RESUMEN

This study was conducted as part of the Argentinean Influenza and other Respiratory Viruses Surveillance Network, in the context of the Global Influenza Surveillance carried out by the World Health Organization (WHO). The objective was to study the activity and the antigenic and genomic characteristics of circulating viruses for three consecutive seasons (2010, 2011 and 2012) in order to investigate the emergence of influenza viral variants. During the study period, influenza virus circulation was detected from January to December. Influenza A and B, and all current subtypes of human influenza viruses, were present each year. Throughout the 2010 post-pandemic season, influenza A(H1N1)pdm09, unexpectedly, almost disappeared. The haemagglutinin (HA) of the A(H1N1)pdm09 viruses studied were segregated in a different genetic group to those identified during the 2009 pandemic, although they were still antigenically closely related to the vaccine strain A/California/07/2009. Influenza A(H3N2) viruses were the predominant strains circulating during the 2011 season, accounting for nearly 76 % of influenza viruses identified. That year, all HA sequences of the A(H3N2) viruses tested fell into the A/Victoria/208/2009 genetic clade, but remained antigenically related to A/Perth/16/2009 (reference vaccine recommended for this three-year period). A(H3N2) viruses isolated in 2012 were antigenically closely related to A/Victoria/361/2011, recommended by the WHO as the H3 component for the 2013 Southern Hemisphere formulation. B viruses belonging to the B/Victoria lineage circulated in 2010. A mixed circulation of viral variants of both B/Victoria and B/Yamagata lineages was detected in 2012, with the former being predominant. A(H1N1)pdm09 viruses remained antigenically closely related to the vaccine virus A/California/7/2009; A(H3N2) viruses continually evolved into new antigenic clusters and both B lineages, B/Victoria/2/87-like and B/Yamagata/16/88-like viruses, were observed during the study period. The virological surveillance showed that the majority of the circulating strains during the study period were antigenically related to the corresponding Southern Hemisphere vaccine strains except for the 2012 A(H3N2) viruses.

Asunto(s)

Antígenos Virales/análisis , Genoma Viral , Virus de la Influenza A/clasificación , Virus de la Influenza A/aislamiento & purificación , Virus de la Influenza B/clasificación , Virus de la Influenza B/aislamiento & purificación , Gripe Humana/virología , Argentina/epidemiología , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Humanos , Virus de la Influenza A/genética , Virus de la Influenza A/inmunología , Virus de la Influenza B/genética , Virus de la Influenza B/inmunología , Gripe Humana/epidemiología , Epidemiología Molecular , Datos de Secuencia Molecular , ARN Viral/genética , Análisis de Secuencia de ADN

RESUMEN

OBJECTIVE: To estimate the infection prevalence in Buenos Aires during the outbreak of pandemic influenza A/H1N1 2009 virus (A(H1N1)pdm09). METHODS: A(H1N1)pdm09-specific antibodies were measured by hemagglutination inhibition assay in human serum samples collected 6 months after the outbreak and before the introduction of the A(H1N1)pdm09 vaccine in Argentina. Baseline levels of cross-reactive antibodies to A(H1N1)pdm09 were determined by testing 162 serum samples collected before 2009. RESULTS: The overall seroprevalence of A(H1N1)pdm09 in 150 children and 427 adults was 28.9% (95% confidence interval (CI) 25-33%), with a 58.0% prevalence in children <19 years of age and an 18.7% prevalence in adults ≥19 years of age (p<0.001). The prevalence was 43.5% in children <5 years old and 60.6% among children aged 5-18 years. The prevalence in adults declined with increasing age: 24.9% in 19-39-year-olds, 9.7% in 40-59-year-olds, and 8.1% in those ≥60 years old. The prevalence of specific A(H1N1)pdm09 antibodies was higher compared with the baseline in children (p=0.014), adolescents (p<0.001), and adults <40 years old (p=0.017). Seroprevalence in health care workers was not different from the rest of the population (13.6% vs. 19.3%, respectively; p=0.421). CONCLUSIONS: The prevalence of specific A(H1N1)pdm09 antibodies was high at 28.9%. The highest prevalence was observed in children, adolescents, and young adults.

