Taenia solium/saginata

Question 1

Classification

Answer 1

Metazoan - cestode

Question 2

Indirect or direct

Hosts

Answer 2

Indirect life cycle

Pigs and cattle are intermediate hosts

Humans are final hosts

In T. solium humans can also be accidental hosts

Question 3

Transmission and life cycle

Answer 3

Eggs or gravid proglottids are passed by the feces of an infected final host.

Cattle or pigs ingest these eggs or proglottids and these hatch in the intestines.

They invade the intestinal wall and infect muscle tissue where they develop into cysticerci.

Humans can become infected when eating undercooked meat. The cysticerci develop into tapeworms in the intestines.

These tapeworms release again eggs or gravid proglottids by feces in the environment which can be picked up again by pigs or cattle.

In T. solium a human can be an accidental host. The human ingests the eggs of solium (either by autoinfection or throug another route). The larval stage then develops in the human. The egg hatches in the intestine and invades the intestinal wall and cysticerci develop in the human muscle tissue.

Some cysticerci migrate to the central nervous system causing neurocysticercosis resulting in epilepsy.

Question 4

Diagnosis

Answer 4

Taeniasis
Stool examination, but impossible to distinguish the eggs. The proglottids however, can be distinguished in species.

Antigen detection

PCR

Cysticercosis
Clinical examination: MRI, CT-scan and serology