Antigenic diversity of respiratory syncytial virus subgroup B strains circulating during a community outbreak of infection.

The epidemiological characteristics and relationship between respiratory syncytial virus (RSV) subgroup and virulence during an outbreak of RSV infection occurring in Southeast Texas in the winter season 1991/92 are described. Fifty-two infants and children were diagnosed with RSV infection by rapid viral antigen detection and/or viral isolation. Subgrouping of the isolates was carried out using 11-monoclonal anti-bodies. Ten isolates were found to be subgroup B, and 8 isolates were subgroup A. The subgroup B strains showed 3 different patterns of reaction with monoclonal antibodies; one of these subgroups was examined further by restriction analysis of parts of its nucleocapsid and attachment protein genes. The peak of RSV outbreak was in December 1991. Both subtypes A and B circulated simultaneously in the same territory, and caused lower respiratory tract infections in similar proportions. The more frequent occurrence of the B subgroup and the diversity of its simultaneously circulated RSV strains have made this outbreak unusual.