How to be sure that my daughter is not suffering from TB?

Q: My 8 years old daughter has a knot in the neck and the Elisa test has shown IgM value of 0.75 and IgG value of 235. The doctors are in a confused state because there is no current infection, but the history shows the sign of infection. Please let me know course of action, possible treatment and precautions.

A:A clinical evaluation of your daughter is more important than the results of TB serology, which has poor diagnostic accuracy, low sensitivity and specificity. If there is a single palpable lymph node in the neck, then observation and follow-up are indicated. If there is a clump of enlarged lymph nodes, then additional investigations include CBC, ESR, Mantoux test (or Quantiferon TB gold IT test), chest X-ray, FNAC or biopsy.