First interlaboratory test for the detection of Alaria spp. mesocercariae in meat samples using the Alaria spp. mesocercariae migration technique (AMT)

Abstract

Emerging and re-emerging zoonotic diseases affect both public and animal health and require the development and contemporary implementation of suitable detection methods. A growing number of findings of the mesocercarial stage of the digenean trematode Alaria alata in game inhabiting wetlands have necessitated the development of a specific detection method. With the Alaria spp. mesocercariae migration technique (AMT), a specific and sensitive detection method is now available. To make the method accessible to the official controls, method validation is necessary. In this context, interlaboratory tests (IT) are a key factor to demonstrate both (1) the suitability of the respective method and (2) the reference materials. In the first IT performed on this issue, 15 laboratories from nine German federal states took part. Every lab received two negative and four positive standard samples each as well as a standardized examination device for AMT, and a standard operating procedure. All participating laboratories showed very good results in terms of qualitative analysis: 96.7 % of the samples were assessed correctly positive or negative. An analysis of the qualitative performance shows that 263 (58.4 %) of 450 mesocercariae that were inserted in the meatballs were identified by the participants, and 5 (33.3 %) out of 15 labs were able to count at least 70 % of the Alaria spp. mesocercariae. A direct comparison with the results of the German Trichinella IT, which were conducted since 2004, shows that the overall sensitivity of the AMT is even higher than that registered for the reference method for Trichinella detection (e.g. 93 % in 2010). Also, in terms of quantitative analysis, AMT stands up to the comparison with the results from the German Trichinella IT. The refinement of the implementation protocol of this innovative, easy-to-use and cost-effective method harbours great potential for further optimization and successful implementation in the official controls.