Q: My relative has been diagnosed with tuberculosis in initial stage. He was tested positive for sputum AFB test last week. Basically he is an established case of diabetes. He is on insulin with dosage of 16 in the morning and 10 units in the evening. His treating doctor suggested culture test, if the patient does not respond to the treatment. He has prescribed Pyrazamine tablets along with L Cin. Please throw some light on the proposed culture test. Why and where does one have to undergo this test?

A:The reason AFB or TB culture is recommended is to confirm the diagnosis of TB, since other mycobacteria (non-tuberculous or atypical mycobacteria) can also mimic TB and are positive for AFB on microscopy. Secondly, the culture test can be followed by susceptibility testing, which is very useful, since many cases are now multi-drug resistant, and the drugs susceptibility results can be used to modify the treatment and make it more specific for the patient. This test would be available at government medical colleges as well big TB centres.