title: Association of Helicobacter pylori infection and giardiasis: results from a study of surrogate markers for fecal exposure among children.
abstract: OBJECTIVE
  To investigate whether Helicobacter pylori (H pylori) infection is associated with hepatitis A virus (HAV) infection, presence of enteroparasites, and other surrogates of fecal exposure.
  
  
  METHODS
  We conducted a cross-sectional study in 121 children consecutively admitted at a pediatric hospital in Salvador, Brazil. H pylori and HAV infection were identified by the presence of serum antibodies. Stool specimens were examined for the presence of ova and parasites. A structured questionnaire inquiring about sanitary conditions and life style was applied to each subject.
  
  
  RESULTS
  Fifty-one of the 121 children (42.1%) were found to be seropositive for H pylori, and 45 (37.2%) for HAV. The seroprevalence of H pylori and HAV both increased significantly with age. Cross-tabulation of data showed that 26 (21.5%) were seropositive and 51 (42.1%) were negative for both H pylori and HAV antibodies (chi(2) = 7.18, OR = 2.8, CI 1.30-5.97). The age adjusted OR for an HAV-infected child being H pylori positive was 2.3 (CI 1.02-5.03). The agreement between H pylori and HAV seropositivity was fair (kappa = 0.24). After controlling for possible confounding, the variables remaining independently associated with seropositivity to H pylori were age, presence of Giardia lamblia in feces (OR = 3.2, 95%CI, 1.1-9.5) and poor garbage disposal quality (OR = 2.4, 95%CI, 1.1-5.1).
  
  
  CONCLUSIONS
  Our data suggest that H pylori infection is associated with surrogate markers of fecal exposure. Thus, we conclude that the fecal-oral route is relevant in the transmission of HP among children in an urban setting of a developing country. The association observed between G. lamblia and H pylori infection may have several explanations. Further studies to investigate this relationship are warranted.
authors.affiliation: Department of Epidemiology and Biostatistics, Oswaldo Cruz Foundation, Brazilian Ministry of Health, Rua Waldemar Falcao 121 Salvador, Bahia, CEP 40.295-001, Brazil. edson@cpqgm.fiocruz.br
authors.forename: Edson Duarte
authors.initials: ED
authors.lastname: Moreira
authors.forename: Victor Bastos
authors.initials: VB
authors.lastname: Nassri
authors.forename: Rafaela Sousa
authors.initials: RS
authors.lastname: Santos
authors.forename: Junisia Ferraz
authors.initials: JF
authors.lastname: Matos
authors.forename: Wilson Andrade
authors.initials: WA
authors.lastname: de Carvalho
authors.forename: Celia Stolve
authors.initials: CS
authors.lastname: Silvani
authors.forename: Ciria
authors.initials: C
authors.lastname: Santana e Sant'ana
mesh_terms: D000818:Animals; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003906:Developing Countries; D005243:Feces / Q000469:parasitology; D005260:Female; D016829:Giardia lamblia / Q000302:isolation & purification; D005873:Giardiasis / Q000150:complications*; D016481:Helicobacter Infections / Q000150:complications* / Q000635:transmission; D016480:Helicobacter pylori; D006801:Humans; D007223:Infant; D008297:Male; D014505:Urban Population