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Chinese Medical Journal ; (24): 2429-2436, 2020.
Article in English | WPRIM | ID: wpr-877825


BACKGROUND@#Endothelial cells play a key role in the cytokine storm caused by influenza A virus. MicroRNA-155 (miR-155) is an important regulator in inflammation. Its role in the inflammatory response to influenza A infection, however, has yet to be elucidated. In this study, we explored the role as well as the underlying mechanism of miR-155 in the cytokine production in influenza A-infected endothelial cells.@*METHODS@#Human pulmonary microvascular endothelial cells (HPMECs) were infected with the influenza A virus strain H1N1. The efficiency of H1N1 infection was confirmed by immunofluorescence. The expression levels of proinflammatory cytokines and miR-155 were determined using real-time polymerase chain reaction. A dual-luciferase reporter assay characterized the interaction between miR-155 and sphingosine-1-phosphate receptor 1 (S1PR1). Changes in the target protein levels were determined using Western blot analysis.@*RESULTS@#MiR-155 was elevated in response to the H1N1 infection in HPMECs (24 h post-infection vs. 0 h post-infection, 3.875 ± 0.062 vs. 1.043 ± 0.013, P = 0.001). Over-expression of miR-155 enhanced inflammatory cytokine production (miR-155 mimic vs. negative control, all P < 0.05 in regard of cytokine levels) and activation of nuclear factor kappa B in infected HPMECs (miR-155 mimic vs. negative control, P = 0.004), and down-regulation of miR-155 had the opposite effect. In addition, S1PR1 was a direct target of miR-155 in the HPMECs. Inhibition of miR-155 enhanced the expression of the S1PR1 protein. Down-regulation of S1PR1 decreased the inhibitory effect of the miR-155 blockade on H1N1-induced cytokine production and nuclear factor kappa B activation in HPMECs.@*CONCLUSION@#MiR-155 maybe modulate influenza A-induced inflammatory response by targeting S1PR1.

Down-Regulation , Endothelial Cells , Humans , Influenza A Virus, H1N1 Subtype/genetics , Influenza A virus , Influenza, Human/genetics , MicroRNAs/genetics , Sphingosine-1-Phosphate Receptors
Mem. Inst. Oswaldo Cruz ; 115: e200009, 2020. tab, graf
Article in English | LILACS, SES-SP | ID: biblio-1135259


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.

Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Aged , Young Adult , Respiratory Tract Infections/virology , Influenza, Human/virology , Influenza A Virus, H1N1 Subtype/genetics , RNA, Viral/genetics , Acute Disease , Viral Load , Influenza A Virus, H1N1 Subtype/classification , Influenza A Virus, H1N1 Subtype/pathogenicity , Real-Time Polymerase Chain Reaction , Middle Aged
Rev. méd. Chile ; 143(8): 1070-1075, ago. 2015. ilus, tab
Article in Spanish | LILACS | ID: lil-762673


Bacterial superinfection is a known complication among patients affected by viral respiratory tract infections. Streptococcus pyogenes, a major bacterial agent involved in acute tonsillopharyngitis, skin and soft tissue infections, was reported as a co-infecting microorganism during the 2009 A H1N1 influenza pandemic. We report a 65-year-old male patient who evolved with multifocal pneumonia and multiple organ failure with a fatal outcome. Influenza A H1N1 was detected by a polymerase chain reaction-based technique from a tracheal aspirate sample. S. pyogenes was identified by a rapid test from a nasopharyngeal sample and isolated afterwards from a positive blood culture.

Aged , Humans , Male , Influenza A Virus, H1N1 Subtype/genetics , Influenza, Human/complications , Pneumonia/complications , Streptococcus pyogenes/isolation & purification , Coinfection/microbiology , Fatal Outcome , Influenza, Human/diagnosis , Multiple Organ Failure/complications , Polymerase Chain Reaction , Pneumonia , Superinfection/microbiology
Mem. Inst. Oswaldo Cruz ; 109(7): 912-917, 11/2014. tab, graf
Article in English | LILACS | ID: lil-728806


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.

