title: Helicobacter pylori and risk of gastroenteritis.
abstract: BACKGROUND
  Helicobacter pylori infection is thought to modify susceptibility to gastroenteritis.
  
  
  METHODS
  Members of northern California households with an index case of gastroenteritis were interviewed regarding recent episodes and tested for H. pylori. Conditional logistic regression was used to evaluate the risk of secondary gastroenteritis within households matched for members with secondary gastroenteritis (cases) and those without symptoms (control subjects). Case and control subjects were also tested for hepatitis A virus (HAV).
  
  
  RESULTS
  Of 801 households, 205 (26%) had at least 1 member with secondary gastroenteritis, of which 116 (56%) also included at least 1 member without symptoms (158 case and 285 control subjects). Compared with uninfected members and adjusting for age, those with antibodies to only 1 infection were at a decreased risk of secondary gastroenteritis (odds ratio [OR] for H. pylori infection, 0.25 [95% confidence interval [CI], 0.08-0.82]; OR for HAV, 0.45 [95% CI, 0.23-0.87]). Having antibodies to both H. pylori and HAV did not add to this negative effect (adjusted OR, 0.39 [95% CI, 0.18-0.84]).
  
  
  CONCLUSIONS
  H. pylori did not increase the risk of gastroenteritis in these households. A strong negative association between H. pylori infection and gastroenteritis is likely explained by prior exposure and immunity to other enteric pathogens.
authors.affiliation: Division of Geographic Medicine and Infectious Disease, Stanford University School of Medicine, Stanford, California, USA. shnperry@stanford.edu
authors.forename: Sharon
authors.initials: S
authors.lastname: Perry
authors.forename: Luz
authors.initials: L
authors.lastname: Sanchez
authors.forename: Shufang
authors.initials: S
authors.lastname: Yang
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Haggerty
authors.forename: Philip
authors.initials: P
authors.lastname: Hurst
authors.forename: Julie
authors.initials: J
authors.lastname: Parsonnet
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood; D002140:California; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology / Q000209:etiology*; D016481:Helicobacter Infections / Q000150:complications* / Q000453:epidemiology; D016480:Helicobacter pylori / Q000276:immunology / Q000302:isolation & purification; D006506:Hepatitis A / Q000453:epidemiology; D035922:Hepatitis A Antibodies / Q000097:blood; D030041:Hepatitis A virus / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors
chemical_list: D000907:Antibodies, Bacterial; D035922:Hepatitis A Antibodies