Genetic homogeneity of Fascioloides magna in Austria.

The large American liver fluke, Fascioloides magna, is an economically relevant parasite of both domestic and wild ungulates. F. magna was repeatedly introduced into Europe, for the first time already in the 19th century. In Austria, a stable population of F. magna has established in the Danube floodplain forests southeast of Vienna. The aim of this study was to determine the genetic diversity of F. magna in Austria. A total of 26 individuals from various regions within the known area of distribution were investigated for their cytochrome oxidase subunit 1 (cox1) and nicotinamide dehydrogenase subunit 1 (nad1) gene haplotypes. Interestingly, all 26 individuals revealed one and the same haplotype, namely concatenated haplotype Ha5. This indicates a homogenous population of F. magna in Austria and may argue for a single introduction. Alternatively, genetic homogeneity might also be explained by a bottleneck effect and/or genetic drift.

[Incidence and control of the American giant liver fluke, Fascioloides magna, in a population of wild ungulates in the Danubian wetlands east of Vienna]. / Vorkommen und Bekämpfung des Amerikanischen Riesenleberegels, Fascioloides magna, in einer Schalenwildpopulation in den Donauauen östlich von Wien.

Fascioloides magna,the giant liver fluke, is an introduced parasite imported to Europe with infected game which is endemic in the Austrian wetlands of the Danube from Vienna to the Slovakian border. Due to its pathogenicity (especially in roe deer) and its potential of transmission to domestic ruminants a project on the epidemiology and control of this parasite was carried out between 2000 and 2005. To assess distribution faecal droppings from red deer were collected in an area along the Danube and livers of red and roe deer shot or found dead were examined. Simultaneously, triclabendazole-medicated feed was offered repeatedly in several areas of known fluke presence from 2001. The average prevalence of infection as demonstrated by Fascioloides eggs in droppings (n = 145) was 6.3%, with > 50% in some areas. Infection rates decreased from 11.3% (01/2001) to 1.5% (04/2002) in the whole area. In Fischamend, a highly endemic area, prevalences in monthly samples (n = 25) decreased from 70% (01/2001) to less than 1% (01/2005). Similarly, the number of eggs per gram of faeces was significantly reduced. Of 457 red deer livers 15.8% were positive. In the Fischamend area, a reduction of positive livers was also found (2000:100%; 2005:13%), as well as a reduction of the numbers of flukes/liver. Control of F. magna in the Danubian wetlands by anthelmintic treatment proved to be successful although eradication was not achieved.