Asunto(s)

Anticuerpos Antivirales/sangre , Subtipo H1N1 del Virus de la Influenza A/inmunología , Gripe Humana/epidemiología , Pandemias , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Neutralizantes/sangre , Especificidad de Anticuerpos , Argentina/epidemiología , Niño , Preescolar , Estudios Transversales , Femenino , Hospitales , Humanos , Incidencia , Lactante , Gripe Humana/virología , Masculino , Persona de Mediana Edad , Estudios Seroepidemiológicos , Encuestas y Cuestionarios , Población Urbana , Adulto Joven

RESUMEN

Influenza virus (InfV) infection during pregnancy is a known risk factor for neurodevelopment abnormalities in the offspring, including the risk of schizophrenia, and has been shown to result in an abnormal behavioral phenotype in mice. However, previous reports have concentrated on neuroadapted influenza strains, whereas increased schizophrenia risk is associated with common respiratory InfV. In addition, no specific mechanism has been proposed for the actions of maternal infection on the developing brain that could account for schizophrenia risk. We identified two common isolates from the community with antigenic configurations H3N2 and H1N1 and compared their effects on developing brain with a mouse modified-strain A/WSN/33 specifically on the developing of dopaminergic neurons. We found that H1N1 InfV have high affinity for dopaminergic neurons in vitro, leading to nuclear factor kappa B activation and apoptosis. Furthermore, prenatal infection of mothers with the same strains results in loss of dopaminergic neurons in the offspring, and in an abnormal behavioral phenotype. We propose that the well-known contribution of InfV to risk of schizophrenia during development may involve a similar specific mechanism and discuss evidence from the literature in relation to this hypothesis.

Asunto(s)

Encéfalo/virología , Neuronas Dopaminérgicas/virología , Subtipo H1N1 del Virus de la Influenza A , Subtipo H3N2 del Virus de la Influenza A , Infecciones por Orthomyxoviridae/virología , Efectos Tardíos de la Exposición Prenatal/virología , Esquizofrenia/virología , Animales , Conducta Animal/fisiología , Encéfalo/inmunología , Encéfalo/fisiopatología , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Aprendizaje por Laberinto/fisiología , Ratones , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/fisiopatología , Embarazo , Efectos Tardíos de la Exposición Prenatal/inmunología , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Reconocimiento en Psicología/fisiología

RESUMEN

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.

Asunto(s)

Antivirales/farmacología , Farmacorresistencia Viral , Virus de la Influenza A/efectos de los fármacos , Virus de la Influenza B/efectos de los fármacos , Vigilancia de la Población , Amantadina/farmacología , Animales , Argentina/epidemiología , Línea Celular , Perros , Farmacorresistencia Viral Múltiple/genética , Humanos , Subtipo H1N1 del Virus de la Influenza A/efectos de los fármacos , Subtipo H1N1 del Virus de la Influenza A/genética , Virus de la Influenza A/genética , Virus de la Influenza A/aislamiento & purificación , Virus de la Influenza B/genética , Virus de la Influenza B/aislamiento & purificación , Gripe Humana/epidemiología , Gripe Humana/virología , Morbilidad/tendencias , Mutación Missense , Neuraminidasa/antagonistas & inhibidores , Neuraminidasa/genética , Oseltamivir/farmacología , Mutación Puntual , Estaciones del Año , Cultivo de Virus , Zanamivir/farmacología

Asunto(s)

Brotes de Enfermedades , Subtipo H1N1 del Virus de la Influenza A/patogenicidad , Gripe Humana/virología , Animales , Planificación en Desastres , Salud Global , Humanos , Subtipo H1N1 del Virus de la Influenza A/clasificación , Subtipo H1N1 del Virus de la Influenza A/genética , Virus de la Influenza A/clasificación , Virus de la Influenza A/genética , Gripe Aviar/epidemiología , Gripe Aviar/virología , Gripe Humana/epidemiología , Mamíferos/virología , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/veterinaria , Infecciones por Orthomyxoviridae/virología , Aves de Corral/virología , Virus Reordenados/genética , Virus Reordenados/patogenicidad , Especificidad de la Especie , Porcinos/virología

Asunto(s)

Humanos , Brotes de Enfermedades , Subtipo H1N1 del Virus de la Influenza A , Gripe Humana/epidemiología , Laboratorios , Argentina/epidemiología , Subtipo H1N1 del Virus de la Influenza A/inmunología , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/diagnóstico , Gripe Humana/prevención & control , Gripe Humana/virología

