In a dengue outbreak investigation, a patient presents on Day 3 of fever. Which combination of tests is MOST appropriate to maximise diagnostic sensitivity at this stage?
- A NS1 antigen + IgM ELISA only
- B IgM and IgG ELISA (paired serology)
- C NS1 antigen + dengue RT-PCR ✓
- D Platelet count + dengue IgM alone
Correct answer: C. NS1 antigen + dengue RT-PCR
Explanation
NS1 antigen is detectable from Day 1 to Day 9 of fever and is highest in the first 3 days; dengue RT-PCR detects viral RNA from Day 1 to Day 5. Together, NS1 antigen and RT-PCR offer the best sensitivity in the first week of illness. IgM antibodies typically appear from Day 4–5 and are more useful in the second week. IgG alone is useful for identifying past infection or secondary dengue. Platelet count alone has no diagnostic utility.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.