Genetic distribution of group A human rotavirus types isolated in Gyunggi province of Korea, 1999-2002

Background: Human rotavirus genotypes G1-G4 and G9 are the major etiological agents of infantile gastroenteritis. G1 was the most prevalent in Korea during the 10-year period prior to 1997. However, between 1998 and 1999, G4 was the predominant type in Korea, as it was in other Asian countries. Objectives: The circulating pattern and genetic variability of group A human rotavirus in Gyunggi, Korea, 1999-2002, were examined in 189 stool specimens. Study design: Stool samples were collected from children with diarrhea, and group A human rotavirus type was determined using multiplex RT-PCR in those specimens found to be positive for rotavirus by ELISA. Each genotype was sequenced, and phylogenetic analysis was performed on the sequences. Result: We found significant variability from year to year in the prevalence of different G and P types of rotavirus. We also found relatively high prevalence rates for types normally considered to be uncommon. Furthermore, we found that the most prevalent combination of G and P types changed from year to year. Although the combination of G and P types changed every year, the sequence of G genotypes showed a high level of similarity (>97%) compared to those of strains from other Asian countries. Conclusion: We report the types of rotavirus circulating in Gyunggi province, Korea from 1999 to 2002. This information on rotavirus diversity has important implications for rotavirus vaccine efficacy and future vaccine development.