Asunto(s)

Brotes de Enfermedades , Subtipo H1N1 del Virus de la Influenza A , Gripe Humana/epidemiología , Laboratorios , Argentina/epidemiología , Humanos , Subtipo H1N1 del Virus de la Influenza A/inmunología , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/diagnóstico , Gripe Humana/prevención & control , Gripe Humana/virología

Asunto(s)

Animales , Humanos , Brotes de Enfermedades , Subtipo H1N1 del Virus de la Influenza A/patogenicidad , Gripe Humana/virología , Planificación en Desastres , Salud Global , Subtipo H1N1 del Virus de la Influenza A/clasificación , Subtipo H1N1 del Virus de la Influenza A/genética , Virus de la Influenza A/clasificación , Virus de la Influenza A/genética , Gripe Aviar/epidemiología , Gripe Aviar/virología , Gripe Humana/epidemiología , Mamíferos/virología , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/veterinaria , Infecciones por Orthomyxoviridae/virología , Aves de Corral/virología , Virus Reordenados/genética , Virus Reordenados/patogenicidad , Especificidad de la Especie , Porcinos/virología

Asunto(s)

Control de Infecciones , Laboratorios , Vigilancia de la Población , Humanos

Asunto(s)

Humanos , Control de Infecciones , Laboratorios , Vigilancia de la Población

RESUMEN

By the end of year 2002 there was an outbreak of atypical pneumonia in Southeast Asia which soon spread to other continents. This new severe acute respiratory syndrome (SARS) was produced by a novel coronavirus. Due to the severity of the situation and risk of introduction of this pathology in our country, the need to arrange specific laboratory diagnostic tests arose. Classic techniques, such as the electron microscopy and molecular biology test such as retrotranscription followed by the polymerase chain reaction (RT-PCR) were implemented. The araldit included cells infected with bovine coronavirus which allowed the viral particles to be visualized easily but it took more time in comparison with the negative staining of free particles from viral cultures. RT-PCR was able to detect RNA of isolated viruses from cases in Hong Kong and Germany.

Asunto(s)

Urgencias Médicas , Salud Global , Síndrome Respiratorio Agudo Grave/diagnóstico , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/aislamiento & purificación , Técnicas de Laboratorio Clínico , Brotes de Enfermedades , Humanos , Reacción en Cadena de la Polimerasa/métodos , Síndrome Respiratorio Agudo Grave/epidemiología

RESUMEN

By the end of year 2002 there was an outbreak of atypical pneumonia in Southeast Asia which soon spread to other continents. This new severe acute respiratory syndrome (SARS) was produced by a novel coronavirus. Due to the severity of the situation and risk of introduction of this pathology in our country, the need to arrange specific laboratory diagnostic tests arose. Classic techniques, such as the electron microscopy and molecular biology test such as retrotranscription followed by the polymerase chain reaction (RT-PCR) were implemented. The araldit included cells infected with bovine coronavirus which allowed the viral particles to be visualized easily but it took more time in comparison with the negative staining of free particles from viral cultures. RT-PCR was able to detect RNA of isolated viruses from cases in Hong Kong and Germany.

RESUMEN

The presence of respiratory syncytial virus (RSV) in nasopharyngeal aspirates (NPA) were studied in 254 hospitalized Argentinean children with acute lower respiratory infection tract (ALRI). The specific humoral immune response and partial sequences of the G protein gene were studied in a subset of 22 children with RSV confirmed infection. The RSV IgM detection and the RSV IgG titration were made by immunofluorescence assay (IFA) in pairs of sera. The partial RSV G gene sequences were obtained by an RT-PCR amplification directly from de NPAs. RSV was present in 44.5% of the children. The RSV IgM was detected in 22.7 and 68.8% of the first and second sera, respectively. The IgG geometric mean titers of the acute and convalescent sera were 8 and 589. The RSV IgG titration was able to define 86.4% of the RSV confirmed cases. The percentage of coincidence between RSV IgM detection in the second sera and diagnosis by RSV IgG titration was 72.7% and no significant differences were observed. The nucleotide sequence of one group A and three group B viruses were identified. The first one was related with circulating viruses in Madrid, Montevideo and Mozambique during 1992, 1989 and 1999, respectively. The three sequences identified as group B viruses were closely related with circulating viruses in 1998 from South Africa and Canada during 1999 and 2000. The data obtained in our study provide the first approach at the molecular level (nucleotide) of the RSV circulating strains in Argentina and the lack of genotype patterns previously determined make necessary a continuous molecular surveillance in order to contribute to the understanding of the behavior of this virus in our community.

