Molecular epidemiology of rotavirus infections in Uppsala, Sweden, 1981: disappearance of a predominant electropherotype.

The molecular epidemiology of rotavirus infections was studied in children with acute gastroenteritis in Uppsala, Sweden, during 1981. Altogether 118 virus strains were investigated by analysis of the RNA migration pattern in silver-stained polyacrylamide gels. Six different electropherotypes were seen: two with "short" and four with "long" RNA migration patterns. Forty-two strains (36%) exhibited "short" patterns. The seasonal distribution showed that strains with "long" and "short" RNA patterns cocirculated in equal frequency during the first seven months of the year, until the predominant "short" RNA electropherotype suddenly disappeared. More than 11 RNA segments were seen in two stool specimens. A complete correlation was found between the electrophoretic migration of segments 10 and 11 and the serological defined subgroup specificity.