title: Effect of sewage treatment plants and diffuse pollution on the occurrence of protozoal parasites in the course of a small river.
abstract: In Germany, protozoal parasites are detected frequently in surface waters. This study aims to assess the parasitological pollution in a river course and two of its tributaries under regular weather conditions. Cryptosporidium was detected in 67% of all samples. The median concentration was 4 oocysts/100l. Giardia lamblia were detected in 90% of the samples. The median concentration of G. lamblia was 22 cysts/100l and increased significantly following the river course. A statistically significant correlation was found between both parasites and the faecal indicators Clostridium perfringens and Escherichia coli. The intermittent occurrence of Cryptosporidium in the streams investigated was ascribed primarily to diffuse pollution, particularly during rainfall events. The relatively frequent detection of G. lamblia derived mainly from sewage treatment plants. The pathogen concentrations observed present a relevant public health risk as the river is used for recreational activities and agricultural purposes.
authors.affiliation: Institute for Hygiene and Public Health, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn, Germany. thomas.kistemann@ukb.uni-bonn.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Kistemann
authors.forename: Esther
authors.initials: E
authors.lastname: Rind
authors.forename: Christoph
authors.initials: C
authors.lastname: Koch
authors.forename: Thomas
authors.initials: T
authors.lastname: Claßen
authors.forename: Charis
authors.initials: C
authors.lastname: Lengen
authors.forename: Martin
authors.initials: M
authors.lastname: Exner
authors.forename: Andrea
authors.initials: A
authors.lastname: Rechenburg
mesh_terms: D003458:Cryptosporidium / Q000302:isolation & purification*; D005858:Germany; D016829:Giardia lamblia / Q000302:isolation & purification*; D045483:Rivers / Q000469:parasitology*; D012722:Sewage; D014876:Water Pollution / Q000706:statistics & numerical data*
chemical_list: D012722:Sewage