A novel detection method for Alaria alata mesocercariae in meat

Abstract

Distomum musculorum suis (DMS), the mesocercarial stage of the trematode Alaria alata, can cause severe damages within their hosts, and since several reports about cases of human larval alariosis have been published, it became apparent that infected game animals and in particular wild boars are a potential source of infection for both humans and animals. A final statement concerning the health risks for consumers could not be given due to the lack of information about both the prevalence of DMS and the suitability of Trichinella inspection methods to detect this parasite in wild boar meat. Our studies concentrate on (1) the verification of suitability of the official digestion methods for Trichinella spp. for DMS detection in wild boars, (2) development, optimization, and validation of methods, and (3) the distribution of the parasites within their paratenic hosts. A total of 868 individual samples/digests from 48 wild boars were analyzed by the reference method for Trichinella detection in meat samples according to regulation (EC) No. 2075/2005. In addition to the official protocol, a method modification with Pankreatin(c) and bile acid was applied for analysis of adipose tissue samples (n = 89). On the basis of our results, a new detection method based on a larvae migration technique was developed and used for detection of DMS in 574 single samples. Furthermore, the distribution patterns of DMS in wild boars in a total of 1377 single sample migrations/digestions from 35 positive animals were analyzed by application of all three methods. The official digestion method for Trichinella spp. in wild boars meat is inapplicable for the detection of A. alata mesocercariae as it shows shortcomings in both digestion and sampling. A direct comparison between the newly developed A. alata mesocercariae migration technique and the official digestion method for Trichinella spp. based on 574 single samples from 18 animals clearly shows that the sensitivity to detect A. alata developmental stages in tissues of wild boars of the new method is nearly 60% higher compared with the magnetic stirrer method for pooled sample digestion as laid down in regulation (EC) No. 2075/2005. Among other advantages, this method offers a simple, highly applicable, fast, and cost effective way to detect DMS in wild boars which is already applicable in routine veterinary inspection.

Free-living snakes as a source and possible vector of Salmonella spp. and parasites

“…The digestion method was arbitrary chosen based on the assumption that small rodents, a component of snake's diet, are reservoirs of Trichinella (Flis 2011). Unexpected Alaria alata mesocercariae might have been efficiently detected with migration method, since a percentage of DMS is destroyed by acid concentration and pepsine or stuck on the sieve (Riehn et al 2010). These, along with the finding of still unidentified nematodes, show the area for further investigation and possible knowledge gaps.…”

Schistosomatoidea and Diplostomoidea

“…Use of compression method or pooled digestion method according to the protocols for Trichinella larvae seems to have limited sensitivity. Recently, a new detection method based on larval migration technique has been introduced [ 152 ]. As well as, a new PCR assay for identifi cation and characterization of A. alata mesocercariae has successfully been tested; it can be used for diagnostic and epidemiological purposes [ 153 ].…”

Las Zoonosis Transmitidas Por Alimentos Pueden Afectar Su Epidemiología, Producto Del Cambio Climático Y Los Procesos De Globalización

“…Las tendencias actuales de consumo de carne de fauna exótica ha significado que la carne de caza se está incorporando cada vez más en restaurantes exclusivos, tanto de Europa como de Estados Unidos, pero también la carne de caza ha sido importada para satisfacer las necesidades de las comunidades de inmigrantes de diversos países, generándose así un riesgo alimenticio (Robertson et al, 2014). De este modo Alaria alata en carne de jabalí procedente de Hungría se ha reportado en Francia (Riehn et al, 2010). Spirometra mansoni spargana se han encontrado en ancas de rana importadas desde Indonesia a los Países Bajos (Zhang et al, 2012).…”