Tuberculosis in the 21th century: Current status of diagnostic methods

Analysis and mapping of global research publications on point-of-care testing for infectious diseases

RATIONALE

This study presents the first comprehensive analysis and mapping of scientific research on point-of-care testing (POCT) in infectious diseases, filling a gap in understanding the evolving landscape of this field. The identification of research themes and global contributions offers valuable insights.

AIMS AND OBJECTIVES

This manuscript aims to analyse and map scientific research on POCT in the context of infectious diseases.

METHODS

The study employed a comprehensive search strategy using terms related to POCT and infectious diseases. The search was conducted on the Scopus database, refining results based on inclusion and exclusion criteria. The dataset of 1719 research articles was then subjected to descriptive analysis and mapping using VOSviewer.

RESULTS

The research findings indicate an exponential growth in POCT-related publications, with 46.8% published post the COVID-19 pandemic. Plos One journal led in publication frequency, and Biosensors and Bioelectronics received the highest citations per article. North America and Western Europe dominated contributions, with notable participation from China, South Africa, and India. The research landscape revealed the following research themes: detection technologies, human immunodeficiency virus (HIV)/sexually transmitted infection (STI) diagnosis, antibiotic optimisation, and schistosomiasis. Clinical trials focused on antibiotic prescribing, HIV, STIs, and specific infections. The findings suggest a shifting landscape towards POCT, emphasising the need for future planning and investment in healthcare systems. The research identifies areas for future exploration, such as the impact of POCT on antibiotic prescribing and its role in combating infectious diseases in low- and middle-income countries.

CONCLUSION

Implementation of POCT has the potential to revolutionise infectious disease management, improve patient outcomes, and reduce the global burden of diseases. Better public awareness, healthcare team management, and planning for POCT at entry points are crucial for societal benefit. Results demonstrated the evolving role of POCT in infectious disease management and prevention.

The Value of FujiLAM in the Diagnosis of Tuberculosis: A Systematic Review and Meta-Analysis

Background: Timely and accurate diagnosis of tuberculosis (TB) remains a major challenge. Lipoarabinomannan (LAM) is a specific component of the cell envelope of Mycobacterium tuberculosis and is also a potential biomarker for the diagnosis of TB. Recently, the Fujifilm SILVAMP TB LAM test (FujiLAM), as a novel urine lateral flow LAM test, was developed for the diagnosis of TB and is convenient and timely. Because of a difference in the diagnostic value of FujiLAM in the original studies, we conducted a meta-analysis to comprehensively assess the diagnostic value of FujiLAM in TB.

Data Sources: We performed a literature search using the PubMed and EMBASE databases and commercial Internet search engines to identify studies.

Methods: Searches of databases using relevant terms (“tuberculosis” or “TB”) and (“Fujifilm SILVAMP TB LAM” or “FujiLAM”) were performed. Screening, study reviewing, data extracting and assessing data quality was performed independently by two reviewers. We calculated the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio. To minimize potential heterogeneity, we performed subgroup analyses.

Results: Nine articles were included in the meta-analysis. When using the microbiological reference standard (MRS), the results showed that the sensitivity and specificity of FujiLAM were 0.70 and 0.93, respectively, in adults with TB, while the sensitivity and specificity of FujiLAM in children with TB were 0.51 and 0.87. When using a comprehensive reference standard (CRS), the sensitivity and specificity of FujiLAM in adults with TB were 0.59 and 0.96, respectively, while the results showed that the sensitivity and specificity of FujiLAM in children with TB were 0.27 and 0.86, respectively. Subgroup analysis showed that FujiLAM had higher diagnostic sensitivity in patients with human immunodeficiency virus infection or CD4 cell counts < 200 cells/μL, both in adults and children.

Conclusions: This meta-analysis suggests that FujiLAM has a high value in the diagnosis of adults with TB.

Revisiting the methods for detecting Mycobacterium tuberculosis: what has the new millennium brought thus far?

