Parasitology Training Manual
Hookworm
- Abbreviation: Hw
- Egg size: 55 - 80 microns
- Adult worm length: 5 - 13 mm
- Two species important to man.
- Necator americanis(new world) has anterior cutting teeth.
- Ancylostoma duodenale(old world) has anterior cutting plates.
- The egg is usually blunt on both ends with parallel sides.
- A fine outer shell is also present.
- The rhabditiform larva of Hookworm maybe distinguished from that of S. stercoralis by its long
buccal cavity.
- The rhabditiform larva of hookworm is also at about 300 microns.
- The genital primordia is less pronounced.
Click on the images below to enlarge.
Hookworm Life Cycle
Adults in the intestine of man release eggs that are passed in the feces. In soil they become embryonated
and hatch in 24 - 48 hours. Rhabditiform larva develop into infective filariform larva that penetrate
the skin and migrate via the blood stream to the lungs. As with S. stercoralis they break out of
the lungs migrate to the epiglottis and are swallowed, maturing in the intestine.
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