Female , Humans , Pregnancy , Hemagglutinins/genetics , Influenza A Virus, H1N1 Subtype/genetics , Influenza, Human/epidemiology , Neuraminidase/genetics , Pandemics , Antiviral Agents/therapeutic use , Biomarkers/analysis , Brazil/epidemiology , Drug Resistance, Viral/physiology , Gene Frequency/genetics , Influenza A Virus, H1N1 Subtype/classification , Influenza A Virus, H1N1 Subtype/pathogenicity , Influenza, Human/virology , Mutation/genetics , Oseltamivir/therapeutic use , Phylogeny , RNA, Viral/analysis , Sequence Analysis, DNA/methods , Virulence , Virulence Factors/genetics
Mem. Inst. Oswaldo Cruz ; 108(3): 392-394, maio 2013.
Article in English | LILACS | ID: lil-676978


The neuraminidase (NA) genes of A(H1N1)pdm09 influenza virus isolates from 306 infected patients were analysed. The circulation of oseltamivir-resistant viruses in Brazil has not been reported previously. Clinical samples were collected in the state of Rio Grande do Sul (RS) from 2009-2011 and two NA inhibitor-resistant mutants were identified, one in 2009 (H275Y) and the other in 2011 (S247N). This study revealed a low prevalence of resistant viruses (0.8%) with no spread of the resistant mutants throughout RS.

Humans , Antiviral Agents/pharmacology , Drug Resistance, Viral/genetics , Influenza A Virus, H1N1 Subtype/drug effects , Mutation , Neuraminidase/genetics , Oseltamivir/pharmacology , Brazil , Influenza A Virus, H1N1 Subtype/enzymology , Influenza A Virus, H1N1 Subtype/genetics , Microbial Sensitivity Tests , Reverse Transcriptase Polymerase Chain Reaction , RNA, Viral/genetics
Yonsei Medical Journal ; : 927-934, 2013.
Article in English | WPRIM | ID: wpr-99043


PURPOSE: Pneumonia was an important cause of death in 2009 H1N1 influenza pandemic (pH1N1). Clinical characteristics of pH1N1 have been described well, but discriminative characteristics suggesting pH1N1 infection in pneumonia patients are not evident today. We evaluated differences between clinical and radiologic characteristics for those associated and not associated with pH1N1 influenza during the pandemic period. MATERIALS AND METHODS: We reviewed all patients with pneumonia who visited the Armed Forces Capital Hospital between July 2009 and February 2010. During this period, all pneumonia patients were tested for pH1N1 by reverse transcription-polymerase chain reaction (RT-PCR) using nasopharyngeal specimens. RESULTS: In total, 98 patients with pneumonia were enrolled. Their median age was 20 years and all patients were males. Forty-nine (50%) of patients had pH1N1 infection and the others (50%) had negative results in pH1N1 RT-PCR. Patients with pH1N1 infection complained of dyspnea more commonly (83.3% vs. 29.0%; p<0.001), had higher Acute Physiology and Chronic Health Evaluation (APACHE) II scores [5 (range, 0-12) vs. 3 (range, 0-11); p<0.01], fewer days of prehospital illness [2 (range, 0-10) vs. 4 (range, 0-14); p=0.001], and a higher chance of bilateral infiltrates on chest X-ray (CXR) (67.3% vs. 14.3%; p<0.001) and ground-glass opacity (GGO) lesions on computed tomography (CT; 48.9% vs. 22.0%; p<0.001) than patients without pH1N1 infection. CONCLUSION: Dyspnea, bilateral infiltrates on CXR, and GGO on CT were dominant features in pH1N1-associated pneumonia. Understanding these characteristics can help selection of patients who require prompt antiviral therapy.

Adolescent , Adult , Antiviral Agents/therapeutic use , Dyspnea/virology , Humans , Influenza A Virus, H1N1 Subtype/genetics , Influenza, Human/complications , Male , Middle Aged , Pneumonia/etiology , Pneumonia, Viral/drug therapy , Radiography, Thoracic , Tomography, X-Ray Computed , Young Adult
Indian J Med Microbiol ; 2012 Jul-Sept; 30(3): 346-349
Article in English | IMSEAR | ID: sea-143982


