Molecular characterization and multiple infections of rotavirus, norovirus, sapovirus, astrovirus and adenovirus in outpatients with sporadic gastroenteritis in Shanghai, China, 2010-2011

Rotavirus (RV), norovirus (NoV), sapovirus (SaV), human astrovirus (HAstV) and human adenovirus (HAdV) are significant because they are the most common pathogens that cause diarrhea in young children. The aim of this study was to investigate the genetic characteristics and compare the roles of these five viruses in outpatient children with diarrhea in Shanghai. A total of 436 fecal samples were collected from pediatric patients with acute gastroenteritis from January 2010 to December 2011. The selected samples were subjected to reverse transcription PCR (RT-PCR) or PCR to detect and genotype RV, NoV, SaV, HAstV and HAdV. RV (43.3 %, 189/436) was the most prevalent virus, followed by NoV (28.9 %, 126/436), HAdV (7.1 %, 31/436). HAstV (1.8 %, 8/436) and SaV (0.5 %, 2/436). The percentage of multiple infection cases was 14.9 % (65/436), and RV + NoV was the predominant mixed infection. The RV genotype combinations of P[8]G3 (52/189, 27.5 %), P[8]G1 (51/189, 26.9 %) and P[8]G9 (48/189, 25.4 %) occurred most frequently. The predominant NoV genotype was GII.4 (73.0 %, 92/126), and the majority of GII.4 clustered as GII.4-2006b (65.2 %, 60/92). Two of the SaV cases were identified as GI.2 and GII.1. All HAstV-positive samples belonged to HAstV-1. The predominant HAdV type was HAdV-41 (45.2 %, 14/31). This study clearly shows the diversity of the viral causative agents of acute gastroenteritis in outpatient children in Shanghai, which will provide baseline information for future vaccination strategies and development in this area.