RESUMO
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), is a global health threat with the potential to cause severe disease manifestations in the lungs. Although COVID-19 has been extensively characterized clinically, the factors distinguishing SARS-CoV-2 from other respiratory viruses are unknown. Here, we compared the clinical, histopathological, and immunological characteristics of patients with COVID-19 and pandemic influenza A(H1N1). We observed a higher frequency of respiratory symptoms, increased tissue injury markers, and a histological pattern of alveolar pneumonia in pandemic influenza A(H1N1) patients. Conversely, dry cough, gastrointestinal symptoms and interstitial lung pathology were observed in COVID-19 cases. Pandemic influenza A(H1N1) was characterized by higher levels of IL-1RA, TNF-α, CCL3, G-CSF, APRIL, sTNF-R1, sTNF-R2, sCD30, and sCD163. Meanwhile, COVID-19 displayed an immune profile distinguished by increased Th1 (IL-12, IFN-γ) and Th2 (IL-4, IL-5, IL-10, IL-13) cytokine levels, along with IL-1ß, IL-6, CCL11, VEGF, TWEAK, TSLP, MMP-1, and MMP-3. Our data suggest that SARS-CoV-2 induces a dysbalanced polyfunctional inflammatory response that is different from the immune response against pandemic influenza A(H1N1). Furthermore, we demonstrated the diagnostic potential of some clinical and immune factors to differentiate both diseases. These findings might be relevant for the ongoing and future influenza seasons in the Northern Hemisphere, which are historically unique due to their convergence with the COVID-19 pandemic.
Assuntos
COVID-19 , Citocinas , Vírus da Influenza A Subtipo H1N1 , Influenza Humana , Metaloproteinase 1 da Matriz , Metaloproteinase 3 da Matriz , Receptores Imunológicos , Adulto , Idoso , COVID-19/sangue , COVID-19/epidemiologia , COVID-19/imunologia , Citocinas/sangue , Citocinas/imunologia , Feminino , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H1N1/metabolismo , Influenza Humana/sangue , Influenza Humana/epidemiologia , Influenza Humana/imunologia , Masculino , Metaloproteinase 1 da Matriz/sangue , Metaloproteinase 1 da Matriz/imunologia , Metaloproteinase 3 da Matriz/sangue , Metaloproteinase 3 da Matriz/imunologia , Pessoa de Meia-Idade , Estudos Prospectivos , Receptores Imunológicos/sangue , Receptores Imunológicos/imunologia , Células Th1/imunologia , Células Th2/imunologiaRESUMO
The differentiation between influenza and coronavirus disease 2019 (COVID-19) could constitute a diagnostic challenge during the ongoing winter owing to their clinical similitude. Thus, novel biomarkers are required to enable making this distinction. Here, we evaluated whether the surfactant protein D (SP-D), a collectin produced at the alveolar epithelium with known immune properties, was useful to differentiate pandemic influenza A(H1N1) from COVID-19 in critically ill patients. Our results revealed high serum SP-D levels in patients with severe pandemic influenza but not those with COVID-19. This finding was validated in a separate cohort of mechanically ventilated patients with COVID-19 who also showed low plasma SP-D levels. However, plasma SP-D levels did not distinguish seasonal influenza from COVID-19 in mild-to-moderate disease. Finally, we found that high serum SP-D levels were associated with death and renal failure among severe pandemic influenza cases. Thus, our studies have identified SP-D as a unique biomarker expressed during severe pandemic influenza but not COVID-19.
