Emerging transmitted drug resistance in treatment-naïve human immunodeficiency virus-1 CRF06_cpx-infected patients in Estonia

Abstract

Human immunodeficiency virus (HIV)-1 transmitted drug resistance in the drug-naïve population is of growing relevance in Estonia, where the number of antiretroviral (ARV) treatment-experienced subjects has been exponentially increasing during the last 10 y. The aim of this study was to estimate the rate of transmitted drug resistance among newly diagnosed subjects in Estonia in 2008. Genotypic resistance testing for viral genomic RNA was conducted for 201 subjects tested HIV-positive between 1 April and 30 November 2008. Of 145 genotyped viral strains in newly diagnosed patients, 123 were CRF06_cpx, 2 were subtype A1 and 3 were subtype B; in 17 cases viral sequences revealed recombinant structures similar to CRF06_cpx, subtype A1 and CRF02_AG. Resistance mutations were found in 8 (5.5%) virus strains, and 3 strains were resistant to at least 2 ARV classes. A total of 2.8% of sequences harboured mutations indicating nucleoside/nucleotide reverse transcriptase inhibitor resistance (M41L, M184V, M184I, T215C and T215D), 2.1% non-nucleoside reverse transcriptase inhibitor resistance (K103N, P225H) and 2.8% protease inhibitor resistance (M46I, L90M). These data suggest the need to extend genotypic HIV-1 drug resistance testing to newly diagnosed HIV-positive subjects to prevent potential ARV treatment failure.

Acknowledgements

The authors are grateful to Maarit Maimets for critical manuscript review. Financial support was provided by the Centre of Excellence of Translational Research of Neuroimmunology (project SFOS WP1-NeuroAIDS), Basic Financing and Target Financing of the Estonian Ministry of Education and Research (grant SF0182726s06), the Estonian Science Foundation (grants 8004 and 8415), the European Union through the European Regional Development Fund, and by the Archimedes Foundation.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.