Molecular detection and characterization of sapovirus in hospitalized children with acute gastroenteritis in the Philippines

Abstract

BackgroundHuman sapovirus (SaV) is a causative agent of acute gastroenteritis. Recently, SaV detection has been increasing worldwide due to the emerging SaV genotype I.2. However, SaV infection has not been reported in the Philippines. ObjectivesTo evaluate the prevalence and genetic diversity of SaV in hospitalized children aged less than 5 years with acute gastroenteritis. Study designStool samples were collected from children with acute gastroenteritis at three hospitals in the Philippines from June 2012 to August 2013. SaV was detected by reverse transcription real-time PCR, and the polymerase and capsid gene sequences were analyzed. Full genome sequencing and recombination analysis were performed on possible recombinant viruses. ResultsSaV was detected in 7.0% of the tested stool samples (29/417). In 10 SaV-positive cases, other viruses were also detected, including rotavirus (n=6), norovirus (n=2), and human astrovirus (n=2). Four known SaV genotypes (GI.1 [7], GI.2 [2], GII.1 [12], and GV [2]) and one novel recombinant (n=3) were identified by polymerase and capsid gene sequence analysis. Full genome sequencing revealed that the 5ʹ nontranslated region (NTR) and nonstructural protein region of the novel recombinant were closely related to the GII.1 Bristol/98/UK variant, whereas the structural protein region and 3ʹ NTR were closely related to the GII.4 Kumamoto6/Mar2003/JPN variant. Discussion and conclusionsSaV was regularly detected in hospitalized children due to acute gastroenteritis during the study period. A novel recombinant, SaV GII.1/GII.4, was identified in three cases at two different study sites.