HIV drug resistance levels in adults failing first-line antiretroviral therapy in an urban and a rural setting in South Africa

Abstract

OBJECTIVES : Urban and rural HIV treatment programmes face different challenges in the long-term management of patients. There are few studies comparing drug resistance profiles in patients accessing treatment through these programmes. METHODS : HIV drug resistance data and associated treatment and monitoring information from adult patients failing first-line therapy in an urban and rural programme were collected. Data were curated and managed in SATuRN RegaDB before statistical analysis using Microsoft Excel 2013 and Stata Ver14 where clinical parameters, resistance profiles and predicted treatment responses were compared. RESULTS : Data from 595 patients were analyzed: 492 rural and 103 urban. The urban group had lower CD4 counts at treatment initiation (98 versus 126 cells/μl, p=0.05), had more viral loads done per year (median 3 versus 1.4, p< 0.01) and was more likely to have no drug resistance mutations detected (35.9% versus 11.2%, p<0.01). Patients in the rural group were more likely to have been on first-line treatment for a longer period, failed for longer, and have thymidine analogue mutations. Notwithstanding these differences, both groups had a comparable predicted response to standard second-line regimen, based on the genotypic susceptibility score. Mutations accumulated in a sigmoidal fashion over failure duration. CONCLUSIONS : The frequency and patterns of drug resistance, as well the intensity of virological monitoring, in adults with first-line therapy failure differed between the urban and rural site. Despite these differences, based on the genotypic susceptibility scores, the majority of patients across both sites would be expected to respond well to the standard second-line regimen.