recommended by WHO in 2018, but they were significantly different from the vaccine strain A/Kansas/14/2017 recommended by WHO in 2019. Genetic analysis showed that the 20 strains were divided into two branches, and the strains that were prevalent in 2019 were located in different branches, with marked genetic differences. Key site analysis showed mutations in antigenic determinants A, B, C, and E and mutations in the anterior and posterior walls of receptor binding sites. Key site analysis also showed that there was an increase in the number of glycosylation sites compared with the vaccine strains prevalent in the same year. Genetic distance, antigen sites, and glycosylation sites were slightly different between virus strains prevalent in 2017-2018 and virus strains prevalent in 2019. Conclusion:The HA gene of the influenza A virus subtype H3N2 in Guizhou province from 2017 to 2019 showed heterogeneity and gene mutation, especially in 2019. Therefore, close monitoring of the genetic evolution of the influenza A virus subtype H3N2 is necessary.

The role of mammalian target of rapamycin inhibitor in virus infection of organ transplant recipients / 器官移植

At present, mammalian target of rapamycin (mTOR) inhibitors are commonly-used immunosuppressive drugs after organ transplantation, including sirolimus (rapamycin) and everolimus. mTOR inhibitors not only exert an immunosuppressive effect by inhibiting T cell proliferation, but also possess multiple potential functions, such as antiaging, anti-tumor and anti-virus infection, etc. Virus infection is one of the most common complications after organ transplantation. Current anti-viral treatments are limited and yield poor efficacy. In this article, the role of mTOR pathway in virus infection, the mechanism of common mTOR inhibitors and the role of mTOR inhibitors in different types of virus infections were reviewed, aiming to provide reference for clinical application and subsequent research of mTOR inhibitors in organ transplant recipients.

Effects of metformin on peripheral blood Treg/Th17 cells and related cytokines in patients with type 2 diabetes mellitus and influenza A / 中国医师进修杂志

Objective:To explore the effects of metformin on levels of peripheral blood regulatory T cells (Treg)/Th17 cells and related cytokines in patients with type 2 diabetes mellitus (T2DM) and influenza A.Methods:A total of 108 patients with T2DM and influenza A treated in Zhejiang Veteran Hospital were prospectively enrolled between April 2021 to April 2022. According to different medication methods, they were divided into observation group (54 cases, oseltamivir + metformin) and control group (54 cases, oseltamivir + gliclazide). The average usage time and dosage of oseltamivir, concentration of blood lactate and blood gas level, counts of Th17 and Treg cells, and levels of related cytokines in the two groups were compared before and after treatment.Results:The average usage time and dosage of oseltamivir, and concentration of blood lactate were higher in observation group than control group: (8.94 ± 0.88) d vs. (7.23 ± 0.79) d, (1.32 ± 0.15) g vs. (1.08 ± 0.11) g, (1.83 ± 0.43) mmol/L vs. (1.61 ± 0.32) mmol/L, P<0.05. The differences in pH, partial pressure of arterial oxygen (PaO 2) and partial pressure of arterial carbon dioxide (PaCO 2) between the two groups had no statistically significant before and after treatment ( P>0.05). After treatment, the differences in count of Treg cells, interleukin-10 (IL-10), interleukin-4 (IL-4), CD 3+, CD 4+ and CD 4+/CD 8+ between the observation group and the control group were statistically significant: (35.48 ± 5.64)% vs. (42.53 ± 6.17)%, (30.49 ± 4.72) ng/L vs. (35.64 ± 5.08) ng/L, (32.15 ± 3.06) ng/L vs. (35.33 ± 3.12) ng/L, (61.39 ± 3.28) % vs. (66.27 ± 3.05)%, (34.12 ± 1.93)% vs. (36.59 ± 2.61)%, 1.26 ± 0.34 vs. 1.52 ± 0.41, P<0.05. After treatment, the count of Th17 cells, Th17/Treg, interleukin-17 (IL-17) and γ-interferon (IFN-γ) in the observation group were higher than those in the control group:(8.69 ± 1.42)% vs. (7.94 ± 2.03)%, 0.24 ± 0.06 vs. 0.19 ± 0.05, (17.67 ± 3.11) ng/L vs. (12.18 ± 3.42) ng/L, (287.48 ± 45.12) ng/L vs. (254.27 ± 41.09) ng/L, P<0.05. During treatment, the difference in incidences of adverse reactions between the two groups had no statistically significant ( P>0.05). Conclusions:Oseltamivir combined with metformin can recover the balance of Th17/Treg cells in patients with T2DM and influenza A to a certain extent. Clinically, level of blood lactate should be monitored.

