Molecular epidemiology of non-tuberculous mycobacteria in clinical samples from Jiangxi Province, 2021-2023.

BACKGROUND

Non-tuberculous mycobacteria (NTM) pose diagnostic and therapeutic challenges in tuberculosis (TB)-endemic regions like Jiangxi Province, China, due to clinical and radiological similarities to TB. This study elucidates the molecular epidemiology of NTM in Jiangxi (2021–2023).

METHODS

A retrospective analysis of 20,724 clinical specimens from Jiangxi Chest Hospital was conducted using PCR-reverse blot hybridization assay (PCR-REBA) for NTM species identification. Inclusion required clinical/radiological suspicion of mycobacterial disease and specimens with sufficient volume (≥ 2 mL for liquid samples or ≥ 0.5 g for tissue). Statistical analyses determined prevalence, species distribution, and predictors.

RESULTS

Among 5,331 Mycobacterium-positive specimens, 333 (1.60%; 95% CI: 1.43–1.77) were NTM. Males had significantly lower odds of infection than females (aOR 0.499, P < 0.001), with the highest prevalence observed in individuals aged ≥ 65 years (2.64%) compared to the ≤ 24 years reference group (aOR 12.922, 95% CI: 5.288–31.578, P < 0.001). Dominant species were Mycobacterium intracellulare (MIN, 51.7%), Mycobacterium abscessus (MAB, 30.9%), and Mycobacterium avium (MAV, 9.3%). MIN and MAB predominated in pulmonary samples (97.9% of cases), while MAV showed significant extrapulmonary tropism (42.9% vs. 8.6% pulmonary, P = 0.02). Detection rates fluctuated temporally (peak: 1.93% in 2021; trough: 1.20% in 2022; P = 0.004), potentially influenced by the COVID-19 pandemic.

CONCLUSION

Jiangxi exhibits a distinct NTM profile with elevated MAB prevalence, emphasizing the need for species-level diagnosis to prevent misclassification as multidrug-resistant TB. Age, sex, and temporal trends emphasizing the critical need for species-level identification to facilitate early, targeted antimicrobial therapy and prevent the misclassification of NTM as multidrug-resistant TB.