Long-term Virologic Response in a Cohort of HIV-infected Patients in South Africa

Abstract

Background: While much is known about virologic response to antiretroviral therapy (ART) in resource rich settings, much less is known about long-term rates of virologic suppression in resource-limited settings. We aimed to describe virologic response on ART over 8 years among a cohort of patients initiating ART the first year of the public sector roll out in South Africa. Methodology: We included all ART-naïve patients, ≥18 years, who initiated first-line ART from April 2004-March 2005 at 4 public sector HIV treatment clinics in Gauteng and Mpumalanga Provinces. Patients were followed from ART initiation until death, transfer, loss to follow-up (LTF) or dataset close (May 2013). LTF was defined as being ≥3 months late for a scheduled visit with no subsequent visit. Virologic suppression was defined as a viral load (VL) <400 copies/ml while a failing VL was defined as >1000 copies/ml. A transient elevated viral load (TEV) was defined as a failing VL followed by a suppressed VL. Results: 2357 patients were included. 68.8% were female with a median (IQR) age of 35.4 (30.5-42.0) years and a median (IQR) baseline CD4 count of 80 (34-141) cells/mm3. Patients were followed for a median (IQR) of 6.2 (2.1-8.3) years. At the end of follow-up, 18.0% of patients had died, 24.4% of patients were LTF, and 30.1% of patients had transferred. 1912 (81.1%) patients had ≥1 VL recorded with a median (IQR) of 11 (6-14) VLs over the duration of follow-up. Of those, 96.0% (n=1835) achieved virologic suppression and 68.4% (n=1255) of those patients suppressed on their first VL. Among those 1255 patients, 53.2% remained suppressed at every subsequent VL (median: 11; 1QR: 6-13). For the 535 patients who did not remain suppressed, patients experienced a median (IQR) of 2 (1-3) detectable VLs and the first detectable VL occurred in a median (IQR) of 2.7 (1.1-6.1) years after the first suppressed VL (Figure). 704 (36.8%) patients experienced ≥1 TEV and were less likely to die (7.7%) or become LTF (15.6%) compared to patients who never experienced a TEV (death: 13.1%; LTF: 23.0%), potentially due to increased monitoring of patients experiencing adverse virologic response. Conclusions: Long-term suppression is common in this cohort of HIV-infected individuals. However, over 70% of patients left the cohort (died, transferred, or left care) by the end of follow-up. Further research is needed to determine successful interventions for retaining patients in care in order to ensure continued success of the ART program in South Africa.

Conference: CROI conference 2014, Boston, USA