Polymorphisms of host tropism relating amino acid sites in influenza A virus / 上海预防医学

ObjectiveTo discover and analyze single or several correlative key amino acid sites that influence the host tropism during the influenza A virus （IAV） infection based on complete internal protein gene segments of IAV strains， and to provide evidence for the study of human host-adaptive mutations of IAV. MethodsThe full-length nucleotide sequences of 43 671 IAV strains containing 6 complete internal gene segments were downloaded from the GISAID EpiFluTM database， and 698 human-tropic （HU） and 1 266 avian-tropic （AV） representative strains were included. The consensus coding sequences of the representative strains from the amphitropic category were compared by R script， and the differential amino acid sites and their polymorphisms were then obtained. The multi-site combination analysis of differential sites was conducted with R script. ResultsA total of 49 and 57 conserved differential sites were obtained from the consensus sequence comparison between AV and H1N1 （subtype from HU）， and comparison between AV and H3N2 （another subtype from HU）， separately. 79 and 65 multi-site combinations were found between HU and AV strains through 3 and 4 sites combination analysis， respectively， and a total of 11 conserved sites were involved： site 271 and 684 in PB2； site 336， 486， 581 and 621 in PB1； site 204 and 356 in PA； site 33， 305 and 357 in NP. No eligible differential sites were found in M1 and NS1. ConclusionSeveral conserved amino acid differential sites， between HU and AV strains of IAV， are found in PB2， PB1， PA and NP proteins. Instead of working as single units， these sites may have interactions， forming specific amino acid combinations that determine the host tropism of IAV collectively.

A fatal case of COVID-19-associated meningoencephalitis in a patient coinfected with influenza A

ABSTRACT We report a case of COVID-19-associated meningoencephalitis with a fatal outcome in a male patient with concomitant influenza A, who had been hospitalized at the beginning of 2022, in the Northeastern region of Brazil. He died due to cardiopulmonary arrest after developing status epilepticus on the third day of hospitalization. The SARS-CoV-2 RNA was detected in cerebrospinal fluid and Influenza A was detected in the nasopharyngeal swab. Meningoencephalitis due to COVID-19 is a rare manifestation and physicians must be aware of this complication, mainly during the pandemic. In viral co-circulation situations, the possibility of respiratory coinfections should be remembered.

Influenza A(H3N2) infection followed by separate COVID-19 infection / Infección por el virus de la gripe A (H3N2) seguida de infección separada por el virus causante de la COVID-19 / Infecção por influenza A (H3N2) seguida de infecção independente por COVID-19

ABSTRACT This study describes the case of a health professional infected first by influenza virus A(H3N2) and then by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 11 days later. Respiratory samples and clinical data were collected from the patient and from close contacts. RNA was extracted from samples and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to investigate the viruses. The patient presented with two different illness events: the first was characterized by fever, chest and body pain, prostration and tiredness, which ceased on the ninth day; RT-qPCR was positive only for influenza virus A(H3N2). Eleven days after onset of the first symptoms, the patient presented with sore throat, nasal congestion, coryza, nasal itching, sneezing and coughing, and a second RT-qPCR test was positive only for SARS-CoV-2; in the second event, symptoms lasted for 11 days. SARS-CoV-2 sequencing identified the Omicron BA.1 lineage. Of the patient's contacts, one was coinfected with influenza A(H3N2) and SARS-CoV-2 lineage BA.1.15 and the other two were infected only with SARS-CoV-2, one also with Omicron BA.1.15 and the other with BA.1.1. Our findings reinforce the importance of testing for different viruses in cases of suspected respiratory viral infection during routine epidemiological surveillance because common clinical manifestations of COVID-19 mimic those of other viruses, such as influenza.

RESUMEN Este estudio describe el caso de un profesional de la salud que contrajo la infección primero por el virus de la gripe A (H3N2) y a continuación por el coronavirus 2 del síndrome respiratorio agudo grave (SARS-CoV-2) 11 días después. Se recogieron muestras respiratorias y datos clínicos del paciente y sus contactos cercanos. Se extrajo ARN de muestras y se utilizó la reacción en cadena de la polimerasa cuantitativa con transcripción inversa (RT-qPCR, por su sigla en inglés) para investigar los virus. El paciente presentó dos procesos infecciosos distintos: el primero se caracterizó por fiebre, dolor corporal y torácico, postración y cansancio, que cesó en el noveno día. La prueba mediante RT-qPCR solo fue positiva en el virus de la gripe A (H3N2). Once días después del inicio de los primeros síntomas, el paciente manifestó dolor de garganta, congestión nasal, catarro, picazón nasal, estornudos y tos. Una segunda prueba mediante RT-qPCR solo fue positiva para el SARS-CoV-2 y durante este segundo proceso los síntomas duraron 11 días. La secuenciación del SARS-CoV-2 identificó el linaje ómicron BA.1. De los contactos del paciente, uno presentaba una coinfección por el virus de la gripe A (H3N2) y el linaje BA.1.15 del SARS-COV-2, y los otros dos presentaban infecciones únicamente por SARS-CoV-2, uno también del linaje ómicron BA.1.15 y el otro de BA.1.1. Estos hallazgos refuerzan la importancia de realizar pruebas para detectar diferentes virus en casos de sospecha de infección viral respiratoria durante la vigilancia epidemiológica de rutina porque las manifestaciones clínicas comunes de COVID-19 son similares a las de otros virus, como en el caso de la gripe.

