CHAPTER: Intestinal, ExtraIntestinal, Blood, Tissue

• Ascaris lumbricoides

  Large intestinal roundworm, roundworm of man
• Causesof Ascaris lumbricoides

  Ascariasis, roundworm infection
• Ascaris lumbricoides

  • Fertilized egg
  • Unfertilized egg
  • Adult
• Fertilized eggof Ascaris lumbricoides

  • 40-75 um by 30-50 um
  • Rounder than non-fertilized
  • "Sunny side up egg" shape
  • Underdeveloped unicellular embryo
  • Thick chitin shell
• Unfertilized eggof Ascaris lumbricoides

  • 85-95 um by 38-45 um
  • Varies in shape
  • Unembryonated, amorphous mass of protoplasm
  • Thin shell
• Adultof Ascaris lumbricoides

  • Female: 22-35 cm long
  • Male: up to 30 cm long
  • Cream white, pink tint
  • Female: pencil lead thickness
  • Male: prominent incurved tail
• CausesTrichuris trichiura

  Trichuriasis or whipworm infection
• Trichuris trichiuraParasite

  • Egg
  • Adult
• Eggof Trichuris trichiura

  • 50-5 by 25 um
  • Barrel, football shape
  • Hyaline polar plug at each end
  • "Lemon", "Japanese lantern" shape
  • Unicellular, underdeveloped
  • Smooth, yellow-brown color because of bile contact
• Adultof Trichuris trichiura

  • 2.5-5 cm long
  • Males usually smaller than females
  • Anterior end: colorless, resembles whip, contains slender esophagus
  • Posterior end: pinkish gray, resembles whip handle, contains digestive & reproductive systems
• Hookworms

  Parasitic nematodes
• Hookworms

  • Ancylostoma duodenale (egg)
  • Necator americanus (egg)
  • Adult
• Ancylostoma duodenale (egg)

  • 55-60 um width
  • 35-40 cm width
  • Colorless shell
• Necator americanus (egg)

  • 60-75 um width
  • 35-40 um width
  • Colorless shell
• Adultform of Necator americanus and Ancelystoma duodenale

  • Female: 9-12 mm long, 0.25-0.50 mm wide
  • Male: 5-10 mm long, 0.2-0.4 mm wide
  • Grayish-white to pink color
  • Somewhat thick cuticle
  • Anterior end: conspicuous bend, hook
  • Male: prominent posterior copulatory bursa
• Buccal capsuleof Hookworm

  • Necator: pair of cutting plates
  • Ancylostoma: actual teeth
• Rhabditiform larvaof Hookworm

  • Newly hatched, 5 days old
  • 270 by 15 mm
  • 540-700 um long
  • Long buccal cavity, small genital primordium
• Filariform larvaof Hookworm

  • Infective stage
  • Length: short
  • Tail: pointed
• Causesof Strongyloides stercoralis

  Strongyloidiasis, threadworm infection
• Strongyloides stercoralis

  • Egg
  • Rhabditiform larva
  • Filariform larva
  • Adult female
• Eggof Strongyloides stercoralis

  • 48-35 um
  • Embryonic cleavage: 2, 4, or 8 cell
  • Thin, hyaline shell
• Rhabditiform larvaStrongyloides stercoralis

  • 220 by 15 um
  • Short buccal cavity, prominent genital primordium
• Filariform larva

  • Length: 690 um
  • Long esophagus, tail is notched
• Adult femaleof Strongyloides stercoralis

  • 2 by 0.4 mm
  • Colorless transparent body, finely striated cuticle, short buccal cavity, long & slender esophagus
• Enterobius vermicularis

  Pinworm, seatworm
• Causesof Enterobius vermicularis

  Enterobiasis, pinworm infection
• Enterobius vermicularis

  • Egg
  • Adult
• Eggof Enterobius vermicularis

  • 48-60 um long, 20-35 um wide
  • Oval, one-side flattened
  • Stage of development varies; may be unembryonated, embryonated/mature
  • Double-layered, thick & colorless shell
• Adultof Enterobius vermicularis

  • Female: 7-14 mm long, up to 0.5 mm wide
  • Male: 2-4 mm long, <= 0.3 mm wide
  • Yellowish-white color
  • Female tail: pointed, resembles pinhead
• Capillaria philippinensis

  Pudoc worm
• Capillaria philippinensis

  • Egg
  • Adult
• EggCapillaria philippinensis

  • 36-45 um by 20 um
  • Peanut-shaped with striated shells and flattened bipolar plugs
  • "Chinese lantern" shape
  • Must reach water to be ingested by snail species of freshwater or brackish water
• Adultof Capillaria philippinensis

  • Female: 1.5-3.9 mm long
  • Male: 2.3-5.3 mm long
  • Anterior end: thin filamentous
  • Posterior end: slightly thicker and shorter
  • Stichocytes: rows of secretory cells in esophagus
  • Stichosome: entire esophageal structure
• Dracunculus Medinensis

  Guinea worm
• CausesDracunculus Medinensis

  Dracunculus, dracunculiasis, guinea worm infections
• Dracunculus Medinensis

  • Definitive host
  • Intermediate host
  • Infective form
  • Mode of transmission
  • Incubation period
• Definitive hostof Dracunculus medinensis

  • Man/human
• Intermediate hostof Dracunculus medinensis

  • Cyclops (copepods)
• Infective formof Dracunculus medinensis

  • 3rd stage larva present in the hemocele of infected cyclops
• Mode of transmissionof Dracunculus medinensis

  • Drinking unfiltered water containing infected cyclops