Emerging trends in the epidemiology of human astrovirus infection among infants, children and adults hospitalized with acute watery diarrhea in Kolkata, India

► Systematic active surveillance of acute diarrhea during Nov' 2007-Oct' 2009 in Kolkata. ► Sixty (2.3%) HAstV positives (sole and mixed infections) in all age groups hospitalized with AGE. ► High prevalence of HAstVs in diarrheic adults (sole 21.7% and mixed 36.7%). ► Kolkata HAstV_G1 & G3 strains showed genetic relatedness to Japanese and Thai strains. ► Full genome analyses of HAstVs are required to understand the genetic diversity.