RESUMO Este estudo descreve o caso de uma profissional de saúde infectada primeiro pelo vírus influenza A (H3N2) e, 11 dias depois, pelo coronavírus da síndrome respiratória aguda grave 2 (SARS-CoV-2). Amostras respiratórias e dados clínicos foram coletados da paciente e de contatos próximos. RNA foi extraído das amostras, e o método de reação em cadeia da polimerase via transcriptase reversa quantitativa (RT-qPCR) foi utilizado para investigar os vírus. A paciente apresentou dois quadros clínicos distintos. O primeiro foi caracterizado por febre, dor no peito e no corpo, prostração e fadiga, que cessou no nono dia. A RT-qPCR foi positiva apenas para o vírus da influenza A (H3N2). Onze dias após o início dos primeiros sintomas, a paciente apresentou dor de garganta, congestão nasal, coriza, prurido nasal, espirros e tosse. Um segundo teste de RT-qPCR foi positivo apenas para SARS-CoV-2. No segundo evento, os sintomas duraram 11 dias. O sequenciamento do SARS-CoV-2 identificou a cepa Ômicron BA.1. Dentre os contatos da paciente, um teve coinfeção por influenza A (H3N2) e SARS-COV-2 (cepa BA.1.15), e os outros dois foram infectados apenas por SARS-CoV-2 (um também pela cepa Ômicron BA.1.15 e o outro pela BA.1.1). Nossos achados reforçam a importância de testes para a detecção de diferentes vírus em casos de suspeita de infecção viral respiratória durante a vigilância epidemiológica de rotina, visto que as manifestações clínicas comuns da COVID-19 imitam as de outros vírus, como o vírus influenza.

Mechanism of Huashi Baidu Prescription in Treating Influenza Viral Pneumonia Based on Transcriptome / 中国实验方剂学杂志

ObjectiveTo clarify the therapeutic effect of Huashi Baidu prescription on pneumonia in mice caused by influenza A （H1N1） virus and explore its mechanism based on the transcriptome. MethodA mouse influenza viral pneumonia model was built by intranasal infection with influenza A virus， and mice were continuously administered the drug for five days， so as to investigate the general condition， lung index， viral load， pathological morphology of lung tissue， survival time， and prolongation rate of survival time of mice and clarify the therapeutic effect of Huashi Baidu prescription on influenza viral pneumonia. Transcriptome technology was used to detect the differentially expressed genes in the lung tissue of mice in the model group and the normal group， as well as the Huashi Baidu prescription group and the model group， and the potential core target of the Huashi Baidu prescription for the treatment of influenza viral pneumonia was screened. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to verify the effect of Huashi Baidu prescription on the mRNA expression level of core target genes. ResultCompared with the normal group， the lung index and viral load in the lung tissue of the model group were significantly increased （P<0.05， P<0.01）. Compared with the model group， the high-dose group of Huashi Baidu prescription significantly prolonged the survival time of mice infected with influenza A virus （P<0.05） and significantly reduced the lung index value of mice （P<0.05） and the viral load of lung tissue. The high-dose， medium-dose， and low-dose groups of Huashi Baidu prescription could significantly reduce lung tissue inflammation， blood stasis， swelling， and other pathological changes in mice （P<0.05， P<0.01）. Transcriptome analysis of lung tissue showed that core genes were mainly enriched in the nuclear transcription factor-κB （NF-κB） signaling pathway， interleukin-17 （IL-17） signaling pathway， cytokine-cytokine receptor interaction， and other pathways after the intervention of Huashi Baidu prescription. TRAF6， NFKBIA， CCL2， CCL7， and CXCL2 were the top five node genes with combined score values. Real-time PCR validation showed that Huashi Baidu prescription significantly downregulated the mRNA expression of key genes TRAF6 and NFKBIA in the NF-κB signaling pathway， as well as chemokines CCL2， CCL7， and CXCL2 （P<0.05， P<0.01）. ConclusionHuashi Baidu prescription has a therapeutic effect on influenza viral pneumonia， possibly by inhibiting the expression of key nodes TRAF6 and NFKBIA in the NF-κB signaling pathway and that of chemokines CCL2， CCL7， and CXCL2， reducing the recruitment of inflammatory cells and viral load， and exerting anti-influenza viral pneumonia effects.

Research progress of m 6A methylation modification in respiratory viruses replication and host immune response / 中华临床感染病杂志

N 6-methyladenosine (m 6A) modification is the most prevalent internal modification of eukaryotic mRNA and is dynamically regulated by a variety of m 6A modifying enzymes, including methylation transferases, demethylases and specific binding proteins. Respiratory viral infections have received much attention in recent years, and the process of virus replication and metabolism in host cells is regulated by m 6A. This article reviews the mechanism of m 6A-regulated enzymes, the roles of m 6A modifications in respiratory viruses replication and the host immune response to viruses, including adenovirus, influenza A virus, severe acute respiratory syndrome coronavirus 2, respiratory syncytial virus, and human metapneumovirus. It would provide a reference for exploring the regulatory role of viral episodic transcriptome modifications and antiviral targets or vaccine development.

