Parasite
Hookworm (Ancylostoma/Necator)
Skin-penetrating cause of iron-deficiency anemia
HOOK-werm
High-yield clue
Filariform larvae penetrating bare feet cause 'ground itch,' and chronic gut attachment produces iron-deficiency anemia.
Overview
Soil-transmitted nematodes (Ancylostoma duodenale and Necator americanus) whose filariform larvae penetrate skin and whose adults attach to the small intestine, a classic model for chronic intestinal blood loss.
Classification
- Nematode (roundworm)
- Soil-transmitted helminth
- Filariform larvae penetrate skin
- Adults attach to small intestine mucosa
Lab & identification clues
- Thin-shelled oval egg with clear space around the morula
- Rhabditiform larvae distinguished from Strongyloides by long buccal cavity
- Eggs identified on stool examination
Associations
- Larvae penetrate skin, migrate through lungs to gut
- Chronic intestinal blood loss and iron-deficiency anemia
- Barefoot exposure to contaminated soil
- Tropical and subtropical distribution
Commonly confused with
- Strongyloides stercoralis
- Ascaris lumbricoides
Frequently asked questions
What is Hookworm (Ancylostoma/Necator)?
Soil-transmitted nematodes (Ancylostoma duodenale and Necator americanus) whose filariform larvae penetrate skin and whose adults attach to the small intestine, a classic model for chronic intestinal blood loss.
What are the lab clues for Hookworm (Ancylostoma/Necator)?
Lab clues for Hookworm (Ancylostoma/Necator) include Thin-shelled oval egg with clear space around the morula, Rhabditiform larvae distinguished from Strongyloides by long buccal cavity, and Eggs identified on stool examination.
What is Hookworm (Ancylostoma/Necator) commonly confused with?
Hookworm (Ancylostoma/Necator) is commonly confused with Strongyloides stercoralis and Ascaris lumbricoides.
Original student-study summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment, dosing, or specimen-handling guidance.