A 5-year study of the prevalence and genetic diversity of human caliciviruses associated with sporadic cases of acute gastroenteritis in young children admitted to hospital in Melbourne, Australia (1998-2002).

The prevalence and genetic diversity of human caliciviruses causing sporadic cases of acute gastroenteritis in young children hospitalized in a large pediatric hospital in Melbourne, Australia over 5 years (incorporating January 1998-December 2002) was studied by reverse transcription and sequence analysis of part of the polymerase gene. The overall prevalence of calicivirus infection in children aged <5 years during the 5 year study was 9.2% (113/1,233), with 95% of the strains belonging to the Norovirus genera. Strains of the norovirus G11-4 cluster were the most common type identified in 4 of the 5 years studied (1998, 1999, 2001, and 2002), with strains of norovirus cluster G11-5 the most common type during 2000. Additional norovirus genetic clusters GI-3, GII-1, GII-2, GII-3, GII-6, and GII-7, were also identified, but comprised only 17/94 of norovirus genogroup II strains. Five sapovirus strains were also identified. These results highlight the divergence of norovirus strains identified in a pediatric population. (c) 2005 Wiley-Liss, Inc.