Caracterización demográfica y clínica de pacientes críticos con neumonía por influenza A H1N1 / Demographic and clinical characterization of critically ill patients with influenza A H1N1 pneumonia

INTRODUCCIÓN. La epidemia de influenza y sus complicaciones profundizaron el estudio de las neumonías virales en cuidados intensivos. En nuestro país hay pocos datos sobre este tema. OBJETIVOS. Realizar una caracterización demográfica y clínica de pacientes críticos con neumonía por Influenza A H1N1 en un hospital de tercer nivel de complejidad. MATERIALES Y MÉTODOS. Estudio observacional, analítico, retrospectivo, con análisis univariante y multivariante. Población de 293 y muestra de 44 datos de historias clínicas electrónicas de pacientes diagnosticados con A H1N1 ingresados a la Unidad de cuidados intensivos del Hospital de Especialidades Carlos Andrade Marín en el período enero 2016 a diciembre de 2018. Como criterios de inclusión se consideró a todos los pacientes adultos mayores de 18 años que ingresaron a la UCI, con el diagnóstico de neumonía comunitaria grave con confirmación por reacción de cadena de polimerasa en tiempo real para influenza A H1N1 en hisopado nasal o aspirado traqueal. Se excluyó a pacientes embarazadas con diagnóstico de influenza A H1N1, pacientes con más de 48 horas de ingreso hospitalario previo a su ingreso a UCI, pacientes con datos insuficientes en los registros. Los datos se obtuvieron del sistema AS-400. El análisis estadístico se realizó en el programa Statistical Package for Social Sciences, versión 22. El nivel de significación fue una p<0.05. RESULTADOS. La prevalencia en pacientes críticos de neumonía por influenza A H1N1 durante 2016-2018 fue de 16,72%, la mediana de edad fue de 55 años, 25% masculinos, 34% obesos, 34% con hipertensión arterial. Escala "Acute Physiology and Chronic Health Evaluation II" 23,50, "Simplified Acute Physiologic Score III" 54, "Sepsis related Organ Failure Assessment" 11,50, Lactato deshidrogenasa 99,50, Procalcitonina 0,99; 9 días de ventilación mecánica invasiva, 10,50 días de estancia en la unidad. El 91% presentó shock séptico, 59% lesión renal aguda. El 89% tuvo Síndrome de Distrés Respiratorio del Adultos, 69% fue grave, 87% usó ventilación mecánica, 38,50% corticoides, 36% posición prona, Presión parcial de oxígeno/Fracción inspirada de oxígeno 74, volumen tidal/kilogramo de 7 mililitros, presión plateau de 27,50 centímetros de agua. La mortalidad general en la Unidad de Cuidados Intensivos fue de 38,63% y a los 28 días de 63,60%, en shock séptico fue 42,50% y en Síndrome de Distrés Respiratorio del Adultos del 41,02%. El análisis de regresión logística multivariable identificó como factores independientes asociados a mortalidad el incremento de Lactato deshidrogenasa (OR 2,69, 9% IC 1,090-6,642) y Procalcitonina (OR 2,51, IC 1,005-6,272). CONCLUSIONES. Las características, frecuencia y mortalidad de este grupo de pacientes críticos con neumonía por influenza A H1N1 son similares a lo reportado en la literatura mundial.

INTRODUCTION. The influenza epidemic and its complications deepened the study of viral pneumonias in intensive care. In our country there is little data on this subject. OBJECTIVES. To perform a demographic and clinical characterization of critical patients with pneumonia due to pneumonia due to Influenza A H1N1 in a third level hospital. MATERIALS AND METHODS. Observational, analytical, retrospective study, with univariate and multivariate analysis. We compared the groups of dead patients and survivors. The significance level was p<0,05. RESULTS. The prevalence in critically ill patients of influenza A H1N1 pneumonia during 2016-2018 was 16,72%, 44 cases were collected, median age 55 years, 25% male, 34% obese, 34% with arterial hypertension. APACHE II 23,50, SAPS III 54, SOFA 11,50, LDH 99,50, PCT 0,99, 9 days of invasive mechanical ventilation, 10,50 days of unit stay. 91% presented septic shock, 59% with acute kidney injury 89% had ARDS, 69% were severe, 87% used mechanical ventilation, 38,50% corticosteroids, 36% prone position, PaO2/FiO2 74, tidal volume/kg of 7 ml, plateau pressure of 27,50 cmH2O. Overall mortality in the ICU was 38,63% and at 28 days was 63,60%, in septic shock it was 42,50% and in Adult Respiratory Distress Syndrome it was 42,50%. was 42,50% and 41,02% in Adult Respiratory Distress Syndrome. The ultivariate logistic regression analysis identified as independent factors associated with mortality, the increase in LDH (OR 2,69, 9% CI 1,090-6,642) and PCT (OR 2,51, CI 1,005-6,272). CONCLUSIONS. The characteristics, frequency and mortality of this group of critical patients with pneumonia due to influenza A H1N1 are similar to those reported in the world literature.

