INTRODUCTION: Acute respiratory infections (ARIs) are an important cause of morbidity and mortality among children in developing countries. The viral etiology of such infections is not always known in Brazil. Furthermore, studies on viral ARIs in children with underlying diseases (UD) are scanty. OBJECTIVE: The objective of this study was to determine the viral etiology of these infections among children under 5 years of age treated at Instituto Fernandes Figueira/Fundação Oswaldo Cruz (IFF/FIOCRUZ), Rio de Janeiro. METHOD: Two hundred and eighty-five samples of nasopharyngeal aspirate, which had been obtained from 204 children with ARI from May/2005 to June/2006, were analyzed. RESULTS: Samples were tested through indirect immunofluorescence assay and 90 of them (31.6%) were positive for the following viral agents: respiratory syncytial virus (21.4%), adenovirus (3.5%), parainfluenza 3 (3.1%), influenza A (2.5%), parainfluenza 1 (0.7%), and influenza B (0.4%). One hundred and ninety-five samples were negative, from which 156 were tested for human metapneumovirus, and 15 of them (9.6%) were positive. CONCLUSION: The viral prevalence among outpatients was 42.8% and among inpatients it was 30%; 83.3% of the children were carriers of one or more UD associated with ARI, resulting in long-term admission to hospital. Some children had multiple admissions and multiple clinical diagnoses of ARI during the studied period.
Acute respiratory infections; Viral infection Children; Imunofluorescence
