Trichobilharzia regenti, a pathogen of the avian and mammalian central nervous systems

The development of nasal avian schistosomes of the genus Trichobilharzia in their final host is poorly known. Therefore, an experimental infection of ducklings (Anas platyrhynchos f. dom.) by T. regenti was performed. The inf ection resulted in leg paralysis and orientation/balance disorders of birds . The examination of the duck's spinal cord and brain confirmed the presenc e of developing parasites in pre-patent as well as patent periods. The abse nce of the worms in other tissues strongly supports our hypothesis that the parasite migrates through the central nervous system (CNS) to its final lo cation in bird nasal mucosa. The injury level is probably dependent on numb er of parasites as well as yet unknown host factors. The affinity to the CN S seems to be high; also by exposure of experimental animals to low cercari al doses the growing worms in the CNS were found. In addition to the genera lly accepted view that bird schistosomes may cause cercarial dermatitis of mammals (including man), there is evidence of a partial development of T. v egenti in mouse CNS; in certain cases leg paralysis was also recorded. Ther efore, the pathogenesis spectrum caused by bird schistosomes in birds/mamma ls needs to be reconsidered.