@article {10835,
	title = {Prevalence of drug resistance among HIV-1 treatment-naive patients in Greece during 2003-2015: Transmitted drug resistance is due to onward transmissions.},
	journal = {Infect Genet Evol},
	volume = {54},
	year = {2017},
	month = {2017 Oct},
	pages = {183-191},
	abstract = {BACKGROUND: The prevalence of HIV-1 drug resistance among treatment-na{\"\i}ve patients ranges between 8.3\% and 15\% in Europe and North America. Previous studies showed that subtypes A and B were the most prevalent in the Greek HIV-1 epidemic. Our aim was to estimate the prevalence of resistance among drug na{\"\i}ve patients in Greece and to investigate the levels of transmission networking among those carrying resistant strains.

METHODS: HIV-1 sequences were determined from 3428 drug na{\"\i}ve HIV-1 patients, in Greece sampled during 01/01/2003-30/6/2015. Transmission clusters were estimated by means of phylogenetic analysis including as references sequences from patients failing antiretroviral treatment in Greece and sequences sampled globally.

RESULTS: The proportion of sequences with SDRMs was 5.98\% (n=205). The most prevalent SDRMs were found for NNRTIs (3.76\%), followed by N(t)RTIs (2.28\%) and PIs (1.02\%). The resistance prevalence was 22.2\% based on all mutations associated with resistance estimated using the HIVdb resistance interpretation algorithm. Resistance to NNRTIs was the most common (16.9\%) followed by PIs (4.9\%) and N(t)RTIs (2.8\%). The most frequently observed NNRTI resistant mutations were E138A (7.7\%), E138Q (4.0\%), K103N (2.3\%) and V179D (1.3\%). The majority of subtype A sequences (89.7\%; 245 out of 273) with the dominant NNRTI resistance mutations (E138A, K103N, E138Q, V179D) were found to belong to monophyletic clusters suggesting regional dispersal. For subtype B, 68.1\% (139 out of 204) of resistant strains (E138A, K103N, E138Q V179D) belonged to clusters. For N(t)RTI-resistance, evidence for regional dispersal was found for 27.3\% and 21.6\% of subtype A and B sequences, respectively.

CONCLUSIONS: The TDR rate based on the prevalence of SDRM is lower than the average rate in Europe. However, the prevalence of NNRTI resistance estimated using the HIVdb approach, is high in Greece and it is mostly due to onward transmissions among drug-na{\"\i}ve patients.},
	issn = {1567-7257},
	doi = {10.1016/j.meegid.2017.07.003},
	author = {Paraskevis, D and E Kostaki and Magiorkinis, G and Gargalianos, P and Xylomenos, G and Magiorkinis, E and Lazanas, M and Chini, M and Nikolopoulos, G. and Skoutelis, A and Papastamopoulos, V and Antoniadou, A and Papadopoulos, A. and Psichogiou, M and Daikos, G L and Oikonomopoulou, M and Zavitsanou, A and Chrysos, G and Paparizos, V and Kourkounti, S and Sambatakou, H and Sipsas, N V and Lada, M and Panagopoulos, P and Maltezos, E and Drimis, S and Hatzakis, A}
}
