Incidence and audiometric outcomes of hearing loss among tuberculosis patients receiving all-oral treatment regimens: A prospective cohort study in Nigeria

Objectives: The objective of the study is to determine the incidence of hearing loss and evaluate audiometric changes among patients with drug-susceptible TB (DS-TB) and multidrug-resistant TB (MDR-TB) receiving all-oral anti-TB treatment regimens. Tuberculosis (TB) remains a major global health challenge, with Nigeria among the high-burden countries identified by the World Health Organization. Although all-oral treatment regimens have replaced injectable agents to reduce ototoxicity, concerns persist regarding potential auditory toxicity, particularly among patients treated for MDR-TB. Prospective data evaluating hearing outcomes associated with these newer regimens in high-burden settings remain limited. Methods: We conducted a 1-year prospective cohort study involving 98 adults with newly diagnosed TB and 98 matched healthy controls at a tertiary hospital in south-east Nigeria. Pure tone audiometry (PTA) was performed at baseline, 2 months, and 3 months. Hearing loss was defined using the American Speech-Language-Hearing Association ototoxicity criteria. Audiometric thresholds and incidence rates were compared between DS-TB and MDR-TB treatment groups. Multivariable statistical analyses were performed using STATA version 16, with p < 0.05 considered statistically significant. Results: All participants had normal hearing at baseline. After 3 months of treatment, the overall incidence of sensorineural hearing loss (SNHL) was 4.1% (4/98). The incidence was significantly higher among MDR-TB patients (16.7%; 3/18) compared with DS-TB patients (1.3%; 1/80). Hearing loss severity ranged from mild to moderate and was bilateral in all affected cases. Despite this, mean audiometric thresholds did not differ significantly between treatment and control groups ( p > 0.05). Conclusion: All-oral anti-TB regimens were associated with a low overall incidence of hearing loss. However, patients receiving MDR-TB treatment remain at increased risk. These findings support continued audiological monitoring during MDR-TB therapy, even with injectable-free regimens, and highlight the need for larger longitudinal studies to confirm auditory safety.