Ascaris Lumbricoides Flashcards
Biggest nematodes infecting humans
Ascaris lumbricoides
Most common intestinal nematode of man
Ascaris lumbricoides
Triumvirate:
Ascaris lumbricoides, Trichuris trichiura, & hookwroms
Cosmopolitan (almost everywhere) distribution
Ascaris lumbricoides
Ascaris lumbricoides
____billion people globally affected
______die annually
______years old: age group with highest intensity
______are vulnerable
1.2
2,000
5-15
Children
Ascaris lumbricoides
Habitat:______
Color: Large_____ or _____ worms
Male: 10-31 cm long
Female: 22-35 cm long
_______somatic muscle arrangement
Small intestine
whitish or pinkish
Polymyarian
AL
Anterior End
Mouth with___ lips, and sensory____
Small_____ buccal cavity
three ; papillae
triangular
AL
Posterior End
Male: ventrally_____ with___ spicules
Female:____
curved ; two
tapered
AL
Reproductive Organ in the posterior____
Male: single, long, tortuous tubule
Female: paired reproductive organ (didelphic; 2 tubules)
two-thirds
Production of ________
protects the worm from digestion and phosphorylcholine that suppresses lymphocyte proliferation
pepsin inhibitor 3 (PI-3)
Ascaris lumbricoides
AL
Three layers
Corticated or decorticated
chitinous layer = main protective layer; prevents desiccation (drying)
Ascaroside
Outer mammilated albuminous covering
Thick middle transparent protein layer
Inner lipid layer
AL OVA
Rounder
With undeveloped unicellular embryo
Thick chitinous shell
May be corticated or decorticated
FERTILIZED
AL OVA
85-95um by 38-45 um
variable
unembryonated; amorphous mass of protoplasm
thin
Usually corticated
UNFERTILIZED
AL Infective stage
Embryonated egg
AL LIFE CYCLE
Embryonation in the_____: 2-3 weeks
Egg with___ stage larva: infective stage
With_____ migration stage where larvae undergo molting
Hepato-tracheal migration:____ days
Development of egg-laying adult worm:_____ weeks after ingestion
Life span:____
soil
third
heart-lung
14
9-11
1 year
AL
Diagnostic stages:
Unfertilized egg
Fertilized egg
Adult worm
Philippines:______ prevalence rate AL
80-90%
- refers to the presence of Ascaris eggs in feces of individuals with or without signs and symptoms
Infection rate
- refers to the people infected with the parasite and show signs and symptoms of the disease
Disease rate
AL
Productive capacity of ____ or _____ eggs a day
26 million eggs or 200, 000 eggs per day.
● measures 45 to 70 micra by 35 to 50 micra, shorter than the infertile eggs
● there is an outer coarsely mammilated albuminous covering
● compact yolk granules
Fertilized Egg
● measures 88 to 94 micra by 39 to 44 micra, longer and narrower than fertilized eggs
● it is thin-shelled with an irregular mammilated coating filled refractile granules
● they are difficult to identify and are found only in the absence of males
Unfertilized Egg
● Absence of albuminous coating
Decorticated Egg
Egg 3 layers:
1______- out mammilated covering
2._____ - supporting structure
3.______ - inner membrane
Albuminous covering
Hyaline shell
Vitelline lipoidal layer
Phasmid/ Aphasmid
Phasmid
Host
Humans - accidental
Habitat AL
Small intestine
MOT AL
Ingestion of embryonated egg Inhalation
Infective stage AL
embryonated egg L3
Diagnostic stage
Unembryonated egg ● fertilized or unfertilized eggs in the feces
Pathogenesis & Clinical Manifestations
Loeffler’s Syndrome lungs
Moderate intestinal infection
Lactose intolerance
Vit. A malabsorption
Diagnosis AL
- Direct fecal smear (DFS)
- Kato-Katz Technique
- Formalin-Ether/Ethyl Acetate Concentration Technique
Treatment AL
- Albendazole
- Pipperazine citrate
- Mebendazole or pyrantel pamoate
AL
Disease of poverty:
- Ascariasis
- Ascaris infection
- Roundworm infection
AL
Somatic musculature
Polymyarian
