Question

Larvae of Ascaris hatch out in
A. Soil
B. Intestine
C. Liver
D. Lungs

Answer 1

Hint: We know, consumption of contaminated food is the cause of infections. If the food is contaminated with the egg of Ascaris which is present in the faeces, such infections occur. The egg with the embryo passes into the intestine and the larva in the second stage hatches out from the egg. It then penetrates to the mucus on the wall, and then moves to the lungs through blood stream.

Complete answer:
Ascaris species are very large with their adult females having a size up to 20 to 35 cm and the adult males having a size up to 15 to 30 cm. These are nematodes which function as parasites in the human intestine.
A.lumbricoides is the primary nematode found in the human intestine whereas Ascaris are derived from pigs.
Adult Ascaris live in the lumen of the human intestine.
Adult female Ascaris may produce up to 200,000 eggs on a daily basis.
Unfertilized eggs are not infective even if they are ingested.
The larva after being swallowed hatches and invades the mucosa of the intestine.
So, the correct answer is “Option B”.

Additional Information:
After infection the larva is then carried through the portal and via systemic circulation to the lungs.
It takes 10-14 days time for the larva to mature further in the human lungs after which it penetrates the alveolar wall to ascend through the bronchial tree into the throat for swallowing.
After reaching the intestine, they develop as adult worms. It takes 2 to 3 months for infective eggs ingestion to oviposition.

Note:
Ascariasis is a very serious infection on a global basis. The highest number of cases is being reported in the tropical and subtropical regions where sanitation facilities are inadequate. There can be epidemiologic association to pig farms for these infections in some areas. Heavy infection can cause stunted growth in children due to malnutrition with no acute symptoms. So, keeping good check of the food and water for consumption, we can prevent ascariasis from occurring.