Use of oral fluids for efficient monitoring of influenza viruses in swine herds in Colombia

Background: Influenza A virus (IAV) surveillance in swine is critical not only due to the direct impact of the disease in the pork industry but also because IAV are prone to interspecies transmission (from human to pigs and vice versa); therefore, its monitoring is fundamental from a public and animal health perspective. Several diagnostic techniques have been used to detect IAV infection from nasal samples in swine, while samples of oral fluids (OF) are in use as novel alternatives for pathogen detection. The OF allow for efficient and feasible low-cost disease detection at the herd level, with low risk of stress for the animals. Objective: To describe a surveillance strategy of IAV at the herd level during respiratory disease outbreaks in swine farms at tropical settings using porcine oral fluids. Methods: An active surveillance strategy was conducted in several farms with past records of respiratory disease. The IAV detection was conducted in five purposively selected swine farms from years 2014 to 2017. We investigated a total of 18 respiratory outbreaks of the disease. Swine OF were collected for IAV testing. An OF sample is described as a pen-based specimen collected from a group of >20 pigs per pen and/or per barn (stall-housed individually with close contact among them). The IAV infection was investigated in OF by rRT-PCR testing and confirmed by viral isolation in cell culture Results: We found 107 (7.4%) positives to IAV by rRT-PCR from a total of 1,444 OF samples tested. Additionally, 9 IAV isolates were all further identified as H1 subtype. Conclusions: Our results demonstrate that OF can be easily implemented as a novel, user-friendly, welfare-friendly, accurate and cost-effective sampling method for active surveillance and monitoring of IAV infections in swine farms in tropical settings.

Antecedentes: La vigilancia del Virus Influenza A (IAV) en los cerdos es fundamental debido al impacto directo de la enfermedad en la industria porcina, pero también porque los IAV son propensos de transmisión entre especies (humanos a cerdos y viceversa), y por lo tanto su monitoreo es crítico desde las perspectivas de salud pública y animal. Actualmente existen varias técnicas de diagnóstico disponibles para detectar la infección por IAV a partir de muestras nasales en cerdos, sin embargo, se han implementado otras muestras como los fluidos orales (OF) como nuevas alternativas para la detección de patógenos. El OF permite una detección eficiente y factible de enfermedades a menor costo a nivel de rebaño, con menor riesgo de estrés para los animales. Objetivo: Describir una estrategia de vigilancia de IAV a nivel de hato por medio de fluidos orales porcinos durante brotes de enfermedades respiratorias en granjas porcinas en entornos tropicales. Métodos: Se llevó a cabo una estrategia de vigilancia activa en cinco granjas porcinas seleccionadas con antecedentes de enfermedades respiratorias. Se recolectaron OF porcinos para la prueba de IAV. Una muestra de OF se describió como una muestra grupal recolectada de un grupo de >20 cerdos por corral y/o por establo (si estaban alojados individualmente, pero tenían un contacto cercano entre ellos). La infección por IAV se investigó probando OF mediante rRT-PCR y la confirmación mediante aislamiento viral en cultivo celular. Resultados: La detección de IAV se llevó a cabo en cinco granjas seleccionadas intencionalmente entre 2014- 2017. Investigamos un total de 18 eventos de brotes de enfermedades respiratorias. Del total de 1.444 OF muestras analizadas, encontramos 107 (7,4%) positivos a IAV mediante rRT-PCR. Además, solo se obtuvieron 9 aislamientos de IAV y todos se identificaron además como subtipo H1. Conclusiones: Los resultados de nuestro estudio demostraron cómo la OF puede implementarse fácilmente como un método de muestreo novedoso, fácil de usar, amigable con el bienestar animal, preciso y rentable para la vigilancia activa y el monitoreo de infecciones por IAV en granjas porcinas en entornos tropicales.

Antecedentes: A vigilância do vírus Influenza A (IAV) em suínos é crítica devido ao impacto direto da doença na indústria de suínos, mas também porque os IAV são propensos a transmissão interespécies (de humanos para porcos e vice-versa) e, portanto, seu monitoramento é crítico do ponto de vista da saúde pública e animal. Atualmente, existem várias técnicas de diagnóstico disponíveis para detectar a infecção por IAV em amostras nasais de suínos, no entanto, outras amostras, como fluidos orais (OF), têm sido implementadas como novas alternativas para a detecção de patógenos. O OF permite uma detecção eficiente e viável de doenças com menor custo em nível de rebanho, com menor risco de estresse para os animais. Objetivo: Descrever uma estratégia de vigilância de IAV em nível de rebanho durante surtos de doenças respiratórias em granjas de suínos em ambientes tropicais por meio de fluidos orais suínos. Métodos: A estratégia de vigilância ativa foi conduzida em cinco granjas de suínos selecionadas com histórico de doenças respiratórias. Suínos OF foram coletados para teste de IAV. Uma amostra OF foi descrita como um espécime baseado em curral coletado de um grupo de >20 porcos por curral e/ou por celeiro (se eles foram alojados individualmente, mas tendo contato próximo entre eles). A infecção IAV foi investigada testando OF por rRT-PCR e confirmada por isolamento em cultura de células. Resultados: A detecção do IAV foi realizada em cinco fazendas selecionadas propositalmente entre 2014-2017. Nós investigamos um total de 18 eventos de surto de doença respiratória. Do total de 1.444 amostras de OF testadas, encontramos 107 (7,4%) positivas para IAV por rRT-PCR. Além disso, apenas 9 isolados de IAV foram obtidos, e todos foram posteriormente identificados como subtipo H1. Conclusão: Os resultados de nosso estudo demonstraram como o OF pode ser facilmente implementado como um método de amostragem novo, amigável, amigável com o bem-estar, preciso e de baixo custo para vigilância ativa e monitoramento de infecções IAV em fazendas de suínos em ambientes tropicais.

