Ascaris Lumbricoides

Question 1

Life cycle

Answer 1

1) eggs are ingested
2) larvae hatch in small Intestine, enter blood steam, go to liver
3) larvae migrate to heart
4) larvae reach lung capillaries, enter alveolar spaces
5) larvae migrates up trachea, are swallowed
6) adults mature In small intestines reaching lengths of 30 cm
7) eggs pass out graces, embryonate in soil
- eggs pass out within 2-4 weeks

Question 2

Pathogensis

Answer 2

• during migration –> inflammation caused by release of antigens
• children–> develop malabsorption of fat, protein, and vitamin A, lactose intolerance, impaired intestinal permeability and anorexia

Question 3

Clinical disease

Answer 3

• migratory phase: pheumonitis, hepatitis, and generalised toxicity
• intestinal phase: perforation of intestine, penetration of liver, obstruction of biliary tract or peritonitis
• hepatobiliary ascariasis occurs if adult worms migrate to biliary tree, leading to inflammation of affected organs

Question 4

Diagnosis

Answer 4

1) Identification of eggs in stool

2) ultrasonography and ERCP also needed

Question 5

Where and who does it affect?

Answer 5

• affects mainly children
• wherever poverty occurs
• in developing countries