Parasitology Research

, Volume 115, Issue 3, pp 1027–1037 | Cite as

Molecular diversity of avian schistosomes in Danish freshwater snails

  • Anne Ø. ChristiansenEmail author
  • Annette Olsen
  • Kurt Buchmann
  • Per W. Kania
  • Peter Nejsum
  • Birgitte J. Vennervald
Original Paper


Avian schistosomes are widespread parasites of snails and waterfowl and may cause cercarial dermatitis (swimmer’s itch) in humans, a disease that is frequently reported in European countries. These parasites are known to occur in Denmark, but here, we applied a new approach using molecular tools to identify the parasites at species level. In order to do that, 499 pulmonate freshwater snails (Radix sp., Lymnaea stagnalis, Stagnicola sp. and Planorbarius corneus) were sampled from 12 lakes, ponds, and marshes in the greater Copenhagen area. Avian schistosome cercariae were identified by microscopy and subjected to molecular investigation by sequencing and phylogenetic analysis of the 5.8S and ITS2 ribosomal DNA for species identification. Additionally, snail hosts belonging to the genus Radix were identified by sequencing and phylogenetic analysis of partial ITS2 ribosomal DNA. Three out of 499 snails shed different species of Trichobilharzia cercariae: Trichobilharzia szidati was isolated from L. stagnalis, Trichobilharzia franki from Radix auricularia and Trichobilharzia regenti from Radix peregra. In the light of the public health risk represented by bird schistosomes, these findings are of concern and, particularly, the presence of the potentially neuro-pathogenic species, T. regenti, in Danish freshwaters calls for attention.


Avian schistosomes Trichobilharzia Cercarial dermatitis Denmark ITS rDNA Parasite-host relationship 



The authors would like to thank Thomas K. Kristensen for valuable assistance with the field work.

Supplementary material

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Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Anne Ø. Christiansen
    • 1
    Email author
  • Annette Olsen
    • 1
  • Kurt Buchmann
    • 2
  • Per W. Kania
    • 2
  • Peter Nejsum
    • 1
  • Birgitte J. Vennervald
    • 1
  1. 1.Section for Parasitology and Aquatic Diseases, Department of Veterinary Disease Biology, Faculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CDenmark
  2. 2.Section for Parasitology and Aquatic Diseases, Department of Veterinary Disease Biology, Faculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CDenmark

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