Dataset Information

Feasibility of the TBDx automated digital microscopy system for the diagnosis of pulmonary tuberculosis.

ABSTRACT:

Background

Improved and affordable diagnostic or triage tests are urgently needed at the microscopy centre level. Automated digital microscopy has the potential to overcome issues related to conventional microscopy, including training time requirement and inconsistencies in results interpretation.

Methods

For this blinded prospective study, sputum samples were collected from adults with presumptive pulmonary tuberculosis in Lima, Peru and Ho Chi Minh City, Vietnam. TBDx performance was evaluated as a stand-alone and as a triage test against conventional microscopy and Xpert, with culture as the reference standard. Xpert was used to confirm positive cases.

Findings

A total of 613 subjects were enrolled between October 2014 and March 2015, with 539 included in the final analysis. The sensitivity of TBDx was 62·2% (95% CI 56·6-67·4) and specificity was 90·7% (95% CI 85·9-94·2) compared to culture. The algorithm assessing TBDx as a triage test achieved a specificity of 100% while maintaining sensitivity.

Interpretation

While the diagnostic performance of TBDx did not reach the levels obtained by experienced microscopists in reference laboratories, it is conceivable that it would exceed the performance of less experienced microscopists. In the absence of highly sensitive and specific molecular tests at the microscopy centre level, TBDx in a triage-testing algorithm would optimize specificity and limit overall cost without compromising the number of patients receiving up-front drug susceptibility testing for rifampicin. However, the algorithm would miss over one third of patients compared to Xpert alone.

SUBMITTER: Nabeta P

PROVIDER: S-EPMC5333855 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

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Publications

Feasibility of the TBDx automated digital microscopy system for the diagnosis of pulmonary tuberculosis.

Nabeta Pamela P Havumaki Joshua J Ha Dang Thi Minh DT Caceres Tatiana T Hang Pham Thu PT Collantes Jimena J Thi Ngoc Lan Nguyen N Gotuzzo Eduardo E Denkinger Claudia M CM

PloS one 20170302 3

<h4>Background</h4>Improved and affordable diagnostic or triage tests are urgently needed at the microscopy centre level. Automated digital microscopy has the potential to overcome issues related to conventional microscopy, including training time requirement and inconsistencies in results interpretation.<h4>Methods</h4>For this blinded prospective study, sputum samples were collected from adults with presumptive pulmonary tuberculosis in Lima, Peru and Ho Chi Minh City, Vietnam. TBDx performanc ...[more]

PMID: 28253302

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Project description:Tuberculosis is a rising global public health emergency. Then, it is a priority to undertake innovations in preventive, diagnostic, and therapeutic methods. Improved diagnostic methods for tuberculosis are urgently needed to address this global epidemic. These methods should be rapid, accurate, affordable, and able to detect drug-resistant tuberculosis. The benefits of these new diagnostic technics include earlier diagnosis and treatment, improved patient outcomes, and reduced economic burden. Therefore, we aimed to systematically review the diagnostic performance of droplet digital PCR (ddPCR)-a third-generation PCR-compared with quantitative Real Time-PCR (qPCR) for diagnosing pulmonary and extrapulmonary tuberculosis. We included 14 diagnostic accuracy test studies performed in Asia, Europe, and Latin America, 1,672 participants or biological samples, and 975 events (pulmonary or extrapulmonary tuberculosis). Most of the included studies had a low risk of bias (QUADAS-C tool). Sensitivity and specificity were lower for ddPCR [0.56 (95% CI 0.53-0.58) and 0.97 (95% CI 0.96-0.98), respectively] than for qPCR [0.66 (95% CI 0.60-0.71) and 0.98 (95% CI 0.97-0.99), respectively]. However, the area under the ROC curve (AUC) was higher for ddPCR than for qPCR (0.97 and 0.94, respectively). Comparing both AUCs using the Hanley & McNeil method, we found statistically significant differences (AUC difference of 4.40%, p = 0.0020). In the heterogeneity analysis, we found significant differences between both techniques according to the continent of origin of the study and the location of tuberculosis (pulmonary or extrapulmonary disease). The AUCs of both methods were similar in pulmonary tuberculosis. However, for extrapulmonary tuberculosis, the AUC was higher for ddPCR. We found some limitations: (1) significant heterogeneity of the studies, and (2) we could not perform subgroup analyses according to other relevant variables, such as the age and sex of the participants. Nonetheless, this study is the first meta-analysis that shows that ddPCR has a comparable diagnostic performance than qPCR for pulmonary tuberculosis. However, for extrapulmonary tuberculosis, ddPCR has a better discriminant capacity to differentiate between patients with and without extrapulmonary tuberculosis. We conclude that ddPCR is likely the best diagnostic technic for tuberculosis diagnosis, especially for extrapulmonary tuberculosis. More studies are still needed yet.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022382768, CRD42022382768.

Dataset Information

Feasibility of the TBDx automated digital microscopy system for the diagnosis of pulmonary tuberculosis.

Background

Methods

Findings

Interpretation

Publications

Feasibility of the TBDx automated digital microscopy system for the diagnosis of pulmonary tuberculosis.

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