title: Persistent and transient Helicobacter pylori infections in early childhood.
abstract: BACKGROUND
  Helicobacter pylori, the main cause of peptic ulcer disease and gastric cancer in adult populations, is generally acquired during the first years of life. Infection can be persistent or transient and bacterial and host factors determining persistence are largely unknown and may prove relevant for future disease.
  
  
  METHODS
  Two cohorts of healthy Chilean infants (313 total) were evaluated every 3 months for 18-57 months to determine pathogen- and host-factors associated with persistent and transient infection.
  
  
  RESULTS
  One-third had at least one positive stool ELISA by age 3, with 20% overall persistence. Persistent infections were acquired at an earlier age, associated with more household members, decreased duration of breastfeeding, and nonsecretor status compared to transient infections. The cagA positive strains were more common in persistent stools, and nearly 60% of fully characterized persistent stool samples amplified cagA/vacAs1m1. Persistent children were more likely to elicit a serologic immune response, and both infection groups had differential gene expression profiles, including genes associated with cancer suppression when compared to healthy controls.
  
  
  CONCLUSIONS
  These results indicate that persistent H. pylori infections acquired early in life are associated with specific host and/or strain profiles possibly associated with future disease occurrence.
authors.affiliation: Microbiology and Mycology Program, Institute of Biomedical Sciences.
authors.forename: Miguel L
authors.initials: ML
authors.lastname: O'Ryan
authors.affiliation: Luis Calvo Mackenna Hospital, Department of Pediatrics and Pediatric Surgery (Eastern Campus), Faculty of Medicine, Universidad de Chile.
authors.forename: Yalda
authors.initials: Y
authors.lastname: Lucero
authors.affiliation: Luis Calvo Mackenna Hospital, Department of Pediatrics and Pediatric Surgery (Eastern Campus), Faculty of Medicine, Universidad de Chile.
authors.forename: Marcela
authors.initials: M
authors.lastname: Rabello
authors.affiliation: Microbiology and Mycology Program, Institute of Biomedical Sciences.
authors.forename: Nora
authors.initials: N
authors.lastname: Mamani
authors.affiliation: School of Medical Technology, Faculty of Health, Universidad Santo Tomás.
authors.forename: Ana María
authors.initials: AM
authors.lastname: Salinas
authors.affiliation: Pediatric Service, Sótero del Río Hospital, Santiago, Chile.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Peña
authors.affiliation: Luis Calvo Mackenna Hospital, Department of Pediatrics and Pediatric Surgery (Eastern Campus), Faculty of Medicine, Universidad de Chile.
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Torres-Torreti
authors.affiliation: Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, The Ohio State University School of Medicine, Columbus.
authors.forename: Asunción
authors.initials: A
authors.lastname: Mejías
authors.affiliation: Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, The Ohio State University School of Medicine, Columbus.
authors.forename: Octavio
authors.initials: O
authors.lastname: Ramilo
authors.affiliation: Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, The Ohio State University School of Medicine, Columbus.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Suarez
authors.affiliation: Physiopathology Program Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago.
authors.forename: Henry E
authors.initials: HE
authors.lastname: Reynolds
authors.affiliation: Microbiology and Mycology Program, Institute of Biomedical Sciences.
authors.forename: Andrea
authors.initials: A
authors.lastname: Orellana
authors.affiliation: Microbiology and Mycology Program, Institute of Biomedical Sciences.
authors.forename: Anne J
authors.initials: AJ
authors.lastname: Lagomarcino
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000235:genetics; D058070:Asymptomatic Diseases; D001426:Bacterial Proteins / Q000235:genetics; D002675:Child, Preschool; D002677:Chile / Q000453:epidemiology; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000382:microbiology*; D020869:Gene Expression Profiling; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000276:immunology / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D054884:Host-Pathogen Interactions; D006801:Humans; D007223:Infant; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D013997:Time Factors
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori
keywords: Helicobacter pylori; asymptomatic; children; persistence; virulence genes