Determinants of HIV-1 virological failure and acquired drug resistance with regard to decentralization of HIV care

Background: Tremendous efforts with increased access to antiretroviral therapy (ART) in sub-Saharan Africa have led to reductions in AIDS-related morbidity and mortality. Howev-er, the gaps with HIV monitoring services denote that patients in decentralized settings, in particular, are not optimally managed - which could undermine the attainment of the 90-90-90 treatment goals. We assessed the prevalence and determinants of virological failure (VF) and acquired drug resistance (ADR) amongst patients undergoing first-line ART in Senegal. Methods: In this cross-sectional design, HIV-1-infected adults (≥18 years) on ART for ≥12 months had viral load (VL) measurements between January-March 2015. Patients were re-cruited at the ambulatory treatment center of Dakar (n=157) and, the decentralized site of Saint-Louis’ regional hospital (n=121). VF outcome was expressed as unsuppressed VL≥1000 copies/ml and, ADR as evidence of at least one resistance-associated mutation. Binomial lo-gistic odds ratios (OR) and 95% confidence intervals ([CI]) and, χ2/Fisher-Exact, were used to determine significant predictors of VF and ADR, respectively. Results: Of the 278 enrolled patients on TDF-/AZT-based regimens over a cumulative medi-an duration of 64 months, 32 had VF (11.5%, 95% CI [8.01-15.86]) while 21 had ADR (7.5%, 95% CI [4.74-11.32]). Determinants of VF in multivariable adjustments were: Saint-Louis (vs. Dakar: OR, 5.0; 95% CI [1.98-14.7]; p10000 copies/ml. The pattern of ADR across drug regimens was: NVP>3TC>AZT>TDF>EFV>FTC. Of the samples successfully geno-typed (27/32), prevalent ADR mutations to NRTIs (n=17) were M184VI (n=16), K65R/T215SY (n=5) and to NNRTIs, K103N (n=10), Y181CY (n=6), A98AG (n=5). Conclusion: Being on care in Saint-Louis, having lower CD4 counts and higher VL, predis-posed more to VF and ADR. The interplay between these variables indicates more inherent health facilities based challenges. In line with the 90-90-90 targets for 2020, health systems - including those at decentralized settings - need to strengthen prompt diagnosis and treatment initiation, virological monitoring and counselling.