Emergence of unique variants and inter-genotype recombinants of human astroviruses infecting infants, children and adults in Kolkata, India.

Two conserved genomic fragments viz. 289bp of ORF1a and 449bp of ORF2 amplified by RT-PCR showed emergence of interesting recombinant strains representing new and novel genetic variants (n=5) within eight different genotypes of astroviruses known to date. HAstV-positive cases with ORF1a [HAstV genotype G2 or G8] and ORF2 [HAstV genotype G1, G2, or G3] were detected as sole or mixed infection among infants, children and adults in Kolkata with severe illness owing to acute gastroenteritis that required hospitalization for treatment between 2007 and 2009. The twelve interesting recombinants were of type HAstV _ ORF1a _ ORF2 as HAstV _ G8_ G2 (n=1), HAstV _ G8_ G1 (n=10) and HAstV _ G2_ G3 (n=1).