Macracanthorhynchus hirudinaceus

Classification

Genus of Acanthocephala.

Species

M. hirudinaceus.

Name

Greek: makros = large, acantha = thorn, rhynchos = mouth; Latin: hirudo = leech.

Life Cycle

Acanthocephala/Life Cycle.

Disease

This worm (female 60 cm, male 15 cm) is a parasite of pigs, where it reaches maturity (Fig. 1) and excretes the typical eggs (Fig. 2). In pigs the prepatent period is 8–12 weeks, the incubation period takes only 10 days; then the following symptoms of disease may be seen: enteritis, peritonitis, diarrhea, malnutrition, and abdominal pain. In humans, however, the worm does not reach maturity. It becomes attached with the hooked proboscis at the intestinal wall and may introduce even perforation (acute abdomen with peritonitis). The rather long worm leads to intestinal disturbances within 2–12 weeks (incubation period). The infection of humans and pigs occurs orally by uptake of infected beetles or parts of them (Fig. 3).

Fig. 1

Adult Macracanthorhynchus hirudinaceus from pig