Summary of the Ph.D. project

Schistosome dermatitis is a skin disease caused by cercariae of bird-schistosomes penetrating the skin of people bathing in infected water bodies. Clinical signs appear after bathing in freshwater lakes in Denmark. The infectious agents are larval stages (cercariae) of bird schistosomes, which are parasites that using snails as intermediate and birds as final hosts. Affected people develop an itchy, often small-knotted skin rash, hours-few days after exposure. Some patients have described more severe skin reactions after re-exposure, suggesting sensitization and allergy-like reactions. Both Type I and IV allergy have been postulated, but have never been systematically investigated in Denmark according to our literature search.

 

The Goal

1) To describe clinical characteristics of schistosome dermatitis (swimmer's itch) in Denmark, including both cutaneous and possibly extra-cutaneous symptoms.

2) To determine the occurrence of infected snails in Danish lakes and selected coastal areas with low salinity.

3) Develop a method for identifying parasitic larvae by use of morphometric and molecular methods. DNA sequences (ribosomal and mitochondrial DNA) in adult worms will be compared with similar sequences in larvae from snails.

4) To develop an e-DNA method that allows detection of Trichobilharzia and Bilharziella cercariae in a water body.

5) To highlight the pathogenicity of the Danish isolates in animal models for the assessment of possible extra-dermal migration.