TB treatment end point - do we have any sterilization marker?

TB is a highly contagious infection which usually spreads through droplet. Transmission dynamics of TB aerosols depend on crowding, weather conditions and the extent of exposure. People with prolonged, frequent, or intense contact such as those sharing a long haul flight with infected persons on-board are at highest risk of becoming infected, with an estimated infection rate of 22%. The chain of transmission can therefore, be broken by isolating patients with active disease and starting effective anti-tubercular therapy. After two weeks of such treatment, people with non-resistant active TB generally cease to be contagious. If this is so, then why an extended regimen for six months? Can this be shortened to prevent against liver cirrhosis and toxicity due to anti-TB drugs, rifampicin in particular? I think yes, it can be, but only after an indication that the patient has been ‘sterilized’ and has started to recover. Weight gain, BMI, feeling of wellness and improved appetite etc. could be some of the vague indicators. However, sadly, we do not have any personalized biomarker that determines the end point for this painful treatment course which should I think be very much variable for different individuals. Some of our research efforts are being pushed in this direction. So watch out, patiently!