Parasitology



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


P. HORÁK a1c1, J. DVORÁK a1, L. KOLÁROVÁ a2 and L. TREFIL a1
a1 Department of Parasitology, Charles University, Vinicná 7, CZ-12844 Prague 2, Czech Republic
a2 Department of Tropical Medicine, Faculty Hospital Bulovka, Charles University, Studnickova 7, CZ-12800 Prague 2, Czech Republic

Abstract

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 infection resulted in leg paralysis and orientation/balance disorders of birds. The examination of the duck's spinal cord and brain confirmed the presence of developing parasites in pre-patent as well as patent periods. The absence of the worms in other tissues strongly supports our hypothesis that the parasite migrates through the central nervous system (CNS) to its final location in bird nasal mucosa. The injury level is probably dependent on number of parasites as well as yet unknown host factors. The affinity to the CNS seems to be high; also by exposure of experimental animals to low cercarial doses the growing worms in the CNS were found. In addition to the generally accepted view that bird schistosomes may cause cercarial dermatitis of mammals (including man), there is evidence of a partial development of T. regenti in mouse CNS; in certain cases leg paralysis was also recorded. Therefore, the pathogenesis spectrum caused by bird schistosomes in birds/mammals needs to be reconsidered.

(Received April 27 1999)
(Revised July 6 1999)
(Accepted July 6 1999)


Key Words: Trichobilharzia; schistosomes; cercarial dermatitis; neuroinfection.

Correspondence:
c1 Corresponding author: Department of Parasitology, Charles University, Vinicná 7, CZ-12844 Prague 2, Czech Republic. Tel: +420 2 21953196. Fax: +420 2 299713. E-mail: horak@natur.cuni.cz


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