Impact of Larger Sputum Volume on Xpert® MTB/RIF Assay Detection of Mycobacterium tuberculosis in Smear-Negative Individuals with Suspected Tuberculosis

J Clin Med. 2017 Aug 7;6(8):78. doi: 10.3390/jcm6080078.


As a strategy to improve the sensitivity of nucleic acid-based testing in acid-fast bacilli (AFB) negative samples, larger volumes of sputum (5-10 mL) were tested with Xpert® MTB/RIF from 176 individuals with smear-negative sputum undergoing tuberculosis evaluation. Despite larger volumes, this strategy had a suboptimal sensitivity of 50% (4/8).

Keywords: Xpert MTB/RIF; larger volume sputum; smear-negative suspects.