A 6-week-old infant born to an HIV-infected mother has a positive HIV antibody ELISA. What is the correct next step to determine whether the infant is infected?
- A Repeat the antibody ELISA immediately after 4 weeks
- B Estimate CD4 percentage and start cotrimoxazole prophylaxis if low
- C Perform HIV-1 DNA PCR on whole blood ✓
- D Perform a Western blot to confirm the ELISA result
Correct answer: C. Perform HIV-1 DNA PCR on whole blood
Explanation
Maternal IgG anti-HIV crosses the placenta and persists in the infant up to about 18 months, so antibody-based tests including Western blot cannot diagnose infection before then. Virological testing with HIV-1 DNA PCR, which detects proviral DNA in host cells, is the standard method for early infant diagnosis and is recommended around birth, 6 weeks, and beyond. Repeating serology or confirming it with another serological test would not separate maternal from infant antibody.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.