Molecular epidemiology of human rotavirus infections based on genome segment variations in viral strains.

Molecular epidemiology of rotavirus infections in 621 hospitalized children was investigated by analysis of migration patterns of viral genomic ribonucleic acid (RNA) segments by electrophoresis in polyacrylamide gels. Based on migration patterns of RNA segments of 184 rotavirus strains, seven different electropherotypes were identified: 146 (79.3%) strains were "long," and 38 (20.7%) were "short" electropherotypes; 61% belonged to a single dominant "long" electropherotype, which persisted throughout the 15-month period of study, whereas six other cocirculating types appeared at varying intervals. Electrophoretic migration patterns of RNA from viral isolates of two patients suggested mixed infections with different rotaviruses. There was a lack of correlation between the electrophoretic migration of segments 10 and 11 and serologically defined subgroup specificity in three of the rotavirus strains. Rotavirus infections and different electropherotypes were observed throughout the year.