Hepatitis E,Helicobacter pyloriand peptic ulcers in workers exposed to sewage: a prospective cohort study

Abstract

Objectives: Workers exposed to sewage may have an increased risk of infection by Helicobacter pylori (H. pylori) and hepatitis E virus (HEV). To assess the incidence of clinical hepatitis E (HE) and peptic ulcer disease as well as the seroconversion rate of antibodies to H. pylori and HEV in workers with and without sewage exposure.Methods: 332 workers exposed to sewage and a control group of 446 municipal manual workers (participation: 61 %) entered a prospective cohort study with clinical examination and determination of antibodies to H. pylori and HEV (immunoglobulins G and A or G and M, respectively). Survival curves were examined with log rank tests and Cox regressions. Travelling to endemic areas, socioeconomic level, age, country in which childhood was spent, number of siblings, and personal protective equipment were considered as the main confounding factors.Results: Incidence of clinical HE was not increased in sewage workers. One peptic ulcer and three eradications were recorded in sewage workers whereas no case of peptic ulcer and 12 eradications occurred in control workers. Incidence rates of about 0.01, 0.10, and 0.15 seroconversion / person-year for HE, H. pylori IgG, and H. pylori IgA, respectively, were found in both exposed and non exposed workers. Survival curves did not show an increased risk in sewage workers and no association with any exposure indicator was found. Sensitivity analyses did not alter these results.Conclusions: These results do not support the hypothesis of sewage as a source of occupational infection for H. pylori or HEV in sewage workers trained for this job with available personal protective equipment and working in a region with good sanitation.

Exposure to bioaerosols, respiratory health and lung-specific proteins: a prospective study in garbage and wastewater workers: Table 1

“…Of the 778 subjects who entered the study (see online supplementary table), 603 participated in the entire study (median follow-up: 196 weeks) 2. The proportion of subjects remaining in the study until completion was similar in all three groups (77%, 78% and 78% for wastewater, garbage and controls, respectively; p=0.9).…”

“…To deal with clusters of repeated observations on the same units over time in longitudinal data, random coefficient models were applied using the same set of independent variables plus the follow-up time variable as an independent variable. Calculations were carried out as previously 2 3…”

Hepatitis E Virus in Industrialized Countries: The Silent Threat

“…In Turkey, agricultural workers who used untreated wastewater for irrigation showed a seroprevalence value of 34.8% compared to the 4.4% found in the control group [50]. On the contrary, in Germany, some studies concluded that sewage is not a source of infection for sewage workers [241, 242]. …”

Apparent Incidence of Helicobacter pylori in Adulthood: To What Extent Do New Infections Reflect Misclassification?

“…Thirty‐two articles [3,15–45] were included in the review after screening 4001 references that were identified in the systematic PubMed search. A flowchart of the study search and selection process is presented in Fig.…”

“…This is also supported by the observation that all five studies that were based on gastroscopy found very low incidence rates (between 0 and 0.9% per year). For three of the serologic studies that found high incidences [33,39,45], no test characteristics are given, but reported cumulative incidences are still well in the range of the apparent cumulative incidence calculated for other studies. In one of these publications, a fecal antigen test was used and the authors state that there might have been false‐negative classification at baseline [39].…”