Influence of Living Environment during Childhood on Helicobacter pylori Infection in Japanese Young Adults

Abstract

<b><i>Introduction:</i></b> <i>Helicobacter pylori</i> infection is usually established during childhood, for which certain responsible environmental factors have been identified. However, the details of the infection routes remain unclear. <b><i>Objective:</i></b> To determine the relation between <i>H. pylori</i> infection statuses and living environment of Japanese young adult. <b><i>Methods:</i></b> The subjects were 449 healthy young adult medical students of Tsukuba University (299 men and 150 women, mean age: 22.8 years). The <i>H. pylori</i> infection statuses were investigated using the rapid urease test or urine antibody. Questionnaires regarding sanitary conditions including usage of pit toilet or well water and experience of living with one’s grandparents during childhood were surveyed. Each item was compared between the <i>H. pylori</i>-positive and -negative groups. <b><i>Results:</i></b> Among all participants, 33 (7.3%) were <i>H. pylori</i>-positive. The usage rates of pit toilets were 12.1 and 3.1% for the <i>H. pylori</i>-positive and -negative groups respectively (<i>p</i> = 0.03; OR 4.35, 95% CI 1.33–14.22). The usage rates of well water were 24.2 and 13.7% for the <i>H. pylori</i>-positive and -negative groups respectively (<i>p</i> = 0.07; OR 2.12, 95% CI 0.91–4.98). The proportion of participants with a history of living with their grandparents was significantly greater in the <i>H. pylori</i>-positive group (46.7%) than in the -negative group (20.9%; <i>p</i> = 0.03; OR 3.28, 95% CI 1.13–9.54). Only a history of living with one’s grandparents during childhood showed statistical significance in the multivariate regression analysis (<i>p</i> = 0.04; OR 3.20, 95% CI 1.08–9.49). <b><i>Conclusions:</i></b> These results suggest that <i>H. pylori</i> infection is more strongly related to living with one’s grandparents than living in a hygienic environment.