Electrophoretic RNA genomic profiles of rotavirus strains prevailing among hospitalized children with acute gastroenteritis in tehran, iran.

BACKGROUND: Human rotavirus has now been established as the most important cause of childhood gastroenteritis worldwide. The RNA genomic electrophoretic diversity of group A rotavirus strains in Tehran, Iran, during April 2002 through March 2005, was investigated in 1250 stool specimens. METHODS: Stool samples were obtained from young children with acute gastroenteritis. RNA electrophoretype of group A rotavirus strains was determined using RNA polyacrylamide gel electrophoresis in those samples found to be positive for rotavirus by enzyme immunoassay. RESULTS: The predominant RNA profile detected was the long electrophoretype (90%) followed by the short profile (8.8%). Four patients (1.1%) had patterns of mixed infection. Fourteen different electrophoretic RNA patterns, eight of long and six of short, were detected in the study area. A long RNA electrophoretype persisted during the years of the study with peak incidence in cool seasons. The long pattern occurred throughout the study period and in patients aged one to 60 months, but the short profile identified only in infants at varying intervals. CONCLUSION: Our data demonstrate epidemiologic differences between the incidence of long and short electrophoretypes. The long profiles appear to circulate continuously in the area, whereas the short patterns appear in an episodic fashion.