Assuntos
COVID-19/genética , Expressão Gênica , Interações Hospedeiro-Patógeno/genética , Vírus da Influenza A Subtipo H1N1 , Influenza Humana/genética , Proteína D Associada a Surfactante Pulmonar/genética , SARS-CoV-2 , Adulto , Idoso , Biomarcadores , COVID-19/sangue , COVID-19/diagnóstico , COVID-19/virologia , Coinfecção , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Influenza Humana/diagnóstico , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Proteína D Associada a Surfactante Pulmonar/sangue , Índice de Gravidade de Doença , Avaliação de Sintomas , Adulto JovemRESUMO
(1) Background: The influenza A/H1N1 pdm09 virus rapidly spread throughout the world. Despite the inflammatory and virus-degradation pathways described in the pathogenesis of influenza A virus (IAV) infection, little is known about the role of the single nucleotide polymorphisms (SNPs) in the genes involved in the processing and antigenic presentation-related mechanisms. (2) Methods: In this case-control study, we evaluated 17 SNPs in five genes (TAP1, TAP2, TAPBP, PSMB8, and PSMB9). One hundred and twenty-eight patients with influenza A/H1N1 infection (INF-P) and 111 healthy contacts (HC) were included; all of them are Mexican mestizo. (3) Results: In allele and genotype comparison, the rs241433/C allele (TAP2), as well as AG haplotype (rs3763365 and rs4148882), are associated with reduced risk for influenza A/H1N1 infection (p < 0.05). On the other hand, the rs2071888G allele (TAPBP) and GG haplotype (rs3763365 and rs9276810) are associated with a higher risk for influenza A/H1N1 infection. In addition, after adjustment for covariates, the association to a reduced risk for influenza A/H1N1 infection remains with rs241433/C allele (p < 0.0001, OR = 0.24, 95% CI = 0.13-0.43), and the association with TAPBP is also maintained with the G allele (p = 0.0095, OR = 1.89, 95% CI = 1.17-3.06) and GG genotype models (p < 0.05, OR = 2.18, 95% CI = 1.27-3.74). (4) Conclusion: The rs241433/C allele and AC genotype (TAP2) and the AG haplotype are associated with a reduced risk for influenza A/H1N1 infection. In addition, the rs2071888/G allele and GG genotype (TAPBP) and the GG haplotype are associated with a higher risk for developing influenza A/H1N1 infection in a Mexican mestizo population.
Assuntos
Apresentação de Antígeno/genética , Predisposição Genética para Doença/etnologia , Vírus da Influenza A Subtipo H1N1/imunologia , Influenza Humana/epidemiologia , Polimorfismo de Nucleotídeo Único , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença/epidemiologia , Genótipo , Haplótipos , Humanos , Influenza Humana/etnologia , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
BACKGROUND Influenza viral load (VL) can be a decisive factor in determining the antiviral efficacy in viral clearance. OBJECTIVE This study aimed to evaluate the rate of infection and the role of influenza VL on the clinical spectrum of illnesses among different patient groups attended at a tertiary hospital in Brazil. METHODS Samples were collected from patients presenting acute respiratory infection from 2009 to 2013. Overall, 2262 samples were analysed and distributed into three groups: (i) asymptomatic (AS); (ii) symptomatic outpatients (OP); and (iii) hospitalised patients (HP). VL (expressed in Log10 RNA copies/mL) was calculated through a quantitative real-time one-step reverse transcription-polymerase chain reaction (RT-PCR) assay aimed at the M gene, with human RNAseP target as internal control and normalising gene of threshold cycle values. FINDINGS A total of 162 (7.16%) H1N1pdm09 positive samples were analysed. Patients aged from 0.08 to 77 years old [median ± standard deviation (SD): 12.5 ± 20.54]. Children with 5 to 11 years old presented the highest detection (p < 0.0001). AS patients had the lowest VL, with a significant difference when compared with symptomatic patients (p = 0.0003). A higher VL was observed within two days of disease onset. Ten patients (HP group) received antiviral treatment and were followed up and presented a mean initial VL of 6.64 ± 1.82. A complete viral clearance for 50% of these patients was reached after 12 days of treatment. MAIN CONCLUSIONS It is important to evaluate AS patients as potential spreaders, as viral shedding was still present, even at lower VL. Our results suggest that patients with underlying diseases and severe clinical symptoms may be considered for prolonged viral treatment.
Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Lactente , Pré-Escolar , Criança , Adolescente , Adulto , Idoso , Adulto Jovem , Infecções Respiratórias/virologia , Influenza Humana/virologia , Vírus da Influenza A Subtipo H1N1/genética , RNA Viral/genética , Doença Aguda , Carga Viral , Vírus da Influenza A Subtipo H1N1/classificação , Vírus da Influenza A Subtipo H1N1/patogenicidade , Reação em Cadeia da Polimerase em Tempo Real , Pessoa de Meia-IdadeRESUMO
The clinical effects and immunological response to the influenza vaccine in women who later become pregnant remain to be thoroughly studied. Here, we report the medical outcomes of 40 women volunteers who became pregnant after vaccination with an experimental virus-like particle (VLP) vaccine against pandemic influenza A(H1N1)2009 (influenza A(H1N1)pdm09) and their infants. When included in the VLP vaccine trial, none of the women were pregnant and were randomly assigned to one of the following groups: (1) placebo, (2) 15 µg dose of VLP vaccine, or (3) 45 µg dose of VLP vaccine. These 40 women reported becoming pregnant during the follow-up phase after receiving the placebo or VLP vaccine. Women were monitored throughout pregnancy and their infants were monitored until one year after birth. Antibody titers against VLP were measured in the mothers and infants at delivery and at six months and one year after birth. The incidence of preeclampsia, fetal death, preterm delivery, and premature rupture of membranes was similar among groups. All vaccinated women and their infants elicited antibody titers (≥1:40). Women vaccinated prior to pregnancy had no adverse events that were different from the nonvaccinated population. Even though this study is limited by the sample size, the results suggest that the anti-influenza A(H1N1)pdm09 VLP experimental vaccine applied before pregnancy is safe for both mothers and their infants.
