Combined PCR Positivity for Mycobacterium tuberculosis Complex and Nontuberculous Mycobacterium Species in Patients...

Intraocular dual infection by Mycobacterium tuberculosis complex (MTBC) and non-tuberculous mycobacteria (NTM) is rarely reported.

This study describes the clinical features, aetiology, and treatment outcomes of patients with dual infection from MTBC and NTM-related uveitis.

A retrospective study was conducted on 146 clinically suspected tubercular uveitis (TBU) patients who underwent diagnostic or therapeutic pars plana vitrectomy as plan of laboratory diagnosis-based management between June 2023 and December 2024. Undiluted vitreous samples were analysed with nested MTBC-NTM multiplex real-time PCR assay kit.

Six out of 146 patients (4.11%) were found infected with dual infection from MTBC and NTM. All six cases showed severe clinical presentation characterised by bilateral panuveitis (5/6 patients), with significant structural sequelae. Optic atrophy was universal and occurred more frequently than in isolated TBU, while complicated cataract and hypotony-related maculopathy were also common. Despite the dual etiology, all patients achieved inflammatory resolution and visual recovery (mean BCVA improving from 20/400 to 20/100) following standard anti-tubercular therapy (ATT) and corticosteroids, with no recurrence during follow-up.

Concurrent MTBC and NTM infection drives a distinct, aggressive form of panuveitis characterized by optic nerve pallor, anterior segment complications of complicated cataract or uveitic membranes and maculopathy. Despite this severity, standard ATT remained an effective first-line strategy, likely either due to therapeutic cross-coverage against NTM or MTBC being the primary driver of uveitis in the present study. The concurrent positivity also highlights the need for vitreous molecular profiling and further research in co-infections in infectious posterior uveitis.