Question

The causative agent of the disease 'sleeping sickness' in human beings is an

• A. Intracellular parasite found in RBC.
• B. Extracellular parasite found in blood plasma.
• C. Intracellular parasite found in WBC.
• D. Extracellular parasite found on the surfaces of platelets.

Answer 1

Answer: (B)

Extracellular parasite found in blood plasma.

Trypanosomonas is the causative agent for sleeping sickness. This parasite is present in the blood plasma. When the fly bites the host, the metacyclic trypomastigotes enter the blood and from the trypomastigotes. These increase in number and can cross blood brain barrier and affect the brain.

Thus, the correct answer is option B.