Remarks This recommendation was informed by evidence from recent national surveys of TB disease prevalence in four high TB burden countries. Indirectness of the evidence was classified as serious, given that the methods applied in TB prevalence surveys differ from usual programmatic conditions (e.g. symptom screen limited to cough for 14 days or more, and a requirement in surveys to have the results of both symptom screen and chest radiography available). In addition, inconsistency of the evidence was also classified as serious, owing to variability of the data from different countries. As a result, certainty in the estimates of effect was downgraded to low for sensitivity and moderate for specificity. The recommendation applies only to the use of Xpert MTB/RIF or Xpert Ultra for clinical case management in situations where an immediate decision on patient treatment needs to be made and recourse to supplementary tests is not available or would incur delays. It does not apply to scientific studies with other objectives, such as the reliable estimation of the prevalence of TB disease in the community, for which alternative testing algorithms are required (in particular, to address the issue of false positive results, as illustrated in Table 1.17). Recommendations about the screening and diagnostic algorithms to be used in such studies are beyond the scope of this GDG. Recommendations for the diagnostic algorithm(s) to recommend in national TB prevalence surveys specifically are being developed by WHO and are scheduled for release in 2020.