The application of SAT for diagnosing in pulmonary tuberculosis patients

Abstract

Objective To evaluate the value of simultaneous amplification and testing method for diagnosing in patients with pulmonary tuberculosis. Methods Total of 277 sputum samples were detected by SAT, Lowenstein-Jensen (L-J) culture and Ziehl-neelsen staining. Chi-square test was used to compare and analysis the statistical difference in positive detection rates. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of SAT for early diagnosing and judging curative effect were calculated respectively when the clinical diagnosis and L-J culture used as its reference standard. Results The positive detection rates of the three methods for detecting Mycobacterium tuberculosis from the 277 sputum samples were 47.3%(131/277), 30.3%(84/277), 29.6%(82/277), there was a significant difference between SAT and L-J culture(χ2=16.8, P<0.05)and Ziehl-neelsen(χ2=18.3, P<0.05)by chi-square test. Before treatment was commenced, using clinical diagnosis as its reference, the sensitivity, specificity, PPV and NPV of SAT were 59.0%(95/161), 97.4%(37/38)、99.0%(95/96)and 35.9%(37/103); After intensive treatment was over, taking culture as its standard, the results were 11/11, 64.2%(43/67), 31.4%(11/35), 100%(43/43). Conclusions SAT can be useful for early diagnosis of clinically suspicious TB case, it has a more sensitive detecting values of SAT for living bacilli and a shorter test period, which implied it can help judging the response to anti-TB treatment. Key words: Tuberculosis, pulmonary; Mycobacterium, tuberculosis; Nucleic acid amplification techniques; Fluorescence antibody technique