Dynamics and phylogenetic relationships of HIV-1 transmitted drug resistance according to subtype in Italy over the years 2000-14

Lavinia Fabeni, C. Alteri, D. Di Carlo, N. Orchi, L. Carioti, A. Bertoli, C. Gori, F. Forbici, F. Continenza, G. Maffongelli, C. Pinnetti, A. Vergori, A. Mondi, A. Ammassari, V. Borghi, M. Giuliani, Gabriella De Carli, S. Pittalis, S. Grisetti, A. CristaudoE. Girardi, A. Antinori, C. F. Perno, M. M. Santoro, E. Girardi, M. R. Capobianchi, C. F. Perno, N. Orchi, A. Navarra, A. Palummieri, I. Abbate, A. Ammassari, R. D'Arrigo, Gabriella De Carli, F. M. Fusco, C. Gori, S. Grisetti, A. Mariano, E. Nicastri, C. Pinnetti, S. Pittalis, V. Puro, A. Sampaolesi, M. R. Sciarrone, P. Scognamiglio, M. Selleri, C. Sias, M. Zaccarelli, A. Di Carlo, M. Giuliani, on behalf of the SENDIH Study Group

Research output: Contribution to journalArticlepeer-review


Background Transmitted drug-resistance (TDR) remains a critical aspect for the management of HIV-1-infected individuals. Thus, studying the dynamics of TDR is crucial to optimize HIV care. Methods In total, 4323 HIV-1 protease/reverse-transcriptase sequences from drug-naive individuals diagnosed in north and central Italy between 2000 and 2014 were analysed. TDR was evaluated over time. Maximum-likelihood and Bayesian phylogenetic trees with bootstrap and Bayesian-probability supports defined transmission clusters. Results Most individuals were males (80.2%) and Italian (72.1%), with a median (IQR) age of 37 (30-45) years. MSM accounted for 42.2% of cases, followed by heterosexuals (36.4%). Non-B subtype infections accounted for 30.8% of the overall population and increased over time (<2005-14: 19.5%-38.5%, P < 0.0001), particularly among Italians (<2005-14: 6.5%-28.8%, P < 0.0001). TDR prevalence was 8.8% and increased over time in non-B subtypes (<2005-14: 2%-7.1%, P = 0.018). Overall, 467 transmission clusters (involving 1207 individuals; 27.9%) were identified. The prevalence of individuals grouping in transmission clusters increased over time in both B (<2005-14: 12.9%-33.5%, P = 0.001) and non-B subtypes (<2005-14: 18.4%-41.9%, P = 0.006). TDR transmission clusters were 13.3% within the overall cluster observed and dramatically increased in recent years (<2005-14: 14.3%-35.5%, P = 0.005). This recent increase was mainly due to non-B subtype-infected individuals, who were also more frequently involved in large transmission clusters than those infected with a B subtype [median number of individuals in transmission clusters: 7 (IQR 6-19) versus 4 (3-4), P = 0.047]. Conclusions The epidemiology of HIV transmission changed greatly over time; the increasing number of transmission clusters (sometimes with drug resistance) shows that detection and proper treatment of the multi-transmitters is a major target for controlling HIV spread.

Original languageEnglish
Pages (from-to)2837-2845
Number of pages9
JournalJournal of Antimicrobial Chemotherapy
Issue number10
Publication statusPublished - Oct 1 2017

ASJC Scopus subject areas

  • Pharmacology
  • Pharmacology (medical)
  • Infectious Diseases


Dive into the research topics of 'Dynamics and phylogenetic relationships of HIV-1 transmitted drug resistance according to subtype in Italy over the years 2000-14'. Together they form a unique fingerprint.

Cite this