Prevalence and clinical aspects of respiratory syncytial virus A and B groups in children seen at Hospital de Clínicas of Uberlândia, MG, Brazil

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.

Longitudinal study of acute respiratory diseases in Rio de Janeiro: occurrence of respiratory viruses during four consecutive years

Investigamos, durante um periodo de 4 anos (1982 a 1985), a ocorrencia de virus em secrecoes de nasofaringe coletadas de criancas com menos de 5 anos de idade apresentando quadro clinico de infeccao respiratoria aguda (IRA), residentes na cidade do Rio de Janeiro. Foram encontrados todos os virus conhecidos como associados a IRA, com excessao do virus influenza C e parainfluenza 1, 2 e 4. Virus foram isolados mais frequentemente de criancas internadas em salas de emergencia e enfermarias que daquelas atendidas em ambulatorio. Este fato esta claramente relacionado com a alta incidencia do virus sincicial respiratorio (RSV) nos casos mais severos de IRA. Especimes positivos para RSV aparecem principalmente durante o outono, nos 4 anos consecutivos, indicando uma ocorrencia sazonal. As salas de emergencias sao a melhor fonte de dados para vigilancia do RSV, onde um aumento no numero de casos positivos corresponde a um aumento no numero total de casos de IRA internados. Os adenovirus ocupam o segundo lugar entre os virus frequentemente isolados, sendo predominante os sorotipos 1, 2 e 7. Embora em menor numero os virus influenza e parainfluenza tipo 3 tambem sao encontrados. Virus influenza A foram isolados igualmente em criancas internadas em enfermarias, salas de emergencia e nos pacientes atendidos em...