Antigenic characterization of respiratory syncytial virus associated with acute respiratory infections in Uruguayan children from 1985 to 1987.

The occurrence of subgroup A and B strains of respiratory syncytial virus (RSV) was studied during three epidemic years, 1985 to 1987, in Uruguay. A set of monoclonal antibodies was selected according to their reactivity with local RSV isolates and used for the typing of RSV directly in nasopharyngeal cells by indirect immunofluorescence. Of 77 specimens, 69 could be typed as belonging to subgroup A or B, 5 could not be typed with the restricted set of monoclonal antibodies employed, and 3 reacted with both subgroup-specific antibodies. In 1985 and 1986 subgroup A predominated, accounting for 65.7% of all typed specimens, but in 1987 subgroup B surpassed subgroup A, accounting for 82.4% of the samples.