Provincial and national prevalence estimates of transmitted HIV-1 drug resistance in South Africa measured using two WHO-recommended methods.

Background: Sentinel surveillance of transmitted HIV drug resistance (TDR) among recently infected populations within a country was recommended by the World Health Organization from 2004 to 2015. Methods: Serum specimens collected as part of the 2010, 2011 and 2012 National Antenatal Sentinel HIV Prevalence Surveys were used to estimate provincial and national TDR prevalence in South Africa. Results: Moderate (5-15%) levels of transmitted non-nucleoside reverse transcriptase inhibitor (NNRTI) drug class resistance were detected in three of five provinces surveyed in 2010 and 2011 (Eastern Cape, Free State and KwaZulu-Natal). Inclusion of all nine of South Africa's provinces in the 2012 survey enabled calculation of a national TDR point prevalence estimate: TDR to the NNRTI drug class was 5.4% (95% CI 3.7, 7.8%), with K103N and V106M being the most frequently detected mutations. TDR estimates for the nucleoside reverse transcriptase inhibitor (NRTI) drug class were 1.1% (95% CI 0.5, 2.4%) and 0.6% (95% CI 0.1, 1.6%) for protease inhibitors (PI). Conclusions: These data provide national TDR estimates for South Africa in 2012 and indicate that levels of TDR were low to moderate for the NNRTI drug class and low for NRTIs and Pls in the population surveyed.