Roundworms: Ascariasis

Question 1

What is the most common human worm infection?

Answer 1

Ascariasis (Roundworm)

Question 2

What percentage of the world population is infected with Ascariasis?

Answer 2

20-25% of world population

Question 3

How many new cases of Ascariasis emerge annually, and how many deaths annually?

Answer 3

50,000,000 (50 million) new cases annually

70,000 deaths annually

Question 4

In what regions is Ascariasis most common?

Answer 4

In areas of poor sanitation.

Less common in US

Question 5

Explain the life cycle of Ascariasis

Answer 5

• Adult worms lay eggs that are passed in stool to soil, etc.
• Eggs are ingested.
• Eggs hatch and larvae migrate via portal circulation to liver, heart, lung.

Question 6

What are the clinical manifestations of a LIGHT infection of Ascariasis?

Answer 6

• Tend to be asymptomatic, discovered when patient passes a worm

Question 7

What are the clinical manifestations of a HEAVY infection of Ascariasis?

Answer 7

• Malnutrition, impaired physical/cognitive function
• Biliary obstruction if worms migrate there
• Lower intestinal obstruction d/t mass effect
  
  • Appendicitis
  • Large bowel obstruction
  • Pancreatitis
• Lung symptoms – cough, hemoptysis, lung infiltrates transiently on xray, increased eosinophils (Loeffler’s Syndrome/PIE). Asthma-like symptoms – worms can be coughed up.

Question 8

How do you diagnose Ascariasis?

Answer 8

Stool exam for eggs – not hard to find in a heavy infection. May need to concentrate in a light infection.

Question 9

How do you treat Ascariasis?

Answer 9

Look it up! There is treatment!

Question 10

How do you prevent Ascariasis?

Answer 10

• Eggs in soil survive well – better sanitation, personal hygiene, education, etc.
• Mass Rx
• No vaccine