Table 2.

Recent techniques for TB diagnosis.

S.No.	Test	Type	Sensitivity (%)	Specificity (%)	Turnaround duration	Description	References
1.	CRISPR/Cas12a	Gene editing	90%	98%	7 and 14 days	Advantages	[117,118]
						•Detection of Mtb in lower sample input
						•Detect multiple sites in Mtb genome associated with drug resistance and susceptibility
						Drawbacks
						•Cas protein has a lower sensitivity
						•Target selection is crucial as long target selection near the PAM sequence is advantageous
						•CRISPR-Cas system is prone to mutation and hence may provide false negative results
						•Multiplexing is another challenge of CRISPR-Cas
2.	AI Processing	Artificial intelligence	68–96%	72–85%	NA	Advantages	[119]
						•Accurate and efficient clinical decision making
						•Improved precision in screening, diagnosis, and treatment
						•Reduced labour
						Drawbacks
						•Need to maintain curative data sets
						•Privacy concerns, breach of medical data
3.	MinIONNanopore-sequencing (OxfordNanpore technologies, U.K.)	Detection of Rifampicin resistance supersedes	94.8%	98%	6 h	Advantages	[120]
						•Real-time analysis in a scalable format
						•Minimum sample preparation
						•Cost effective
						•Portable
						•Independent of length of the fragment
						Drawbacks
						•Resolution should be improved so that it can detect even a single base before commercialization
4.	Whole-genome sequencing	Next-generation sequencing (NGS)	95%	95%	up to 72 h	Advantages	[121]
						•Detect drug resistance and genetic diversity
						Drawbacks
						•High cost of equipment
						•Requirement of technical training
						•Clinical interpretation of NGS data is challenging
5.	miRNA	PCR based assay	24.7–39.9%	>90%	24 h	Advantages	[122,123,124]
						•Differential expression of miRNAs represents different states of pathogenesis
						•Disrupted miRNA expression profile allows in differentiation between active TB and LTBI
						•Can be performed using diverse sample type such as; whole blood, serum, plasma, PBMCs, pleural fluid, sputum, urine and EBC
						Drawbacks
						•expression pattern of miRNAs depends on the study design
6.	Raman spectroscopy	Raman scattering	Active TB: 84.62% LTBI:86.84%	Active TB: 89.47% LTBI: 65%	2 h	Advantages	[125]
						•Does not require unnecessary sample preparation.
						•A high degree of intrinsic specificity
						•Direct measurement can be performed from clinical sample without microbial culture
						•Easy to use non-invasive
						•Can detect TB from cerebrospinal fluid samples
						Drawbacks
						•Adoption of Raman spectroscopy in a clinical lab is a challenge
7.	Aeonose (eNose BV,Netherlands	Detection of VOC(breath analyzer)	75–92%	44–65%	10 min	Advantages	[126]
						•High specificity
						•Shorter test time
						•Immediate data analysis
						•Promising negative predictive value
						•Non-inavsive
						•Useful test for HIV positive TB patients
						Drawbacks
						•External validation and standardization required
						•Need to be validated for larger population.