title: Seroepidemiology of Norovirus GII.3 and GII.4 Infections in Children with Diarrhea in Xi'an, China.
abstract: OBJECTIVE
  The objective of this study was to investigate the seroepidemiology of immunoglobulin G (IgG) antibodies against Norovirus (NoV) GII.3 and GII.4 genotypes among children younger than 5 years with acute diarrhea in Xi'an, China.
  
  
  METHODS
  A total of 362 serum samples were collected from diarrheal children in the Department of Digestive Diseases of Xi'an Children's Hospital between March 2009 and October 2012. Recombinant capsid proteins of NoV genotypes GII.3 and GII.4 were expressed using the baculovirus expression system. The viruslike particles (VLPs) were examined by electron microscopy and Western blot, and VLPs were used as antigens for serological IgG tests using enzyme-linked immunosorbent assays.
  
  
  RESULTS
  The overall seroprevalence for GII.4 (86.2%) was significantly higher (p<0.01) than for GII.3 (67.9%). The seroprevalence remained in a high and stable level (70.9% for GII.3 and 88.7% for GII.4) in children under 1 year of age, then dropped in the age group 12-17 months (49.3% for GII.3 and 68.1% for GII.4), and finally increased to 77.8% for GII.3 and 96.8% for GII.4 in the group >18 months. The seroprevalence in the age group 12-17 months showed more statistically significant differences than the other age groups for both GII.3 and GII.4 (p<0.05).
  
  
  CONCLUSIONS
  In conclusion, seroprevalence of NoV GII.3 and GII.4 was high in young children in Xi'an, China, and the anti-GII.4-positive rates were statistically higher than GII.3 across all the age groups.
authors: 1 Department of Pediatrics, The First Affiliated Hospital, Medical School of Xi'an Jiaotong University , Xi'an, Shaanxi Province, China .
authors: Xiaohong
authors: X
authors: Liu
authors: 2 Hubert Department of Global Health, Rollins School of Public Health, Emory University , Atlanta, Georgia .
authors: Pengbo
authors: P
authors: Liu
authors: 1 Department of Pediatrics, The First Affiliated Hospital, Medical School of Xi'an Jiaotong University , Xi'an, Shaanxi Province, China .
authors: Jiao
authors: J
authors: Wang
authors: 2 Hubert Department of Global Health, Rollins School of Public Health, Emory University , Atlanta, Georgia .
authors: Christine
authors: C
authors: Moe
authors: 3 Lab Center of Public Health Department, School of Medicine, Xi'an Jiaotong University , Xi'an, Shaanxi Province, China .
authors: Senke
authors: S
authors: Hu
authors: 4 Department of Nursing, School of Medicine, Xi'an Jiaotong University , Xi'an, Shaanxi Province, China .
authors: Li
authors: L
authors: Cheng
authors: 5 College of Medicine, Xi'an Jiaotong University , Xi'an, Shaanxi Province, China .
authors: Wei
authors: W
authors: Gu
authors: 6 Department of Statistics and Epidemiology, School of Medicine, Xi'an Jiaotong University , Xi'an, Shaanxi Province, China .
authors: Xiaoqin
authors: X
authors: Wang
mesh_terms: D000208:Acute Disease; D000367:Age Factors; D000914:Antibodies, Viral / Q000032:analysis; D017250:Caliciviridae Infections / Q000097:blood / Q000453:epidemiology* / Q000503:physiopathology / Q000821:virology; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003967:Diarrhea / Q000209:etiology*; D003968:Diarrhea, Infantile / Q000209:etiology*; D004198:Disease Susceptibility; D005243:Feces / Q000821:virology; D005260:Female; D005759:Gastroenteritis / Q000097:blood / Q000453:epidemiology* / Q000503:physiopathology / Q000821:virology; D006776:Hospitals, Pediatric; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007223:Infant; D008297:Male; D058889:Molecular Typing; D029322:Norovirus / Q000145:classification / Q000276:immunology* / Q000302:isolation & purification / Q000648:ultrastructure; D011994:Recombinant Proteins / Q000378:metabolism; D016036:Seroepidemiologic Studies
chemical_list: D000914:Antibodies, Viral; D036022:Capsid Proteins; D007074:Immunoglobulin G; D011994:Recombinant Proteins