Question

The infective stage of Ancylostoma duodenale in humans is
A. Egg containing larvae
B. Filariform larvae
C. Microfilaria larvae
D. Rhabditiform larvae

Answer 1

Hint: The hookworms reside in warmer conditions and need 4 inches of rainfall for their eggs to hatch. They are present in the sandy and loamy soil initially and the rainfall provides the best conditions for the eggs to hatch.

Complete answer: The third stage of the larvae is the filariform stage. It is called the L3 or filariform larva. The filariform stage of the larva is the infective stage of the parasite. They live in moist soil and are extremely motile so that they can get better chances of penetrating the skin of the host and cause the infection. After the larva has entered the host it travels to the lungs and other parts of the body by lymphatic vessels and venules. The filariform larva then enters the small intestine and then matures. Ancylostoma duodenale can adapt in cooler conditions. The infection of hookworms occurs due to larvae and not eggs. Around 30,000 eggs in a day are laid by the female hookworm in the intestine of the host and are passed through the feces. These eggs can easily reside in the warm soil where they start their maturation.
-The microfilaria stage is the early stage of infection of the nematodes in the host.
-The eggs hatched from the fecal matter form larvae. The first and the second stage of the larva is called the rhabditiform stage or L1 and L2. The rhabditiform larvae can survive up to 7days in moist soil. They then mature to the third stage of the larva.
Hence, the correct answer is option (B).

Note: Ancylostomiasis and necatoriasis are infections that can be caused by hookworms in humans. The infection causes intestinal diseases like diarrhea, abdominal pain, intestinal irritation, etc.