This is not a Trichinella!
From an establishment processing game meat, samples were submitted of nematode larvae that were found in the muscle tissue artificial digestor for the diagnosis of Trichinella. The larvae are very different from Trichinella spp. but the inspector was curious about what species it were and what was its origin.
Larvae were sent to the European Union Reference Laboratory for Parasites were, by means of PCR techniques, were identified as larvae of Toxocara cati a quite common intestinal nematode of cats.
The finding of "contaminant" nematode larvae, different from Trichinella spp., is not uncommon. Besides T.cati other nematodes have also been found such as Toxocara canis (dog parasite that infests the intestine). The eggs of both ascarid species are excreted with faeces, after a while larvae form witihn the eggs but do not hatch. When the larvae containing eggs, that contaminate dirt, are ingested by paratenic or accidental hosts the larvae are set free and can migrate to different tissues, but will be unable to complete their development. Wild boars can acquire them accidentally when they root in dirt contaminated with the eggs. In humans these larvae are responsible for the parasite disease known as toxocariasis or visceral larva migrans.
The presence of Metastrongylus spp. (wild boar lung nematode) has also been described as well as of Panagrolaimus spp. which are free-living nematodes. Those are, however, accidental contamination that pose no zoonotic hazard.
For further reading about this subject, we recommend the following publication:
Molecular identification of nematode larvae different from those of the Trichinella genus detected by muscle digestion. Marucci G, Interisano M, La Rosa G, Pozio E. Vet Parasitol. 2013 May 20;194(2-4):117-20. doi: 10.1016/j.vetpar.2013.01.034. Epub 2013 Feb 5.
Toxocara cati larvae found in the digestionliquid of the Trichinella diagnostic digestor. Image credit: Dr. E.Pozio.
In this image a Toxocara cati larvae (bottom) is compared with one of Trichinella britovi (top left), the two are clearly distinguisahable from each other due to size and morphological differences. Image credit: Dr. E.Pozio.
In the next video you can observe a larvae similar to those described in this post:
https://youtu.be/Lsl11Q1-EPw
