RESUMEN
The presence of viral and/or inframicrobial antigens was investigated by the immunofluorescence (IF) technique in exfoliated pharyngeal cells collected from 85 children aged 0-5 years, with acute infections of the upper or lower respiratory tract. Positive IF reactions were recorded in 83% of the children with bronchopneumonia, 81.8% of those with acute pharyngitis, 77.7% of those with acute upper respiratory tract infections and 66.6% of those with acute bronchitis. In 68.75% of the IF-positive cases 2-5 different antigens were simultaneously visualized. Herpes and parainfluenza virus antigens appeared to be predominant. The proportion of positive IF reactions was much lower (20%) in a control group of 20 apparently healthy children, where a single viral antigen (parainfluenza 1) was detected.