This has details about Ascaris lumblicoides

1. Helminthic Infections
Nematoda
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2. Ascaris lumbricoides
• Common Name : Round Worm
• Morphology
– Largest nematode
– Lives in small intestine
– Use anti peristaltic movements
– Creamy white
– Do not suck blood and damage to got lumen
– Life span (Adult) – 1 Year
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3. Ascaris lumbricoides
• Male
– Small
– 15 -30 cm
– Has a curved tail with spicules
• Female
– Large
– 20-40 cm
– No curved tails
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4. Ascaris lumbricoides
• Female lays eggs, pass out in the feaces and under
favorable condition
• L2 larva develop inside the egg (10-14 days)
• Favourable conditions
– Humid climate
– Moist
– Clay soil
– Shaded area
• Eggs are destroyed by direct sunlight (45 c)
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5. Ascaris lumbricoides
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6. Ascaris lumbricoides
• Swallowed infective eggs 
• Intestine (Release L2 larva)
• Travels trough intestinal wall
• Enter to the portal circulation
• Liver,  IVC
• Lungs
• Stayed for about 2 weeks
• Undergo 2 moults (L2  L3  L4)
• Burst out through the walls of the alveolus into the
cavity of the lung
• Trachea  swallowed to oesophagus
• Then aging to intestine
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7. Ascaris lumbricoides : Transmission
• Infection can be acquired only by
swallowing infective eggs
– Directly
• From soil contaminated with human faeces
– Indirectly
• Through uncooked food items that are
contaminated with soil
• Backyard transmission
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8. Ascaris lumbricoides : Clinical features
• Most are asymptomatic
• Heavy infections :
– Lung : Pneumonitis
• Pneumonitis is partly due to damage to the
alveolar walls by the relatively large larvae, &
partly due to hypersensitivity reaction
– Cough, fever, wheeze, dyspnea ; Loeffler’s
Syndrome
– High eosinophillia
JMJ 8

9. Ascaris lumbricoides : Clinical features
– Chronic malnutrition
– Vit A Deficiency
– Acute obstruction of the intestinal lumen
(ileocoecal valve)
– Bile duct : biliary colic or cholangitis
– Pancreatic duct : pancreatitis
– Appendix ; acute appendicitis
– Can migrate to larynx, block it death
– Mild abdominal pain
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10. Ascaris lumbricoides : Diagnosis
• Identifying adult worms that have been
passed out in faeces or vomitus
• Finding a characteristic eggs in the faeces
• Fertilized egg : oval, transparent shell /
unsegmented embryo
• Unfertilized egg : longer and narrower
• Decorticated eggs : smooth & oval
• The intensity of an
JMJ 10

11. Ascaris lumbricoides : Treatment
• Albendazole
• Mebendazole
• Pyrantel pamoate
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