The relative frequencies of G serotypes of rotaviruses recovered from hospitalized children with diarrhea: A 10-year survey (1987-1996) in Japan with a review of globally collected data.

Since rotavirus vaccines aim to protect children from severe diarrhea, knowledge of the prevailing G serotypes among rotaviruses from hospitalized children is essential. Thus, we determined the G serotypes of rotaviruses collected from children with acute diarrhea in a local referral hospital in Akita, Japan, over the 10-year period between January 1987 and December 1996. Based on the assumption that rotaviruses with an identical electropherotype possess the same G serotype, the G serotypes of 488 rotavirus-positive specimens that were classified into 63 electropherotypes were determined by enzyme-linked immunosorbent assay with a supplementary use of G typing by reverse transcription-PCR. The relative frequencies over the 10-year period were 77.0 (G1), 14.5 (G2), 2.7 (G3) and 5.3% (G4), leaving the possibility that only 0.4% had G serotypes uncommon to human rotaviruses. Of 24,050 rotaviruses extracted by reviewing 63 serotyping studies in literature, the relative frequencies of the four major G serotypes were 50.6 (G1), 9.3 (G2), 7.2 (G3) and 11.6% (G4). As to uncommon G serotypes, only 0.9% were described as serotypes other than G1-4, and our estimate for potential uncommon serotypes were at most 8.1%. Thus, both this long-term study focusing on the rotaviruses only from severe cases in a single hospital in Japan and the global review of G serotypes published to date indicate that the primary target of any rotavirus vaccines should be rotaviruses possessing serotypes G1-4.