Operational Handbooks

1. WHO consolidated guidelines on tuberculosis Module 4: Treatment – drug-susceptible tuberculosis treatment. Geneva: World Health Organization; 2022.
2. WHO operational handbook on tuberculosis Module 4: Treatment – tuberculosis care and support. Geneva: World Health Organization; 2022.
3. The End TB Strategy (WHO/HTM/TB/2015.19). Geneva: World Health Organization; 2015 (https://www.

In November 2020, the WHO Global TB Programme (WHO/GTB) convened an online consultation and released new definitions of TB treatment outcomes, which were the same for DS-TB and DR-TB (97-99).

The principles guiding the update of the definitions were as follows:

DS-TB is largely curable with treatment that is affordable and widely accessible. If a TB treatment regimen is not administered correctly, it may fail to deliver a relapse-free cure, thus increasing transmission and accelerating the emergence of drug-resistance. Monitoring the effectiveness of TB treatment is thus critically important in both clinical practice and surveillance, to maximize the quality of individual patient care and the effectiveness of public health action.

Any patient not clinically responding to therapy after several weeks should be considered as being at risk for failure. In particular, patients should be considered as being at high risk for treatment failure if they had at least 3 months of full adherence to what was deemed to be an effective treatment regimen with quality-assured drugs, but show evidence of active disease – either clinical, radiographic or bacteriological (DST or culture) – or reappearance of disease. The following steps are recommended in such a situation.]

Confirm treatment

In the first few months of treatment, the patient’s chest radiograph may appear unchanged or show only slight improvement. Although there are no formal recommendations on this, it is prudent to undertake CXR at baseline, at the end of the second month of treatment and at the end of treatment, to document progress and to use for comparison if the patient’s clinical condition changes at any time after the achievement of treatment success (91). A chest radiograph at the end of treatment is also useful to optimally manage TB pulmonary sequelae after treatment (91).