Trichobilharzia is the largest genus within the family Schistosomatidae, covering over 40 species of avian parasites. To clarify the existing confusion in the systematics of the genus, we recommend combining knowledge of life cycles and developmental stages, snail/bird hosts, cytogenetical and molecular data together with morphological criteria for the characterization of particular species. The high specificity of Trichobilharzia for the intermediate host is a likely reflection of the ability to avoid the internal defence of specific snails. The spectrum of final hosts (birds) seems to be much wider. The infection of birds--trichobilharziasis--may lead to considerable tissue injuries, caused by eggs of the parasite or migration of immature/mature worms through the body. Most Trichobilharzia (visceral species) migrate through the viscera of the host, but nasal species display a neurotropic mode of migration. Due to a low specificity of penetrating cercariae, mammals (including humans) can be attacked. This leads to cercarial dermatitis, predominantly in sensitized hosts. Experimental infections indicate that Trichobilharzia never mature in an incompatible (mammalian) host. However, not all cercariae and schistosomula are necessarily trapped and eliminated in the skin, and parasites may migrate throughout the viscera and the nervous system of mammals. These findings suggest that the pathogenicity of Trichobilharzia may have been underestimated in the past and health risks associated with trichobilharziasis need to be studied further.

Department of Parasitology Charles University Vinicná 7 CZ 12844 Prague 2 Czech Republic

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Other Schistosomatoidea and Diplostomoidea

Molecular identification of Trichobilharzia species in recreational waters in North-Eastern Poland

Somatic Dimorphism in Cercariae of a Bird Schistosome

Molecular evidence for distinct modes of nutrient acquisition between visceral and neurotropic schistosomes of birds

Cercarial dermatitis: a systematic follow-up study of human cases with implications for diagnostics

Impact of trematode infections on periphyton grazing rates of freshwater snails

Having bird schistosomes in mind-the first detection of Bilharziella polonica (Kowalewski 1895) in the bird neural system

The Early Worm Catches the Bird? Productivity and Patterns of Trichobilharzia szidati Cercarial Emission from Lymnaea stagnalis

Comparative Transcriptomic Exploration Reveals Unique Molecular Adaptations of Neuropathogenic Trichobilharzia to Invade and Parasitize Its Avian Definitive Host

Antibody response of definitive hosts against antigens of two life stages of the neuropathogenic schistosome Trichobilharzia regenti

Avian schistosomes and outbreaks of cercarial dermatitis

Influence of Trichobilharzia regenti (Digenea: Schistosomatidae) on the defence activity of Radix lagotis (Lymnaeidae) Haemocytes

Cercarial dermatitis, a neglected allergic disease

Pathogenicity of Trichobilharzia spp. for Vertebrates

In vitro cultivation of early schistosomula of nasal and visceral bird schistosomes (Trichobilharzia spp., Schistosomatidae)

The functional expression and characterisation of a cysteine peptidase from the invasive stage of the neuropathogenic schistosome Trichobilharzia regenti

Antibody responses induced by Trichobilharzia regenti antigens in murine and human hosts exhibiting cercarial dermatitis

Trichobilharzia szidati: the lung phase of migration within avian and mammalian hosts

In vitro stimulation of penetration gland emptying by Trichobilharzia szidati and T. regenti (Schistosomatidae) cercariae. Quantitative collection and partial characterization of the products

Validity reassessment of Trichobilharzia species using Lymnaea stagnalis as the intermediate host