The species composition of the definitive hosts of the trematode <i>Bilharziella polonica</i> (Schistosomatidae) of Southern Karelia (Northwestern Russia)

We performed a parasitological survey of helminths of 398 waterfowl specimens from an ecologically unique territory of southern Karelia (North-West Russia). This is the first study of species composition and infection of birds that are definitive hosts of Bilharziella polonica have been obtained. The trematoda of Bilharziella polonica has been recorded only in seven species of birds — mallard, teal, garganey, goldeneye, tufted duck, shoveler, and red-necked grebe. The species of B. polonica has been recorded of red-necked grebe for the North-West of Russia for the first time. The role of infected birds of Bilharziella polonica in support of schistosomiasis, a disease that causes morbidity for causing human cercarial dermatitis or swimmer’s itch, were shown. We present data that life cycle of Bilharziella polonica is successfully implemented in the conditions of Karelia.