Question

The Duffy antigen on erythrocytes is a receptor for

• A. P. falciparum
• B. P. vivax
• C. P. ovale
• D. P. malariae

Hint:

Recall which malaria species needs a specific blood group antigen to enter red cells.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks which malaria parasite uses the Duffy antigen on red blood cells to gain entry.

Step 2: Key Concept or Approach:
The Duffy blood group antigen present on the erythrocyte surface acts as the specific receptor that Plasmodium vivax merozoites use to attach to and invade red blood cells. Individuals who are Duffy-negative, a trait common in West Africa, are largely resistant to P. vivax infection because their red cells lack this receptor.

Step 3: Working Through the Options:
P. falciparum invades red cells mainly through glycophorin receptors, not the Duffy antigen. P. vivax specifically requires the Duffy antigen for invasion, which is the classic association tested here. P. ovale and P. malariae do not depend on the Duffy antigen for red cell entry.

Step 4: Conclusion:
The correct answer is P. vivax, the species whose erythrocyte invasion depends on the Duffy antigen.