RESUMEN
Two hundred and twenty infants and children with fever and respiratory distress below three years of age [8.9 +/- 2.6 months] were examined for the diagnosis of viral etiology. Nasopharyngeal aspirates [NPA] was used for viral isolation by tissue culture and compared to the demonstration of viral antigens in the specimens by indirect immunoflourescent test using the Baxter Bartel respiratory screening and identification kit. In a series of 220 NPAs tested. 139 [63.1%] respiratory viral agents were isolated on tissue culture. Respiratory syncetail virus [RSV] was the most commonly isolated agent particularly among infants below 1 year of age with a peak below 6 months of age. Other isolated virsus included influenza A and B, Parainfluenza 1, 2 and 3 and adnoviruses. Direct antigen detection by immunofluorescent technique gave a high level of sensitivity and specificity compared to the culture as a standard measure, Viral ARI is a common pediatric problem. RSV is a common infectious agent of ARI below 1 year. The rapid, cheaper, sensitive and specific immunoflourescent test for antigen detection is of great help for paediatricians to take a rapid decision regarding the etiology and need of antimicrobial agents in ARI