Epidemiology of HIV drug resistance in HIV patients with virologic failure of first-line therapy in the country of Georgia.

Human immunodeficiency virus (HIV) drug resistance is a major threat to the sustained impact of antiretroviral therapy (ART). We studied the epidemiology of drug resistance in the country of Georgia. The study included all adult patients who experienced virologic failure on first line ART and received HIV drug resistance testing between 2005 and 2016. The Stanford HIV Sequence Database was used for interpretation of the resistance data. Patient-level data were extracted from the national AIDS health information system. Of the 447 patients included, 85.5% harbored the subtype A6 virus, 8.0% - subtype B, 2.9% - subtype G, and other subtypes were <1%. The most frequent first-line regimens were Tenofovir/Emtricitabine/Efavirenz (28.4%), Zidovudine/Lamivudine/Efavirenz (28.4%), and Abacavir/Lamivudine/Efavirenz (15.9%). A total of 85.0% of the patients with treatment failure developed at least one drug resistance mutation affecting their susceptibility to ART. The most frequent nucleoside reverse transcriptase inhibitor mutations were M184V (65.3%), K65R (19.7%) and L74V (17.0%). At least three thymidine analogue mutations were detected in 6.3% of the patients. From non-nucleoside reverse transcriptase inhibitor mutations, G190S was shown to be the most prevalent (49.4%), followed by K101E (27.10%) and K103N (24.4%). G190S and K101E were more common in subtype A as compared with non-A viruses (G190S: 54.9% vs 11.3%, P < 0.0001; K101E: 29.8% vs 11.3%, P = 0.005). On the other hand, K103N was more frequent in non-A subtypes (43.4%) compared with subtype A (22.2%), P = 0.0008. A majority of persons failing on ART had HIV drug resistance. Drug resistance patterns may vary by subtype. K65R mutation remains below 20%, but given the high use of Tenofovir in the country, continuing surveillance of drug resistance is needed.