Helicobacter Pylori Infection in Waste Pickers: A Case Control Seroprevalence Study

BACKGROUND: The epidemiology of Helicobacter pylori (H. pylori) infection in waste pickers had not been previously studied. This study aims to determine the association of H. pylori seropositivity and waste picking activity; and to determine socio-demographic, clinical, work, and behavioral characteristics associated with H. pylori seropositivity in waste pickers. METHODS: Through a case-control study design, we examined 90 waste pickers and 90 age- and gender-matched control subjects for the presence of anti-H. pylori IgG antibodies using enzyme-linked immunoassays. Seroprevalence association with socio-demographic, clinical, work and behavioral characteristics of the waste pickers were also investigated. RESULTS: Antibodies to H. pylori were found in 60 (66.7%) of the 90 waste pickers and in 51 (56.7%) of the 90 controls (P = 0.16). Stratification by age showed that waste pickers aged 14 -30 years old had significantly higher frequency of H. pylori infection than controls of the same age group (56.5% versus 35.6%, respectively; P = 0.04). The seroprevalence of H. pylori infection was not influenced by gender, age, educational level, socioeconomic status, residence, or housing conditions of waste pickers. The presence of underlying diseases and the frequency of gastritis were similar among H. pylori positive and H. pylori negative waste pickers. Logistic regression analysis showed that the duration (years) in the waste picking activity was positively associated with H. pylori exposure (OR = 2.76; 95% CI: 1.22 - 6.25; P = 0.01). In contrast, consumption of alcohol was negatively associated with H. pylori exposure (OR = 0.27; 95% CI: 0.09 - 0.78; P = 0.01). Other work or behavioral characteristics of waste pickers including washing hands before eating, eating from the garbage, animal contacts, consumption of unpasteurized milk, unwashed raw vegetables, fruits, or untreated water, and contact with soil were not associated with H. pylori exposure. CONCLUSIONS: This is the first report on the seroprevalence of H. pylori infection among waste pickers and the factors contributing to such exposure. Results warrant for further research on the potential role of contact with garbage for H. pylori infection.