Association of Helicobacter pylori infection and giardiasis: results from a study of surrogate markers for fecal exposure among children.
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.
Moreira
Edson Duarte
ED
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
Nassri
Victor Bastos
VB
Santos
Rafaela Sousa
RS
Matos
Junisia Ferraz
JF
de Carvalho
Wilson Andrade
WA
Silvani
Celia Stolve
CS
Santana e Sant'ana
Ciria
C
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