《人体寄生虫学 Human parasitology》课程教学课件（讲稿）Lectures 9.Pinworm

Pinworm:Scientific Name:Enterobiusvermicularis p227

Scientific Name: Enterobius vermicularis p227 Pinworm:

GeneralIntroduction:1.The adult worms inhabit the cecum and colon2. No host other than man.3. Affecting mainly children below the age of 12years

1.The adult worms inhabit the cecum and colon. 2. No host other than man. 3. Affecting mainly children below the age of 12 years. General Introduction:

I.Morphology1. Adultslook like a pin and are whitein color.Female: 8 ~13 mm, fusiformin shape.Male: 2-5mm. The tail of amale is curved. They die rightafter mating, thus males arerarely seen.MaleFemale

I. Morphology 1. Adults look like a pin and are white in color. Female: 8 ~13 mm, fusiform in shape. Male: 2-5mm. The tail of a male is curved. They die right after mating, thus males are rarely seen

PinwormMale&Female adultMaleFenale

Pinworm Male &Female adult

The anterior end tapers and is flanked on each side by cuticularextensions called“cephalic alae"The esophagus is slenderterminating in a prominent posterior bulb, which is calledesophagealbulbCephalicalaeesophagealbulb

The anterior end tapers and is flanked on each side by cuticular extensions called “ cephalic alae”. The esophagus is slender, terminating in a prominent posterior bulb, which is called esophageal bulb

MorphologyEgg: 50-60 by 20-30 μm,大persimmon seed-like, ovoidbut asymmetrically flattened虫卵on one side, colorless andtransparent, thick andasymmetric shell, content is atadpole larva

 Egg: 50-60 by 20-30 µm, persimmon seed-like, ovoid but asymmetrically flattened on one side, colorless and transparent, thick and asymmetric shell, content is a tadpole larva. Morphology

X100. EnlargedX 400. Enlarged

×400. Enlarged ×100. Enlarged

eggs are thin shelled, ovoid and flattened on oneside and measure 50-60 by 20-30 μm; theyoften are embryonated

eggs are thin shelled, ovoid and flattened on one side and measure 50-60 by 20-30 µm; they often are embryonated

LEmbryonatedeggsingestedbyhuman2Larvaehatchin small intestineEggsonperianalfoldsAdults in lumenLarvae inside the eggsofcecummaturewithin4to6hoursInfectiveStageGravidmigrates5gDiagnostic Stagetoperianalregion1atnighttolayeggs

EggsEgg is ingestedEggscontaminatefingersEggsLarvae hatch incontaminatesmall intestinetingersLarvae hatchinsmall intestineLarvaemigrateto colonEggs embryonateonperianumAdultsAdults lay eggsmaturein colononperianal regionAdult matureEggs embryonatein colononperinearegionAdults lay eggs on perianum