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Trichinellosis is a zoonotic disease in humans caused by Trichinella spp. According to international regulations and guidelines, serological surveillance can be used to demonstrate the absence of Trichinella spp. in a defined domestic pig population. Most enzyme-linked immunosorbent assay (ELISA) tests presently available do not yield 100% specificity, and therefore, a complementary test is needed to confirm the diagnosis of any initial ELISA seropositivity. The goal of the present study was to evaluate the sensitivity and specificity of a Western Blot assay based on somatic Trichinella spiralis muscle stage (L1) antigen using Bayesian modeling techniques. A total of 295 meat juice and serum samples from pigs negative for Trichinella larvae by artificial digestion, including 74 potentially cross-reactive sera of pigs with other nematode infections, and 93 meat juice samples from pigs infected with Trichinella larvae were included in the study. The diagnostic sensitivity and specificity of the Western Blot were ranged from 95.8% to 96.0% and from 99.5% to 99.6%, respectively. A sensitivity analysis showed that the model outcomes were hardly influenced by changes in the prior distributions, providing a high confidence in the outcomes of the models. This validation study demonstrated that the Western Blot is a suitable method to confirm samples that reacted positively in an initial ELISA

Introduction: Foxes are hosts of a range of zoonotic parasites including Echinococcus multilocularis, Toxocara canis and Trichinella spp. Vulpine trichinellosis has long been known in Austria, but generally at low prevalence. This study presents prevalence data from endemic areas of Trichinella infections in foxes. Materials and methods: Masseter and tongue samples from 1,546 foxes with known origin (sample coordinates from the provinces of Carinthia [n=401], Salzburg [108], Styria [493], Tyrol [395] and Vorarlberg [149] were determined by Geographic Information System), sent to the State Veterinary Laboratory in Moedling for rabies testing, were examined for Trichinella with the compression technique. Positive samples were evaluated quantitatively by digestion and differentiated by PCR. Results: 24 foxes (1.55%) were positive (Carinthia: 1.52%, Salzburg: 2.77%, Styria: 1.62%, the Tyrols: 1.26%, Vorarlberg: 1.44%). In addition to the formerly known distribution of vulpine trichinellosis, positive animals were also found close to the border to Slovenia. Highest numbers of larval per gram muscle tissue (lpg) were found in the tongues (1-257 lpg compared to 0-43 lpg in masseter muscle tissue). Molecular differentiation identified all samples as T. britovi. Conclusion: Detection of larvae is more sensitive in tongue samples than in masseter muscle and can conveniently be done alongside with the rabies testing. Samples should be examined from single animals, not pooled, since this can decrease the sensitivity of the test. Although the observed prevalence of Trichinella in foxes is most likely underestimated due to the low sensitivity of the compression technique, it is at a low level, comparable to other endemic areas, and appears to be stable, especially in Carinthia and Styria. In remote areas, the parasites' life cycle is obviously maintained in the fox population. Since transmission from wildlife to domestic pigs has been reported for T. britovi (the species ident