Fig 1. Testing protocols in the smear/culture and Xpert^® based TB diagnostic algorithms in PHC facilities in Cape Town.

The diagram shows the simplified sequence of TB diagnostic tests recommended in each algorithm and the action taken based on test results. Low MDR-TB risk was defined as ≤four weeks previous TB treatment and high MDR-TB risk as >four weeks previous TB treatment, from congregate settings or with a known MDR-TB contact. Abbreviations: TB—tuberculosis, LPA—line probe assay, DST—drug susceptibility testing, HIV—human immunodeficiency virus, MTB—mycobacterium tuberculosis, PHC—primary health care.