RESUMO
Respiratory syncytial virus (RSV) is well recognized as the most important pathogen causing acute respiratory disease in infants and young children, mainly in the form of bronchiolitis and pneumonia. Two major antigenic groups, A and B, have been identified; however, there is disagreement about the severity of the diseases caused by these two types. This study investigated a possible association between RSV groups and severity of disease. Reverse transcription-polymerase chain reaction was used to characterize 128 RSV nasopharyngeal specimens from children less than five years old experiencing acute respiratory disease. A total of 82 of 128 samples (64.1%) could be typed, and, of these, 78% were group A, and 22% were group B. Severity was measured by clinical evaluation associated with demographic factors: for RSV A-infected patients, 53.1% were hospitalized, whereas for RSV B patients, 27.8% were hospitalized (p = 0.07). Around 35.0% of the patients presented risk factors for severity (e.g., prematurity). For those without risk factors, the hospitalization occurred in 47.6% of patients infected with RSV A and in 18.2% infected with RSV B. There was a trend for RSV B infections to be milder than those of RSV A. Even though RSV A-infected patients, including cases without underlying condition and prematurity, were more likely to require hospitalization than those infected by RSV B, the disease severity could not to be attributed to the RSV groups.
Assuntos
Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano/classificação , Infecções Respiratórias , Doença Aguda , Brasil/epidemiologia , Criança , Pré-Escolar , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Lactente , Masculino , Nasofaringe/virologia , Prevalência , RNA Viral/genética , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estações do Ano , Índice de Gravidade de DoençaRESUMO
Respiratory syncytial virus (RSV) is well recognized as the most important pathogen causing acute respiratory disease in infants and young children, mainly in the form of bronchiolitis and pneumonia. Two major antigenic groups, A and B, have been identified; however, there is disagreement about the severity of the diseases caused by these two types. This study investigated a possible association between RSV groups and severity of disease. Reverse transcription-polymerase chain reaction was used to characterize 128 RSV nasopharyngeal specimens from children less than five years old experiencing acute respiratory disease. A total of 82 of 128 samples (64.1 percent) could be typed, and, of these, 78 percent were group A, and 22 percent were group B. Severity was measured by clinical evaluation associated with demographic factors: for RSV A-infected patients, 53.1 percent were hospitalized, whereas for RSV B patients, 27.8 percent were hospitalized (p = 0.07). Around 35.0 percent of the patients presented risk factors for severity (e.g., prematurity). For those without risk factors, the hospitalization occurred in 47.6 percent of patients infected with RSV A and in 18.2 percent infected with RSV B. There was a trend for RSV B infections to be milder than those of RSV A. Even though RSV A-infected patients, including cases without underlying condition and prematurity, were more likely to require hospitalization than those infected by RSV B, the disease severity could not to be attributed to the RSV groups.
Assuntos
Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Infecções por Vírus Respiratório Sincicial , Infecções Respiratórias , Vírus Sincicial Respiratório Humano/classificação , Doença Aguda , Brasil/epidemiologia , Técnica Indireta de Fluorescência para Anticorpo , Nasofaringe/virologia , Prevalência , Reação em Cadeia da Polimerase Via Transcriptase Reversa , RNA Viral/genética , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Estações do Ano , Índice de Gravidade de DoençaRESUMO
A collection of 92 epidemiologically unrelated isolates of Ad1 (n = 14), Ad2 (n = 29), Ad3 (n = 19), Ad5 (n = 16), and Ad7 (n = 14) collected in the cities of Belem do Pará (1 degree S 48 degrees W) and Rio de Janeiro (23 degrees S 43 degrees W) between 1976 and 1995 from patients with respiratory disease and conjunctivitis were characterized by restriction enzyme analysis of genomic DNA. Among the strains of subgenus B, two different genome types of serotype 7, 7b and 7e, were identified. The analysis of their temporal distribution throughout the study period suggested an alternating appearance of these two DNA variants. Only one genome type of Ad3, 3p, was detected during the sampling period. Further analysis with Xba I, Bcl I, and Hpa I indicated that it is a p1-like genome type. Both previously described and new genomic variants were identified among subgenus C strains. Genome types D1, D7, D10, and one not previously described were identified among the 14 Ad1 strains analyzed. Genome types D2, D5, D25, and 13 new DNA variants were identified among the 29 Ad2 isolates. Genome type D38 and 5 new variants were found among the 16 strains of Ad5. In spite of the relatively small size of the sample analyzed, the results of this study confirm the important genetic variability previously observed for members of subgenus C by other authors.
Assuntos
Adenoviridae/genética , Genoma Viral , Adenoviridae/classificação , Adulto , Brasil , Criança , Pré-Escolar , Enzimas de Restrição do DNA/metabolismo , DNA Viral/genética , DNA Viral/metabolismo , Feminino , Humanos , Lactente , Masculino , SorotipagemRESUMO
Enteroviruses were investigated in respiratory secretions collected from patients with acute respiratory infections (ARI) over a seven year period (1985-1991), as part of a longitudinal study of ARI aetiology. All the viruses that are most commonly associated with ARI were found in this study. Among the virus isolates, enteroviruses were only less frequent than respiratory syncytial viruses, adenoviruses and influenzaviruses. Forty five enterovirus samples were isolated from patients with either upper respiratory tract infections (URTI) or lower respiratory tract infections (LRTI). From these enterovirus isolates, thirty one samples were identified as poliovirus (n = 18) and non polio enterovirus (n = 13) by serum neutralization. Poliovirus were identified as type 1 and 2 and all of them were vaccinal strains. From thirteen non polio enterovirus, twelve were identified as echovirus serotypes 1, 2, 7, 11, 19 and 31. The remainder was identified as coxsackievirus B4.
Assuntos
Infecções por Enterovirus/virologia , Enterovirus/isolamento & purificação , Nasofaringe/virologia , Infecções Respiratórias/virologia , Doença Aguda , Adulto , Brasil , Pré-Escolar , Humanos , Lactente , Estudos Longitudinais , População UrbanaRESUMO
Forty isolates of adenovirus type 7 were analized by restriction enzyme digestion with BamHI, SmaI, EcoRI and HindIII. These isolates were obtained from acute respiratory disease patients during the years 1980 to 1991. Only two genomic types were found: Ad7b and Ad7e, with Ad7b (87.5%) being more frequent than Ad7e (12.5%). The genomic type Ad7e appeared in the years 1980, 1981 and 1983. Ad7b appeared in 1982 and it was the only genomic type found from 1984 to 1991. Both genomic types were responsible for lower (LRTI) and upper (URTI) respiratory tract infection, but the proportion LRTI/URTI is higher for Ad7b (25/6) than for Ad7e (1/4).
Assuntos
Adenoviridae/genética , Genoma Viral , Infecções Respiratórias/virologia , Doença Aguda , Adenoviridae/isolamento & purificação , Adulto , Brasil , Pré-Escolar , Enzimas de Restrição do DNA , Humanos , LactenteRESUMO
The presence of respiratory syncytial virus (RSV) was investigated by immunofluorescent antibody (IFA) technique and by an enzyme immunoassay (EIA) in 169 samples of nasopharyngeal secretions of infants and children with acute respiratory infections. Of 31 samples positive by EIA, 25 were positive by IFA. In 24 samples from a retrospective study, RSV positive by IFA and/or tissue culture isolation (TCI), 22 were also positive by EIA. The EIA was also evaluated with 111 RSV isolates in Hep2 cell cultures representing different RSV subgroups. All were positive by EIA.