Burden and determinants of recurrent tuberculosis among patients undergoing treatment: A cross-sectional study in Chennai, a major metropolitan city in South India

<h2>ABSTRACT</h2><h3>Problem considered</h3> Recurrent Tuberculosis (rTB) refers to the reappearance of TB in a patient previously declared as successfully treated, either cured or having completed treatment. This study aimed to estimate the prevalence of rTB and identify associated risk factors among registered TB patients. <h3>Methods</h3> We conducted a cross-sectional study in Chennai, South India, among TB patients registered across three treatment units under the National TB Elimination Program (NTEP). We included 302 of 337 patients registered between January and June 2019. Socio-demographic information, diagnostic details, and treatment history from the previous TB episode were obtained from TB unit registers. Additionally, we interviewed participants using a structured interview schedule to capture data on current clinical presentation, medical history, risk behaviours and comorbidities. <h3>Results</h3> The prevalence of rTB was 15.6% (95% CI:11.7-20.2), with a mean age of 42.3 years (SD: 11.5). Higher rTB rates were observed among males, individuals aged over 35 years, current or former tobacco and alcohol users, pulmonary TB patients, those undergoing or who did not complete previous TB treatment, underweight patients, HIV-positive individuals, and patients with comorbidities such as diabetes and hypertension. Multivariable analysis identified tobacco use, microbiologically confirmed TB, non-completion of previous TB treatment, undernutrition, HIV-positivity, and the presence of comorbidities as significant predictors of rTB. <h3>Conclusion</h3> The study highlights the significant burden of rTB and the complexity of TB recurrence, emphasising the need for comprehensive and continuous care. The findings support the implementation of targeted, context-specific, tailored strategies and interventions that address modifiable risk factors, towards achieving the national goal of eliminating TB by 2025.