Helicobacter pylori in the Canadian arctic: Seroprevalence and detection in community water samples

OBJECTIVE: Many North American arctic communities are characterized by risk markers associated with Helicobacter pylori (H. pylori) infection, includi ng overcrowded housing and inadequate water supply and sanitation systems. Our aim was to determine the seroprevalence of H. pylori infection in two t raditional Inuit communities in the central Canadian arctic and to test for the presence of H. pylori, by polymerase chain reaction (PCR), in local wa ter supplies. METHODS: Samples of venous whole blood from adults and capillary blood from children were collected and analyzed by enzyme immunoassay and Helisal Rap id Test, respectively, for IgG antibody to H. pylori. Antibodies to CagA we re detected by enzyme immunoassay, and ABO and Lewis antigens were also det ermined. Demographic and clinical information were collected by questionnai re. Water samples from each community were tested for H. pylori by PCR. RESULTS: One hundred-thirty (50.8%) of 256 subjects from the two communitie s were positive for H. pylori IgG antibodies. Seropositive subjects were mo re likely to be male, compared with seronegative individuals (p = 0.01). An tibody status did not differ with respect to age, community, alcohol or cig arette use, number of persons per household, gastrointestinal complaints or previous investigations, medications, or presence of blood group O, Lewis a-b+. CagA antibodies were detected in 78 (61.9%) of 126 H. pylori-seroposi tive subjects tested; however, 41 (35.3%) of 116 H. pylori-seronegative sub jects were also CagA positive. Water samples taken from the water delivery truck in Chesterfield Inlet and two lakes near Repulse Bay were positive fo r H. pylori. CONCLUSION: The seroprevalence of H. pylori in the study group was higher t han rates in southern Canadian populations, but lower than the seroprevalen ce previously documented in a Canadian subarctic Indian (First Nations) com munity. The detection of H. pylori in local water supplies may indicate a n atural reservoir for the organism or possible contamination from human sewa ge. (Am J Gastroenterol 1999;94:1823-1829. (C) 1999 by Am. Coll. of Gastroe nterology).