Helminths And Nematodes

• What are helminths?

  Parasitic worms living inside humans
• How do helminths affect human health?

  They feed off nutrients, causing health issues
• How many cases of helminth infections occur globally each year?

  About a billion cases
• What is the geographic preference of helminths?

  They prefer tropical areas with warmth
• What is a binomial name in relation to helminths?

  Scientific name with genus and species
• What diseases are caused by helminths and their symptoms?

  • Ascariasis: Ascaris lumbricoides; symptoms: abdominal pain, nausea, vomiting, diarrhea
  • Trichuriasis: Trichuris trichiura; symptoms: bloody stools, abdominal pain, diarrhea, weight loss
  • Enterobiasis (Pinworm): Enterobius vermicularis; symptoms: itching around the anus, difficulty sleeping
• How do helminths spread through ingestion?

  By eating contaminated food or water
• What is skin penetration in helminth transmission?

  Larvae burrow through the skin from soil
• How do insects contribute to helminth transmission?

  They carry and transmit the worms
• What are the life cycle types of helminths?

  • Direct: One host, no intermediate hosts (e.g., Roundworms)
  • Indirect: Two hosts, one intermediate host (e.g., Tapeworms)
  • Complex: Multiple hosts, several intermediate hosts (e.g., Flukes)
• What are the two types of nematode life cycles based on infectivity?

  Type I and Type II
• How do Type I nematodes infect humans?

  Through ingestion of embryonated eggs
• What is the life cycle of Type 1 nematodes?

  1. Ingestion of embryonated eggs
  2. Hatching in the intestine
  3. Larval development
  4. Maturation and reproduction
  5. Egg shedding
• Describe the development of embryonated eggs in Type 1 nematodes.

  1. Ingestion: Eggs enter the body
  2. Hatching: Eggs release larvae
  3. Development: Larvae mature into adults
  4. Reproduction: Adults reproduce and lay eggs
  5. Egg Shedding: Eggs excreted in feces