Assuntos
Anticorpos Antivirais/sangue , Surtos de Doenças , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Pandemias , Vacinação , Adulto , Estudos de Coortes , Feminino , Humanos , Lactente , Recém-Nascido , Vacinas contra Influenza/efeitos adversos , Influenza Humana/epidemiologia , Influenza Humana/virologia , Masculino , México , Gravidez , Resultado da Gravidez , Vacinas de Partículas Semelhantes a Vírus/imunologia , Adulto JovemRESUMO
Influenza is a leading cause of respiratory tract infections worldwide and there is limited information on the impact of the influenza A(H1N1)pdm virus on mortality after the 2009 pandemic. Using national mortality register data through 1998-2015 in Mexico, influenza-associated mortality was estimated for respiratory, cardiovascular, and all-cause events. The proportion of influenza-associated respiratory and cardiovascular deaths among different age groups were compared. There were 8,853,986 death registries included for the 1998-2015 winter seasons, average influenza-associated respiratory, cardiovascular, and all-cause mortality rates were 5.2, 6.3, and 19.6 deaths/100,000 population, respectively. The largest number of respiratory influenza-associated deaths occurred in adults 60 years of age and older, followed by children <5 years of age; during the 2009 pandemic, 2011-2012, and 2013-2014 winter seasons there was a larger number of deaths in the 20-59 years old group. Influenza-associated mortality rates showed a continuous reduction in children <5 years of age. After the 2009 pandemic, influenza A(H1N1)pdm09 virus-associated mortality in Mexico showed a persistent change in the demographic pattern of the most severely affected population, particularly during the 2013-2014 season. Influenza associated-mortality has decreased in children <5 years of age and continue to be elevated in adults >60 years of age.
Assuntos
Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/mortalidade , Influenza Humana/virologia , Fatores Etários , Humanos , Influenza Humana/epidemiologia , México/epidemiologia , Estações do Ano , Análise de SobrevidaRESUMO
Influenza A(H1N1)pdm09 was responsible for the first global flu pandemic in 21st century affecting all the world. In Brazil, A(H1N1)pdm09 is still circulating as a seasonal virus, causing deaths every year. Nevertheless, the viral diffusion process that yearly seeds new influenza strains in the country was not investigated yet. The aim of the current study was to describe the phylodynamics and phylogeography of influenza A(H1N1)pdm09 in Brazil between 2009 and 2014. Neuraminidase sequences from Brazil and other regions of the World were retrieved and analyzed. Bayesian phylogeographic and phylodynamic model approaches were used to reconstruct the spatiotemporal and demographic history of influenza A(H1N1)pdm09 in Brazil (divided in subtropical and tropical regions) and related countries. Our analyses reveal that new influenza A(H1N1)pdm09 lineages are seeded in Brazil in almost each year and the main sources of viral diversity are North America, Europe and East Asia. The phylogeographic asymmetric model also revealed that Brazil, mainly the subtropical region, seeds viral lineages into other countries. Coalescent analysis of the compiled dataset reconstructed the peak of viral transmissions in the winter months of Southern hemisphere. The results presented in this study can be informative to public health, guide intervention strategies and in the understanding of flu virus migration, which helps to predict antigenic drift and consequently the developing of new vaccines.
