When patients fail UNAIDS’ last 90 - the “failure cascade” beyond 90-90-90 in rural Lesotho, Southern Africa: a prospective cohort study

INTRODUCTION HIV-infected individuals on first-line antiretroviral therapy (ART) in resource-limited settings who do not achieve the last "90" (viral suppression) enter a complex care cascade: enhanced adherence counselling (EAC), repetition of viral load (VL) and switch to second-line ART aiming to achieve resuppression. This study describes the "failure cascade" in patients in Lesotho. METHODS Patients aged ≥16 years on first-line ART at 10 facilities in rural Lesotho received a first-time VL in June 2014. Those with VL ≥80 copies/mL were included in a cohort. The care cascade was assessed at four points: attendance of EAC, result of follow-up VL after EAC, switch to second-line in case of sustained unsuppressed VL and outcome 18 months after the initial unsuppressed VL. Multivariate logistic regression was used to assess predictors of being retained in care with viral resuppression at follow-up. RESULTS Out of 1563 patients who underwent first-time VL, 138 (8.8%) had unsuppressed VL in June 2014. Out of these, 124 (90%) attended EAC and 116 (84%) had follow-up VL (4 died, 2 transferred out, 11 lost, 5 switched to second-line before follow-up VL). Among the 116 with follow-up VL, 36 (31%) achieved resuppression. Out of the 80 with sustained unsuppressed VL, 58 were switched to second-line, the remaining continued first line. At 18 months' follow-up in December 2015, out of the initially 138 with unsuppressed VL, 56 (41%) were in care and virally suppressed, 37 (27%) were in care with unsuppressed VL and the remaining 45 (33%) were lost, dead, transferred to another clinic or without documented VL. Achieving viral resuppression after EAC (adjusted odds ratio (aOR): 5.02; 95% confidence interval: 1.14-22.09; p = 0.033) and being switched to second-line in case of sustained viremia after EAC (aOR: 7.17; 1.90-27.04; p = 0.004) were associated with being retained in care and virally suppressed at 18 months of follow-up. Age, gender, education, time on ART and level of VL were not associated. CONCLUSIONS In this study in rural Lesotho, outcomes along the "failure cascade" were poor. To improve outcomes in this vulnerable patient group who fails the last "90", programmes need to focus on timely EAC and switch to second line for cases with continuous viremia despite EAC.