Hookworm Department of Medical Parasitology
Hookworm Department of Medical Parasitology
Introduction Hookworm refers to nematodes of Family Ancylostomatidae Highly developed buccal capsule --remarkable morphological characteristic of adults Adults parasite in small intestine and result in hookworm disease,heavy infection may evoke anemia known as yellow Laziness World-wide distribution,about 900 million infections in the world The most harmful one among human digestive track nematodes
Introduction • Hookworm refers to nematodes of Family Ancylostomatidae • Highly developed buccal capsule -- remarkable morphological characteristic of adults • Adults parasite in small intestine and result in hookworm disease, heavy infection may evoke anemia known as Yellow Laziness • World-wide distribution, about 900 million infections in the world • The most harmful one among human digestive track nematodes
Classification and Species 1.Classification Phylum Nemathelminthes Class Nematoda Order Strongylata Family Ancylostomatidae 2.Species Ancylostoma duodenale,A.d Necator americanus,N.a
Phylum Nemathelminthes Class Nematoda Order Strongylata Family Ancylostomatidae 1. Classification Ancylostoma duodenale，A.d Necator americanus，N.a 2. Species Classification and Species
Morphology -Adult- ·A.d-"C"shape;N.a--"s”shape Pinkish-white in color,white when fixed with formalin Male --5 to 10cm,female --9 to 12mm A.d N.a
Morphology -- Adult • A.d -- “C” shape; N.a -- “S” shape • Pinkish-white in color, white when fixed with formalin • Male -- 5 to 10cm, female -- 9 to 12mm A.d N.a
Head--curved dorsally,giving hooked appearance,from which the name "hookworm"is derived ·Buccal capsule A.d--contains two pairs of actual teeth N.a--contains a pair of cutting plates
• Head--curved dorsally, giving hooked appearance, from which the name “hookworm” is derived • Buccal capsule A.d--contains two pairs of actual teeth N.a--contains a pair of cutting plates
·Posterior end of male--copulatory bursa ·Branches of dorsal ribs A.d--1,2,3 N.a--0,2,2
• Posterior end of male--copulatory bursa • Branches of dorsal ribs A.d--1, 2, 3 N.a--0, 2, 2
Morphology -Larva Rhabditiform larva and filariform larva Rhabditiform larva Filariform larva
Rhabditiform larva and filariform larva Rhabditiform larva Morphology -- Larva Filariform larva
Morphology -Egg Ovoid in shape,60X40um in average,embryo cells inside Thin,clear and colorless egg shell,eggs recovered in freshly passed stool are usually at four-cell stage A clear space between the developing embryo and the thin eggshell
Morphology -- Egg • Ovoid in shape, 60×40μm in average, embryo cells inside • Thin, clear and colorless egg shell, eggs recovered in freshly passed stool are usually at four-cell stage • A clear space between the developing embryo and the thin eggshell
Life cycle molt 2 times molt 2 times Adults---Eggs Rhabditiform Filariform Adults larvae larvae Human Soil Human
molt 2 times molt 2 times Adults Eggs Rhabditiform Filariform Adults larvae larvae Human Soil Human Life cycle
Development in Man Infection Filariform larvae Stage (infective stage larvae) Mode Penetrate through skin Oral ingestion
Infection Filariform larvae (infective stage larvae) Penetrate through skin Oral ingestion Development in Man Stage Mode