Geographical distribution of the giant liver fluke (Fascioloides magna) in the Czech Republic and potential risk of its further spread
Abstract
Fascioloides magna is of interest due to high pathogenic potential and continuous spreading to new areas, especially in Europe. During the years 2009 and 2010, 1622 survey forms focused on monitoring of fascioloidosis were distributed in the community of Czech Inspectors of Hunted Game, and 21.3% of forms containing positive or negative response about F. magna occurrence were returned.
The administrative units monitored were geographically equally distributed and therefore we believe that also the recorded distribution of F. magna in wild-life animals reflects the real situation in the Czech Republic. A significant number of cases of F. magna infection were repeatedly reported from areas in the south-west part of the Czech Republic.
Moreover, our report contains also some unique records of several new F. magna foci in the western (close to the German border), northern (close to the Polish border) and central parts of the Czech Republic, supporting the assumption that the parasite is spreading further throughout Europe. In five game administrative units F. magna infection was directly confirmed by examination of dissected deer livers or by microscopic examination of coprological samples, followed by isolation of DNA from adults and eggs and further molecular analyses.
Fascioloides magna intermediate host snails (Galba truncatula and Radix spp.) were collected during 2009 and 2010 from different localities of the Czech Republic, kept in aquaria, examined for shedding of F. magna cercariae, dissected and parasite/snail DNA was isolated. After PCR with specific primers for parasite/snail internal transcribed region number two (ITS-2) the obtained sequences confirmed identification of the following species: F. magna, G. truncatula, R. peregra, R. lagotis, R. labiata and R. auricularia.
The number of areas with positive cases of fascioloidosis is still growing and the risk is generally underestimated.