title: Molecular detection and characterization of sapovirus in hospitalized children with acute gastroenteritis in the Philippines.
abstract: BACKGROUND
  Human 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.
  
  
  OBJECTIVE
  To evaluate the prevalence and genetic diversity of SaV in hospitalized children aged less than 5 years with acute gastroenteritis.
  
  
  METHODS
  Stool 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.
  
  
  RESULTS
  SaV 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 5' 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 3' NTR were closely related to the GII.4 Kumamoto6/Mar2003/JPN variant.
  
  
  CONCLUSIONS
  SaV 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.
authors.affiliation: Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-Machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Pediatrics, Kushiro city General Hospital, 1-12 Shunkodai, Kushiro, Hokkaido 085-0822, Japan.
authors.forename: Dai
authors.initials: D
authors.lastname: Yamamoto
authors.affiliation: Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-Machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan; Tohoku-RITM Collaborating Research Center on Emerging and Re-emerging Infectious Diseases, FCC, Alabang, Muntinlupa 1781, Philippines.
authors.forename: Mariko
authors.initials: M
authors.lastname: Saito
authors.affiliation: Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-Machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Imagawa
authors.affiliation: Molecular Biology Laboratory, Research Institute for Tropical Medicine (RITM), FCC, Alabang, Muntinlupa 1781, Philippines.
authors.forename: Adrianne
authors.initials: A
authors.lastname: Ablola
authors.affiliation: Department of Virology, Research Institute for Tropical Medicine (RITM), FCC, Alabang, Muntinlupa 1781, Philippines.
authors.forename: Amado O
authors.initials: AO
authors.lastname: Tandoc
authors.affiliation: Molecular Biology Laboratory, Research Institute for Tropical Medicine (RITM), FCC, Alabang, Muntinlupa 1781, Philippines.
authors.forename: Edelwisa
authors.initials: E
authors.lastname: Segubre-Mercado
authors.affiliation: Research Institute for Tropical Medicine (RITM), FCC, Alabang, Muntinlupa 1781, Philippines.
authors.forename: Socorro P
authors.initials: SP
authors.lastname: Lupisan
authors.affiliation: Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-Machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Okamoto
authors.affiliation: Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-Machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Furuse
authors.affiliation: Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-Machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan. Electronic address: msaitop@med.tohoku.ac.jp.
authors.forename: Mayuko
authors.initials: M
authors.lastname: Saito
authors.affiliation: Department of Virology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-Machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Oshitani
mesh_terms: D017250:Caliciviridae Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology*; D002673:Child, Hospitalized; D002675:Child, Preschool; D016000:Cluster Analysis; D005243:Feces / Q000821:virology; D005260:Female; D005759:Gastroenteritis / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology*; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008969:Molecular Sequence Data; D010679:Philippines / Q000453:epidemiology; D010802:Phylogeny; D011446:Prospective Studies; D011995:Recombination, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D029341:Sapovirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D017422:Sequence Analysis, DNA; D017385:Sequence Homology
keywords: Gastroenteritis; Recombination; Sapovirus; The Philippines