Secondary infections following tuberculosis: epidemiology, pathogenesis and clinical implications

This review brings together global data on bacterial, fungal, nontuberculous mycobacterial (NTM) and viral infections that complicate the course of individuals following the diagnosis of pulmonary or extrapulmonary tuberculosis (TB). It shows how residual structural lung damage (bronchiectasis, cavitation, residual fibrotic lesions) and persistent immune dysregulation create niches for pathogens, most notably Pseudomonas aeruginosa, Aspergillus spp., Mycobacterium avium complex and herpes zoster virus. Although bacterial infections in post-TB bronchiectasis are the most consistently documented, chronic pulmonary aspergillosis and NTM disease add substantial morbidity. Viral complications beyond herpes zoster and influenza remain poorly characterised, underscoring a critical evidence gap. In extrapulmonary TB survivors, organ-specific sequelae pose additional infection risks that are rarely quantified. Across all categories, inconsistent case definitions, under-utilisation of the 10th revision of the International Classification of Diseases coding, and lack of prospective cohorts have obscured the true burden of post-TB infections. The review concludes by calling for standardised diagnostic criteria, enhanced epidemiological tracking, and integrated post-treatment care pathways including preventive vaccinations to mitigate long-term health consequences in this vulnerable population.