Tracing TB: Are there predictors for active TB disease in patients with Xpert Ultra trace results?. (January 2022)

• Record Type: Journal Article
• Authors: Dowling, Wentzel Bruce; Whitelaw, Andrew; Nel, Pieter
• Is Part Of: International journal of infectious diseases. Volume 114(2022)
• Page Start: 115
• Page End: 123
• Publication Date: 2022-01
• Subjects: Xpert Ultra -- Mycobacterium tuberculosis -- TB culture -- Trace results; Communicable diseases -- Periodicals; Communicable Diseases -- Periodicals; Communicable diseases; Periodicals; Electronic journals; 616.9
• DOI: 10.1016/j.ijid.2021.10.056
• Languages: English
• ISSNs: 1201-9712

Abstract

Highlights: Interpreting Xpert Ultra trace results is complex in high-burden tuberculosis (TB) settings. This study investigated predictors of TB culture positivity in patients with trace results. Extra-pulmonary TB, no previous TB disease, and TB symptoms are predictors for active TB disease. The trace predictive tool methodology could be applied in other settings. Abstract: Objectives: The Xpert MTB/Rif Ultra (Xpert Ultra; Cepheid, USA) has increased sensitivity compared with its predecessor (Gene Xpert), due to the addition of multicopy amplification targets and a novel trace call. The World Health Organization suggests that tuberculosis (TB) treatment should be initiated in HIV, paediatric, and extra-pulmonary TB patients with trace results. However, other factors such as previous TB disease may complicate the interpretation of trace results in high-burden TB settings. This study aimed to clarify the positive predictors for active TB disease in patients with trace results and to investigate if previous TB disease influences TB culture positivity. Methods: A retrospective descriptive study was performed on 290 patients with trace results, to determine what the positive predictors for active TB are by comparing clinical factors to TB culture. Results: The key findings of this study were that extra-pulmonary TB samples (OR, 2.7; p=0.012), no previous TB disease (OR, 4.5; p=0.001) and symptoms suggestive of TB (OR, 6.4; p<0.001) are independent predictors for active TB disease. Conclusion: This study found readily available clinical predictors that can aid clinicians with TB management decisions in patients with trace results.