Heterophyiasis

Heterophyiasis is an intestinal fluke that causes abdominal pain and diarrhea. Infection occurs after eating raw or undercooked, freshwater fish.
The disease is endemic to the Far East, Middle East, and Egypt and may cause intestinal hemorrhage, obstruction, and protein-losing enteropathy.

CASES/YEAR
0 (US); 5,000,000 (Global)
CATEGORY
Trematodes
AGENT TYPE
Helminths
OTHER NAMES
Heterophyes heterophyes infection; Metagonimus yokogawai infection; Intestinal flukes (Heterophyiasis, Metagonimiasis, Haplorchiasis)
ACUITY
Subacute/Chronic
INCUBATION
Adults produce eggs in about 9 days; [PPID, p. 3460]]
INITIAL SYMPTOMS
Abdominal pain and diarrhea;
PRECAUTIONS
COMMENTS
Symptoms include abdominal pain and diarrhea. Infection occurs after eating raw or undercooked, freshwater fish. [Merck Manual, p. 1721-2] Snails are the intermediate hosts and freshwater fish the second intermediate hosts. The adult worms are found in the small intestine. Flukes attach to the intestinal where they live for a few months. Occasionally flukes penetrate the mucosa and eggs may embolize causing myocarditis and brain/spinal cord lesions. [PPID, p. 3452t, 3460] Of the 10 or more human species, Heterophyes heterophyes, H. nocens, and Metagonimus yokogawai are the most prevalent. [Guerrant, p. 866] May cause intestinal hemorrhage, obstruction, and protein-losing enteropathy; [Cecil, p. 2126-7]
DIAGNOSTIC
Identification of eggs in stool sample;
SCOPE
Endemic to the Far East, Middle East, and Egypt; [Merck Manual, p. 1721] H. heterophyes: Nile delta, Tunisia, Turkey, and Iran; M. yokogawai: most prevalent in Far East; [PPID, p. 3460]]
SIGNS & SYMPTOMS
  • G abdominal pain
  • G blood in stool
  • G diarrhea
  • H eosinophilia
  • *bowel obstruction
  • *brain abscess or lesion
  • *myelitis
  • *myocarditis
ANTIMICROBIC

Yes

VACCINE

No

ENTRY
Ingestion
SOURCE
Animal Tissue, Eating Contaminated Food, Eating Infected or Toxin-Containing Fish
RESERVOIR
Fish and Shellfish
RISK FACTORS
  • Eat undercooked meat or fish
  • Travel to endemic area
DRUG LINK
Merck Manual: Heterophyiasis and Related Trematode Infections
REFERENCES FOR CASES/YEAR
1.
2. (Global) 56 million suffered and 7000 died from foodborne trematodiases in 2005; [Fact sheets from WHO] See "Fasciolopsiasis."