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The effect of sputum quality and volume on the yield of bacteriologically-confirmed TB by Xpert MTB/RIF and smear
oleh: Onani Zimba, Tsaone Tamuhla, Joyce Basotli, Gaoraelwe Letsibogo, Sherri Pals, Unami Mathebula, Anikie Mathoma, Christopher Serumola, Kitso Ramogale, Rosanna Boyd, Tiffany Tran, Alyssa Finlay, Andrew Auld, Anand Date, Heather Alexander, Violet Chihota, Tefera Agizew
| Format: | Article |
|---|---|
| Diterbitkan: | The Pan African Medical Journal 2019-06-01 |
Deskripsi
INTRODUCTION: The World Health Organization endorsed (2010) the use of Xpert MTB/RIF and countries are shifting from smear microscopy (smear)-based to Xpert MTB/RIF-based tuberculosis (TB) diagnostic algorithms. As with smear, sputum quality may predict the likelihood of obtaining a bacteriologically-confirmed TB when using Xpert MTB/RIF. METHODS: From 08/12-11/2014, all people living with HIV were recruited at 22 clinics. For patients screened positive using the four TB symptoms their sputa were tested by Xpert MTB/RIF and smear. Laboratorians assessed and recorded sputum appearance and volume. The yield of bacteriologically-positive sputum evaluated using Xpert MTB/RIF and smear, likelihood-ratios were calculated. RESULTS: Among 6,041 patients enrolled 2,296 were presumptive TB, 1,305 (56.8%) had 1 sputa collected and 644/1,305 (49.3%) had both Xpert MTB/RIF and smear results. Since 1 sputa collected from 644 patients 954 sputa were tested by Xpert MTB/RIF and smear. Bacteriologically-positive sputum was two-fold higher with Xpert MTB/RIF 11.4% versus smear 5.3%, p = 0.001. Sputum appearance and quantity were not predictive of bacteriologically-positive results, except volume of 2ml to 3ml, tested by Xpert MTB/RIF LR+=1.26 (95% CI, 1.05,1.50). CONCLUSION: Xpert MTB/RIF test yield to bacteriologically-positive sputum was superior to smear. Sputum quality and quantity, however, were not consistently predictive of bacteriologically-positive results by Xpert MTB/RIF or smear.