report hookworms
Post on 10-Jul-2016
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HOOKWORMS
Ancylostoma duodenaleNecator americanus
Necator americanus(New World Hookworm)
Ancylostoma duodenale(Old World Hookworm)
Soil-transmitted helminths
They are blood sucking nematodes that attach to the mucosa of the small intestineAll hookworms have the meromyarian type of somatic muscle arrangement where the cells are few in number—two to five per dorsal or ventral half
Infective Stage Filariform larvaDiagnostic Stage Egg
Mode of transmission Skin penetration of infective tissue
Ancylostoma duodenale Necator americanus
Size Bigger Smaller
Body curvature C shaped S shaped
Dental pattern 2 pairs of teeth Semi-lunar cutting plates
Copulatory bursa of the male
Circle (top view)Trigiditate/tripartite with
unfused spicules
Oval (top view)Bidigitate/bipartite with
fused spicules Habitat Small intestine
(duodenum)Small intestine
(jejunum)
Necator americanus
• Small, cylindrical, fusiform, grayish-white nematodes
• Female: 9-11mm by 0.35mm
• Male: 5-9mm by 0.30mm
• Male posterior end is broad, membranous caudal bursa with rib-like rays for copulation
Ancylostoma duodenale
• Adult: buccal capsule has 2 pairs of curved ventral teeth
Rhabditiform larvae of N. americanus and A. duodenale are indistinguishable. They resemble Strongyloides stercoralis, but are somewhat larger, more attenuated posteriorly and have a longer buccal cavity.
Buccal spears of the filariform larva Necator americanus Ancylostoma duodenale
Conspicuous and parallel throughout their lengths
Insconspicuous buccal spears
Conspicuous transverse striations are present on the
sheath in the tail region
Inconspicuous transverse striations are present on the
sheath in the tail region
Eggs• Bluntly rounded ends • Single thin transparent hyaline shell• Unsegmented at oviposition and in the 2- to 8-
cell stages of division in fresh feces
Life Cycle
Pathology• Hookworm infections involve: 1. skin at the site of
entry of the filariform larvae 2. the lung during larval migration 3. the small intestine, the habitat of adult worms
• Maculopapular lesions and localized erythema• Ground itch or dew itch• Papulovesicular eruption• Lungs: bronchitis or pneumonitis• Abdominal pain, steatorrhea, blood Eosinophilia, diarrhea with blood and mucus• hypoalbuminemia
Diagnosis1. Direct fecal smear2. Kato-Katz Method3. Concentration methods (ZnSO4 centrifugal
flotation and the formalin-ether concentration method)
4. Culture method: Harada-Mori
Treatment
• Mebendazole - Not recommended for children less than 2
years of age and pregnant women- 500 mg single dose• Albendazole- Drug of choice- Larvicidal and ovicidal - 400 mg single dose
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