We aimed at evaluating the characteristics of HIV-1 molecular transmission clusters (MTCs) among natives and migrants living in Italy, diagnosed between 1998 and 2018. Phylogenetic analyses were performed on HIV-1 polymerase (pol) sequences to characterise subtypes and identify MTCs, divided into small (SMTCs, 2-3 sequences), medium (MMTCs, 4-9 sequences) and large (LMTCs, ≥10 sequences). Among 3499 drug-naïve individuals enrolled in the Italian Cohort Naive Antiretroviral (ICONA) cohort (2804 natives; 695 migrants), 726 (20.8%; 644 natives, 82 migrants) were involved in 228 MTCs (6 LMTCs, 36 MMTCs, 186 SMTCs). Migrants contributed 14.4% to SMTCs, 7.6% to MMTCs and 7.1% to LMTCs, respectively. HIV-1 non-B subtypes were found in 51 MTCs; noteworthy was that non-B infections involved in MTCs were more commonly found in natives (n = 47) than in migrants (n = 4). Factors such as Italian origin, being men who have sex with men (MSM), younger age, more recent diagnosis and a higher CD4 count were significantly associated with MTCs. Our findings show that HIV-1 clustering transmission among newly diagnosed individuals living in Italy is prevalently driven by natives, mainly MSM, with a more recent diagnosis and frequently infected with HIV-1 non-B subtypes. These results can contribute to monitoring of the HIV epidemic and guiding the public health response to prevent new HIV infections.
Evaluation of HIV Transmission Clusters among Natives and Foreigners Living in Italy / Fabeni, Lavinia; Santoro, Maria Mercedes; Lorenzini, Patrizia; Rusconi, Stefano; Gianotti, Nicola; Costantini, Andrea; Sarmati, Loredana; Antinori, Andrea; Ceccherini-Silberstein, Francesca; d'Arminio Monforte, Antonella; Saracino, Annalisa; Girardi, Enrico; On Behalf Of The Icona Foundation Study Cohort, Null. - In: VIRUSES. - ISSN 1999-4915. - STAMPA. - 12:8(2020), p. 791. [10.3390/v12080791]