Q: I am 48 years old. Based on the CT scan of my chest P+C, I was diagnosed with tuberculosis last year. As per my last CT scan, there was significant improvement and complete regression of the lymph nodes in pretracheal, right hiliar & subcarinal regions. The radiologist pointed presence of tiny osteolytic lesions, irregularity in manubrium with adjacent soft tissue thickening and few nodular lesions in right apex suggesting possibility of active disease. On my doctors advice I continued Rcinex 600, Solonex 100 & Combutol 600 (2 tablets) per day till earlier this year and then discontinued it, as their was no sputum & cough. I was fine till 2 months ago. But for the last one month, when I start my physical activity in the morning, the sputum (white in colour) comes out. The frequency is about 20-25 times. Moreover it also comes out with any food intake during the day and I have to clean the throat 2-3 times. I don't cough only sometimes sputum comes out with cough. My recent Chest PA view x-ray shows bilateral hiliar prominence and other things are normal. My doctor has advised me for MT and sputum for AFB test whereas these test were negative last time also before I started anti TB drugs. Is it a relapse of TB?

A:You seem to have taken anti-tubercular treatment (ATT) only for 4 months as against the standard regimen of 6-9 months, the exact duration based on the clinical profile. For bone TB, the duration of treatment is extended for 12 months. In documented MDR TB cases the duration of treatment is usually 18-24 months, depending the resistance pattern. Sputum microscopy for the diagnosis of TB from sputum or urine samples has to be done on 3 consecutive days, since there is intermittent shedding of the bacteria in the sputum or urine. For a definitive diagnosis, AFB culture is also recommended, and is currently the gold standard for the diagnosis of TB. Though there are a number of other investigations including molecular tests (PCR, NASBA, GenProbe, etc.), Mantoux test, Quantiferron gold (for diagnosing latent or active TB), serology (IgG, IgM, IgA antibody levels against Mycobacterium tuberculosis), antigen detection, etc, these should be done after a thorough clinical evaluation by your doctor. Serial ESR estimations may be used for monitoring the disease activity. In the absence of conclusive evidence of TB in your case, other differentials should also be actively ruled out by clinical evaluation and relevant investigations, so that specific treatment can be started.