A child who received BCG vaccination at birth now undergoes Mantoux test at 5 years of age showing an induration of 14 mm. The child has no symptoms. What is the most appropriate interpretation and action?
- A BCG-induced reaction; no further action needed
- B Positive test; LTBI cannot be excluded; chest X-ray and clinical evaluation required ✓
- C Negative; BCG typically produces >15 mm reactions
- D Perform IGRA (Interferon-Gamma Release Assay) only if induration >20 mm
Correct answer: B. Positive test; LTBI cannot be excluded; chest X-ray and clinical evaluation required
Explanation
A Mantoux induration of ≥10 mm in a BCG-vaccinated child from a TB-endemic country (India) is considered positive for latent TB infection (LTBI) per Indian guidelines when contact history or clinical suspicion exists, because BCG-induced reactions rarely exceed 10 mm beyond 5 years post-vaccination. A 14 mm reaction 5 years after BCG cannot be attributed to vaccination alone and warrants chest X-ray and clinical evaluation to rule out active or latent TB. IGRA can help differentiate but is not the immediate first step.
Reference: Ghai Essential Pediatrics, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.