A natural focus of the blood fluke Orientobilharzia turkestanica (Skrjabin, 1913) (Trematoda: Schistosomatidae) in red deer (Cervus elaphus) in Hungary

The large American liver fluke, Fascioloides magna - introduced to Europe before 1875 - was the first non-indigenous trematode to be detected in Hungarian cervids in 1995. As the most precious deer population became infected in the Gemenc game reserve a study has been launched to assess the extent and the effect of F. magna infections and to examine the options for the treatment of infected deer populations. Livers of red deer shot during regular hunting were submitted for the survey and were investigated by necropsy for the presence of F. magna and other liver dwelling trematodes. Recovered parasites were counted, sorted and stored in 70% ethanol. Unexpectedly, blood flukes were found in liver blood vessels at necropsy. They were identified as Orientobilharzia turkestanica (Skrjabin, 1913) by their morphological features as well as by molecular methods. This parasite is widespread in the middle belt of Asia from Korea to the eastern part of Turkey and infects mainly bovids. It was never found in red deer until now and this is the first report of its occurrence in Hungary and Europe. A subsequent search for the local intermediate host of O. turkestanica in the Gemenc area identified only the pulmonate snail Radix auricularia (Linnaeus, 1758) [syn: Lymnaea auricularia] as a vector capable of producing cercariae of this trematode. Cercariae of O. turkestanica were examined morphologically and were confirmed to be the larvae of this trematode by PCR. O. turkestanica appears to be fairly common in red deer of the Gemenc area. No clinical or pathological effect of the infection could be identified in this study. A form of cercarial dermatitis locally called "water mange" was formerly attributed to the larvae of avian shistosomes. It regularly occurred among fishermen fishing in shallow ponds remaining after floods along the Danube in the Gemenc area. This isolated habitat of O. turkestanica presents an exceptional opportunity to study epidemical situations of typical mammalian schistosomosis under temperate climatic conditions.