VP7 and VP4 genotypes among rotavirus strains recovered from children withgastroenteritis over a 3-year period in Valencia, Spain

Between September 1996 and May 1999, the incidence and distribution of the main human rotavirus G genotypes (VP7 associated: G1-G4) and P genotypes (V P4 associated: P[8], P[4], P[6] and P[9]) among children with rotavirus gas troenteritis were determined using reverse transcription and polymerase cha in reaction (RT-PCR)-based genotyping methods. From a total of 145 rotaviru s strains examined, we identified the G type in 131 (90.3%) and the P type in 127 (87.5%) of the samples. An overall predominance of genotypes P[8] G1 (42.7%) and P[8] G4 (32.4%) was found during the period of study, with muc h lower incidence of genotypes P[4] G2 (5.5%) and P[8] G3 (2%). P[6] and P[ 9] types were not detected, neither were unusual combinations of P and G ty pes. A significant genotypic shift was observed: whereas P[8] G4 was the mo st prevalent genotype during the first year of the study (60%), the genotyp e P[8] G1 gradually increased to account for 62.3% of the strains analysed in the following winter season. Mixed G types revealing dual infections G1/ G4 and G3/G4 were found at low frequency (2%).