In the normal life cycle:
(1) there are both male and female worms
(2) the gravid female releases larva-containing eggs into the feces of the host
(3) the larva invades an insect or crustacean (intermediate host)
(4) the larve develops into an immature worm (cystacanth) which encysts in the tissue of the host
(5) if the intermediate host is ingested by a suitable host then the cystacanth emerges and develops into an adult
Humans may become infected by:
(1) ingesting an uncooked insect or insect larva that is infected
(2) ingesting an uncooked crustacean that is infected
Eating the infected source may be intentional or accidental.
Accidental ingestion can occur if:
(1) the patient is a young child or mentally disabled person who often puts foreign objects into the mouth
(2) the person eats foor into which an insect has crawled