The H1N1 2009 influenza pandemic took the health care workers by surprise in spite of warning about influenza pandemic. Influenza A virus has the ability to overcome immunity from previous infections through the acquisition of genetic changes by shift or drift. Thus, understanding the evolution of the viruses in human is important for the surveillance and the selection of vaccine strains. A total of 23 pandemic A/H1N1 2009 viral HA gene sequences were downloaded from NCBI submitted during March and May 2010 by NIV and were analysed. Along with that the vaccine strain A/California/07/2009 was also downloaded from NCBI. All the sequences were used to analyse the evolution of the haemagglutinin (HA) by phylogenetic analysis. The HA gene could be divided into four groups with shift from 1 to lV revealing that the HA genes of the influenza A viruses evolved in a sequential way, in comparison to vaccine strain A/California/07/2009. Amino acid sequence analysis of the HA genes of the A/H1N1 2009 isolates, revealed mutations at positions 100, 220 and additional mutations in different positions 114, 171, 179, 190, 208, 219, 222, 239, 240, 247, 251, 260 and 285 .The mutations identified showed the adaptation of the new virus to the host that could lead to genetic changes inherent to the virus resulting in a reassortant which could be catastrophic, hence continuous monitoring of strains is mandatory.

Cluster Analysis , Computational Biology/methods , Evolution, Molecular , Genetic Variation , Hemagglutinins, Viral/genetics , Humans , India , Influenza A Virus, H1N1 Subtype/classification , Influenza A Virus, H1N1 Subtype/genetics , Mutation, Missense , Phylogeny
Rev. argent. microbiol ; 44(1): 0-0, mar. 2012. tab
Article in English | LILACS | ID: lil-639714


At the time of influenza A (H1N1) emergency, the WHO responded with remarkable speed by releasing guidelines and a protocol for a real-time RT-PCR assay (rRT-PCR). The aim of the present study was to evalúate the performance of the "Real Time Ready Influenza A/H1N1 Detection Set" (June 2009)-Roche kit in comparison to the CDC reference rRT-PCR protocol. The overall sensitivity of the Roche assay for detection of the Inf A gene in the presence or absence of the H1 gene was 74.5 %. The sensitivity for detecting samples that were only positive for the Inf A gene (absence of the H1 gene) was 53.3 % whereas the sensitivity for H1N1-positive samples (presence of the Inf A gene and any other swine gene) was 76.4 %. The specificity of the assay was 97.1 %. A new version of the kit (November 2009) is now available, and a recent evaluation of its performance showed good sensitivity to detect pandemic H1N1 compared to other molecular assays.

Durante la pandemia de influenza A (H1N1), la OMS recomendó algoritmos y protocolos de detección del virus mediante RT-PCR en tiempo real. El objetivo del presente estudio fue evaluar el desempeño del equipo que comercializa la empresa Roche, Real Time Ready Influenza A/H1N1 Detection Set (junio de 2009), en comparación con el protocolo de RT-PCR en tiempo real de los CDC. La sensibilidad global del ensayo de Roche para la detección del gen Inf A en presencia o ausencia del gen H1 fue 74,5 %. La sensibilidad para la detección de muestras positivas solo para el gen Inf A (ausencia del gen H1) fue 53,3 % y la sensibilidad para la detección de muestras positivas para H1N1 (presencia del gen Inf A y cualquier otro gen porcino) fue 76,4 %. La especificidad fue 97,1 %. Existe una nueva versión del equipo (noviembre 2009) que, según se ha descrito, presenta buena sensibilidad en comparación con otros ensayos moleculares para detectar H1N1 pandémica.

Humans , Influenza A Virus, H1N1 Subtype , Influenza, Human/diagnosis , Reagent Kits, Diagnostic , Argentina/epidemiology , Centers for Disease Control and Prevention, U.S. , Disease Outbreaks , Hemagglutinin Glycoproteins, Influenza Virus/genetics , Influenza A Virus, H1N1 Subtype/genetics , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza, Human/epidemiology , Influenza, Human/virology , Nasal Cavity/virology , Pharynx/virology , Reproducibility of Results , RNA, Viral/genetics , RNA-Binding Proteins/genetics , Real-Time Polymerase Chain Reaction/methods , Sensitivity and Specificity , United States , Viral Core Proteins/genetics
Article in English | WPRIM | ID: wpr-157107


Plastic bronchitis is an uncommon disorder characterized by the formation of bronchial casts. It is associated with congenital heart disease or pulmonary disease. In children with underlying conditions such as allergy or asthma, influenza can cause severe plastic bronchitis resulting in respiratory failure. A review of the literature showed nine cases of plastic bronchitis with H1N1 including this case. We report a case of a child with recurrent plastic bronchitis with eosinophilic cast associated with influenza B infection, who had recovered from plastic bronchitis associated with an influenza A (H1N1) virus infection 5 months previously. To the best of our knowledge, this is the first case of recurrent plastic bronchitis related to influenza viral infection. If patients with influenza virus infection manifest acute respiratory distress with total lung atelectasis, clinicians should consider plastic bronchitis and early bronchoscopy should be intervened. In addition, management for underlying disease may prevent from recurrence of plastic bronchitis.

