Nematodes

• Who is the author of the overview of medically important nematodes?

  Dr. Abdullahi Nasiru
• What are the general characteristics of nematodes?

  • Bilaterally symmetrical and triploblastic
  • Cylindrical shape
  • Tissue level organization
  • Presence of a pseudocoelom
  • Distinct alimentary canal with mouth and anus
  • Sexually dimorphic
  • Lack of circulatory and respiratory systems
  • Free-living or parasitic
• What is the significance of the cuticle in nematodes?

  The cuticle moults periodically, allowing growth and development
• What is the specific name of Ascaris lumbricoides derived from?

  Its resemblance to the earthworm (Lumbricus)
• How many people are estimated to be infected with Ascaris lumbricoides worldwide?

  About a billion people
• What is the life cycle of Ascaris lumbricoides characterized by?

  It involves only one host, with humans as the only natural host
• What is the infective form of Ascaris lumbricoides?

  Embryonated eggs
• How does infection with Ascaris lumbricoides typically occur?

  By swallowing eggs containing infective rhabditiform larvae
• What is a common mode of transmission for Ascaris lumbricoides?

  Through fresh vegetables grown in fields manured with human feces
• What happens to the fertilized egg of Ascaris lumbricoides after it is passed in feces?

  It undergoes a period of incubation in soil before becoming infective
• What is the significance of the larvae hatching in the duodenum?

  They penetrate the intestinal mucosa and enter the portal vessels
• How long does it take for Ascaris lumbricoides larvae to become sexually mature?

  About 6-12 weeks
• What is the disease caused by Ascaris lumbricoides called?

  Ascariasis
• What are the symptoms due to migrating larvae of Ascaris lumbricoides?

  Allergic reactions, low-grade fever, dry cough, and wheezing
• What is Loeffler's syndrome associated with?

  Allergic reactions to migrating larvae in the lungs
• What are the pathological effects caused by adult Ascaris lumbricoides?

  Spoliative action, toxic action, mechanical effects, and wandering effects
• What is the lifespan of an adult Ascaris lumbricoides?

  12-20 months
• How is the definitive diagnosis of ascariasis made?

  By demonstrating eggs in feces
• What is the role of eosinophilia in diagnosing ascariasis?

  Eosinophilia indicates an allergic response to the infection
• What is the treatment for ascariasis?

  Pyrantel pamoate, Albendazole, or Mebendazole
• What is a key method of prophylaxis for ascariasis?

  Preventing fecal contamination of soil
• What are the characteristics of hookworms?

  • Two species: Ancylostoma duodenale and Necator americanus
  • Affects about 900 million people
  • Causes significant blood loss daily
  • Adult worms live in the small intestine
  • Life cycle completed in a single host (humans)
• What is the infective form of hookworms?

  Third-stage filariform larva
• How do hookworms typically enter the human body?

  By penetrating the skin of a person walking barefoot
• What are the clinical manifestations due to migrating larvae of hookworms?

  Ground itch and mild transient pneumonitis
• What are the effects of adult hookworms in the human body?

  Epigastric pain, dyspepsia, nausea, and iron deficiency anemia
• What is the best method for diagnosing hookworm infection?

  Demonstration of characteristic oval segmented hookworm eggs in feces
• What is the most effective drug for treating hookworm infection?

  Albendazole (400 mg single dose)
• What are the preventive measures for hookworm infection?

  • Prevent soil pollution with feces
  • Use footwear to prevent skin penetration
  • Proper disposal of night soil
  • Treatment of infected individuals
• What is the common name for Enterobius vermicularis?

  Pinworm
• Where is Enterobius vermicularis most commonly found?

  In affluent nations in cold and temperate regions
• What does the name Enterobius vermicularis mean?

  A tiny worm living in the intestine
• What is the distribution of Enterobius vermicularis?

  It is worldwide in distribution
• How does the prevalence of Enterobius vermicularis differ in affluent nations compared to others?

  It is far more common in affluent nations
• What is the best method for diagnosing hookworm eggs in feces?

  Direct wet microscopy or concentration methods
• Why can't the eggs of A. duodenale and N. americanus be differentiated?

  They cannot be differentiated by morphology
• What may sometimes be seen in feces as a sign of adult hookworms?

  Adult hookworms
• What are the indirect methods for diagnosing hookworm infection?

  • Blood examination reveals microcytic, hypochromic anemia and eosinophilia
  • Stool examination may show occult blood and Charcot Leyden crystals
  • Chest X-ray may show pulmonary infiltrates in the migratory phase
• What is the most practical and effective drug for treating hookworm infections?

  Albendazole (400 mg single dose)
• Which drug is effective and can be used during pregnancy for hookworm treatment?

  Pyrantel pamoate