Epidemiological and clinical characteristics of pediatric gastroenteritis associated with new viral agents.

A 22-month study (2008-2009) was carried out on 273 patients (average age 40 months), admitted with gastroenteritis to the Pediatric Unit of L. Sacco University Hospital in Milan, Italy. Fecal samples were investigated for rotavirus (HRV), norovirus (NoV), adenovirus (AdV), sapovirus (SaV), enterovirus, astrovirus and bocavirus (HBoV). A 38.3% incidence of infection was observed for HRV, followed by NoV (16.2%), HBoV (13.6%), AdV (2.6%) and SaV (0.6%). Clinical evaluation of 109 gastroenteritis patients with confirmed diagnosis was graded by the Ruska-Vesikari scoring system, showing vomiting (78%), diarrhea (96%) and fever (80%). A total of 25 NoV-positive samples were selected for nucleotide sequence analysis. The severity of AdV-associated infection was lower than for NoV, HRV and HBoV. These latter viruses caused similar symptoms that were indistinguishable using clinical information. NoV, HRV and HBoV were often present as mixed infections (13.1%). Sequencing of NoV-positive samples allowed identification of GII.2, GII.3 and GII.4 2006 variants.