Test | Sensitivity | Specificity | Cost | Availability | Comment |
Tests to detect NTM in respiratory samples 12 22 | |||||
Microscopy (AFB smear) | Low | Moderate | Low | High | Rapid, but variable sensitivity and cannot distinguish NTM from Mycobacterium tuberculosis |
Direct molecular detection on primary sample | Moderate | High | Moderate | Low | NTM-specific: costly and less sensitive than conventional AFB culture. Limited uptake: TB PCR is useful as a rule-out test for NTM on smear-positive samples |
Mycobacterial culture | High | High | Low | High | Most sensitive method to detect NTM from respiratory samples. Optimal results require the use of both solid and liquid media. Slow results, taking days to weeks |
Tests to speciate and type NTM in respiratory samples 12 22 | |||||
| Moderate | High | Moderate/high | Low/moderate | Enables species identification, including subspecies of M. abscessus. May require phenotypical drug sensitivity testing to determine inducible macrolide resistance |
WGS | High | High | Moderate/high | Low/moderate | Improved discrimination of strains enables WGS to be used to investigate possible person-to-person transmission events |
AFB, acid-fast bacilli; MALDI-TOF, matrix-assisted laser desorption ionisation-time of flight ; NTM, non-tuberculous mycobacteria; NTM-PD, non-tuberculous mycobacterial pulmonary disease; PCR, polymerase chain reaction; TB, tuberculosis; WGS, whole-genome sequencing.