SP5-19 What is the role of occupational transmission in the epidemiology of Helicobacter pylori?

Introduction One of the surprising features of H pylori , is that we still do not know how the organism is usually acquired. Two possible avenues for transmission are direct infection from person to person, or through an intermediary such as the water supply, flies or animals. If transmission is person to person, the organism may be transmitted by faeco-oral, oro-oral, or by gastro-oral route. Methods In order to study some of these aspects we performed a number of cross-sectional studies, the results of which are reported here. Results Faeco-oral transmission: In a cross-sectional study in 587 employees working in 2 institutions for children with mental disabilities with a documented high prevalence of H pylori infection, using multiple regression analysis to adjust for confounding variables, we found an almost 2.5 increased risk in workers having contact with faeces of inhabitants. Other risk factors for H pylori infection were not significant in multiple regression analysis. In another cross-sectional study in 198 nursing home workers, the age-adjusted prevalence of H pylori was not higher than in a reference population and no association with any other risk factors was found. Waterborne transmission: In a cross-sectional study in 317 wastewater workers, the age-adjusted prevalence of H pylori was not higher than in a reference population and there was no association with any activity by which workers were exposed to wastewater. Conclusions Results of our studies show the difficulty in interpreting cross-sectional studies. There is a need for cohort studies with an exact exposure assessment to all possible transmission routes.