Infectious Disease and Microbiology – Echinostoma ilocanum

Overview

Echinostoma ilocanum is a trematode helminth (intestinal fluke) that can infect the human gastrointestinal tract. Human infection is uncommon and primarily occurs in parts of Southeast and East Asia.

The parasite is a rare cause of small-bowel infection.

Microbiologic Characteristics

Echinostoma ilocanum is a trematode helminth belonging to the group of intestinal flukes.

The adult parasite resides within the small intestine, where it can produce eggs that are subsequently passed in the stool.

Epidemiology

Human E. ilocanum infection has been reported particularly in:

• Philippines

• Indonesia

• Malaysia

• China

The infection is relatively rare even within endemic regions.

Transmission

Human echinostomiasis is a foodborne trematode infection.

Infection is generally acquired by consuming raw or inadequately cooked intermediate hosts containing infective metacercariae, such as certain freshwater snails or other aquatic organisms.

Clinical Infection

E. ilocanum is a rare cause of small-bowel infection.

Many infections may produce few or nonspecific manifestations.

When symptomatic, intestinal irritation may result in gastrointestinal complaints, particularly with a greater parasite burden.

Gastrointestinal Manifestations

Possible manifestations of intestinal echinostomiasis include:

• Abdominal discomfort or pain

• Diarrhea

• Other nonspecific gastrointestinal symptoms

The severity of illness generally depends on the intensity of infection.

Diagnosis

Diagnosis is based primarily on parasitologic examination of stool specimens.

The recommended approach in the source is:

Examination of concentrated stool specimens for parasite eggs

Microscopic identification of characteristic trematode eggs supports the diagnosis.

Treatment

The treatment described in the source is:

Praziquantel 25 mg/kg orally every 8 hours for 2 days

Praziquantel is used to eliminate the intestinal trematode infection.

High-Yield Clinical Pattern

Exposure in Southeast or East Asia

• ●

Intestinal/small-bowel symptoms

• ●

Trematode eggs detected in concentrated stool

→ Consider Echinostoma ilocanum

Exam Essentials

Organism: Echinostoma ilocanum

Type: Trematode helminth

Location of infection: Small intestine

Geographic distribution: Philippines, Indonesia, Malaysia, and China

Frequency: Rare human infection

Major disease: Intestinal echinostomiasis

Diagnosis: Concentrated stool examination for parasite eggs

Treatment: Praziquantel 25 mg/kg PO every 8 hours for 2 days

Key clinical pearl: Echinostoma ilocanum is a rare intestinal trematode of Southeast and East Asia that causes small-bowel infection and is diagnosed by finding parasite eggs in concentrated stool specimens.