Association ofHelicobacter pyloriinfection and giardiasis: Results from a study of surrogate markers for fecal exposure among children

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.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.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).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.