INTESTINAL PARASITES (Helminths)
TREMATODA Order: Echinostomata

ECHINOSTOMA ILOCANUM

eilo1-ic

Echinostoma spp: intestinal flukes are common infections in South-East Asia
where they have a high prevalence (from 1 to 30%).
The infections are acquired by eating raw or undercooked freshwater snails,
clams, and fish containing the metacercariae.
Adults (measuring 5 to 15 by 1 to 2 mm) live in the small intestine
of the definite host (bird, mammals) and are characterized by a collar
of one or two rows of spinose processes around the circumoral disc.
About 15 species of Echinostoma have been described in man:
E.ilocanum, E.revolutum, E.malayanum are the most common
but other species have been recorded: E. echinatum, E.hortense,
E.caproni, E.recurvatum, E.macrochis, E.lindoense, E.pertiolatus.
Infections are usually asymptomatic.
Heavy infections are characterized by inflammation and ulceration
of the intestinal wall and may cause diarrhoea with blood and abdominal pain.
Diagnosis is obtained by finding operculated eggs in faeces.
Eggs measure 80-140 by 58-90 µm.
Several drugs are active: mebendazole, albendazole, praziquantel and niclosamide.
Egg of Echinostoma ilocanum.

eilo2-ic

Echinostoma caproni is an intestinal fluke of waterfowls.
Occasionally humans become infected by consuming raw snails
containing excysted metacercariae.
Adult worm grown in ovo.
The worm is attached and feeding in the chick chorioallantoic membrane.