Current tools available for the diagnosis of drug-resistant tuberculosis.

Drug-resistant tuberculosis (DR-TB) poses a major threat to control of tuberculosis worldwide. Diagnosis and treatment of DR-TB are considerably more difficult than for drug-susceptible tuberculosis (TB) and require higher level infrastructure and proficiency from laboratory specialists and clinicians. The World Health Organization (WHO) End TB Strategy calls for early diagnosis and initiation of appropriate treatment of all persons of all ages with any form of drug-susceptible TB or DR-TB. This requires ensuring access to WHO-recommended rapid diagnostics and universal drug susceptibility testing (DST) for all persons with signs and symptoms of TB. There are a number of laboratory tools available for diagnosis of DR-TB, including phenotypic culture-based DST as well as molecular methods. Optimal and complementary use of the available diagnostic tools at the different levels of the tiered network of TB laboratories, as well as correct interpretation of the diagnostic results provided by them is critical for accurate and timely diagnosis of DR-TB thus enabling effective treatment and care of patients.