Can hookworm infection cause intestinal bleeding without diarrhea?

Hookworm Infection Can Cause Intestinal Bleeding Without Diarrhea

Yes, hookworm infections can cause intestinal bleeding without diarrhea. Hookworms parasitize the proximal small intestine and can lead to chronic intestinal hemorrhage or acute gastrointestinal bleeding without necessarily causing diarrhea 1, 2.

Pathophysiology and Clinical Presentation

• Hookworms (Ancylostoma duodenale and Necator americanus) attach to the small intestinal mucosa where they can cause blood loss, anemia, and wasting 3
• While hookworm infections can sometimes present with abdominal pain, nausea, and diarrhea, intestinal bleeding can occur independently of these symptoms 4, 1
• The UK guidelines for investigation and management of eosinophilia specifically note that hookworm can cause intestinal bleeding as a distinct symptom from diarrhea 4

Evidence of Bleeding Without Diarrhea

• Multiple case studies have documented patients with acute gastrointestinal bleeding due to hookworm without reporting diarrhea as a concurrent symptom 1, 2, 5
• In a study of patients with obscure gastrointestinal bleeding, hookworm was identified as the cause in 7.3% of cases, with melena and hematochezia being the primary presentations rather than diarrhea 1
• Patients may present with:
  • Melena (black, tarry stools) 6
  • Hematochezia (bright red blood in stool) 6, 5
  • Hematemesis (vomiting blood) in some cases 6
  • Iron deficiency anemia from chronic blood loss 3

Diagnostic Considerations

• Hookworm infection should be considered in the differential diagnosis for patients with obscure gastrointestinal bleeding, especially those who have traveled to or live in endemic areas 1, 2
• Diagnostic methods include:
  • Concentrated stool microscopy or fecal PCR to detect hookworm eggs 4
  • Endoscopic procedures (enteroscopy, capsule endoscopy) may directly visualize worms and bleeding sites in the small intestine 6, 5
  • Blood tests may show iron deficiency anemia and eosinophilia 3

Treatment

• The recommended treatment for hookworm infection is:
  • Albendazole 400 mg daily for 3 days 4
  • Prednisolone 40-60 mg once daily may be suggested in severe disease 4
  • Iron supplementation and blood transfusion may be necessary in cases of significant anemia 1, 3

Clinical Pearls and Pitfalls

• Hookworm infection is often overlooked as a cause of acute gastrointestinal bleeding, especially in non-endemic areas 1, 2
• The absence of diarrhea should not rule out hookworm infection as a potential cause of intestinal bleeding 4, 1
• In patients with unexplained gastrointestinal bleeding who have traveled to endemic areas, specific testing for hookworm should be considered even without other intestinal symptoms 1, 2
• Capsule endoscopy and enteroscopy have improved the diagnosis of hookworm as a cause of obscure gastrointestinal bleeding 6, 5