Asunto(s)

Anticuerpos Antivirales/sangre , Infecciones por Virus Sincitial Respiratorio/epidemiología , Virus Sincitiales Respiratorios/genética , Virus Sincitiales Respiratorios/inmunología , Infecciones del Sistema Respiratorio/epidemiología , Enfermedad Aguda , Niño , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Filogenia , Infecciones por Virus Sincitial Respiratorio/inmunología , Infecciones por Virus Sincitial Respiratorio/virología , Virus Sincitiales Respiratorios/clasificación , Infecciones del Sistema Respiratorio/inmunología , Infecciones del Sistema Respiratorio/virología , Análisis de Secuencia de ADN , Proteínas Virales/genética

RESUMEN

Patients hospitalized with community acquired pneumonia were studied prospectively in two hospitals located in the surroundings of Buenos Aires city. Fifty two patients from General Hospital Manuel Belgrano (HMB) were included from March 1998 to February 1999 and 23 patients from Hospital Dr A. Cetrangolo (HCET) for respiratory disease, were included from June 2000 to May 2001. Patients with lung tuberculosis, lung neoplasia and HIV infection were excluded. Clinical background, signs and symptoms were recorded. Microbiological examinations performed included bacteria, respiratory viruses and mycobacteria. Studies for "atypical" bacteria (Chlamydia spp., Coxiella burnetii, Mycoplasma pneumoniae and Legionella spp.) were carried out by serological methods. No differences in age and gender were observed between both groups. Most frequently observed comorbidities in the HMB group included COPD, diabetes and cardiac failure while in the HCET group these were COPD, asthma and lung fibrosis. Etiology was established in 48% and 65.2% of the patients in the first and second group, respectively. Most frequent agents were Mycoplasma pneumoniae, Streptococcus pneumoniae, influenza A and Legionella spp.; the last one was detected in 12% of the patients. Most of these patients were from HMB and presented a good outcome. Mortality was similar in both groups (13.3%). In the HBM group it was related to the presence of comorbidities in 7 out of 8 cases, and in the HCET group it was a consequence of the worsening of their chronic respiratory failure.

Asunto(s)

Neumonía Bacteriana/microbiología , Adolescente , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Argentina/epidemiología , Infecciones Comunitarias Adquiridas/microbiología , Infecciones Comunitarias Adquiridas/mortalidad , Comorbilidad , Femenino , Humanos , Virus de la Influenza A/aislamiento & purificación , Masculino , Persona de Mediana Edad , Mycoplasma pneumoniae/aislamiento & purificación , Neumonía Bacteriana/mortalidad , Estudios Prospectivos , Factores de Riesgo , Distribución por Sexo , Streptococcus pneumoniae/aislamiento & purificación

RESUMEN

Patients hospitalized with community acquired pneumonia were studied prospectively in two hospitals located in the surroundings of Buenos Aires city. Fifty two patients from General Hospital Manuel Belgrano (HMB) were included from March 1998 to February 1999 and 23 patients from Hospital Dr A. Cetrangolo (HCET) for respiratory disease, were included from June 2000 to May 2001. Patients with lung tuberculosis, lung neoplasia and HIV infection were excluded. Clinical background, signs and symptoms were recorded. Microbiological examinations performed included bacteria, respiratory viruses and mycobacteria. Studies for "atypical" bacteria (Chlamydia spp., Coxiella burnetii, Mycoplasma pneumoniae and Legionella spp.) were carried out by serological methods. No differences in age and gender were observed between both groups. Most frequently observed comorbidities in the HMB group included COPD, diabetes and cardiac failure while in the HCET group these were COPD, asthma and lung fibrosis. Etiology was established in 48% and 65.2% of the patients in the first and second group, respectively. Most frequent agents were Mycoplasma pneumoniae, Streptococcus pneumoniae, influenza A and Legionella spp.; the last one was detected in 12% of the patients. Most of these patients were from HMB and presented a good outcome. Mortality was similar in both groups (13.3%). In the HBM group it was related to the presence of comorbidities in 7 out of 8 cases, and in the HCET group it was a consequence of the worsening of their chronic respiratory failure (AU)

