title: Antibiotics taken for other illnesses and spontaneous clearance of Helicobacter pylori infection in children.
abstract: OBJECTIVE
  Factors that determine persistence of untreated Helicobacter pylori (H. pylori) infection in childhood are not well understood. We estimated risk differences for the effect of incidental antibiotic exposure on the probability of a detected clearance at the next test after an initial detected H. pylori infection.
  
  
  METHODS
  The Pasitos Cohort Study (1998-2005) investigated predictors of H. pylori infection in children from El Paso, Texas, and Juarez, Mexico. Children were screened for infection at 6-month target intervals from 6 to 84 months of age, using the 13C-urea breath test corrected for body-size-dependent variation in CO2 production. Exposure was defined as courses of any systemic antibiotic (systemic) or those with anti-H. pylori action (HP-effective) reported for the interval between initial detected infection and next test. Binomial regression models included country of residence, mother's education, adequacy of prenatal care, age at infection, and interval between tests.
  
  
  RESULTS
  Of 205 children with a test result and antibiotic data following a detected infection, the number of children who took > or =1 course in the interval between tests was 74 for systemic and 33 for HP-effective. The proportion testing negative at the next test was 66% for 0 courses, 72% for > or =1 systemic course, and 79% for > or =1 HP-effective course. Adjusted risk differences (95%CI) for apparent clearance, comparing > or =1 to 0 courses were 10% (1-20%) for systemic and 11% (0-21%) for HP-effective.
  
  
  CONCLUSIONS
  Incidental antibiotic exposure appears to influence the duration of childhood H. pylori infection but seems to explain only a small portion of spontaneous clearance.
authors.affiliation: University of Texas School of Public Health, Houston, TX, USA. gnp2@cdc.gov
authors.forename: Cheryl S
authors.initials: CS
authors.lastname: Broussard
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Goodman
authors.forename: Carl V
authors.initials: CV
authors.lastname: Phillips
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Smith
authors.forename: Lori A
authors.initials: LA
authors.lastname: Fischbach
authors.forename: R Sue
authors.initials: RS
authors.lastname: Day
authors.forename: Corinne C
authors.initials: CC
authors.lastname: Aragaki
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001944:Breath Tests; D002247:Carbon Isotopes; D002648:Child; D002675:Child, Preschool; D016481:Helicobacter Infections / Q000175:diagnosis / Q000208:ethnology / Q000382:microbiology*; D016480:Helicobacter pylori; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D008800:Mexico / Q000453:epidemiology; D015233:Models, Statistical; D011446:Prospective Studies; D012044:Regression Analysis; D012075:Remission, Spontaneous; D012307:Risk Factors; D013781:Texas / Q000453:epidemiology; D013997:Time Factors; D014508:Urea / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D002247:Carbon Isotopes; D014508:Urea