Molecular Epidemiology of HIV-1 Subtypes and Primary Antiretroviral Resistance Profiles in Northern Cyprus: First Data Series

The distribution of human immunodeficiency virus-1 (HIV-1) subtypes indicates difference from region to region and in risk groups acquiring the disease worldwide. Although subtype C is more in terms of total cases, subtype B is dominant in certain regions, especially in western and central Europe. Molecular epidemiological studies are essential for the control, effective treatment, and understanding in transmission routes of HIV-1 infection. This study aims to determine the molecular epidemiology and antiretroviral drug resistance profiles of HIV-1 in northern Cyprus. The study involved 71 naive HIV-positive patients diagnosed in northern Cyprus between 2016 and 2022. HIV-1 subtypes and circulating recombinant forms (CRFs) were identified by phylogenetic analysis (neighbor-joining method) of pol gene sequences. Drug resistance mutations were analyzed using the World Health Organization (WHO) lists of mutations for surveillance. The Stanford University HIVdb program was used to interpret drug resistance mutations. In our study, 40 of 71 samples were successfully sequenced. Subtype B of HIV-1 was dominant with a rate of 52.5%, followed by CRF02_AG (20%) and G (7.5%) subtypes. The rate of subtype B (71.4%) in northern Cyprus was significantly higher than in the other country of origin (p = .028). Antiretroviral drug resistance was found in 15% of the sequenced serum samples. Nucleoside/nucleotide reverse transcriptase inhibitor (NRTI), non-nucleoside nucleotide reverse transcriptase inhibitor (NNRTI), and protease inhibitor (PI) resistance rates were 10% (4/40), 7.5% (3/40), and 2.5% (1/40), respectively. According to the results, it is noteworthy that the dominant subtype circulating in northern Cyprus is the B subtype, and CRFs were detected at a higher rate than expected.