Asunto(s)

Humanos , Masculino , Femenino , Adolescente , Adulto , Persona de Mediana Edad , Anciano , Neumonía Bacteriana/microbiología , Anciano de 80 o más Años , Estudios Prospectivos , Argentina/epidemiología , Infecciones Comunitarias Adquiridas/mortalidad , Comorbilidad , Factores de Riesgo , Mycoplasma pneumoniae/aislamiento & purificación , Streptococcus pneumoniae/aislamiento & purificación , Distribución por Sexo , Distribución por Edad , Virus de la Influenza A/aislamiento & purificación , Neumonía Bacteriana/mortalidad , Infecciones Comunitarias Adquiridas/microbiología

RESUMEN

Patients hospitalized with community acquired pneumonia were studied prospectively in two hospitals located in the surroundings of Buenos Aires city. Fifty two patients from General Hospital Manuel Belgrano (HMB) were included from March 1998 to February 1999 and 23 patients from Hospital Dr A. Cetrangolo (HCET) for respiratory disease, were included from June 2000 to May 2001. Patients with lung tuberculosis, lung neoplasia and HIV infection were excluded. Clinical background, signs and symptoms were recorded. Microbiological examinations performed included bacteria, respiratory viruses and mycobacteria. Studies for "atypical" bacteria (Chlamydia spp., Coxiella burnetii, Mycoplasma pneumoniae and Legionella spp.) were carried out by serological methods. No differences in age and gender were observed between both groups. Most frequently observed comorbidities in the HMB group included COPD, diabetes and cardiac failure while in the HCET group these were COPD, asthma and lung fibrosis. Etiology was established in 48% and 65.2% of the patients in the first and second group, respectively. Most frequent agents were Mycoplasma pneumoniae, Streptococcus pneumoniae, influenza A and Legionella spp.; the last one was detected in 12% of the patients. Most of these patients were from HMB and presented a good outcome. Mortality was similar in both groups (13.3%). In the HBM group it was related to the presence of comorbidities in 7 out of 8 cases, and in the HCET group it was a consequence of the worsening of their chronic respiratory failure

Asunto(s)

Humanos , Masculino , Femenino , Adolescente , Adulto , Persona de Mediana Edad , Neumonía Bacteriana , Distribución por Edad , Anciano de 80 o más Años , Argentina , Infecciones Comunitarias Adquiridas , Comorbilidad , Virus de la Influenza A , Mycoplasma pneumoniae , Neumonía Bacteriana , Estudios Prospectivos , Factores de Riesgo , Distribución por Sexo , Streptococcus pneumoniae

RESUMEN

Patients hospitalized with community acquired pneumonia were studied prospectively in two hospitals located in the surroundings of Buenos Aires city. Fifty two patients from General Hospital Manuel Belgrano (HMB) were included from March 1998 to February 1999 and 23 patients from Hospital Dr A. Cetrangolo (HCET) for respiratory disease, were included from June 2000 to May 2001. Patients with lung tuberculosis, lung neoplasia and HIV infection were excluded. Clinical background, signs and symptoms were recorded. Microbiological examinations performed included bacteria, respiratory viruses and mycobacteria. Studies for [quot ]atypical[quot ] bacteria (Chlamydia spp., Coxiella burnetii, Mycoplasma pneumoniae and Legionella spp.) were carried out by serological methods. No differences in age and gender were observed between both groups. Most frequently observed comorbidities in the HMB group included COPD, diabetes and cardiac failure while in the HCET group these were COPD, asthma and lung fibrosis. Etiology was established in 48

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and 65.2

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of the patients in the first and second group, respectively. Most frequent agents were Mycoplasma pneumoniae, Streptococcus pneumoniae, influenza A and Legionella spp.; the last one was detected in 12

---

of the patients. Most of these patients were from HMB and presented a good outcome. Mortality was similar in both groups (13.3

---

). In the HBM group it was related to the presence of comorbidities in 7 out of 8 cases, and in the HCET group it was a consequence of the worsening of their chronic respiratory failure.

Asunto(s)

Técnicas Microbiológicas , Virología

Asunto(s)

Técnicas Microbiológicas , Virología