scholarly journals Diagnostic performance of nucleic acid tests in tuberculous pleurisy

2019 ◽  
Author(s):  
He-ping Xiao ◽  
Liping Yan ◽  
Min Han

Abstract Background: Tuberculous pleurisy (TBP) is the most common form of extrapulmonary tuberculosis (TB). However, rapid diagnostic methods with high accuracy for tuberculous pleurisy are urgently needed. In the present study, we evaluated the diagnostic accuracy of Xpert MTB/RIF, LAMP and SAT-TB assay with pleural fluids from from culture-positive TBP patients. Methods: We prospectively enrolled 300 patients with exudative pleural effusions used as the samples for Xpert MTB/RIF, LAMP and SAT-TB assay. Of these, 265 including 223 patients diagnosed with TP and 42 non-TB patients used as controls were analyzed. Results: The sensitivities of Xpert MTB/RIF (27.4%) , LAMP (26.5%) and SAT-TB assay (32.3%) were significantly higher than that of pleural effusion smear (14.3% , X2 = 20.65, P < 0.001), whereas they were much lower than expected for the analysis of pleural effusion samples. Both SAT-TB assay and Xpert MTB/RIF demonstrated high specificities (100%) and PPVs (100%), but the NPVs of all of the tests were < 22%. The area under ROC curve of pleural effusion smear, LAMP, Xpert MTB/RIF and SAT-TB assays was 0.524 (95% CI 0.431–0.617), 0.632 (95% CI 0.553–0.71), 0.637 (95% CI 0.56–0.714) and 0.673 (95% CI 0.6–0.745). SAT-TB assays had the highest AUC. Conclusion: Nucleic acid amplification tests are not the first choice in the diagnosis of tuberculous pleurisy. In this type of test, SAT-TB is recommended because of its low cost, relatively more accurate compared with the other two tests. This prospective study was approved by The Ethics Committee of the Shanghai Pulmonary Hospital (approval number: K19-148). ClinicalTrials.gov identifier: ChiCTR1900026234.

2020 ◽  
Author(s):  
Min Han ◽  
He-ping Xiao ◽  
Liping Yan

Abstract Background: Tuberculous pleurisy (TBP) is the most common form of extrapulmonary tuberculosis (TB). However, rapid diagnostic methods with high accuracy for tuberculous pleurisy are urgently needed. In the present study, we evaluated the diagnostic accuracy of Xpert MTB/RIF, LAMP and SAT-TB assay with pleural fluids from from culture-positive TBP patients. Methods: We prospectively enrolled 300 patients with exudative pleural effusions used as the samples for Xpert MTB/RIF, LAMP and SAT-TB assay. Of these, 265 including 223 patients diagnosed with TP and 42 non-TB patients used as controls were analyzed. Results: The sensitivities of Xpert MTB/RIF (27.4%) , LAMP (26.5%) and SAT-TB assay (32.3%) were significantly higher than that of pleural effusion smear (14.3% , X 2 = 20.65, P < 0.001), whereas they were much lower than expected for the analysis of pleural effusion samples. Both SAT-TB assay and Xpert MTB/RIF demonstrated high specificities (100%) and PPVs (100%), but the NPVs of all of the tests were < 22%. The area under ROC curve of pleural effusionsmear, LAMP, Xpert MTB/RIF and SAT-TB assays was 0.524 (95% CI 0.431–0.617), 0.632 (95% CI 0.553–0.71), 0.637 (95% CI 0.56–0.714) and 0.673 (95% CI 0.6–0.745). SAT-TB assays had the highest AUC. Conclusion: Nucleic acid amplification tests are not the first choice in the diagnosis of tuberculous pleurisy. In this type of test, SAT-TB is recommended because of its low cost, relatively more accurate compared with the other two tests. This prospective study was approved by The Ethics Committee of the Shanghai Pulmonary Hospital (approval number: K19-148). ClinicalTrials.gov identifier: ChiCTR1900026234. Key words : Xpert MTB/RIF; AmpSure simultaneous amplification and testing; loop-mediated isothermal amplification; diagnosis; tuberculosis


