RESUMO
Background: Human bocavirus (HBoV) is a newly discovered parvovirus found in children with acute respiratory tract infections (ARTI). Objectives: To describe the epidemiological and clinical profile of children < 5 years old consulting for ARTI, comparing cases of HBoV monoinfection and coinfection with other known respiratory viruses. Furthermore, we aimed to estimate the prevalence of viral shedding in asymptomatic children and perform phylogenetic analysis. Patients and Methods: We investigated the presence of HBoV in nasopharyngeal secretions from children consulting for AlRTI and among asymptomatic controls, between 2007 and 2008, by polymerase chain reaction. Results: HBoV was detected in 79 (21.8 percent) of 362 nasopharyngeal swabs obtained from children with ARTI. In 60/79 (76 percent), coinfection with other respiratory viruses was confirmed. Most common symptoms were cough, fever and rhinorrhea. Children infected only with HBoV showed significantly lower frequencies of respiratory distress, oxygen requirements and hospital admission than those with coinfection. HBoV was detected in 6/16 (37.5 percent) samples from asymptomatic children. The phylogenetic analysis of viruses from Chilean patients revealed that circulating HBoV was closely related to original strains. Conclusions: HBoV was found either in symptomatic and asymptomatic children. The severity of the disease was greater when HBoV was associated to other respiratory viruses.
Introducción: Bocavirus humano (HBoV) es un nuevo parvovirus encontrado en niños con infecciones respiratorias agudas (IRA). Objetivos: Describir la epidemiología y perfil clínico en niños < 5 años con IRA, comparando aquellos con HBoV como único agente identificado, con los que tenían co-infección con otro virus respiratorio. Además se evaluó su prevalencia en niños asintomáticos, y se realizó análisis filogenético. Materiales y Métodos: Se investigó la presencia de HBoV, por medio de reacción de polimerasa en cadena, en muestras de secreción nasofaríngea obtenida en niños con IRA y en controles asintomáticos, entre 2007 y 2008. Resultados: Se detectó HBoV en 79 (21,8 por ciento) de 362 muestras obtenidas en pacientes con IRA. En 60/79 (76 por ciento), se demostró co-infección. Los síntomas más frecuentes fueron tos, fiebre y rinorrea. Los pacientes con HBoV como único agente identificado mostraron frecuencias significativamente menores de dificultad respiratoria, requerimiento de oxígeno y hospitalización, comparado con los co-infectados. HBoV se detectó en 6/16 (37,5 por ciento) muestras de niños asintomáticos. El análisis filogenético de las cepas chilenas demuestra estrecha relación con las cepas originales. Conclusiones: HBoV está presente en niños chilenos con IRA y asintomáticos. La gravedad de la enfermedad fue mayor en el grupo con co-infección.
Assuntos
Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Bocavirus Humano/genética , Infecções por Parvoviridae/virologia , Infecções Respiratórias/virologia , Doença Aguda , Chile/epidemiologia , Métodos Epidemiológicos , Bocavirus Humano/isolamento & purificação , Nasofaringe/virologia , Reação em Cadeia da Polimerase , Infecções por Parvoviridae/diagnóstico , Infecções por Parvoviridae/epidemiologia , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/epidemiologia , Estações do AnoRESUMO
BACKGROUND: Human bocavirus (HBoV) is a newly discovered parvovirus found in children with acute respiratory tract infections (ARTI). OBJECTIVES: To describe the epidemiological and clinical profile of children < 5 years old consulting for ARTI, comparing cases of HBoV monoinfection and coinfection with other known respiratory viruses. Furthermore, we aimed to estimate the prevalence of viral shedding in asymptomatic children and perform phylogenetic analysis. PATIENTS AND METHODS: We investigated the presence of HBoV in nasopharyngeal secretions from children consulting for AlRTI and among asymptomatic controls, between 2007 and 2008, by polymerase chain reaction. RESULTS: HBoV was detected in 79 (21.8%) of 362 nasopharyngeal swabs obtained from children with ARTI. In 60/79 (76%), coinfection with other respiratory viruses was confirmed. Most common symptoms were cough, fever and rhinorrhea. Children infected only with HBoV showed significantly lower frequencies of respiratory distress, oxygen requirements and hospital admission than those with coinfection. HBoV was detected in 6/16 (37.5%) samples from asymptomatic children. The phylogenetic analysis of viruses from Chilean patients revealed that circulating HBoV was closely related to original strains. CONCLUSIONS: HBoV was found either in symptomatic and asymptomatic children. The severity of the disease was greater when HBoV was associated to other respiratory viruses.
Assuntos
Bocavirus Humano/genética , Infecções por Parvoviridae/virologia , Infecções Respiratórias/virologia , Doença Aguda , Pré-Escolar , Chile/epidemiologia , Métodos Epidemiológicos , Feminino , Bocavirus Humano/isolamento & purificação , Humanos , Lactente , Masculino , Nasofaringe/virologia , Infecções por Parvoviridae/diagnóstico , Infecções por Parvoviridae/epidemiologia , Reação em Cadeia da Polimerase , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/epidemiologia , Estações do AnoRESUMO
Andes hantavirus (ANDV) infection in Chile has a variable clinical expression, and infected individuals may present with different grades of disease severity. This study aimed to determine if clinical expression of ANDV infection in Chilean patients is associated with the HLA system. HLA alíeles A, B, DRB1 and DQB1, were studied in two groups of patients with confirmed ANDV infection: 41 patients with a mild disease course (without respiratory failure and cardiovascular shock) and 46 patients with a severe disease course (with respiratory failure and shock). Molecular typing of HLA system was performed by SSP-PCR. The HLA-DRB 1*15 alíele, was significantly more common in the group of patients with mild disease (p = 0,007) and thus for possibly associated with a protective effect against ANDV infection. Conversely, HLA-B*08 was more common in patients with severe disease (p = 0,06). Although the association was marginally significant, alíele HLA-B*08 may be linked to an increased susceptibility to the severe clinical course of HCPS by ANDV.
