Abstract
BACKGROUND: In Ethiopia, tuberculosis (TB) is a significant cause of death among individuals living with HIV, especially in resource-limited areas and those who have experienced treatment failure. However, there is the paucity of data regarding TB among treatment failures experienced people living with HIV. This study aimed to estimate the rate and identify predictors of tuberculosis among patients who received second-line treatment in North Wollo, Northeast Ethiopia. METHODS: A retrospective follow-up study was conducted on 474 HIV-infected patients who experienced treatment failure. The study period ranged from January 2015 to September 30, 2021. The incidence of TB was assessed using a Cox proportional hazard regression model, after ensuring that all assumptions were met. Factors associated with active TB were determined by analyzing adjusted hazard ratios and 95% confidence intervals. RESULTS: In a study of 474 HIV-positive patients on second-line antiretroviral treatment, we found an incidence rate of 3.6% with 17 new cases of TB observed over 4412.4 persons per year (PPY). The overall incidence density rate was estimated to be 0.39 cases per 100 PPY (95% CI: 0.239-0.618). Regarding the occurrence of active TB in second-line patients, WHO clinical treatment stage (T3 and T4), missed isoniazid preventive therapy had a significantly higher risk (AHR: 13.225, 95% CI: 2.894-60.434, p = 0.001), while being married was associated with a lower risk (AHR: 0.203, 95% CI: 0.045-0.907, p = 0.001). CONCLUSION: A high incidence of active TB was observed shortly after initiating second-line antiretroviral treatment. Factors such as being in the WHO clinical treatment stage (T3 and T4) and marital status were determinants for active TB. To improve overall survival rates, it is vital to enhance early TB screening and implement effective isoniazid preventive therapy.