ABSTRACT
I. BACKGROUND Caliciviruses are a group of enteric viruses that infect a broad variety of terrestrial and marine animals (1-3). Although human caliciviruses are currently classified in three genogroups, the human viruses are of two basic morphological and biological types: the classic human caliciviruses and the Norwalk-like viruses (NLVs). The latter are also referred to in the literature as small round structured viruses (SRSVs). Although examples of classic calicivirus strains causing gastroenteritis in adults have been reported (4), classic caliciviruses are normally associated with self-limiting gastroenteritis in infants and children. Overall, the classic caliciviruses only account for a small portion of infantile gastroenteritis cases (5). Consequently, classic caliciviruses are generally considered of less medical and foodborne significance than the NLVs.