2020 ◽  
Author(s):  
Min Han ◽  
He-ping Xiao ◽  
Liping Yan

Abstract Background: Tuberculous pleurisy (TBP) is the most common form of extrapulmonary tuberculosis (TB). However, rapid diagnostic methods with high accuracy for tuberculous pleurisy are urgently needed. In the present study, we evaluated the diagnostic accuracy of Xpert MTB/RIF, LAMP and SAT-TB assay with pleural fluids from from culture-positive TBP patients. Methods: We prospectively enrolled 300 patients with exudative pleural effusions used as the samples for Xpert MTB/RIF, LAMP and SAT-TB assay. Of these, 265 including 223 patients diagnosed with TP and 42 non-TB patients used as controls were analyzed. Results: The sensitivities of Xpert MTB/RIF (27.4%) , LAMP (26.5%) and SAT-TB assay (32.3%) were significantly higher than that of pleural effusion smear (14.3% , X 2 = 20.65, P < 0.001), whereas they were much lower than expected for the analysis of pleural effusion samples. Both SAT-TB assay and Xpert MTB/RIF demonstrated high specificities (100%) and PPVs (100%), but the NPVs of all of the tests were < 22%. The area under ROC curve of pleural effusionsmear, LAMP, Xpert MTB/RIF and SAT-TB assays was 0.524 (95% CI 0.431–0.617), 0.632 (95% CI 0.553–0.71), 0.637 (95% CI 0.56–0.714) and 0.673 (95% CI 0.6–0.745). SAT-TB assays had the highest AUC. Conclusion: Nucleic acid amplification tests are not the first choice in the diagnosis of tuberculous pleurisy. In this type of test, SAT-TB is recommended because of its low cost, relatively more accurate compared with the other two tests. This prospective study was approved by The Ethics Committee of the Shanghai Pulmonary Hospital (approval number: K19-148). ClinicalTrials.gov identifier: ChiCTR1900026234. Key words : Xpert MTB/RIF; AmpSure simultaneous amplification and testing; loop-mediated isothermal amplification; diagnosis; tuberculosis


Author(s):  
Shinnosuke Inoue ◽  
Woon-Hong Yeo ◽  
Jong-Hoon Kim ◽  
Jae-Hyun Chung ◽  
Kyong-Hoon Lee ◽  
...  

Tuberculosis (TB) is an epidemic affecting one-third of the world’s population, mostly in developing and low-resource settings. People having active pulmonary TB are considered highly infectious; therefore, it is critical to identify and treat these patients rapidly before spreading to others. However, the most reliable TB diagnostic methods of bacterial culture or nucleic acid amplification are time-consuming and expensive. The challenge of TB diagnosis lies in highly sensitive and specific screening with low cost. Here, we present an LNA-modified microtip-sensor, which is capable of selectively detecting low-abundance DNA from bacteria. When genomic DNA of Bacillus Calmette-Gue´rin (BCG, a surrogate marker of Mycobacterium bovis), and genomic DNA of Staphylococcus epidermidis (S. epi) are used, the microtip-sensor yields the detection limit of 1,000 copies/mL within 20 minutes. The high sensitivity and specificity approaching nucleic acid amplification methods can potentially overcome the current challenges for rapid TB screening.


2020 ◽  
Vol 154 (1) ◽  
pp. 115-123
Author(s):  
Sanchita Das ◽  
Kathy A Mangold ◽  
Nirav S Shah ◽  
Lance R Peterson ◽  
Richard B Thomson ◽  
...  

Abstract Objectives Tuberculosis (TB) is a significant global health problem. In low-prevalence areas and low clinical suspicion, nucleic acid amplification tests (NAAT) for direct detection of Mycobacterium tuberculosis complex (MTBC) can speed therapy initiation and infection control. An NAAT assay (TBPCR) targeting MTBC IS6110 is used for detecting MTBC in our low-prevalence population. Methods Fifteen-year review of patient records identified 146 patients with culture-positive pulmonary tuberculosis (PTB) or extrapulmonary tuberculosis (EPTB). Laboratory-developed TBPCR was retrospectively compared with standard stain and cultures for PTB and EPTB diagnoses. Results TBPCR assay was used in 57% of patients with PTB and 33% of patients with EPTB. TBPCR detected 88.4% of all TB (smear-positive, 97%; smear-negative, 79%) with 100% specificity. Low bacterial load was indicated in TBPCR-negative PTB (P = .002) and EPTB (P &lt; .008). Conclusions TBPCR performance was optimum but significantly underused. Guidelines are proposed for mandated use of TBPCR that capture patients with clinically suspected PTB. Focused TBPCR use in low prevalence populations will benefit patient care, infection prevention, and public health.


