Acanthocephalan Infections

Attachment

Generally, acanthocephalans that have a short neck do not deeply penetrate into the host’s intestinal wall with their praesoma, i.e. they do not create lesions reaching as deep as the muscular layers of the intestinal wall (see Acanthocephala/Fig. 4, Acanthocephala/Fig. 5, Acanthocephala/Fig. 6). In contrast, many Acanthocephalans possess a long neck which may comprise a bulbus as an inflated part of the neck (Fig. 1). The bulbus functions as a dowel enabling the worm to occupy a permanent point of attachment at one site. The perforation of the intestinal wall may be supported by proteolytic enzymes or occur in thin walls (Fig. 2).

Cellular Host Responses

Successive Cell Assemblages

The specific composition of host cells accumulating at the worm’s praesoma follows a certain sequence which is related to the worm’s mode of attachment. During the first days p. i. only necrotic tissue surrounding the praesoma can be found. After about 3–5 days p. i. a belt of inflammatory tissue...