WORM INFESTATION

 

🪱 WORM INFESTATIONS (HELMINTHIASIS)

🔹 INTRODUCTION

• Helminthiasis = Infection by parasitic worms (helminths) in humans.
• Worms live in the host and derive nutrition, leading to deficiency in the host.
• Common intestinal worms (visible to naked eye):
• Roundworm – Ascaris lumbricoides
• Whipworm – Trichuris trichiura
• Hookworm – Necator americanus

🔹 MODE OF TRANSMISSION

• Feco-oral route (most common)
• Contaminated food/water containing eggs/larvae
• Skin penetration
• Walking barefoot (hookworm larvae)
• Other routes
• Undercooked meat/fish
• Poor hygiene (unclean hands, objects)
• Animal or human contact

⚠️ Strongly associated with:

• Open defecation
• Poor sanitation
• Contaminated soil

🔹 PATHOPHYSIOLOGY (IN SHORT)

• Eggs/larvae enter body → develop into adult worms in intestine
• Worms:
• Compete for nutrients → malnutrition
• Cause intestinal inflammation & granuloma
• May cause mechanical obstruction (heavy load)
• Some migrate to organs → liver, lungs

🔹 SIGNS & SYMPTOMS

Gastrointestinal:

• Diarrhea / Constipation
• Abdominal pain
• Vomiting
• Distended abdomen
• Bowel obstruction (severe cases)

Systemic:

• Fever
• Fatigue
• Malnutrition / weight loss
• Dehydration

Others:

• Eosinophilia (important exam point)
• Cough (larval migration in lungs)
• Hepatosplenomegaly
• Perianal itching (especially pinworm)

🔹 COMPLICATIONS

• Intestinal obstruction
• Severe anemia (hookworm)
• Malabsorption syndrome
• Growth retardation in children

🔹 PHARMACOTHERAPY (ANTHELMINTICS)

1. Mebendazole

Class: Benzimidazole

Mechanism:

• Inhibits microtubule synthesis
• Blocks glucose uptake → ↓ glycogen → worm death

Indications:

• Roundworm, whipworm, hookworm, pinworm

Key Point:

• Worm death occurs within 2–3 days

Adverse Effects:

• Abdominal pain
• Diarrhea
• Rare: neutropenia, thrombocytopenia

2. Albendazole

Mechanism:

• Similar to mebendazole (microtubule inhibition)

Indications:

• Broad-spectrum
• Neurocysticercosis
• Hydatid disease
• Tapeworm infections

Adverse Effects:

• Hepatotoxicity (important)
• Leukopenia
• Thrombocytopenia

3. Quinacrine

Indications:

• Giardiasis
• Some tapeworm infections

Note:

• Less commonly used today (replaced by safer drugs like metronidazole)

🔹 PREVENTION

• Proper sanitation (avoid open defecation)
• Hand hygiene
• Wash fruits & vegetables properly
• Cook meat thoroughly
• Wear footwear
• Safe drinking water
• Mass deworming programs

🔹 QUICK REVISION POINTS (VERY IMPORTANT)

• Most common route → Feco-oral
• Key lab finding → Eosinophilia
• Drug of choice (most cases) → Albendazole / Mebendazole
• Hookworm → Anemia + barefoot transmission
• Complication → Intestinal obstruction