Assuntos
Alelos , Predisposição Genética para Doença/genética , Antígenos HLA/genética , Infecções por Hantavirus/virologia , Doença Aguda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Chile , Feminino , Marcadores Genéticos/genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/métodos , Índice de Gravidade de DoençaRESUMO
En Chile, la infección por hantavirus Andes (ANDV) tiene una expresión clínica variable, reconociéndose diversos grados de severidad. El presente estudio se realizó con el objeto de analizar la posible asociación entre la constitución genética de pacientes chilenos para el sistema HLA y la expresión clínica de la infección por ANDV. Se analizaron los alelos HLA A, B, DRB1 y DQB1, en dos grupos de pacientes con infección por ANDV: 41 pacientes con evolución clínica leve (sin insuficiencia respiratoria severa y sin requerimientos de ventilación mecánica) y 46 pacientes con evolución clínica grave (con insuficiencia respiratoria grave y/o shock). La determinación molecular del sistema HLA se realizó mediante SSP-PCR. El alelo HLA DRB1 * 15, se encontró en una frecuencia significativamente más alta en los pacientes leves (p = 0,007). Por lo tanto, el alelo DRB 1*15 se asociaría al curso clínico leve de la enfermedad. El alelo HLA-B*08, se encontró en una frecuencia mayor en los pacientes graves, la diferencia alcanzó una significación estadística marginal (p = 0,06). Así, el alelo HLA-B*08, podría estar asociado al curso clínico grave de síndrome cardiopulmonar ocasionado por hantavirus Andes.
Andes hantavirus (ANDV) infection in Chile has a variable clinical expression, and infected individuals may present with different grades of disease severity. This study aimed to determine if clinical expression of ANDV infection in Chilean patients is associated with the HLA system. HLA alíeles A, B, DRB1 and DQB1, were studied in two groups of patients with confirmed ANDV infection: 41 patients with a mild disease course (without respiratory failure and cardiovascular shock) and 46 patients with a severe disease course (with respiratory failure and shock). Molecular typing of HLA system was performed by SSP-PCR. The HLA-DRB 1*15 alíele, was significantly more common in the group of patients with mild disease (p = 0,007) and thus for possibly associated with a protective effect against ANDV infection. Conversely, HLA-B*08 was more common in patients with severe disease (p = 0,06). Although the association was marginally significant, alíele HLA-B*08 may be linked to an increased susceptibility to the severe clinical course of HCPS by ANDV.
Assuntos
Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Alelos , Predisposição Genética para Doença/genética , Antígenos HLA/genética , Infecções por Hantavirus/virologia , Doença Aguda , Chile , Genótipo , Marcadores Genéticos/genética , Reação em Cadeia da Polimerase/métodos , Índice de Gravidade de DoençaRESUMO
Background: The availability of a serologic test for cat scratch disease in humans has allowed the diagnosis of an increasing number of cases of this disease in Chile. Aim: To perform a serological survey for Bartonella henselae among cats in Chile. Material and methods: Blood samples from 187 cats living in three Chilean cities were obtained. IgG antibodies againts Bartonella henselae were measured using indirect immunofluorescence. Blood cultures were done in 60 samples. The presence of Bartonella henselae in positive cultures was confirmed by restriction fragment length polymorphism polimerase chain reaction (RFLP-PCR). Results: The general prevalence of IgG antibodies against Bartonella henselae was 85.6%. No differences in this prevalence were found among cats younger or older than 1 year, or those infested or not infested with fleas. However domestic cats had a lower prevalence when compared with stray cats (73 and 90% respectively, p <0.01). Bartonella henselae was isolated in 41% of blood cultures. All the isolated were confirmed as Bartonella henselae by RFLP-PCR. Conclusions: This study found an important reservoir of Bartonella henselae in Chilean cats and therefore a high risk of exposure in humans who have contact with them.
Assuntos
Animais , Bartonella henselae/isolamento & purificação , Gatos/microbiologia , Reservatórios de Doenças/microbiologia , Anticorpos Antibacterianos/sangue , Bartonella henselae/imunologia , Distribuição de Qui-Quadrado , Chile , Técnica Indireta de Fluorescência para Anticorpo , Imunoglobulina G/sangue , Estudos SoroepidemiológicosRESUMO
Amantadina es un fármaco eficaz para el tratamiento y prevención de influenza A. Su mecanismo de acción es inhibir la proteína M2. Su uso por períodos prolongados puede generar resistencia, la cual ocurre por mutaciones en el gen que codifica para la proteína M2. La mutación más frecuentemente encontrada se ubica en la posición 31. El uso de técnicas de biología molecular permite detectar estas mutaciones. Los objetivos fueron determinar la existencia de resistencia a amantadina en cepas de virus influenza A aisladas entre los años 2001 y 2002 en un laboratorio de virología en Santiago de Chile, y validar un nuevo método de biología molecular para reconocer cepas resistentes. Para ello se utilizó metodología de RPC y análisis de tamaño de fragmentos de restricción. En 31 cepas procesadas no se observó la presencia de cambios en la posición 31. Estos hallazgos sugieren que la resistencia a amantadina es muy baja o está ausente en nuestro medio. Esto podría explicarse por un limitado uso de este fármaco en esta población. El método descrito puede servir de base para un monitoreo prospectivo de resistencia, que pueda ser de utilidad al médico clínico.
