A clinical laboratory validates a new rapid diagnostic test (RDT) for malaria using 200 confirmed positive and 200 confirmed negative samples. The test correctly identifies 186 positives and 190 negatives. What are the sensitivity and specificity respectively?

• A Sensitivity 95%, Specificity 93%
• B Sensitivity 90%, Specificity 97%
• C Sensitivity 93%, Specificity 93%
• D Sensitivity 93%, Specificity 95% ✓

Explanation

Sensitivity = True Positives / (True Positives + False Negatives) = 186 / 200 = 93%. Specificity = True Negatives / (True Negatives + False Positives) = 190 / 200 = 95%. In malaria diagnostics, high sensitivity is critical to avoid missing cases (false negatives lead to untreated disease). High specificity avoids unnecessary treatment. WHO requires RDTs for malaria to have ≥95% sensitivity for P. falciparum at parasite densities ≥200 parasites/µL. This test at 93% sensitivity and 95% specificity meets reasonable thresholds for field use.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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