4. Necator americanus
Historical Notes
Predominant human hookworm in the Philippines
Agent in the production of “laziness” in poor white
population in the Southern USA;
“Tropical Anemia” of Puerto Rico and tropical areas in
Western hemisphere
5. Necator americanus
Morphology
Adult Worm
• Attenuated anterior end w/ a buccal capsule
• Ventral and dorsal pair of semilunar cutting
plates
• Strongly flexed dorsal ward the anterior end
6. Necator americanus
Morphology
Adult Worm
• Amphidial (secretes anticoagulant), excretory
and esophageal glands for exodigestive function
• Grayish yellow at times reddish
12. Necator americanus
Morphology
Diagnosis
• Presence of Charcot Leyden crystals in the feces
(heavy infection : prepatent period)
• 24 hour fecal specimen preservation at room
temp for egg hatching to hookworm larvae
14. Necator americanus
STORYANG BUTBOT
A. duodenale N. americanus
Strong Weak
Larger and thicker Smaller and more slender
Stunted Children Growth and Mental
Retardation
(I Have Enough Power)
Iron-deficiency anemia, Hypothermia,
Eosinophilia, Protein Malnutrition
Classic Hookworm Disease
6 Ventral Cutting Teeth 4 Ventral Cutting Plate
No Lung Migration Requires Lung Migration
Tripartite Dorsal Ray Bipartite Dorsal Ray
Present Spine Absent Spine
Anterior end bends in same direction Anterior end bends in opposite direction