Hookworm

(Redirected from Necator americanus)

Background

  • Caused by Necator americanus
  • Larvae penetrate through intact skin on contact with feces-contaminated soil
    • Enter the bloodstream, ascend the trachea, descend the esophagus to differentiate into adult worms, and migrate to the upper intestine where they attach to the mucosal wall and feed on host blood
  • Commonly occurs in warmer climates (tropics, Southeast United States). [1]

Clinical Features

  • Morbidity is related to number of worms harbored in intestines
  • Light infections often asymptomatic
  • Heavier infections with variety of manifestations including GI symptoms (abdominal pain, diarrhea, blood in stool, rectal prolapse), malaise, weakness, impaired cognitive / physical development, malnutrition[2]
  • Iron-deficiency anemia
    • Hypochromic microcytic anemia
    • Adult worms attach to intestinal wall to feed, causing ongoing luminal blood loss

Differential Diagnosis

Helminth infections

Cestodes (Tapeworms)

Trematodes (Flukes)

Nematodes (Roundworms)

Evaluation

  • Stool ova and parasites - ova found in stool
  • Stool culture
  • CBC

Management

  • Albendazole 400mg x 1 dose (high efficacy) OR mebendazole 500mg x 1 dose (low to moderate efficacy)
  • Iron supplementation for anemia

Disposition

  • Generally may be discharged

See Also

External Links

References

  1. Becker BM, Cahill JD: Parasitic Infections, in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 7. St. Louis, Mosby, Inc., 2010, (Ch) 131:p 1751-1762
  2. Wilcox S, Thomas S, Brown D, Nadel E. “Gastrointestinal Parasite.” The Journal of Emergency Medicine, 2007; 33(3):277-280

Authors:

Ross Donaldson