Surveillance of Transmitted HIV-1 Drug Resistance in Gauteng and KwaZulu-Natal Provinces, South Africa, 2005–2009

Abstract

Surveillance of human immunodeficiency virus type 1 transmitted drug resistance (TDR) was conducted among pregnant women in South Africa over a 5-year period after the initiation of a large national antiretroviral treatment program. Analysis of TDR data from 9 surveys conducted between 2005 and 2009 in 2 provinces of South Africa suggests that while TDR remains low (<5%) in Gauteng Province, it may be increasing in KwaZulu-Natal, with the most recent survey showing moderate (5%-15%) levels of resistance to the nonnucleoside reverse transcriptase inhibitor drug class.

Moderate Levels of Pre-Treatment HIV-1 Antiretroviral Drug Resistance Detected in the First South African National Survey

“…This level of pre-treatment drug resistance was only detected in three South African studies prior to this survey: 9.3% in Limpopo [19] and 7.4 [15] and 13.5% [13] in KwaZulu-Natal. However, the increasing prevalence over the years might be explained by the hypothesis that mature ART programmes can be a proxy for higher levels of pre-treatment drug resistance [11].…”

“…The studies conducted in Gauteng, Free State and Mpumalanga consistently detected a low prevalence of TDR [11–14]. The detected prevalence in KwaZulu-Natal changed from low levels in 2005 and 2007 to moderate levels of TDR in 2008 and 2009 [13]. These moderate levels were confirmed by one study [15], but not by two additional studies from the region [16, 17].…”

Drug resistance among newly diagnosed HIV-infected children in the era of more efficacious antiretroviral prophylaxis

“…We hypothesize that poor maternal recall, lack of understanding, poor record- keeping or failure to recall exposures in prior pregnancies may explain some of these cases [13]. Mothers may have been infected with and transmitted resistant variants although rates are higher than expected based on the prevalence of resistance in drug-naïve adults from surveillance studies in this population [14]. There may also have been unacknowledged or inadvertent postnatal drug exposures.…”

Different Effects of Nonnucleoside Reverse Transcriptase Inhibitor Resistance Mutations on Cytotoxic T Lymphocyte Recognition between HIV-1 Subtype B and Subtype A/E Infections

“…Drug treatment often increases the risk of subsequent transmission of drug resistance in new cases of an HIV infection. The Y181C mutation was also reported in treatment-naive individuals among different cohorts (see Table S1 in the supplemental material) at 2.3% (1/43), 1.1% (1/91), 0.6% (1/156), 3.0% (3/101), and 1.6% (2/129) of treatment-naive subtype C-infected individuals in Mozambique (42), in South India (43), in KwaZulu-Natal Provinces in South Africa (44), in Tanzania (45), and in China (46), respectively, and 0.43% of 1,389 treatment-naive individuals in southern Vietnam, where subtype A/E virus was the most prevalent subtype (47). The Y181C mutation or the Y181C/I mutation was detected in 0.4%, 0.3% (1/303), 0.2% (4/2,655), and 1.8% (6/336) of treatment-naive individuals in northern Poland (48), Brazil (49), Mexico (50), and Hondurans (51), respectively, where subtype B was the most prevalent.…”