Assuntos
Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/epidemiologia , Influenza Humana/virologia , Pandemias , Topografia Médica , Brasil , Humanos , Epidemiologia Molecular , Neuraminidase/genética , Filogeografia , Estações do Ano , Análise Espaço-Temporal , Proteínas Virais/genéticaRESUMO
It is important to characterize the clinical and epidemiological pattern of the influenza A (H1N1) pdm09 virus and compare it with influenza A (H3N2) virus, as surveyed in just a few studies, in order to contribute to the implementation and strengthening of influenza control and prevention strategies. The aims in this study were to describe influenza clinical and epidemiological characteristics in hospitalized patients, caused by influenza A (H1N1)pdm09 and influenza A (H3N2) viruses during 2013, in Santa Fe, Argentina. A retrospective study was conducted over 2013 among hospitalized patients with laboratory-confirmed influenza diagnosis. In contrast to patients with influenza A (H3N2) (20.5%), a higher proportion of hospitalizations associated with influenza H1N1pdm were reported among adults aged 35-65 years (42.8%). Of all patients, 73.6% had an underlying medical condition. Hospitalized patients with H1N1pdm were subject to 2.6 (95%CI, 1.0-6.8) times higher risk of severity, than those hospitalized with influenza A (H3N2). This results demonstrate the impact in the post-pandemic era of H1N1pdm virus, with increased risk of severe disease, in relation to H3N2 virus, both viruses co-circulating during 2013.
Assuntos
Vírus da Influenza A Subtipo H1N1 , Vírus da Influenza A Subtipo H3N2 , Influenza Humana/epidemiologia , Adolescente , Adulto , Idoso , Argentina/epidemiologia , Criança , Pré-Escolar , Feminino , Hospitalização , Humanos , Lactente , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/imunologia , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Influenza Humana/diagnóstico , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Pandemias , Reação em Cadeia da Polimerase , Estudos Retrospectivos , Índice de Gravidade de Doença , Adulto JovemRESUMO
This retrospective cohort study investigated the presence of bacteria in respiratory secretions of patients hospitalized with acute respiratory infections and analyzed the impact of viral and bacterial coinfection on severity and the mortality rate. A total of 169 patients with acute respiratory infections were included, viruses and bacteria in respiratory samples were detected using molecular methods. Among all samples, 73.3% and 59.7% were positive for viruses and bacteria, respectively; 45% contained both virus and bacteria. Bacterial coinfection was more frequent in patients infected by community respiratory viruses than influenza A H1N1pdm (83.3% vs. 40.6%). The most frequently bacteria detected were Streptococcus pneumoniae and Haemophilus influenzae. Both species were co-detected in 54 patients and identified alone in 22 and 21 patients, respectively. Overall, there were no significant differences in the period of hospitalization, severity, or mortality rate between patients infected with respiratory viruses alone and those coinfected by viruses and bacteria. The detection of mixed respiratory pathogens is frequent in hospitalized patients with acute respiratory infections, but its impact on the clinical outcome does not appear substantial. However, it should be noted that most of the patients received broad-spectrum antibiotic therapy, which may have contributed to this favorable outcome.
Assuntos
Infecções Bacterianas/complicações , Coinfecção , Infecções Respiratórias/microbiologia , Infecções Respiratórias/virologia , Viroses/complicações , Doença Aguda , Idoso , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Infecções Bacterianas/microbiologia , Estudos de Coortes , Feminino , Haemophilus influenzae/genética , Haemophilus influenzae/isolamento & purificação , Haemophilus influenzae/patogenicidade , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Masculino , Pessoa de Meia-Idade , Infecções Respiratórias/mortalidade , Estudos Retrospectivos , Índice de Gravidade de Doença , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/isolamento & purificação , Viroses/virologia , Vírus/genética , Vírus/isolamento & purificaçãoRESUMO
The aim of this paper was to analyze the spatiotemporal variations of cases of influenza A(H1N1)pdm09 in Argentina. A space-time permutation scan statistic was performed to test the non-randomness in the interaction between space and time in reported influenza A(H1N1)pdm09 cases. In 2009, two clusters were recorded in the east of Buenos Aires Province (May and June) and in the central and northern part of Argentina (July and August). Between 2011 and 2012, clusters near areas bordering other countries were registered. Within the clusters, in 2009, the high notification rates were first observed in the school-age population and then extended to the older population (15-59 years). From 2011 onwards, higher rates of reported cases of influenza A(H1N1)pdm09 occurred in children under five years in center of the country. Two stages of transmission of influenza A(H1N1)pdm09 can be characterized. The first stage had high rates of notification and a possible interaction with individuals from other countries in the major cities of Argentina (pattern of hierarchy), and the second stage had an increased interaction in some border areas without a clear pattern of hierarchy. These results suggest the need for greater coordination in the Southern Cone countries, in order to implement joint prevention and vaccination policies.
