الديدان الاسطوانية Round Worm (الاسكارس Ascaris lumbricoides)

Ascaris lumbricoides

✧الاسم الشائع لها

الديدان الاسطوانية Round Worm

•Phylum: Nematode

•Class: Secernentea

•Family: Ascarididae

•Genus:Ascaris

●Ascaris lumbricoides

كلمة Ascaris تعني Askaris ومعناه ديدان الامعاء ،

وكلمة Lumbricus تعني مشابهة لدودة الارض Earthworm

◎مواصفات البويضة

✸MORPHOLOGICAL CHARACTERISTICS:

━ Fertile Ascaris:

– Size 55-75 x 35-50 μm

– Spherical/Subspherical shape

━ Infertile Ascaris:

– Size 85-95 x 43-47 μm

– Long, oval shape

· Mamillated shell may exist (corticated) or not (decorticated)

· Yellowish brownish-grey colour

✿OBSERVATIONS:

Morphological characteristics of this specie are identical to the Ascaris in pig, A. suum.

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@LabMed201

💮طريقة انتقال الاسكارس

💮Mode of infection

¤ Ingestion of Embryonated egg through contaminated food or water

¤ The source of transmission is from soil and vegetation on which fecal matter containing eggs has been deposited.

¤ Intimate contact with pets which have been in contact with contaminated soil may result in infection

❇ الامراضية

❇ Pathogenesis:

Generally the disease passes in 2 stages:

1-Migratory stage larva pass to the lung leads to loffler`s syndrome.

 In heavy infection, larva passes to venous circulation then to the heart then go to different body organs causing visceral larva migrains.

2-Intestinal stage

In this stage Ascariasis symptoms include:

▶ Nutritional deficiency (Ascaris takes most of its nutrients from the partially digested host food in the intestine)

▶ Indigestion and malabsorption due to production of anti enzymes interfere with digestion (specially protein indigestion)

♦Complications:

Heavy worm infection may cause intestinal obstruction .

#Parasitology
@LabMed2016

Ascaris lumbricoides (A) adult male; (B) adult female (arrow shows vulvar waist)

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Ascaris lumbricoides Ova types

♻LIFE CYCLE of Ascaris lumbricoides

♻LIFE CYCLE of Ascaris lumbricoides

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التشخيص المخبري للاسكارس

✺ Laboratory diagnosis Ascaris lumbricoides

⇛Detection of the parasite.

→Egg detection(stool examination)

— fertilized and unfertlized eggs.

→Adult worm detection

—X-ray (Trolley car lines), USG and Barium meal of GIT

→Larva detection (sputum/gastric aspirate)

⇛Serology (antibody detection)

—ELISA, IFA, IHA test

⇛ Other findings such as eosinophilia and

charcot leyden crystals in sputum and stool

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