A. lumbricoides

• Common name - giant intestinal roundworm
• pathogenesis - enteritis, inflammation, obstruction, toxicity, eosinophilia, hemorrhage, trauma by penetrating adults
• contains substance ascaron which is toxic to the body
• Habitat - small intestine
• reservoir host - swine (pigs)
• infective form - embryonated egg containing L3 larvae
• mode of infection - ingestion (which can lead to Ascariasis)
• specimen of choice - feces
• Ascariasis is a major parasitic disease globally
• Pig roundworm (Ascaris suum) can also infect humans
• color - hyaline (brownish in color)
• Operculum (head cap) - none
• shape - oval to round
• operculum serves as an opening
• When the larva embryonates inside the egg, it will go out of the operculum. The operculum will open for the larva to get out
• Since Ascaris lumbricoides do not have an operculum, it simple disintegrates
• Ascaris lumbricoides is corticated. It has an outer mammillatedd, albuminoid layer
• Uncorticated A. lumbricoides egg floats in brine
• unfertilized egg is produced by female worms in absence of male worms
• unfertilized egg is narrower, longer, bile-stain, heavy, does not float in brine
• Size of the adult is

  Male - 15 - 30 cm

  Female - 25 - 35 cm
• Ascaris lumbricoides, Strongyloides stercoralis, and hookworm are associated with the heart to lung migration
• Ascaris lumbricoides is a constant wanderer
• heart to lung migration:

  intestine - blood - lungs - heart - trachea - pharynx - small intestine