I. Drug-resistant tuberculosis Guo Xin, Department of Tuberculosis Medicine, Heilongjiang Tuberculosis Hospital Drug-resistant tuberculosis definition Drug-resistant tuberculosis refers to patients with tuberculosis that is resistant to one or more anti-tuberculosis drugs. [1] The classification of drug-resistant tuberculosis can be divided into: primary drug resistance, acquired drug resistance according to whether the tuberculosis patient has received anti-tuberculosis drug treatment; drug-resistant tuberculosis can be divided into: drug-resistant tuberculosis, multidrug-resistant tuberculosis, and extensively drug-resistant tuberculosis according to the number of species of anti-tuberculosis drug resistance.