Chapter 102: Antihelmintics

Question 1

What is the main risk factor for helminthiasis?

Answer 1

Exposure to poor sanitation, especially soil or water contaminated with human feces containing helminth eggs or larvae.

Question 2

What is the main method of preventing helminth infections?

Answer 2

Improved sanitation, hygiene (handwashing, wearing shoes), safe food handling, and periodic deworming in endemic areas.

Question 3

Why is helminthiasis more prevalent in some regions than globally?

Answer 3

Warm, moist climates; poverty; poor sanitation; and environmental factors like soil type promote endemic transmission in tropical/subtropical areas.

Question 4

What are the three major classes of parasitic worms and their common names?

Answer 4

Nematodes (roundworms), Cestodes (tapeworms), Trematodes (flukes)

Question 5

Where are nematodes, cestodes, and trematodes generally found in the body?

Answer 5

• Nematodes: Mainly intestines (some extraintestinal).
• Cestodes: Intestines (adults) or tissues (larvae).
• Trematodes: Intestines, liver, lungs, bladder, or blood vessels.

Question 6

How do nematodes, cestodes, and trematodes typically infect humans?

Answer 6

• Nematodes: Ingestion of eggs or skin penetration (e.g., hookworm).
• Cestodes: Ingesting larvae in undercooked meat/fish.
• Trematodes: Skin penetration in freshwater or ingesting infected aquatic food.

Question 7

What are the main therapies for helminthiasis?

Answer 7

Anthelmintic drugs such as Mebendazole, Albendazole, Pyrantel pamoate, Praziquantel, and Ivermectin.

Question 8

When is drug therapy for helminthiasis definitely indicated?

Answer 8

Symptomatic infections or preventive chemotherapy in endemic areas for high-risk groups, especially with heavy worm burden.

Question 9

What factors may preclude or limit helminth drug therapy?

Answer 9

Drug allergies, pregnancy, young age, liver/renal disease, seizure disorders, certain parasitic conditions, and drug interactions.