[VP7 typing of rotavirus from children with diarrhea in Chongqing Region]

To study VP7 type of rotavirus from children with diarrhea in Chongqing area from 1998 to 2000.

Double-strand RNA of rotavirus extracted from stool samples was used as the template for reverse transcription of gene VP7, which was followed by nested PCR for VP7 typing. Nucleotide sequence analysis was used for VP7 typing.

Among the 130 fecal specimens from pediatric patients with acute gastroenteritis during the epidemic season of 1998-1999, fifty specimens (38.46%) were identified as rotavirus-positive by RT-PCR. Of these, serotype G1 was found to be largely predominant and accounted for 88% (44/50), while serotype G3 accounted for 8% (4/50), coinfection of G1 and G3 accounted for 4% (2/50) respectively. While during the next epidemic season from 1999 to 2000, thirty-eight (33.93%) rotavirus positive specimens were detected from 112 stool samples by RT-PCR. Serotype G3 increased significantly-up to 78.95% (30/38) and became the most prevalent serotype in that season. It was found that only 13.16% (5/38) were serotype G1, 7.89% (3/38) were G1 and G3 mixture. The nucleotide sequence analysis results agreed with the RT-PCR typing assay.

Serotype G1 and G3 were the prevalent VP7 types in Chongqing, China from 1998 to 2000. A shift from G1 to G3 was observed in the last two successive epidemic seasons of rotavirus epidemics.