This study was conducted as a retrospective matched case control study from a prospective cohort of 8424 newly registered pulmonary TB patients who received treatment in the outpatient department of the TB clinic at the CCIT from January 2007 to December 2013. Cases were patients with pulmonary MDR-TB. Pulmonary MDR-TB was defined as sputum culture showing M. tuberculosis and where DST revealed drug-resistance to both INH and RMP [35]. Controls were pulmonary TB patients with sputum culture showing M. tuberculosis and where DST revealed drug-sensitivity to all four first-line anti-TB drugs, i.e., INH, RMP, EMB, and SM.