HIV-1 subtypes distribution and resistance to ART in HIV-infected persons in Slovakia (2019-2021).

Aim: The aim of the study was to describe the prevalence of HIV-1 subtypes and HIV-1 strains resistant to antiretroviral therapy (ART) in HIV-positive persons newly diagnosed in Slovakia in 2019-2021.

Materials and methods: The study group consisted of 184 HIV-positive naïve patients newly diagnosed in Slovakia from 2019 to 2021. The viral HIV-1 RNA was isolated from plasma by the QIAamp Viral RNA Mini Kit (QIAGEN, Germany). For RT-PCR and sequencing of the HIV pol region, in-house procedures were used according to the ANRS AC11 protocol for RT (reverse transcriptase), PRO (protease), and IN (integrase) [ANRS AC11 Resistance Study Group, 2015]. Analysis of sequences was performed using Sequencing Analysis Software v5.3 (Applied Biosystems®). HIV sequences were manually edited using BioEdit (version 7.2.5), compared with consensus HIV-1 sequences in the Los Alamos Sequence Database (URL 2), aligned using CLUSTAL W [Labarga et al., 2007] and BioEdit software packages (version 7.2 .5) [Hall, 1999]. HIVDB Algorithm (version 9.0) of the Stanford HIV Drug resistance database (URL 1.) was used for sequence evaluation. For HIV-1 subtype analysis, the REGA HIV-1 Subtyping Tool [De Oliviera et al., 2005] and phylogenetic analysis MEGA X [Kumar et al., 2018] were used.

Results: Phylogenetic analyses performed in samples of 184 persons revealed the most prevalent subtype B (129/184, 70.11%), detected to the greatest extent in the population of men who have sex with men (MSM) (96/129 74.42%). Concerning non-B subtypes (55/184, 29.89%), subtype A was found with the highest prevalence (48/184, 26.09%) compared to subtype F (F1) (3; 1.63%), C (1; 0.54%) and circulating recombinant forms CRF02_AG (2; 1.09%), CRF01_AE (1; 0.54%). In 9.24% (17/184) of samples, 25 mutations clinically relevant and associated with HIV resistance ART were detected, of which 7.07% (13/184) to reverse transcriptase inhibitors, 1.66% (3/181) to protease inhibitors and 1.32% (2/151) to integrase inhibitors. In addition, multiclass resistance was present in 1.63% (3/184) of patients. Mutations associated with HIV resistance to ART were found in 9.30 % of persons infected with subtype B.

Conclusion: Our study confirmed ongoing highest prevalence of subtype B with a slightly decreasing trend compared to last years. Detection of mutations causing HIV resistance to ART underlines the need for resistance testing in naïve patients even before the initiation of ART in Slovakia.