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General Reference

Nejm 2004;351:799

Pathophys and Cause

Cause: Ancylostoma duodenaleandNecator americanus

Pathophys:Skin penetration, into circulation, then to lung, into trachea, to pharynx where swallowed and then attach to small intestine where they result in chronic blood loss

Epidemiology

Larvae penetrate skin in filariform stage (5 d older than rhabditiform stage), or larvae ingested in feces

Africa, Far East, southern Europe and US, associated w barefoot walking and poor sewage

Signs and Symptoms

Sx: "Ground itch" rash at entry site, usually feet. Cough and sore throat 10 d later when larvae migrate to lungs to be coughed up and swallowed. Apathy from iron deficiency anemia

Si:Anemia, 150-200 cc/d with ancylostomawhen severe infestations; necator1/5 as much, ~0.03 cc/d/worm

Complications

CHF, anasarca

r/o Ancylostoma caninum, dog hookworm that can infect humans and cause abdominal pain (Ann IM 1994;120:369)

Lab and Xray

Lab:

Bact:Stool O+P shows eggs same size as ascaris, w thin delicate shell; hatch in 24 h into rhabidiform larvae, which molt into filariform larvae. Can quantify eggs and estimate number of worms

Hem:Hgb as low as 1-3 gm; Fe deficiency anemia; esosinophilia

Treatment

Rx:

Mebendazole (Vermox) 500 mg po × 1 or 100 mg bid × 3 d; or albendazole 400 mg po × 1; either dosing is for all ages and weights

FeSO4 for the anemia