Hearing Loss in Drug-Resistant Tuberculosis Patients: A Retrospective Analysis of Audiometric Findings and Associated Risk Factors

Background: Hearing loss is a significant global health issue, affecting around 1.5 billion people worldwide. Certain drugs used to treat conditions such as cancer, tuberculosis, human immunodeficiency virus (HIV), and various infections can have ototoxic effects, potentially leading to hearing damage. In South Africa, where rates of HIV and tuberculosis are among the highest in the world, a larger portion of the population may be impacted by hearing loss resulting from the medications used to treat these illnesses. The study aimed to examine how demographic factors (age, gender), lifestyle factors (smoking, alcohol use, occupational noise exposure), and clinical variables (DR-TB classification, treatment outcomes, comorbidities like HIV, hypertension, and diabetes) affect hearing outcomes. Methods: Retrospective studies were conducted between 2018 and 2020; data was collected from 456 drug-resistant tuberculosis (DR-TB) patients at four TB clinics and one referral hospital in the Oliver Reginald Tambo (O.R.) District, Eastern Cape. The study included patients who completed treatment and audiometric assessments. Demographic and clinical data were collected from electronic health records, identifying risk factors influencing hearing outcomes. Interaction terms were analysed to explore the combined effect of variables on hearing outcomes. This study was conducted in a referral hospital and four TB clinics in the O.R. Tambo District Municipality. Clinics located in rural and underprivileged areas with high disease burdens were chosen because they are essential primary care facilities for the diagnosis and treatment of tuberculosis (TB), particularly drug-resistant TB (DR-TB). Results: A final cohort of 438 individuals was selected from a study that examined 456 patients diagnosed with drug-resistant tuberculosis (DR-TB). However, 18 participants were disqualified due to insufficient audiometry data. Notably, 37.2% of these individuals experienced some form of hearing loss, raising concerns about treatment approaches for DR-TB. The mean age of the participants was 36 years. Conclusion: This study illustrates the intricate interactions between age, therapy, DR-TB type, HIV status, and lifestyle variables on HL risk. Despite the successful treatment being associated with improved hearing outcomes, audiometric monitoring may be necessary for patients with severe DR-TB, ineffective or partial therapies, and certain socioeconomic comorbidities.