Question

The definitive host in echinococcosis is
A. Man
B. Dog
C. Snail
D. Sheep

Answer 1

Echinococcosis- a parasitic disease caused by infection with tiny tapeworms of the genus Echinococcus. Echinococcosis is assessed as either cystic echinococcosis or alveolar echinococcosis.

Step by step answer: Cystic echinococcosis, is caused by infection with the larval stage of Echinococcus granulosus, a tapeworm found in dogs and sheep, cattle, goats, and pigs. Although most infections in humans are asymptomatic, CE causes harmful, slowly enlarging cysts within the liver, lungs, and other organs that always grow unnoticed and neglected for years. Alveolar echinococcosis (AE) disease is caused by infection with the larval stage of Echinococcus multilocularis, a tapeworm found in foxes, coyotes, and dogs. Small rodents are intermediate hosts for E. multilocularis. Although cases of AE in animals in endemic areas are relatively common, human cases are rare. AE poses a way greater health threat to people than CE, causing parasitic tumors that will form within the liver, lungs, brain, and other organs. If left untreated, AE will be fatal. AE is found across the world and is very prevalent within the northern latitudes of Europe, Asia, and North America. The adult tapeworm is generally found in foxes, coyotes, and dogs. Infection with the larval stages is transmitted to people through ingestion of food or water contaminated with tapeworm eggs. The parasite is transmitted to dogs after they ingest the organs of other animals that contain hydatid cysts. The cysts convert into adult tapeworms within the dog. Infected dogs shed tapeworm eggs in their feces which contaminate the bottom. Sheep, cattle, goats, and pigs ingest tapeworm eggs within the contaminated ground; once ingested, the eggs hatch and turn out to be cysts within the internal organs. The foremost common mode of transmission to humans is by the accidental consumption of soil, water, or food that has been contaminated by the BM of an infected dog. Echinococcus eggs that are deposited in soil can stay viable for up to a year. The disease is most typically found in people involved in raising sheep, as a result of the sheep’s role as a host of the parasite and also the presence of working dogs that are allowed to eat the offal of infected sheep.
Therefore, the correct answer is B, i.e., Dog.

Note: Various imaging techniques, like CT scans, ultrasonography, and MRIs, are accustomed to detect cysts. After a cyst has been detected, serologic tests could also be accustomed to confirm the diagnosis. Alveolar echinococcosis is often found in older people. Imaging techniques like CT scans are wont to visually confirm the parasitic vesicles and cyst-like structures and serologic tests can confirm the parasitic infection.