Intestinal Nematodescontinued Clinical Microbiology Review 247
NEMATODE ROUTE OF INFECTION DIAGNOSTIC STAGE OTHER
Necator americanus
Ancylostoma duodenale
American hookworm. “Ground itch.”
Larval migration through lungs.
Eosinophilia. Can lead to anemia.Old World hookworm.Skin penetration or ingestion
of filariform larva.Same as Necator.Ovoid ovum. 40 × 60 μm. Colorless.
Contains segmented embryo 2- to
8-cell stage surrounded by clear
outer zone.Same as Necator.(From Leventhal R, Cheadle RF. Medical Para-
sitology: A Self-Instructional Text, 5th ed.
Philadelphia: FA Davis; 2002:22.)continued...