Síndrome Respiratória Aguda Grave por Influenza A/B: Análise da Situação Vacinal / Severe Acute Respiratory Syndrome due to Influenza A/B: Analysis of Vaccination Status

Introdução: A Influenza é uma doença respiratória altamente contagiosa, prevenível por vacinação, afetando todos os grupos etários,com morbidade e mortalidade variáveis. O objetivo deste estudo foi analisar a relação da situação vacinal dos pacientes com Influenza A/B atendidos com Síndrome Respiratória Aguda Grave. Métodos: Estudo retrospectivo, a partir das notificações do Sistema de Informação de Agravos de Notificação Compulsório do Brasil, de pacientes com esquema vacinal conhecido para Influenza A/B em um hospital-escola do interior do Rio Grande do Sul (2012 a 2018). Resultados: Foram incluídos 596 casos de SRAG, sendo 179 (30,0%) por vírus respiratórios [92 (51,4%) Influenza A/B e 87 (48,6%) outros vírus respiratórios]. Na faixa etária de maiores de 50 anos, a frequência foi 28,2%, 6 meses a 1 ano foi de 19,6%, seguido de 13% no grupo etário de 2 a 4 anos. O esquema vacinal estava completo em 59,8% dos casos, sendo que em 37,5% dos pacientes apresentavam esquema vacinal incompleto. O tratamento antiviral foi administrado em 90,2% do pacientes com SRAG por Influenza A/B, e a alta hospitalar ocorreu em 91,3% dos casos. Conclusão: A vacinação é uma estratégia para prevenção de complicações relacionadas à Influenza. No entanto, a SRAG é uma apresentação com diagnóstico diferencial amplo, e as causas virais necessitam de confirmação para uma otimização da terapêutica antiviral. A equipe de saúde deve estar atenta a pacientes com riscos de SRAG, a fim de minimizar os desfechos negativos, mesmo nos vacinados.

Introduction: Influenza is a highly contagious respiratory disease, preventable by vaccination, affecting all age groups, with variable morbidity and mortality. The objective of this study was to analyze the relationship between the vaccination status of Influenza A/B patients seen with Severe Acute Respiratory Syndrome. Methods: Retrospective study, from notifications of the Brazilian Compulsory Notification Agencies Information System (Sistema de Informação de Agravos de Notificação Compulsório do Brasil), of patients with known vaccination schemes for Influenza A/B in a teaching hospital in the interior of Rio Grande do Sul (2012 to 2018). Results: Of the 596 cases of SARS included, 179 (30.0%) were due to respiratory viruses [92 (51.4%) Influenza A/B and 87 (48.6%) other respiratory viruses]. In the age group over 50 years, the frequency was 28.2%, from 6 months to 1 year old was 19.6%, followed by 13% in the age group of 2 to 4 years. The vaccination schedule was complete in 59.8% of cases, with 37.5% having an incomplete vaccination scheme. Antiviral treatment was administered in 90.2% of the patients with SARS by Influenza A/B, and hospital discharge occurred in 91.3% of the cases. Conclusion: Vaccination is a strategy to prevent complications related to Influenza. However, SARS is a presentation with wide differential diagnosis, and the viral causes need confirmation for an optimization of the antiviral therapy. The healthcare team must be aware of patients at risk of SARS to minimize negative outcomes, even in vaccinated patients.

Plataforma laboratorial para monitorear el SARS-CoV-2 basada en la vigilancia de influenza y otros virus respiratorios en Perú / Laboratory platform for monitoring SARS-CoV-2 based on surveillance of influenza and other respiratory viruses in Peru

RESUMEN En el Perú, la pandemia de la COVID-19 ha evidenciado la utilidad de tener un sistema de vigilancia laboratorial estructurado y en funcionamiento desde hace 22 años, basado en la vigilancia de influenza; inicialmente en modalidad de unidades centinela, y después fortaleciéndose e innovándose, con recursos propios y con apoyo externo, para generar información de calidad. Se han implementado avances biotecnológicos para la confirmación diagnóstica e incrementado las capacidades de la red nacional de laboratorios, manteniendo la eficiencia, considerando las diversas y complejas realidades de los niveles regionales, y superando dificultades de comunicación y articulación entre instituciones. Resulta necesario consolidar este sistema, con trabajo colaborativo y coordinado entre sus componentes, impulsando su eficacia y oportunidad y promoviendo la vigilancia genómica de nuevos virus y variantes, como actualmente ocurre con el SARS-CoV-2.

ABSTRACT In Peru, the COVID-19 pandemic demonstrated the usefulness of having a structured laboratory surveillance system that has been operational for 22 years, based on influenza surveillance; initially in the form of sentinel units, and later strengthened and innovated, with its own resources and with external support, to provide quality information. Biotechnological advances have been implemented for diagnostic confirmation and the capacity of the national laboratory network has been expanded, maintaining efficiency, considering the diverse and complex realities of each region, and overcoming difficulties regarding communication and articulation between institutions. It is necessary to consolidate this system, with collaborative and coordinated work between its components, boosting its effectiveness and timeliness and promoting genomic surveillance of new viruses and variants, as is currently the case with SARS-CoV-2.

