Management of drug-resistant TB with individualised DST--the way forward?

I has the largest TB epidemic in the world with almost 1000 TB related deaths everyday or 2 deaths every 3 minutes. Drug resistance is assuming increasing proportions with the prevalence of multi drug resistant (MDR) tuberculosis (defined as TB resistant to at least both isoniazid (H) and rifampicin (R)) approaching 1.5-2.7% in new and 13-17% in previously treated cases.1 The exact burden of extensively drug resistant (XDR) tuberculosis (defined as MDR strains with additional resistance to any fluoroquinolone (FQ) and at least one of the three second-line antituberculosis injectable agents (IA) —ie, amikacin, kanamycin, or capreomycin) is unknown but estimated to be 10% of all MDR cases.1 In 2012, totally drug resistant (TDR) or XXDR tuberculosis (defined as TB resistant to all drugs that can be tested in the laboratory) was reported from Mumbai.2 In their article, Soman et al have coined the terms MDR+ and pre XDR TB.3 It is a meaningful step, since a significant proportion of drug resistant cases in India fall somewhere in between MDR and XDR TB. A study from Tuberculosis Research Centre, Chennai reported that of the 1498 strains of MDR tuberculosis isolated between 2001-2004 from all across India, 44.8% were resistant to ≥ second line drug (SLD). Prevalence of ethionamide resistance was 32.7%, ofloxacin resistance 16.4% and kanamycin resistance 11.3%; 4.6% strains were XDR.4 Udwadia et al have reported rise in FQ resistance in MTB isolates from 3% in 1996 to 35% in 2004.5 Recent data will be more dismal. This increase Management of Drug-Resistant TB with Individualised DSTThe Way Forward ?