Determinants of Therapy Failure Among Adults on First-line Antiretroviral Therapy in Asmara, Eritrea: A Multicenter Retrospective Matched Case-control Study

Abstract

Background Information on treatment failure (TF) in People living with HIV in data-poor jurisdictions is necessary to counter the rapidly escalating epidemic of TF to first-line combined anti-retroviral therapies (cART) in sub-Saharan Africa (SSA). In this study, we examined the risk factors associated with TF in Asmara, Eritrea.Methods: A multicenter, retrospective 1:2 matched (by age and gender) case-control study was conducted in four major hospitals in Asmara, Eritrea on adults aged >15 years who were on treatment for at least 6 months. Cases were patients with viral load ≥1000 copies/mL anytime between 2019-2021 and/or patients switched to second line cART. Controls were randomly selected from patients on first-line ART with viral load < 1000 copies/mL. Data was extracted using a checklist from the master data set and analyzed using SPSS version 26. Multivariable logistic regression analysis was conducted to identify risk factors for TF. All p-values were 2-sided and the level of significance was set at p < 0.05 for all analyses.Results: Of the 1068 participants, 585 (54.7%) were females. The median age at treatment initiation was 46 years (interquartile range (IQR): 39–51). Median time to combined antiretroviral therapy (cART) failure was 37 months (IQR =24–47). In multivariate analysis factors associated with increased likelihood of virologic failure (VF) were the type of initially used nucleoside reverse transcriptase inhibitors (NRTI) backbone ( (Zidovudine+Lamivudine (AZT+3TC): adjusted odds ratio (aOR): 2.70; 95% Confidence interval (CI): 1.65-4.41, p-value<0.001), (Abacavir+lamivudine (ABC+3TC): aOR: 4.73; 95%CI: 1.18-18.92, p-value=0.028), and (Stavudine+Lamivudine (D4T+3TC): aOR: 5.00; 95% CI: 3.03-8.20, p-value<0.001), prior exposure to ART (aOR: 2.28; 95%CI:1.35–3.86; p=0.002), record of sub-optimal drug adherence (aOR: 3.08; 95%CI: 2.22–4.28; p<0.001), ambulatory/bedridden at presentation (aOR:1.61; 95%CI: 1.12-4.28; p-value=0.010), presence of comorbidities (aOR: 2.37; 95%CI: 1.36-4.10, p-value=0.002), duration of cART (<5 years: aOR: 5.90; 95% CI: 3.95-8.73, p-value<0.001), and use of SMX-TMP prophylaxis ( aOR : 2.00, 95%CI, 1.44-2.78, p-value<0.001). Conclusion: Our findings underscore the importance of optimizing cART adherence, diversification of cART regimens, and interventions directed at enhancing early HIV diagnosis, prompt initiations of treatment and improved patient focused monitoring of treatment response.