Njiro, Belinda J., Kisonga, Riziki, Joachim, Catherine, Sililo, Galus Alfredy, Nkiligi, Emmanuel, Ibisomi, Latifat, Chirwa, Tobias, and Francis, Joel Msafiri
Background: Patients with recurrent TB have an increased risk of higher mortality, lower success rate, and a relatively feeble likelihood of treatment completion than those with new-onset TB. This study aimed to assess the epidemiology of recurrent TB in Tanzania; specifically, we aim to determine the prevalence of TB recurrence and factors associated with unfavourable treatment outcomes among patients with recurrent TB in Tanzania from 2018 to 2021. Methods: In this cross-sectional study, we utilized Tanzania's routinely collected national TB program data. The study involved a cohort of TB patients over a fixed treatment period registered in the TB and Leprosy case-based District Health Information System (DHIS2-ETL) database from 2018 to 2021 in Tanzania. We included patients' sociodemographic and clinical factors, facility characteristics, and TB treatment outcomes. We conducted bivariate analysis and multivariable multi-level mixed effects logistic regression of factors associated with TB recurrence and TB treatment outcomes to account for the correlations at the facility level. A purposeful selection method was used; the multivariable model included apriori selected variables (Age, Sex, and HIV status) and variables with a p-value <0.2 on bivariate analysis. The adjusted odds ratio and 95% confidence interval were recorded, and a p-value of less than 0.05 was considered statistically significant. Findings: A total of 319,717 participants were included in the study; the majority were adults aged 25–49 (44.2%, n = 141,193) and above 50 years (31.6%, n = 101,039). About two-thirds were male (60.4%, n = 192,986), and more than one-fifth of participants (22.8%, n = 72,396) were HIV positive. Nearly two in every hundred TB patients had a recurrent TB episode (2.0%, n = 6,723). About 10% of patients with recurrent TB had unfavourable treatment outcomes (9.6%, n = 519). The odds of poor treatment outcomes were two-fold higher for participants receiving treatment at the central (aOR = 2.24; 95% CI 1.33–3.78) and coastal zones (aOR = 2.20; 95% CI 1.40–3.47) than the northern zone. HIV-positive participants had 62% extra odds of unfavourable treatment outcomes compared to their HIV-negative counterparts (aOR = 1.62; 95% CI 1.25–2.11). Bacteriological TB diagnosis (aOR = 1.39; 95% CI 1.02–1.90) was associated with a 39% additional risk of unfavourable treatment outcomes as compared to clinical TB diagnosis. Compared to community-based DOT, patients who received DOT at the facility had 1.39 times the odds of poor treatment outcomes (aOR = 1.39; 95%CI 1.04–1.85). Conclusion: TB recurrence in Tanzania accounts for 2% of all TB cases, and it is associated with poor treatment outcomes. Unfavourable treatment outcomes were recorded in 10% of patients with recurrent TB. Poor TB treatment outcome was associated with HIV-positive status, facility-based DOT, bacteriologically confirmed TB and receiving treatment at the hospital level, differing among regions. We recommend post-treatment follow-up for patients with recurrent TB, especially those coinfected with HIV. We also propose close follow-up for patients treated at the hospital facility level and strengthening primary health facilities in TB detection and management to facilitate early treatment initiation. Author summary: Why was this study done?: TB recurrence contributes to TB burden and incidence globally, especially among high TB burden countries. Patients previously treated for TB have a high likelihood of acquiring a recurrent TB episode. Recurrent TB is associated with lower cure rates and a high risk of TB drug resistance. A recent systematic review reported successful treatment outcomes in only 68.4% of patients previously treated for TB. In Tanzania, it was reported in 2018 that patients who had previously undergone TB treatment had an approximate 89% success rate, with 6.6% of those who had recurrent TB dying during treatment. The necessity for more studies in this specific re-treatment group is driven by the absence of evidence regarding the treatment outcomes for patients with recurrent TB. What did the researchers do and find?: We analysed a national dataset of all patients with TB diagnosis from 2018 to 2021 recorded in the DHIS2-ETL database countrywide. We determined TB treatment outcome as either favourable if the patients were considered cured or completed treatment; or unfavourable if they were lost to follow-up (default), with treatment failure, or died. We established possible determinants for poor treatment outcomes and considered both individual and facility-level effects in the analysis through a multilevel regression model. About 10% of patients with recurrent TB had unfavourable treatment outcomes; death was the most reported poor outcome affecting 6% of recurrent TB patients. Patients coinfected with HIV, those treated under facility-based DOT, and patients who received treatment in Zanzibar, Coastal, and Central geographical zones had higher rates of poor outcomes. Patients with bacteriologically confirmed TB and who were treated at the hospital were more likely to have unfavourable treatment outcomes. What do these findings mean?: There is a need to design and implement interventions that are specifically targeted for managing patients with TB recurrence, especially for HIV coinfected patients. Drug susceptibility testing and close monitoring after treatment completion are crucial to prevent recurrence. Also, ensuring early detection and treatment and promoting short- and long-term improvements in treatment outcomes for these patients. Capacitating and strengthening Primary health care facilities for TB diagnosis and treatment may be a promising approach to promote early TB detection and treatment initiation and subsequently maintain better outcomes for patients with recurrent TB. This should be coupled with close monitoring of patients treated at the hospital level through an appropriate DOT strategy. [ABSTRACT FROM AUTHOR]