Detection and molecular characterization of enteric viruses in children with acute gastroenteritis in Northern Italy

Enteric viral infections are a major concern for public health, and viral acute gastroenteritis is the principal cause of pediatric morbidity and mortality worldwide, mostly in developing countries. The purpose of this study was to determine the prevalence of different enteric viruses detected in a pediatric population with acute gastroenteritis symptoms, and to characterize the strains detected. Stools were collected from children, aged from 2 months to 15 years old, admitted to one of the main hospitals of Northern Italy, between November 2015 and October 2016. Stools were tested for nine enteric viruses (adenovirus, rotavirus A, norovirus, astrovirus, sapovirus, enterovirus, parechovirus, bocavirus and aichivirus) by molecular methods. Furthermore, rotavirus, norovirus and adenovirus were deeply characterized by nucleotide sequencing and phylogenetic analysis. A total of 151 out of 510 (29.6%) stools analyzed resulted positive for at least one of the enteric virus investigated. The most common virus detected was rotavirus A (53/151, 35.1%), followed by norovirus (39/151, 25.8%), adenovirus (35/151, 23.1%), sapovirus (9/151, 6%), enterovirus (5/151, 3.3%), astrovirus (5/151, 3.3%), parechovirus (4/151, 2.6%) and bocavirus (1/151, 0.6%). Aichi virus was not detected in any sample. Co-infections were detected in 12 out of 510 faecal samples (2.3%). These data improved the knowledge of the enteric viruses circulating in children in Northern Italy. In fact, besides rotavirus, adenovirus and norovirus, several viruses circulated across the whole year in the pediatric population object of this study. The introduction of specific viral diagnosis in our clinical setting will improve patient care by reducing unnecessary use of antibiotics addressing the right etiologic diagnosis.