Administration, Inhalation , Adrenal Cortex Hormones/therapeutic use , Antiviral Agents/therapeutic use , Bronchitis/complications , Bronchoscopy , Child , DNA, Viral/analysis , Dyspnea/etiology , Humans , Hypersensitivity/pathology , Influenza A Virus, H1N1 Subtype/genetics , Influenza B virus/genetics , Influenza, Human/complications , Male , Oseltamivir/therapeutic use , Pulmonary Atelectasis/drug therapy , Real-Time Polymerase Chain Reaction , Tachypnea/etiology , Tomography, X-Ray Computed
Article in English | WPRIM | ID: wpr-47751


BACKGROUND: Validation of hemagglutination inhibition (HI) assays is important for evaluating antibody responses to influenza virus, and selection of erythrocytes for use in these assays is important. This study aimed to determine the correlation between receptor binding specificity and effectiveness of the HI assay for detecting antibody response to pandemic influenza H1N1 (pH1N1) virus. METHODS: Hemagglutination (HA) tests were performed using erythrocytes from 6 species. Subsequently, 8 hemagglutinating units of pH1N1 from each species were titrated by real-time reverse transcription-PCR. To investigate the effect of erythrocyte binding preference on HI antibody titers, comparisons of HI with microneutralization (MN) assays were performed. RESULTS: Goose erythrocytes showed most specific binding with pH1N1, while HA titers using human erythrocytes were comparable to those using turkey erythrocytes. The erythrocyte binding efficiency was shown to have an impact on antibody detection. Comparing MN titers, HI titers using turkey erythrocytes yielded the most accurate results, while those using goose erythrocytes produced the highest geometric mean titer. Human blood group O erythrocytes lacking a specific antibody yielded results most comparable to those obtained using turkey erythrocytes. Further, pre-existing antibody to pH1N1 and different erythrocyte species can distort HI assay results. CONCLUSIONS: HI assay, using turkey and human erythrocytes, yielded the most comparable and applicable results for pH1N1 than those by MN assay, and using goose erythrocytes may lead to overestimated titers. Selection of appropriate erythrocyte species for HI assay allows construction of a more reliable database, which is essential for further investigations and control of virus epidemics.

Adult , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/analysis , Chickens , Erythrocytes/metabolism , Female , Geese , Hemagglutination Inhibition Tests , Horses , Humans , Influenza A Virus, H1N1 Subtype/genetics , Influenza, Human/epidemiology , Male , Middle Aged , Neutralization Tests , Pandemics , Swine , Turkeys
Article in English | WPRIM | ID: wpr-25821


Neurologic complications of children with influenza A H1N1 2009 pandemic, diagnosed in two consecutive influenza seasons were retrospectively reviewed to seek better outcomes in future outbreaks. Patient demographics, clinical manifestations and neurologic outcomes were reviewed. A total of 1,389 children were diagnosed with influenza A H1N1 by real-time reverse transcriptase-polymerase chain reaction. Of these, 23 (1.7%) patients had neurologic involvement. Their mean age was 5.9 +/- 3.6 yr (range, 6 months to 11 yr) and 16 (69.9%) were boys. None of the 23 patients had been vaccinated for influenza A H1N1 and seasonal influenzas. Twenty-two of the 23 patients presented with seizures. Clinical features included febrile convulsion (n = 19), afebrile convulsion (n = 1), aseptic meningitis (n = 1), encephalopathy (n = 1), and acute necrotizing encephalopathy (n = 1). They all were treated with Oseltamivir twice daily for 5 days immediately after nasal and throat swab testing. Twenty-one of the subjects recovered fully, but the youngest two infants experienced severe neurological sequelae. The results indicate that neurologic complications associated with influenza A H1N1 2009 pandemic were mostly mild, but rarely were serious. Prompt intervention leads to a better outcome and vaccination may prevent the disease, thus staving off serious neurological complications following influenza, especially in young infants.

