[Intestinal protozoal infestation in persons with occupational sewage contact].

Intestinal protozoal infestation and antibodies against Entamoeba histolytica were determined in 614 employees of the Hamburg sewage works and compared with control groups without occupational sewage contact. The protozoal infection rate was significantly higher in sewer-men than in control persons. There was a positive correlation between the duration of exposure to sewage and the frequency of intestinal protozoal infestation. The risk of infection by sewage was higher than by a short journey to tropical or subtropical countries. Immunodiagnostic results showed no significant differences of invasive activity of E. histolytica between both investigated groups. On the basis of parasitological results classification of amoebiasis and giardiasis as occupational diseases in exposed persons is recommended.