Trichomonads in birds--a review.
Members of the family Trichomonadidae, mainly Trichomonas gallinae and Tetratrichomonas gallinarum, represent important parasites in birds with worldwide presence, since being reported in the 19th century. Especially Columbiformes, Falconiformes and Strigiformes can be severely affected by trichomonads, whereas the majority of infections in Galliformes and Anatiformes are subclinical although severe infections are occasionally reported. With the recent appearance of deadly infections in wild Passeriformes the protozoan parasite T. gallinae obtained greater attention which will be addressed in this review. Although light microscopy remains the method of choice to confirm the presence of trichomonads molecular studies were introduced in recent years, in order to characterize the parasites and to establish relationships between isolates. Isolation of trichomonads is a prerequisite for detailed in vitro and in vivo studies and different media are reported to obtain suitable material. The limited information about virulence factors will be reviewed in context with the pathogenicity of trichomonads which varies greatly, indicating certain strain heterogeneity of the parasites. Options for treatment characterized by the leading role of imidazoles whose activity is sometimes hampered by resistant parasites remains a challenge for the future. Introducing more standardized genetic studies and investigations concentrating on the host-pathogen interaction should be helpful to elucidate virulence factors which might lead to new concepts of treatment.
Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria.
Aziza
A
Amin
Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria.
Ivana
I
Bilic
Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria.
Dieter
D
Liebhart
Clinic for Poultry and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria.
Michael
M
Hess
D000818:Animals; D001715:Bird Diseases / Q000188:drug therapy / Q000453:epidemiology* / Q000469:parasitology; D001717:Birds; D004351:Drug Resistance; D054884:Host-Pathogen Interactions; D007093:Imidazoles / Q000627:therapeutic use; D046109:Passeriformes; D014244:Trichomonas / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D014245:Trichomonas Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000469:parasitology / Q000662:veterinary*
D007093:Imidazoles