El objetivo de este trabajo es analizar las variaciones espaciotemporales de los casos de gripe A(H1N1)pdm09 en Argentina. Se realizó un escaneo estadístico espacio-temporal por permutaciones para poner a prueba la no aleatoriedad en la interacción entre espacio y tiempo de los casos registrados de gripe A(H1N1)pdm09. Durante 2009 se identificaron dos conglomerados espacio-temporales, en el este de la provincia de Buenos Aires (mayo y junio) y en la mayor parte del centro-norte de la Argentina (julio y agosto). Durante 2011 y 2012 se registraron conglomerados próximos a zonas limítrofes con otros países. Al interior de los conglomerados, primero se observaron mayores tasas de notificación en población de edad escolar para luego extenderse a población mayor (15-59 años). A partir de 2011, las mayores tasas se observaron en menores de 5 años residentes en el centro del país. Se pudieron caracterizar dos etapas de transmisión espacio-temporal de la gripe A(H1N1)pdm09. La primera etapa se caracterizó por altas tasas de notificación y una posible interacción con individuos provenientes de otros países llegados a las grandes ciudades de la Argentina (patrón de jerarquía). La segunda etapa mostró una mayor interacción en algunas zonas fronterizas y sin un patrón claro de jerarquía. Estos resultados plantean la necesidad de generar una mayor coordinación en países del Cono Sur, con el objetivo de implementar políticas más efectivas de prevención y vacunación.
Assuntos
Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Vírus da Influenza A Subtipo H1N1 , Influenza Humana/epidemiologia , Argentina/epidemiologia , Notificação de Doenças , Influenza Humana/virologia , Conglomerados Espaço-TemporaisRESUMO
BACKGROUND AND AIMS: In April 2009, a new strain of influenza A(H1N1) was identified in Mexico and in the U.S. In June 2009, WHO declared this a pandemic. Health care workers constituted a risk group for their close contact with infected individuals. The aim was to estimate seropositivity for A(H1N1)pdm09 in health staff at the Instituto Mexicano del Seguro Social. METHODS: A two-stage cross-sectional study, before and after vaccination in the same workers, was performed on a random sample of health-care workers. A socio-occupational questionnaire was applied and serum antibodies against influenza A(H1N1)pdm09 were determined through neutralization of retroviral pseudotypes; two logistic regression models for both were constructed. RESULTS: The average (median/mean) age of 1378 participants from 13 work centers was 41.7 years and 68.7% (947) were women. Seroprevalence for the first stage was 26.5% (365) (7.4-43%) vs. 20.8% (11) in a control group from the blood bank; for the second stage, the vaccinated group was 33% (215) (18.2-47%) and 27% (196) (11.6-50%) for the unvaccinated group. In regression models, seropositivity was associated with occupational exposure to suspected influenza infected patients, being physicians, and being vaccinated. CONCLUSIONS: Seropositivity against pandemic virus is similar to what was reported, both for vaccinated (2.8-40.9%) and unvaccinated (18.8-64.7%). Low seroprevalence in the vaccinated group indicates that between 67% and 73% were susceptible to infection. Given the relatively low vaccine-induced seropositivity, it is imperative to increase, hygiene and safety for health staff and at-risk populations, and strengthen epidemiological surveillance.
Assuntos
Anticorpos Antivirais/sangue , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/epidemiologia , Adulto , Idoso , Bancos de Sangue , Estudos Transversais , Feminino , Pessoal de Saúde , Humanos , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Modelos Logísticos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Exposição Ocupacional , Médicos , Estudos Soroepidemiológicos , Inquéritos e Questionários , Vacinação , Adulto JovemRESUMO
The 2009 pandemic influenza A virus outbreak led to the systematic use of the neuraminidase (NA) inhibitor oseltamivir (OST). Consequently, OST-resistant strains, carrying the mutation H275Y, emerged in the years after the pandemics, with a prevalence of 1-2%. Currently, OST-resistant strains have been found in community settings, in untreated individuals. To spread in community settings, H275Y mutants must contain additional mutations, collectively called permissive mutations. We display the permissive mutations in NA of OST-resistant A(H1N1)pdm09 virus found in Brazilian community settings. The NAs from 2013 are phylogenetically distinct from those of 2012, indicating a tendency of positive selection of NAs with better fitness. Some previously predicted permissive mutations, such as V241I and N369K, found in different countries, were also detected in Brazil. Importantly, the change D344N, also predicted to compensate loss of fitness imposed by H275Y mutation, was found in Brazil, but not in other countries in 2013. Our results reinforce the notion that OST-resistant A(H1N1)pdm09 strains with compensatory mutations may arise in an independent fashion, with samples being identified in different states of Brazil and in different countries. Systematic circulation of these viral strains may jeopardise the use of the first line of anti-influenza drugs in the future. (AU)
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Vírus da Influenza A , Farmacorresistência Viral , Oseltamivir/farmacologia , Mutação/efeitos dos fármacosRESUMO
After the World Health Organization officially declared the end of the first pandemic of the XXI century in August 2010, the influenza A(H1N1)pdm09 virus has been disseminated in the human population. In spite of its sustained circulation, very little on phylogenetic data or oseltamivir (OST) resistance is available for the virus in equatorial regions of South America. In order to shed more light on this topic, we analysed the haemagglutinin (HA) and neuraminidase (NA) genes of influenza A(H1N1)pdm09 positive samples collected during the pandemic period in the Pernambuco (PE), a northeastern Brazilian state. Complete HA sequences were compared and amino acid changes were related to clinical outcome. In addition, the H275Y substitution in NA, associated with OST resistance, was investigated by pyrosequencing. Samples from PE were grouped in phylogenetic clades 6 and 7, being clustered together with sequences from South and Southeast Brazil. The D222N/G HA gene mutation, associated with severity, was found in one deceased patient that was pregnant. Additionally, the HA mutation K308E, which appeared in Brazil in 2010 and was only detected worldwide the following year, was identified in samples from hospitalised cases. The resistance marker H275Y was not identified in samples tested. However, broader studies are needed to establish the real frequency of resistance in this Brazilian region.
