Quick Review Cards for Medical Laboratory Science

Intestinal Cestodes continued Clinical Microbiology Review 253

GRAVID INTERMEDIATE DIAGNOSTIC

CESTODE SCOLEX PROGLOTTID OVUM HOST TRANSMISSION STAGE OTHER

Hymenolepis
nana

Dwarf tape-

worm. Adult

2.5–4 cm

long. Most

common

tapeworm.

Only tape-

worm without

intermediate

host. Mainly

in children.

Growth

retardation.

Wider than

long. Uterine

branches

obliterated by

eggs. 3 ovoid

irregularly

spaced testes.

Diamond-

shaped.

4 suckers.

Single row of

hooklets

around short

rostellum.

Round. 40 μm.

Colorless. 2

distinct walls.

Slight bulge at

each pole of

inner wall

with 4–8

hair-like polar

filaments.

Ingestion of

eggs in feces of

infected

mice/rats

None Ova in feces

(From Leventhal R, Cheadle RF. Medical

Parasitology: A Self-Instructional Text,

5th ed. Philadelphia: FA Davis; 2002:47.)