title: Hepatitis E, Helicobacter pylori, and gastrointestinal symptoms in workers exposed to waste water.
abstract: BACKGROUND
  Workers exposed to sewage may have an increased risk of infection by Helicobacter pylori and hepatitis E virus (HEV).
  
  
  OBJECTIVE
  To assess the prevalence of clinical hepatitis E (HE) and peptic ulcer disease as well as the seroprevalence of antibodies to H pylori and HEV in workers with and without sewage exposure and to look for symptoms due to exposure to endotoxin.
  
  
  METHODS
  In the first year of a prospective cohort study 349 sewage exposed workers and 429 municipal manual workers (participation: 61%) underwent a complete medical examination. Travelling to endemic areas, socioeconomic level, age, country in which childhood was spent, and number of siblings were considered as the main confounding factors.
  
  
  RESULTS
  Peptic ulcer disease and clinical HE did not occur more often in workers exposed to sewage. Prevalence of antibodies to HEV was 3.3% and overall prevalence of IgG antibodies to H pylori was 42% with large differences between subgroups. Logistic regression did not show an increased risk of seropositivity or antibodies to parietal cells in sewage exposed workers, but disentangling the effect of exposure from that of confounders was extremely difficult. No increase of symptoms due to exposure to endotoxin was found in sewage workers, with the exception of diarrhoea.
  
  
  CONCLUSIONS
  No clear increased risk of infection by H pylori or by HEV in workers exposed to sewage was found in this cross-sectional study, but these results need to be confirmed by follow up.
authors.affiliation: Occupational and Environmental Medicine Unit, Zurich, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Jeggli
authors.forename: D
authors.initials: D
authors.lastname: Steiner
authors.forename: H
authors.initials: H
authors.lastname: Joller
authors.forename: A
authors.initials: A
authors.lastname: Tschopp
authors.forename: R
authors.initials: R
authors.lastname: Steffen
authors.forename: P
authors.initials: P
authors.lastname: Hotz
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood; D005260:Female; D016480:Helicobacter pylori / Q000276:immunology*; D006508:Hepatitis Antibodies / Q000097:blood; D016751:Hepatitis E / Q000097:blood / Q000453:epidemiology*; D016752:Hepatitis E virus / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000097:blood / Q000453:epidemiology*; D016273:Occupational Exposure; D010295:Parietal Cells, Gastric / Q000276:immunology; D010437:Peptic Ulcer / Q000097:blood / Q000453:epidemiology*; D015995:Prevalence; D011446:Prospective Studies; D016036:Seroepidemiologic Studies; D012722:Sewage / Q000009:adverse effects*; D013557:Switzerland / Q000453:epidemiology
chemical_list: D000907:Antibodies, Bacterial; D006508:Hepatitis Antibodies; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D012722:Sewage