Oesophagostomum Species

Name

Greek: stoma = mouth. Latin: oesophagus = oesophagus; dentatus = with teeth; radiates = radiating; venulosus = in veins; bifurcatus = with two terminal spikes; quadrispinulatus = with four spines. English: nodular worms.

Geographic Distribution/Epidemiology

Worldwide. Human cases due to O. bifurcatus in West Africa (Togo, Ghana), which normally occurs in monkeys, have a considerable local medical importance. In European pig farms, Oesophagostomum worms reach prevalence rates of up to 80 %.

Morphology/Life Cycle

Important Oesophagostomum species are

• 1. O. dentatum, O. quadrispinulatum in pigs and boars

• 2. O.venulosum, O. radiatum, O. columbianum in ruminants

• 3. O. bifurcatus in monkeys and humans

The adult worms appear yellow white and live mainly in the colon but also in the cecum, where they induce name-giving nodule formation (Fig. 1). The males measure 6–17 mm in length, while the females reach up to 24 mm. Their mouth capsules are short and rather broad, being surrounded by...