Performance of a Highly Sensitive Mycobacterium tuberculosis Complex Real-Time PCR Assay for Diagnosis of Pulmonary Tuberculosis in a Low-Prevalence Setting: a Prospective Intervention Study

Abstract

The potential impact of routine real-time PCR testing of respiratory specimens from patients with presumptive tuberculosis in terms of diagnostic accuracy and time to tuberculosis treatment inception in low-prevalence settings remains largely unexplored. We conducted a prospective intervention cohort study. Respiratory specimens from 1,020 patients were examined by acid-fast bacillus smear microscopy, tested by a real-time complex PCR assay (Abbott RealTi MTB PCR), and cultured in mycobacterial media. Seventeen patients tested positive by PCR (5 were acid-fast bacillus smear positive and 12 acid-fast bacillus smear negative), and was recovered from cultures for 12 of them. Patients testing positive by PCR and negative by culture ( = 5) were treated and deemed to have responded to antituberculosis therapy. There were no PCR-negative/culture-positive cases, and none of the patients testing positive for nontuberculous mycobacteria ( = 20) yielded a positive PCR result. The data indicated that routine testing of respiratory specimens from patients with presumptive tuberculosis by the RealTi MTB PCR assay improves the tuberculosis diagnostic yield and may reduce the time to antituberculosis treatment initiation. On the basis of our data, we propose a novel mycobacterial laboratory algorithm for tuberculosis diagnosis.

Diagnostic accuracy of centralised assays for TB detection and detection of resistance to rifampicin and isoniazid: a systematic review and meta-analysis

“…Ten studies with 4858 respiratory specimens were included in the meta-analysis that evaluated Abbott RealTime MTB assay for TB detection [10][11][12][13][14][15][16][17][18][19] (figure 2). In all studies, the assay was run directly on specimens, as opposed to positive culture isolates.…”

“…Pooled sensitivity was 88.4% (95% CI 74.0-99. WANG [19] VINUESA [17] VINUESA [18] TANG [16] TAM [15] SCOTT [14] HOFMANN-THIEL [13] HINIC [12] CHEN [11] BERHANU [ WANG [19] VINUESA [17] VINUESA [18] TANG [16] TAM [15] SCOTT [14] HOFMANN-THIEL [13] HINIC [12] CHEN [11] BERHANU [ demonstrated very low sensitivity of 41.0% (95% CI 18.0-67.0), which may partially be explained by the high prevalence of HIV in their study population, meaning that a high proportion of cases suffered from paucibacillary disease. We were not able to explore test performance by HIV status further as most of the studies (60%) did not report HIV prevalence.…”

Two target genes based multiple cross displacement amplification combined with a lateral flow biosensor for the detection of Mycobacterium tuberculosis complex

“…The IS6110 sequence, which belongs to a family of ISs of the IS3 category with high specificity, has been widely applied for MTBC-PCR assays [24]. However, some M. tuberculosis strains lacking the IS6110 gene were found in several clinical investigations [25,26]. Thus, the mpb64 gene, which encodes the RD2 region of the MPB64 protein in the genome of M. tuberculosis [27], was introduced in our study, and it showed excellent specificity for MTBC strains in previous studies [9,27].…”

Two Target Genes Based Multiple Cross Displacement Amplification Combined with Lateral Flow Biosensor for the Detection of Mycobacrterium Tuberculosis Complex

“…The IS6110 gene has been widely applied for PCR detections in the M. tuberculosis complex genome, which belongs to a family of IS of the IS3 category with high speci city [22]. However, some of M. tuberculosis strains absence of IS6110 gene were found in several clinical investigations during recent decades [23,24]. Therefore, in this research, we added another target gene, the mpb64 gene.…”