Genomic diversity of group A rotavirus RNA from children with acute diarrhoea in Chennai, south India.

Group A rotavirus was identified in 51 of 245 (20.8%) cases with acute diarrhoea in Chennai analysed between December 1997 and March 1999. Forty eight of the 51 specimens were subgrouped and serotyped. A total of 110 rotavirus positive specimens (inclusive of 62 rotavirus positive cases reported earlier) were analysed for their subgroup (SG) specificity and genomic profiles. SGI and SGII specificity were detected in 60 per cent and 20 per cent of the cases studied. Twenty two cases showed dual SG specificity (SGI + II). Nine electropherotypic patterns (7 'short' and 2 'long') were observed with a predominance of short pattern in 87 of the 110 (79.1%) positive cases studied. Long electropherotypes were found in 23 (20.9%). Serotyping of the 48 rotavirus positives revealed a higher proportion of serotype-2 (68.8%) followed by serotype-1 (14.6%) and serotype-3 in 1 case. Mixed infection of G1-G2 was observed among 7 cases analysed, which revealed G[2,1], P[4,8] genotype specificity. Dual infection of P[4]-P[8] genotypes was observed in 12 cases with G[2] specificity.