Antiviral Agents/therapeutic use , Child , Child, Preschool , Electroencephalography , Female , Humans , Infant , Influenza A Virus, H1N1 Subtype/genetics , Influenza, Human/complications , Magnetic Resonance Imaging , Male , Oseltamivir/therapeutic use , Pandemics , Republic of Korea/epidemiology , Retrospective Studies , Seizures/etiology
Article in English | WPRIM | ID: wpr-25820


The majority of Korean patients with pandemic influenza A (H1N1) during the 2009 epidemic were under 20 yr of age. The limited data on the clinical characteristics of these children led us to conduct a case note-based investigation of children admitted to 6 university hospitals with 2009 H1N1 influenza. A total of 804 children was enrolled. The median age was 5 yr; 63.8% were males; and 22.4% had at least one chronic underlying disease. Ninety-five of the patients (11.8%) were critically ill and they suffered more from shortness of breath, dyspnea and lymphopenia than the other patients. Among all the patients, 98.8% were treated with antivirals and 73% received treatment within 48 hr of illness onset. All the enrolled patients are alive and appear to have had good outcomes, probably due to the early intervention and antiviral treatment. This study deals with hospitalized children whose diagnoses of influenza A (H1N1) were confirmed, and therefore provides important new information about the clinical patterns of children with influenza A (H1N1) in Korea.

Adolescent , Antiviral Agents/therapeutic use , Child , Child, Hospitalized , Child, Preschool , Critical Illness , Dyspnea/etiology , Female , Humans , Infant , Infant, Newborn , Influenza A Virus, H1N1 Subtype/genetics , Influenza, Human/diagnosis , Lymphopenia/etiology , Male , Oseltamivir/therapeutic use , Pandemics , Republic of Korea/epidemiology , Retrospective Studies
Rev. panam. salud pública ; 30(6): 634-640, Dec. 2011.
Article in English | LILACS | ID: lil-612962


Objective. To describe the virological characteristics of the influenza strains circulating in Argentina in 2005–2008 and to assess the prevalence of antiviral resistance. Methods. On the basis of their geographical spread and prevalence, influenza A and B isolates grown in Madin–Darby canine kidney cells were selected after antigenic and genomic characterization to be analyzed for antiviral resistance by enzymatic assay and pyrosequencing. Amantadine susceptibility was evaluated by pyrosequencing for known resistance markers on 45 strains of influenza A. Susceptibility to oseltamivir and zanamivir was evaluated by enzymatic assay of 67 influenza A and 46 influenza B strains, some of which were further analyzed by sequencing the neuraminidase gene. Results. Resistance to amantadine was observed only on A(H3N2) strains (29/33); all of them carried the mutation S31N in their M2 sequence. Oseltamivir resistance was observed in 12 (34.3%) of the 35 A(H1N1) strains from 2008; all of them carried the mutation H275Y in their neuraminidase sequence. All these viruses remained sensitive to zanamivir. Conclusions. This study describes a high incidence of amantadine-resistant influenza A(H3N2) viruses since 2006 and an unprecedented increase in oseltamivir resistance detected only in influenza A(H1N1) viruses isolated in 2008. Influenza A and B viruses were more sensitive to oseltamivir than to zanamivir, and influenza A viruses were more sensitive to both neuraminidase inhibitors than the influenza B viruses. The national data generated and analyzed in this study may help increase knowledge about influenza antiviral drug resistance, which is a problem of global concern.

Objetivo. Describir las características virológicas de las cepas de virus de la gripe que circulaban en la Argentina entre el 2005 y el 2008, y evaluar la prevalencia de la resistencia a los antivíricos. Métodos. Según su diseminación geográfica y su prevalencia, se seleccionaron aislados de gripe A y B cultivados en células renales caninas de Madin-Darby después de su caracterización antigénica y genómica, y se analizó su resistencia a los antivíricos mediante análisis enzimático y pirosecuenciación. La sensibilidad a la amantadina se evaluó por pirosecuenciación para los marcadores conocidos de resistencia en 45 cepas de gripe A. La sensibilidad al oseltamivir y al zanamivir se evaluó mediante análisis enzimático de 67 cepas de gripe A y 46 cepas de gripe B, algunas de las cuales se analizaron en mayor profundidad mediante la secuenciación del gen de la neuraminidasa. Resultados. Se observó resistencia a la amantadina solo en las cepas de gripe A (H3N2) (29/33); todas ellas tenían la mutación S31N en su secuencia de M2. Se observó resistencia al oseltamivir en 12 (34,3%) de las 35 cepas de gripe A (H1N1) aisladas en el 2008; todas ellas tenían la mutación H275Y en su secuencia de neuraminidasa. Todos estos virus conservaron su sensibilidad al zanamivir. Conclusiones. En este estudio se describe una incidencia elevada del virus de la gripe A (H3N2) resistente a la amantadina desde el 2006 y un aumento sin precedentes de la resistencia al oseltamivir detectada solo en los virus de la gripe A (H1N1) aislados en el 2008. Los virus de la gripe A y B fueron más sensibles al oseltamivir que al zanamivir y los virus de la gripe A fueron más sensibles a ambos inhibidores de la neuraminidasa que los virus de la gripe B. Los datos nacionales generados y analizados en este estudio pueden ayudar a aumentar los conocimientos acerca de la resistencia a los fármacos antivíricos dirigidos contra el virus de la gripe, lo que es un motivo de preocupación mundial.