Diferencias y similitudes clínicas y epidemiológicas de la neumonía viral en dos pandemias

Background: In a decade, we faced two pandemic viruses, influenza A H1N1pdm09 and SARS CoV-2, whose most serious manifestation is pneumonia. Aim: To compare the clinical, epidemiological and management aspects of pneumonias caused by each pandemic virus in adults requiring hospitalization. Material and Methods: Comparative, observational study carried out at a regional Chilean hospital, including 75 patients with influenza A H1N1pdm09 prospectively studied in 2009 and 142 patients with SARS-CoV-2 studied in 2020. Results: Patients with SARS-CoV-2 pneumonia were older (56 and 39.7 years respectively, p < 0.01) and had significantly more comorbidities. Cough, fever and myalgias were more frequent in influenza. Dyspnea was more frequent in COVID-19. Patients with COVID-19 had more extensive lung involvement and a longer hospitalization (13.6 and 8.6 days respectively, p = 0.01). There was no difference on ICU admission requirements and mortality attributable to pneumonia. Patients with influenza had greater APACHE scores and a higher frequency of a PaO2/FiO2 ratio ≤ 200. During COVID-19pandemic chest sean replaced x-ray examination. Also high-flow nasal cannulas and awake prone position ventilation were added as treatments. Conclusions: COVID-19 patients were older, had fewer classic flu symptoms but more dyspnea and longer hospitalization periods than patients with influenza.

Analysis of clinical characteristics of influenza virus pneumonia and risk factors for severe pneumonia in 711 Children / 国际儿科学杂志

Objective:To investigate the clinical characteristics of influenza A and influenza B pneumonia and the risk factors of severe influenza pneumonia in children.Methods:The epidemiology, clinical characteristics, laboratory tests and pathogens of co-infection in children with pneumonia caused by influenza A virus and influenza B virus, and the risk factors of severe influenza pneumonia were retrospectively analyzed.Results:(1) The cases of influenza A infection accounted for 65.1% and those with influenza B infection accounted for 32.9% among the 711 children with influenza pneumonia.The dominant strain was Influenza B Victoria virus in spring and summer, influenza A(H 3N 2) virus in autumn, and influenza A(H1N1) virus in winter.The dominant strain was influenza A virus at the age of < 1 year and ~3 years, influenza A virus and influenza B virus at the age of ~6 years, and influenza B virus at the age of ≥6 years.(2) The gastrointestinal symptoms were more common in children with influenza B pneumonia compared with those with influenza A pneumonia(53.4% vs 44.7%, χ2=4.728, P=0.030), but crackles and wheezing were more common in children with influenza A pneumonia compared with those with influenza B pneumonia(80.1% vs 70.5%, 36.9% vs 25.6%, χ2=8.945, 8.093, all P<0.05). (3) The percentage of decreased lymphocyte count in children with influenza B pneumonia was higher than those with influenza A pneumonia(5.6% vs 1.9%, χ2=6.633, P=0.010). (4) Mixed Mycoplasma Pneumoniae was more common in children with influenza B pneumonia compared with those with influenza A pneumonia(23.9% vs 10.8%, χ2=20.789, P<0.001), and mixed virus and bacteria were more common in children with influenza A pneumonia compared with those with influenza B pneumonia(15.8% vs 8.1%, 50.1% vs 41.9%, χ2=7.934, 4.221, all P<0.05). (5) Multivariate logistic regression analysis showed that age <2 years( OR=1.886, 95% CI 1.149~3.096, P=0.012), increased LDH( OR=1.736, 95% CI 1.080~2.790, P=0.023), the percentage of lymphocyte decreased( OR=2.762, 95% CI 1.669~4.571, P<0.001) and the percentage of CD3 + decreased ( OR=6.019, 95% CI 3.993~9.331, P<0.001)were risk factors for severe influenza pneumonia. Conclusion:Among hospitalized children with influenza pneumonia, there were some differences in the age of infection, clinical characteristics, laboratory tests and pathogens of co-infection between the cases caused by influenza B and influenza A, and clinicians should remain vigilant for the occurrence of severe influenza pneumonia.

Prokaryotic expression and serological analysis of the head domain of influenza A virus hemagglutinin / 中华微生物学和免疫学杂志

Objective:To express the head domain of influenza A virus hemagglutinin (HA) in a prokaryotic expression system and to evaluate its immunogenicity.Methods:The genes encoding the HA head domains of H1N1 and H3N2 influenza viruses were cloned into pET-22b(+ ) prokaryotic expression plasmid. After the induction with IPTG, the fusion proteins rH1N1-HA and rH3N2-HA containing HA head domain and His-tag were expressed and obtained from E. coli BL21. SDS-PAGE and Western blot was used to verify the expression of the recombinant proteins. Rabbits were immunized with multiple doses of the purified recombinant proteins to obtain polyclonal antibodies against the HA head domains of H1N1 and H3N2. The immunogenicity of the recombinant proteins was evaluated in BALB/c mice. Results:rH1N1-HA and rH3N2-HA induced protective antibodies (geometric mean titer ≥40) in mice and could be used as protective antigens. Polyclonal antibodies against rH1N1-HA and rH3N2-HA could be used as important materials for Western blot, ELISA and other immunological assays.Conclusions:The HA head domains prepared in this study could be used as protective antigens to induce protective antibodies in mice. Polyclonal antibodies against the HA head domains could be used for immunological and serological studies of influenza A viruses.