2021 ◽  
pp. sextrans-2020-054690
Author(s):  
Ayoma Ratnappuli ◽  
Melanie Bissessor ◽  
Shehara Arumugam ◽  
Deborah A Williamson ◽  
Eric P F Chow ◽  
...  

BackgroundIn a previous study of men attending Melbourne Sexual Health Centre who had Neisseria gonorrhoeae detected by urine Aptima Combo 2 (AC2) testing, 11% were asymptomatic. This study aimed to determine whether N. gonorrhoeae can be cultured from asymptomatic men screening positive for N. gonorrhoeae by nucleic acid amplification testing (NAAT) of urine.MethodsBetween 1 July 2017 and 31 March 2019, all men attending Melbourne Sexual Health Centre were tested for N. gonorrhoeae by AC2 testing of urine whether urethral symptoms were reported or not. NAAT-positive men were recalled and a urethral swab performed for gonococcal culture using modified Thayer-Martin media with determination of minimum inhibitory concentrations (MICs) by agar dilution.ResultsThere were 1001 cases (860 individuals) positive for N. gonorrhoeae by urine AC2: 892 (89%) reported urethral symptoms; 109 (11%) did not. Twenty-five asymptomatic cases were excluded because of antibiotic use at or following screening. Of the remaining 84 asymptomatic men, 41 (49%) had a urethral swab performed a median of 5 days after screening. Twenty-one men had urethral discharge at the return visit, 11 of whom reported the discharge at the return visit. Of the 41 men who were swabbed, 31 (76%; 95% CI 60% to 88%) were culture positive for N. gonorrhoeae. Among the 21 men who subsequently developed discharge, 19 (90%; 95% CI 70% to 99%) were culture positive. Among the 20 men who remained asymptomatic, 12 (60%; 95% CI 36% to 81%) were culture positive. MIC profiles were obtained from all isolates.ConclusionsGonorrhoea was isolated in most but not all asymptomatic men screening positive for N. gonorrhoeae by urine NAAT. Clinicians should consider performing urethral culture in such men to ensure optimal surveillance for antimicrobial resistance. Isolation of N. gonorrhoeae by culture in men without discharge indicates these are true infections with viable organisms.


Sensors ◽  
2015 ◽  
Vol 15 (9) ◽  
pp. 23418-23430 ◽  
Author(s):  
Pascal Craw ◽  
Ruth Mackay ◽  
Angel Naveenathayalan ◽  
Chris Hudson ◽  
Manoharanehru Branavan ◽  
...  

2015 ◽  
Vol 61 (11) ◽  
pp. 1372-1380 ◽  
Author(s):  
Carlos Cabrera ◽  
Lei Chang ◽  
Mars Stone ◽  
Michael Busch ◽  
David H Wilson

Abstract BACKGROUND Nucleic acid testing (NAT) has become the standard for high sensitivity in detecting low levels of virus. However, adoption of NAT can be cost prohibitive in low-resource settings where access to extreme sensitivity could be clinically advantageous for early detection of infection. We report development and preliminary validation of a simple, low-cost, fully automated digital p24 antigen immunoassay with the sensitivity of quantitative NAT viral load (NAT-VL) methods for detection of acute HIV infection. METHODS We developed an investigational 69-min immunoassay for p24 capsid protein for use on a novel digital analyzer on the basis of single-molecule-array technology. We evaluated the assay for sensitivity by dilution of standardized preparations of p24, cultured HIV, and preseroconversion samples. We characterized analytical performance and concordance with 2 NAT-VL methods and 2 contemporary p24 Ag/Ab combination immunoassays with dilutions of viral isolates and samples from the earliest stages of HIV infection. RESULTS Analytical sensitivity was 0.0025 ng/L p24, equivalent to 60 HIV RNA copies/mL. The limit of quantification was 0.0076 ng/L, and imprecision across 10 runs was &lt;10% for samples as low as 0.09 ng/L. Clinical specificity was 95.1%. Sensitivity concordance vs NAT-VL on dilutions of preseroconversion samples and Group M viral isolates was 100%. CONCLUSIONS The digital immunoassay exhibited &gt;4000-fold greater sensitivity than contemporary immunoassays for p24 and sensitivity equivalent to that of NAT methods for early detection of HIV. The data indicate that NAT-level sensitivity for acute HIV infection is possible with a simple, low-cost digital immunoassay.


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