Assuntos
Feminino , Humanos , Gravidez , Hemaglutininas/genética , Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/epidemiologia , Neuraminidase/genética , Pandemias , Antivirais/uso terapêutico , Biomarcadores/análise , Brasil/epidemiologia , Farmacorresistência Viral/fisiologia , Frequência do Gene/genética , Vírus da Influenza A Subtipo H1N1/classificação , Vírus da Influenza A Subtipo H1N1/patogenicidade , Influenza Humana/virologia , Mutação/genética , Oseltamivir/uso terapêutico , Filogenia , RNA Viral/análise , Análise de Sequência de DNA/métodos , Virulência , Fatores de Virulência/genéticaRESUMO
INTRODUCCIÓN: entre marzo y abril de 2009 se produjeron en México brotes de enfermedad respiratoria, debido a un nuevo virus de influenza proveniente del cerdo, el cual se diseminó rápidamente mediante la transmisión humano-humano. Los métodos moleculares usados en la actualidad eran inadecuados, porque la composición del genoma del nuevo virus era muy diferente del virus influenza A (H1N1) que había circulado hasta el momento. En su composición, estaba formado por segmentos de genes de origen aviar, humano y cerdo. OBJETIVO: teniendo en cuenta las secuencias publicadas, se diseñó un juego de cebadores específicos para el gen de la hemaglutinina, con la finalidad de evaluar un nuevo ensayo de TR-RCP para detectar el nuevo virus pandémico en Cuba. MÉTODOS: se procesó un total de 3 197 muestras clínicas de casos sospechosos de infección por el virus influenza A (H1N1) pandémico (pdm) mediante un ensayo de transcripción reversa-reacción en cadena de la polimerasa. RESULTADOS: el ensayo optimizado permitió obtener una banda de 292 pb, sin reacciones inespecíficas. El nuevo método resultó ser útil en el diagnóstico y subtipado del virus de influenza H1N1 pdm. El producto amplificado fue analizado por secuenciación nucleotídica y se confirmó la identificación del virus. CONCLUSIONES: con la introducción de este nuevo ensayo para la vigilancia de influenza, se fortalece la capacidad diagnóstica del Laboratorio Nacional de Referencia.
INTRODUCTION: from March through April of 2009, Mexico notified outbreaks of respiratory illness, due to a new influenza virus of swine origin, which spread over rapidly via human-to-human transmission. The molecular methods currently in use were not suitable because the genome composition based on gene segments of swine, avian and human origin was quite different from the influenza A virus (H1N1) circulating at that time. OBJECTIVE: based on the published sequences, a set of specific primers for the HA gene was designed to evaluate a new RT-PCR assay. METHODS: the RT-PCR assay processed 3 197 clinical samples from suspected cases of pandemic influenza A (H1N1) infection. RESULTS: the novel optimized method obtained a 262 pb segment, without unspecific reactions. The new method proved to be useful in the diagnosis and subtyping of pandemic HINI influenza virus. The amplified product was verified by nucleotide sequencing, thus confirming the virus. CONCLUSIONS: the introduction of this new assay for the laboratory surveillance of influenza virus strengthens the diagnostic capacity of the National Reference Laboratory.