Operational Handbooks

1.1 Background

Globally, tuberculosis (TB) continues to be a significant public health problem, with an estimated 10.6 million people developing TB in 2022 and 7.5 million reported as being newly diagnosed (1). The gap between the numbers estimated and reported is large, and it worsened during the coronavirus disease (COVID-19) pandemic (2). However, there has been a major recovery after the 2 years of disruptions related to COVID-19.

2.2.4 Moderate complexity automated NAATs

The moderate complexity automated NAATs class of tests includes rapid and accurate tests for the detection of pulmonary TB from respiratory samples. Overall pooled sensitivity for TB detection was 93.0% (95% confidence interval [CI]: 90.9–94.7%) and specificity 97.7% (95% CI: 95.6–98.8%) (Tables 3.1–3.4 in Section 3). Moderate complexity automated NAATs are also able to simultaneously detect resistance to both RIF and INH, and are less complex to perform than phenotypic DST and LPAs. After the sample preparation step, the tests are largely automated.

4.3 Algorithm 3 – DST for second-line drugs for people with RR-TB or MDR-TB

Algorithm 3 is used for further evaluation of people with RR-TB or MDR-TB. In its most recent recommendations (9), WHO stresses the importance of DST before starting the preferred all-oral BDQ-containing MDR-TB regimen, especially for medicines for which mWRDs are available. Two of the key medicines in these regimens are BDQ and FQ. Currently, the only WHO-recommended molecular test to detect mutations associated with BDQ resistance is a targeted NGS test (Deeplex® Myc-TB from GenoScreen).

4.2 Algorithm 2 – LF-LAM testing to aid in the diagnosis of TB among PLHIV

Algorithm 2 is the preferred algorithm for testing to support the diagnosis of TB in PLHIV. It is appropriate for use in settings with a high burden of HIV and for use with individual PLHIV who meet the testing criteria, regardless of the overall HIV burden. The algorithm emphasizes the use of LF-LAM to quickly identify people needing TB treatment; it also emphasizes that all individuals with signs and symptoms of TB should receive a rapid mWRD (Algorithm 1).