Animals , Dogs , Humans , Antiviral Agents/pharmacology , Drug Resistance, Viral , Influenza A virus/drug effects , Influenza B virus/drug effects , Population Surveillance , Amantadine/pharmacology , Argentina/epidemiology , Cell Line , Drug Resistance, Multiple, Viral/genetics , Influenza A Virus, H1N1 Subtype/drug effects , Influenza A Virus, H1N1 Subtype/genetics , Influenza A virus/genetics , Influenza A virus/isolation & purification , Influenza B virus/genetics , Influenza B virus/isolation & purification , Influenza, Human/epidemiology , Influenza, Human/virology , Mutation, Missense , Morbidity/trends , Neuraminidase/antagonists & inhibitors , Neuraminidase/genetics , Oseltamivir/pharmacology , Point Mutation , Seasons , Virus Cultivation , Zanamivir/pharmacology
Rev. salud pública ; 13(6): 897-907, dic. 2011. ilus, tab
Article in English | LILACS | ID: lil-625655


Objective The aim was to verify whether being overweight could have played a critical role in cases of mortality caused byinfluenza A (H1N1) in pregnant women. This virus' prevalence was also analyzed among people suffering from acute respiratory disease being attended at the state of Mexico's Autonomous University's medical research centre. Methods The clinical files of women having influenza A (H1N1) attending the Monica Pretelini maternal-perinatal hospital's (HMPMP) intensive care unit in Toluca, Mexico, were reviewed. According to international recommendations, clinical detection of possible new cases of this disease was kept an open as a second step. Results Five women suffering influenza A (H1N1) was attended at HMPMP's intensive care unit during 2009; only one survived. No differences in body mass index were found when comparing the anthropometric characteristics to another group of women affected by acute respiratory diseases; in fact, this parameter was below the limits for being overweight in both cases. No new case of influenza A (H1N1) was found after the first eight months of 2010. Discussion It could not be verified whether being overweight was a factor of higher mortality due to influenza A (H1N1) amongst pregnant women in the state of Mexico. The key to better survival for pregnant women hospitalized with influenza A (H1N1) seemed to be early treatment with oseltamivir. The cases decreased dramatically after the severe wave of the new pandemic due to unknown reasons.

Objetivo Nuestro objetivo fue verificar si en los casos de mortalidad por influenza A (H1N1) en mujeres embarazadas, el sobrepeso tuvo un papel fundamental. También hemos analizado la prevalencia de este virus entre personas con enfermedad respiratoria aguda atendidas en el Centro de Investigación en Ciencias Médicas de la Universidad Autónoma del Estado de México. Métodos Se revisaron los expedientes clínicos de las mujeres con influenza A (H1N1) atendidos en la Unidad de Cuidados Intensivos Obstétricos del Hospital Materno Perinatal, Toluca, México. De acuerdo con las recomendaciones internacionales, como segunda etapa se mantuvo un programa de detección de este virus en la población general. Resultados Hubo cinco embarazadas con influenza A (H1N1), durante el año 2009, de las cuales sólo una sobrevivió. Al comparar las características antropométricas con otro grupo de mujeres afectadas por enfermedades respiratorias agudas no encontramos diferencias en el índice de masa corporal. De hecho, en ambos casos, este parámetro fue inferior a los límites de sobrepeso. Después de los primeros ocho meses del año 2010 no se encontraron nuevos casos de influenza A (H1N1). Discusión No hemos podido verificar que el sobrepeso sea un factor de mayor mortalidad en casos de infección por influenza A (H1N1) entre las mujeres embarazadas del Estado de México. La clave para una mejor supervivencia en mujeres embarazadas hospitalizadas con influenza A (H1N1) parece ser el tratamiento precoz con Oseltamivir. Por razones desconocidas después de la ola severa de la nueva pandemia los casos disminuyeron.

