Question

Which of the following is the secondary host in the case of blood fluke?
A. Snail
B. Pig
C. Man
D. Sand fly

Answer 1

Schistosoma is a genus of trematode commonly known as blood fluke. It is a flatworm parasite. It is the second most socioeconomic parasitic disease. Thousands of eggs are released and reached either the bladder or the intestine, thus excreted in urine or feces or freshwater. The larvae then get into an intermediate host before entering into the next larvae stage and then infect the next mammal directly penetrating into the skin.

Complete answer:
Schistosoma is a flatworm parasite that is generous with trematodes. According to WHO, it is the second most socioeconomic parasitic infection in the world. It is commonly known as blood fluke.
Depending on the species, Schistosoma eggs are released through feces and urine. The eggs hatch in proper condition and release miracidia, which swims and penetrate the snail as an intermediate host. Inside the snails, various stages are seen and release the cercariae. These inactive cercariae swim and penetrate the human host through the skin. There they develop schistosomula that circulates through the venous blood supply and reaches the heart, lungs, and liver causing various diseases in the human body.
As per the life cycle of the blood fluke the secondary host is the Snail. Man is the final host. Various animals like pigs, rodents, and horses, and goats play the role of reservoirs.
So, the correct answer is “Option A”.

Additional Information:
The disease caused in humans is called schistosomiasis which is not caused by worms rather caused by the eggs laid by the worms. The symptoms include fever, cough, abdominal pain, hepatosplenomegaly, etc. Prevention of this infection can be only maintaining hygiene, avoid swimming in the countries where the parasite infection is more and drinking safe water.

Note:
In the case of a blood fluke, the secondary host is the Snail. Schistosoma lays eggs through feces and urine. These eggs hatched under the proper condition and released miracidia. These miracidia swim and penetrate the intermediate host snail. These larvae before entering into the next stage emerge a new mammal by penetrating the skin and causing a disease called schistosomiasis.