<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Kostaki, E. G.</style></author><author><style face="normal" font="default" size="100%">Papadimitriou, E.</style></author><author><style face="normal" font="default" size="100%">Chatzopoulou, F.</style></author><author><style face="normal" font="default" size="100%">Roussos, S.</style></author><author><style face="normal" font="default" size="100%">Tsirogianni, E.</style></author><author><style face="normal" font="default" size="100%">Psichogiou, M</style></author><author><style face="normal" font="default" size="100%">Goulis, I.</style></author><author><style face="normal" font="default" size="100%">Kalamitsis, G.</style></author><author><style face="normal" font="default" size="100%">Kefala, A. M.</style></author><author><style face="normal" font="default" size="100%">Skoura, L.</style></author><author><style face="normal" font="default" size="100%">Chrysanthidis, T.</style></author><author><style face="normal" font="default" size="100%">Metallidis, S.</style></author><author><style face="normal" font="default" size="100%">Tsiara, C</style></author><author><style face="normal" font="default" size="100%">Paraskeva, D.</style></author><author><style face="normal" font="default" size="100%">Magiorkinis, G</style></author><author><style face="normal" font="default" size="100%">Beloukas, A.</style></author><author><style face="normal" font="default" size="100%">Hatzakis, A</style></author><author><style face="normal" font="default" size="100%">Sypsa, V</style></author><author><style face="normal" font="default" size="100%">Chatzidimitriou, D.</style></author><author><style face="normal" font="default" size="100%">Paraskevis, D</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Molecular investigation of a new HIV-1 outbreak among people who inject drugs in Greece: evidence for a dense network of HIV-1 transmission</style></title><secondary-title><style face="normal" font="default" size="100%">Sex Transm Infect</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Sexually transmitted infections</style></alt-title><short-title><style face="normal" font="default" size="100%">Sexually transmitted infectionsSexually transmitted infections</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">effective reproduction number</style></keyword><keyword><style  face="normal" font="default" size="100%">HIV-1</style></keyword><keyword><style  face="normal" font="default" size="100%">molecular epidemiology</style></keyword><keyword><style  face="normal" font="default" size="100%">outbreak</style></keyword><keyword><style  face="normal" font="default" size="100%">people who inject drugs</style></keyword><keyword><style  face="normal" font="default" size="100%">phylogenetic analysis</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2025</style></year><pub-dates><date><style  face="normal" font="default" size="100%">May 28</style></date></pub-dates></dates><edition><style face="normal" font="default" size="100%">2025/05/30</style></edition><isbn><style face="normal" font="default" size="100%">1368-4973</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">OBJECTIVES: Αn HIV-1 outbreak was identified among people who inject drugs (PWID) in Thessaloniki, Greece, during 2019-2021. We aimed to investigate the characteristics of this outbreak by means of molecular epidemiology. METHODS: We analysed 57 sequences from PWID sampled in Thessaloniki during 2019-2023. Phylogenetic trees were inferred using all subtype A sequences from PWID sampled since 1999 in Greece and reference sequences (n=4824). Phylodynamic analysis was performed using the Bayesian birth-death skyline serial model. RESULTS: Most of the 57 study sequences belonged to sub-subtypes A6 (49, 86%) and A1 (4, 7%). Phylogenetic analysis revealed that two (50%) A1 sequences clustered together and 47 (95.9%) A6 sequences fell within three PWID-specific phylogenetic clusters. The 99.6% and 77.9% of pairwise genetic distances within the largest and second largest PWID clusters were lower than 0.015 substitutions/site. Using a more stringent threshold (0.0015 substitutions/site), we identified five networks of sequences from PWID infected within 1 year. The effective reproduction number (R(e)) started to increase at the beginning of 2019 and remained high almost until the end of 2021. The estimated time from HIV-1 infection to diagnosis showed an increasing trend during 2020-2023 (p&amp;lt;0.001). CONCLUSIONS: The regional clustering of the PWID sequences and their low genetic divergence confirm its local spreading and the recent nature of the outbreak. Using a stringent genetic distance threshold, we showed that HIV-1 transmission occurred among large groups of PWID. The time of epidemic growth coincided with the time of the initial identification, and HIV-1 transmission continued at high rates until 2021.</style></abstract><accession-num><style face="normal" font="default" size="100%">40441776</style></accession-num><notes><style face="normal" font="default" size="100%">1472-3263Kostaki, Evangelia GeorgiaOrcid: 0000-0002-3346-0930Papadimitriou, EvangeliaChatzopoulou, FaniRoussos, SotiriosTsirogianni, EfrosiniPsichogiou, MinaGoulis, IoannisKalamitsis, GeorgiosKefala, Anastasia MariaSkoura, LemoniaChrysanthidis, TheofilosMetallidis, SymeonTsiara, ChrysaParaskeva, DimitraMagiorkinis, GkikasBeloukas, ApostolosOrcid: 0000-0001-5639-0528Hatzakis, AngelosSypsa, VanaChatzidimitriou, DimitriosParaskevis, DimitriosJournal ArticleEnglandSex Transm Infect. 2025 May 28:sextrans-2024-056452. doi: 10.1136/sextrans-2024-056452.</style></notes><auth-address><style face="normal" font="default" size="100%">Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National and Kapodistrian University of Athens, Athens, Greece.National AIDS Reference Centre of Northern Greece, Department of Microbiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.4th Department of Internal Medicine, Hippokratio General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece.Greek Organisation Against Drugs (OKANA), Athens, Greece.1st Department of Internal Medicine, Laiko General Hospital, Medical School, National and Kapodistrian University Athens, Athens, Greece.Hellenic Liver Patient Association &quot;Prometheus&quot;, Athens, Greece.Department of Biomedical Sciences, University of West Attica, Athens, Greece.Infectious Diseases Division, 1st Department of Internal Medicine, AHEPA University Hospital, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.National Public Health Organization, Marousi, Greece.Hellenic Scientific Society for the Study of AIDS, Sexually Transmitted Diseases and Emerging Diseases, Athens, Greece.Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National and Kapodistrian University of Athens, Athens, Greece dparask@med.uoa.gr.</style></auth-address><remote-database-provider><style face="normal" font="default" size="100%">NLM</style></remote-database-provider></record></records></xml>