ABSTRACT
Objetive: To study the viral etiology of lower respiratory tract infection (LRTI)in hospitalized (young) children, less than 1 y O. Methodology: A retrospective review was performed of LRTI patients aged less than 12 month who were admitted to the Hospital de Emergencias Pediatricas between 2001 and 2002. Respiratory viruses in their nasopharingeal secretion were identified by (IFI) indirect inmunofluorescence, viral culture or both. Results: A total of 308 children were included in the study. The mean age was 4.4 +/- 2.92 months andM:F ratio was 1.9:1. The most common diagnosis of LRTI was pneumonia (56 por ciento), followed by bronchiolitis (20 por ciento), pertussis like syndrome (5) por ciento and croup (2 por ciento). Positive IFI rate was 255 (82 por ciento). Influenza A was the commonest virus by IFI(36 por ciento ), followed by respiratory syncytial virus (27 por ciento), adenovirus (22 por ciento). Conclusion: Influenza was the commonest virus isolatedin pneumonia(p =0.040) and VSR was de commonest virus in bronchiolitis (p=0.013). Young children admitted with LRTI had 82 por ciento positive IFI study.