Sessions

Avian trichomonosis is a widespread and well-known disease. Some species cause typical lesions in the oral cavity and the upper part of the esophagus, while others tend to live towards the cloacal end of the intestines, furthermore, anomalies due to trichomonosis were also described in other organs. The disease is well described within poultry, wild pigeons, birds of prey and passerines, however there is limited data about it infecting shorebirds. We focused on the Ruff (Calidris pugnax), because the significance of this species was determined in a previous study, however due to the low number of samples we couldn’t propose long-term conclusions.

During the spring and autumn of the 2025 calendar year, we captured 36 Ruffs and 56 other shorebirds belonging to five species. We collected cloacal swab samples from the birds captured to detect trichomonads. Individuals from three species were positive for trichomonads, the Ruff, the Little Ringed Plover (Thinornis dubius) and the Common Snipe (Gallinago Gallinago), respectively. We smeared samples on to slides then examined them under a microscope, and additionally used PCR detection. The two sequences used for the PCR were the 18S rRNA and alpha-tubulin genes. The molecular examination confirmed our hypothesis that this certain trichomonad is a new species to science. Following the genetical analysis, the trichomonads found form a phylogenetically distinct group within the order Trichomonadida and probably belong to different species. The trichomonad detected in Ruffs is hereby described as Charadriimonas elzamajori gen nov., sp. nov. and the journal article is currently under publication.

73.7% of the Ruffs captured in spring were positive for trichomonad DNA, however only 5.9% was positive in autumn. The most probable reason suggests venereal transmission between the polygamous birds, explaining the high prevalence in spring and the similarity amongst the protozoa. Our results can highlight the importance of shorebirds’ epidemiological role, as their preferred habitats are pastures and adjacent areas. As long-distance migrants, they can easily connect areas far from each other, therefore act as vectors to spread various pathogens between livestock and pastures.