Epidemiological tools to assess the spread of Fascioloides magna

Abstract

The giant liver fluke (Fascioloides magna) has four continuously expanding focus endemics in Europe. The parasite is considered an invasive species in our continent and could affect the local host populations or, after host switching, it can infect other potential host species. Therefore it is important to track this alien species' presence. The authors compared the gold standard test with the effectiveness of two potential screening tests, the conventional sedimentation method and an illustrated guideline-based approach, which could be applicable in the field. The gold standard test was based on the necropsy detection of adult flukes in the liver tissue of hunted animals (N=319). Besides applying the linear regression, the sensitivity and specificity were determined in both approaches. The analysis showed that the shed egg number was moderately associated with the fluke burden (R2=0.5679; p<0.0001) and the flukes' dry mass (R2=0.6016; p<0.0001). The final results of sensitivity (100%; CI95%: 97.2 – 100) and specificity (96.3%; CI95%: 92.5 – 98.5) confirmed that the illustrated guideline-based approach is a capable method for monitoring the F. magna expansion in endemic areas.