Adult , Female , Humans , Male , Pregnancy , Young Adult , Influenza A Virus, H1N1 Subtype , Influenza, Human/epidemiology , Overweight/epidemiology , Pandemics , Pregnancy Complications, Infectious/epidemiology , Body Mass Index , Comorbidity , Cross-Sectional Studies , Hospitals, Maternity/statistics & numerical data , Hospitals, University/statistics & numerical data , Influenza A Virus, H1N1 Subtype/genetics , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza, Human/drug therapy , Influenza, Human/mortality , Mexico/epidemiology , Obesity/epidemiology , Pregnancy, High-Risk , Prevalence , Pregnancy Complications, Infectious/mortality , Puerperal Disorders/mortality , Retrospective Studies , RNA, Viral/blood , Respiration Disorders/epidemiology , Respiratory Distress Syndrome/epidemiology , Respiratory Distress Syndrome/etiology
Rev. Soc. Bras. Med. Trop ; 44(4): 405-411, July-Aug. 2011. tab
Article in English | LILACS | ID: lil-596613


INTRODUCTION: The case definition of influenza-like illness (ILI) is a powerful epidemiological tool during influenza epidemics. METHODS: A prospective cohort study was conducted to evaluate the impact of two definitions used as epidemiological tools, in adults and children, during the influenza A H1N1 epidemic. Patients were included if they had upper respiratory samples tested for influenza by real-time reverse transcriptase polymerase chain reaction during two periods, using the ILI definition (coughing + temperature ≤ 38ºC) in period 1, and the definition of severe acute respiratory infection (ARS) (coughing + temperature ≤ 38ºC and dyspnoea) in period 2. RESULTS: The study included 366 adults and 147 children, covering 243 cases of ILI and 270 cases of ARS. Laboratory confirmed cases of influenza were higher in adults (50%) than in children (21.6%) ( p < 0.0001) and influenza infection was more prevalent in the ILI definition (53%) than ARS (24.4%) (p < 0.0001). Adults reported more chills and myalgia than children (p = 0.0001). Oseltamivir was administered in 58% and 46% of adults and children with influenza A H1N1, respectively. The influenza A H1N1 case fatality rate was 7% in adults and 8.3% in children. The mean time from onset of illness until antiviral administration was 4 days. CONCLUSIONS: The modification of ILI to ARS definition resulted in less accuracy in influenza diagnosis and did not improve the appropriate time and use of antiviral medication.

INTRODUÇÃO: A definição de síndrome gripal é uma ferramenta epidemiológica importante durante epidemias de influenza. MÉTODOS: Foi conduzido estudo de coorte prospectivo para avaliar o impacto das definições de síndrome gripal (SG) e doença respiratória aguda grave (DRAG) como ferramenta de vigilância epidemiológica, em adultos e crianças, durante a epidemia de influenza A H1N1. Os pacientes foram incluídos se tivessem coleta de secreção respiratória alta testada por PCR real time para o vírus da influenza. Os dados clínicos e epidemiológicos foram estudados comparando-se dois períodos: período 1: SG (tosse + temperatura ≤ 38ºC), e período 2: DRAG (tosse + temperatura ≤ 38 e dispnéia). RESULTADOS: Foram incluídos 366 adultos e 147 crianças, em um total de 243 casos de SG e 270 DRAG. A confirmação laboratorial de influenza em adultos (50%) foi significativamente maior do que em crianças (21,6%) (p < 0,0001) e a definição de SG foi mais confirmatória de infecção por influenza (53%) do que DRAG (24,4%) (p < 0,0001). Adultos referiam mais calafrios e mialgias do que as crianças (p = 0,0001). Oseltamivir foi prescrito, respectivamente, em 58% e 46% dos adultos e crianças com influenza A H1N1. A letalidade por influenza A H1N1 foi de 7% em adultos e 8,3% em crianças. CONCLUSÕES: A mudança de definição do critério de vigilância epidemiologia de SG para DRAG resultou em redução significativa da acurácia do diagnóstico de influenza e não contribuiu para melhor indicação do antiviral como também para a sua prescrição no tempo apropriado.

