Detection of Human Caliciviruses and Astroviruses in Stools by RT-PCR

Human caliciviruses (HuCVs) and astroviruses are single-stranded RNA viruses that cause acute gastroenteritis in humans. HuCVs include several prototypes of small, round-structured viruses (SRSVs) as well as morphologically typical caliciviruses. Recent genetic characterization of HuCVs has divided them into three genogroups: Norwalk virus (NV), Snow Mountain agent (SMA), and Sapporo (Sapp) viruses (1 –3 ). Astroviruses include at least seven antigenic types (4 ). Complete genomic sequences of astrovirus types 1 and 2 and partial sequences of other strains have been reported (5 –7 ). In both families, differences in antigenic types appear to correspond to differences in genetic groups.