In the diagnosis of visceral leishmaniasis (kala-azar), the rK39 strip test detects antibodies to a recombinant antigen derived from which Leishmania species?

• A L. tropica
• B L. major
• C L. donovani complex (kinesin-related antigen) ✓
• D L. braziliensis

Explanation

The rK39 immunochromatographic strip test detects IgG antibodies to a 39-amino-acid repeat unit of a kinesin-related protein found in the L. donovani complex (responsible for visceral leishmaniasis). It has sensitivity >90% and specificity >97% for kala-azar in the Indian subcontinent, making it the preferred field rapid diagnostic test. L. tropica and L. major cause cutaneous leishmaniasis; L. braziliensis causes mucocutaneous disease.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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