Adolescent , Adult , Aged , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Young Adult , Epidemics , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza, Human/epidemiology , Population Surveillance/methods , Acute Disease , Antiviral Agents/therapeutic use , Brazil/epidemiology , Cohort Studies , Hospitals, University , Influenza A Virus, H1N1 Subtype/genetics , Influenza, Human/diagnosis , Influenza, Human/drug therapy , Oseltamivir/therapeutic use , Prospective Studies , Reverse Transcriptase Polymerase Chain Reaction , Seasons
Rev. méd. Chile ; 139(7): 833-840, jul. 2011. ilus, tab
Article in Spanish | LILACS | ID: lil-603134


Background: Following the announcement of the Influenza A(H1N1) pandemic by the World Health Organization in April 2009, a surveillance program was carried out in Chile to detect the introduction of the virus in the country and to monitor its propagation and impact. Aim: To describe the onset of the outbreak and the genetic characterization of the pandemic H1N1 influenza virus in the first detected cases in Chile. Material and Methods: Analysis of18 clinical samples coming from suspicious patients, received in a National Reference Laboratory. RNA reverse transcription and real time influenza gene DNA amplification was carried out in a 7500 Fast and Step One Real Time PCR Systems of Applied Biosystems and MxPro-Mx3000P thermocycler from Stratagene. Super Script III Platinum One-Step Quantitative RT-PCR was used. Results: The virus was first detected in three persons returning from the Dominican Republic via Panamá and a child from the east zone of Santiago. Genetic characterization of the virus showed that the child was infected by a different variant of the pandemic virus than the three persons returning from the Caribbean. Conclusions: The onset of the Influenza outbreak in Chile apparently carne from two different epidemiological groups. The spread of the virus detected in the voyagers was limited immediately However the virus of the fourth case was found in different regions of Chile.

Adolescent , Adult , Child , Female , Humans , Male , Middle Aged , Young Adult , Influenza A Virus, H1N1 Subtype/genetics , Influenza, Human/virology , Pandemics , Phylogeny , RNA, Viral/genetics , Chile/epidemiology , Influenza, Human/epidemiology , Mexico , Nucleic Acid Amplification Techniques , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , United States
Braz. j. infect. dis ; 15(3): 220-224, May-June 2011. ilus, tab
Article in English | LILACS | ID: lil-589952


INTRODUCTION: During the first pandemic wave of the influenza A H1N1 2009 virus, morbidity was particularly high in Brazil. Hospitalizations resulting from severe respiratory disease due to suspected influenza-like illness created an opportunity to identify other respiratory viruses causing lower respiratory infections. OBJECTIVE: The purpose of this study was to assess viral etiologies among samples collected during the first pandemic wave of H1N1 2009 from hospitalized patients with suspected cases in a Brazilian Sentinel Hospital. PATIENTS AND METHODS: Viral etiologies were investigated in samples from 98 children and 61 adults with fever, cough and dyspnea who were admitted to São Paulo Sentinel Hospital with suspected H1N1 infection. RESULTS: From August to November 2009, in 19.5 percent (31/159) of the samples 2009 H1N1 virus was detected with 23 percent (14/61) in adults (median age 25 years, range: 14-55 years) and 18.4 percent (17/92) in children (median age 5 years, range: 4 months - 11 years). Among the negative samples, a wide range of causative etiologic agents was identified. Human rhinovirus was the most frequent virus (23.91 percent) in children and human metapneumovirus (11.48 percent) was the second most frequent in adults, following 2009 H1N1 virus (22.95 percent). CONCLUSION: These data highlight the need to diagnose other viral infections that can co-circulate with influenza and may have been neglected by physicians as causes of severe respiratory diseases.

Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Humans , Infant , Infant, Newborn , Middle Aged , Young Adult , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza, Human/virology , Pandemics/statistics & numerical data , Respiratory Tract Infections/virology , Sentinel Surveillance , Brazil/epidemiology , Hospitalization , Influenza A Virus, H1N1 Subtype/genetics , Influenza, Human/epidemiology , Respiratory Tract Infections/epidemiology
Rev. cuba. med. trop ; 63(1): 15-20, ene.-abr. 2011.
Article in Spanish | LILACS | ID: lil-584965


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.

Humans , Influenza A Virus, H1N1 Subtype/genetics , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza, Human/diagnosis , Influenza, Human/virology , Cuba , Molecular Diagnostic Techniques/methods