Tuberculosis (TB) affects around 10 million people worldwide in 2019. Approximately 3.4 % of new TB cases are multidrug-resistant. The gold standard method for detecting Mycobacterium tuberculosis, which is the aetiological agent of TB, is still based on microbiological culture procedures, followed by species identification and drug sensitivity testing. Sputum is the most commonly obtained clinical specimen from patients with pulmonary TB. Although smear microscopy is a low-cost and widely used method, its sensitivity is 50-60 %. Thus, owing to the need to improve the performance of current microbiological tests to provide prompt treatment, different methods with varied sensitivity and specificity for TB diagnosis have been developed. Here we discuss the existing methods developed over the past 20 years, including their strengths and weaknesses. In-house and commercial methods have been shown to be promising to achieve rapid diagnosis. Combining methods for mycobacterial detection systems demonstrates a correlation of 100 %. Other assays are useful for the simultaneous detection of M. tuberculosis species and drug-related mutations. Novel approaches have also been employed to rapidly identify and quantify total mycobacteria RNA, including assessments of global gene expression measured in whole blood to identify the risk of TB. Spoligotyping, mass spectrometry and next-generation sequencing are also promising technologies; however, their cost needs to be reduced so that low- and middle-income countries can access them. Because of the large impact of M. tuberculosis infection on public health, the development of new methods in the context of well-designed and -controlled clinical trials might contribute to the improvement of TB infection control.

Diagnostic accuracy of Mycobacterium tuberculosis cell-free DNA for tuberculosis: A systematic review and meta-analysis

BACKGROUND

Diagnosis of tuberculosis (TB) is still difficult. The purpose of our study was to evaluate the diagnostic accuracy of Mycobacterium tuberculosis cell-free DNA (cfDNA) for diagnosing of TB.

METHODS

We searched relevant databases for studies that used cfDNA to diagnose TB. We evaluated the accuracy of cfDNA compared with the composite reference standard (CRS) and culture. True positive, false positive, false negative, and true negative values for cfDNA were obtained first, then the estimated pooled sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), diagnostic odds ratio (DOR), and the area under the summary receiver operating characteristic (SROC) curve (AUC) of cfDNA for diagnosing TB were calculated with 95% confidence intervals (CIs). Heterogeneity was determined using the I2 statistic. When the heterogeneity was obvious, the source of heterogeneity was further discussed.

RESULTS

We included 14 independent studies comparing cfDNA with the CRS, and 4 studies compared with culture. The pooled sensitivity, specificity, PPV, NPV, DOR, and AUC of the SROC were 68%, 98%,99%, 62%, 83, and 0.97 as compared with the CRS, respectively. The pooled sensitivity, specificity, PPV, NPV, DOR, and AUC of the SROC were 48%, 91%, 92%, 60%, 5, and 0.88 as compared with culture, respectively. The heterogeneity between studies was significant.

CONCLUSIONS

The accuracy of cfDNA testing for TB diagnosis was good compared with CRS and culture. cfDNA can be used for rapid early diagnosis of TB.

Screening of 20 Mycobacterium tuberculosis sRNAs in plasma for detection of active pulmonary tuberculosis

BACKGROUND

Mycobacterium tuberculosis (MTB) sRNAs are abundant. However, the level of MTB sRNA in peripheral blood remains elusive.

METHODS

Twenty MTB sRNAs annotated in the reference genome of H37Rv were detected in the plasma of 170 active pulmonary tuberculosis patients and 124 healthy people by qRT-PCR detection system. The differential expression of sRNAs were analyzed in two groups. The value of sRNAs for diagnosis of active tuberculosis were evaluated by ROC curve analysis.

RESULTS

Eight of the 20 sRNAs (MTS2823, MTS0997, MTS1338, ASdes, G2, C8, mcr15 and MTS1082) were found in at least 50% of the samples detected. The relative expression levels of MTS2823, MTS0997, MTS1338 and ASdes in plasma of tuberculosis patients were statistically higher than those in healthy controls. ROC curve analysis showed that the AUC of MTS0997, MTS1338, MTS2823 and ASdes were 0.8935 (95% CI 0.8109-0.9760), 0.8722 (95% CI 0.7862-0.9581), 0.8208 (95% CI 0.7246-0.9170) and 0.5792 (95% CI 0.4240-0.7344), respectively. The AUC value of combination of MTS0997, MTS1338 and MTS2823 was 0.914 (95% CI 0.8281-0.9926).

CONCLUSIONS

MTB sRNAs MTS2823, MTS0997 and MTS1338 have the potential to be plasma biomarkers for active pulmonary tuberculosis.