A 32-year-old man presents with acute high-grade fever and severe body ache of 3 days' duration in a dengue-endemic district. Which diagnostic test is most appropriate at this point of illness?

• A NS1 antigen detection ✓
• B Dengue IgM capture ELISA
• C Paired sera IgG for seroconversion
• D Peripheral smear for platelet clumps

Explanation

NS1 antigen circulates from day 1 of illness and remains detectable up to about day 5 to 7, making it the correct test during the febrile early phase. IgM becomes reliably positive only after approximately day 5 and peaks later, so IgM ELISA is the test of choice in patients presenting after day 5. Paired IgG is a retrospective epidemiological tool, never an acute diagnostic method.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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