[Histopathologic study of the host-parasite relationship: the earthworm-, wild boar-metastrongyle model]

A histopathological study was conducted on two hosts of metastrongyles (Metastrongylus sp.): earthworms and wild boars (Sus scrofa Linnaeus, 1758). In the earthworm intermediate host there were rare granulomas outside the normal site occupied by larvae (blood sinuses of calciferous glands). Given the small number of these reactions, they could not constitute a limiting factor for parasitism in this host. However, the lungs of wild boars contained numerous lesions associated with the presence of these nematodes. Such lesions, often inflammatory, were part of an immunological defence mechanism which controls the extent of parasitism in wild boar.