Prevalence, rate and predictors of Virologic failure among adult HIV-infected clients on second-line Antiretroviral therapy (art) in Tanzania (2018-2020)

Abstract

ABSTRACT Background: Antiretroviral Therapy (ART) has been proven to be highly effective in reducing the impact of Human Immunodeficiency Virus (HIV) infection. However, as more people receive initial ART treatment, the risk of developing resistance and eventual treatment failure increases, leading to the need for second-line treatment regimens. Understanding the factors that contribute to virologic failure to second-line ART is crucial in preventing switching to the more expensive and toxic third-line regimens. This study provides information on the prevalence, rate, and predictors of virologic failure (VF) among clients on second-line ART in Tanzania. Results: We followed 4,718 clients for 15,100 person-years (PY) of observations. Of them, 1,402(29.72%) experienced virologic failure, at a rate of 92.85 per 1000 PY of observations (95% CI 88.11, 97.84). Factors that were associated with VF included: having a viral load count of ≥1000 copies/mL during first-line ART, with adjusted hazard ratio (aHR) 4.65 (95% CI 3.57, 6.07), using lopinavir (LPV/r) as a protease inhibitor during second-line ART aHR 4.20 (95% CI 3.12, 7.10), having a CD4 count <200 cells/mm3 during second-line ART aHR 1.89 (95% CI 1.46, 2.44), and being on ART for 13-35 months aHR 8.22 (95% CI 2.21, 30.61). Paradoxically, having a CD4 count <200 cells/mm3 during first-line ART treatment was associated with a reduced risk of virologic failure aHR 0.77 (95% CI 0.60, 0.99). Conclusions: In Tanzania, approximately 30% of the adult clients on second-line ART experience VF at a rate of 92.71 per 1000 person-years. This high virologic failure rate highlights the need for targeted interventions for HIV-infected clients on second-line ART to reduce the need for switching to the more costly and relatively more toxic third-line ART therapy and help to achieve the third UNAIDS goal of achieving viral suppression for 95% of those treated by 2030.