Preparation and identification of antibodies targeting influenza A virus N1 subtype neuraminidase / 中华微生物学和免疫学杂志

Objective:To prepare and identify a functional antibody FNA1 targeting the neuraminidase (NA) of influenza A virus N1 subtype.Methods:According to single-chain antibody fragment (scFv) sequence, the heavy chain and light chain variable region sequences of FNA1 were synthesized, and the recombinant expression plasmid pFRT-IgG1κ-FNA1 was constructed by linking the expression vector pFRT-IgG1κ. The FNA1 antibody was expressed in ExpiCHO cells and purified using affinity purification technique. The binding ability of FNA1 to the target proteins, influenza A virus N1 subtype NA antigens, was detected by ELISA. Flow cytometry was performed to analyze the binding ability of FNA1 to the NA antigens expressed on the surface of cell membrane. The in vitro activity of FNA1 against NA was evaluated by infecting 293T cells with pseudovirus. Results:Protein electrophoresis showed that FNA1 with high purity was obtained. FNA1 specifically recognized and bound to N1 subtype NA antigens in a concentration-dependent manner. FNA1 could effectively block NA activity by binding to N1 subtype NA protein expressed on the surface of cell membrane, thus inhibiting the release of packaged pseudovirus from cell surface and further inhibiting target cell infection.Conclusions:An antibody FNA1 targeting influenza A virus N1 subtype NA with in vitro functional activity was obtained.

Construction of a novel bivalent DNA vaccine against SARS-CoV-2 and influenza A virus H3N2 and evaluation of its immunogenicity in mice / 中华微生物学和免疫学杂志

Objective:To construct a bivalent DNA vaccine against SARS-CoV-2 and influenza A virus H3N2 and to evaluate its immunogenicity in mice.Methods:The coding sequences for spike 1 (S1) protein of SARS-CoV-2 Beta variant and hemagglutinin (HA) of influenza A virus Cambodia (H3N2) strain were codon-optimized and synthesized. The two coding genes were ligated by the self-cleaving 2A peptide using over-lapping PCR to construct S1-2A-HA fragment, which was inserted into pVRC vector to construct the bivalent DNA vaccine, named as pVRC-S1-2A-HA. Indirect immunofluorescence assay (IFA) and Western blot were performed to detect the expression of S1 and HA proteins. BALB/c mice were immunized with pVRC-S1-2A-HA by intramuscular injection and electroporation. The humoral immune responses induced in mice were detected by indirect ELISA, pseudovirus neutralization assay and hemagglutination inhibition assay. Cellular immune responses were detected by IFN-γ ELISPOT, intracellular cytokine staining (ICS) and cytometric bead array (CBA).Results:The bivalent DNA vaccine pVRC-S1-2A-HA could express S1 and HA proteins in vitro. Specific cellular immune responses against S1 protein and specific IgG antibody against HA protein were significantly induced in mice with single-dose immunization. The antigen-specific immunity was significantly enhanced after booster immunization. The geometric mean titer (GMT) of specific IgG antibody increased to 3 251 for S1 protein and 45 407 for HA protein after two-dose immunization. Moreover, the S1-specific T cells increased to 1 238 SFC/10 6 cells. ICS results indicated that the booster vaccination induced CD4 + T and CD8 + T cells to produce IL-2, IFN-γ and TNF-α in mice. The secretion of various cytokines including IL-2, IL- 4, IL-6, IL-10 and IFN-γ in mouse splenocytes was induced after single-dose immunization. Conclusions:A bivalent DNA vaccine against SARS-CoV-2 and influenza A virus H3N2 was constructed and could induce S1- and HA-specific humoral and cellular immune responses in mice, suggesting the great potential of it for further development and application.

Preparation and identification of a broad-spectrum antibody targeting hemagglutinin protein of influenza A virus / 中华微生物学和免疫学杂志

Objective:To prepare and identify a broad-spectrum antibody FHA3 targeting influenza A virus hemagglutinin (HA).Methods:According to the single-chain antibody fragment (scFv) sequence, the heavy chain (VH) and light chain (VL) variable regions of FHA3 were amplified by PCR and a recombinant plasmid pFRT-IgG1κ-FHA3 was constructed by linking the expression vector pFRT-IgG1κ. FHA3 was expressed in the ExpiCHO system and purified by affinity purification. The binding activity of FHA3 to influenza A virus HA was detected by ELISA. The neutralizing activity of FHA3 was detected in vitro by infecting host cells with pseudovirus. Results:SDS-PAGE showed that high-purity FHA3 was obtained. FHA3 could bind to H1N1 HA, H2N2 HA, H3N2 HA, H5N1 HA, H7N9 HA and H9N2 HA in a concentration-dependent manner. FHA3 had good neutralizing activity in vitro that was it could effectively block the invasion of H5N1 and H7N9 pseudoviruses into target cells at a low concentration of 5 μg/ml and H1N1 pseudovirus at 0.012 5 μg/ml. Conclusions:A broad spectrum antibody targeting HA protein of influenza A virus with neutralizing activity in vitro was obtained.