Figure 3-6. Beef tapeworm cycle of transmission.
c. Pork Tapeworm (Taenia solium). The cycle of development is similar to
that of the beef tapeworm. In this case, the host for the larval stage is the pig. Humans
are infected by eating undercooked pork containing tapeworm larvae. Humans may
also be infected in two other ways: by another person through fecal contamination and
by auto-infection (infection by one part of the body to another part of the body).
Transmission in the last two ways could be prevented by practicing good personal
hygiene.
d. Fish Tapeworm (Diphyllobothrium latum). Eggs are passed in human or
animal feces into bodies of fresh water. There the eggs mature, hatch, and infect the
first intermediate hosts, copepods. Some species of freshwater fish ingest infected
copepods and become second intermediate hosts. In the second intermediate host, the
worms develop into the larval stage. Humans become infected by eating raw or poorly
cooked fish, the second intermediate host, which contain tapeworm larvae.
Figure 3-7. Fish tapeworm cycle of transmission.
MD0589
3-7
Previous Page
