PT  - JOURNAL ARTICLE
AU  - Lavinia Fabeni
AU  - Claudia Alteri
AU  - Giulia Berno
AU  - Rossana Scutari
AU  - Nicoletta Orchi
AU  - Gabriella De Carli
AU  - Ada Bertoli
AU  - Luca Carioti
AU  - Caterina Gori
AU  - Federica Forbici
AU  - Romina Salpini
AU  - Alessandra Vergori
AU  - Roberta Gagliardini
AU  - Stefania Cicalini
AU  - Annalisa Mondi
AU  - Carmela Pinnetti
AU  - Laura Mazzuti
AU  - Ombretta Turriziani
AU  - Manuela Colafigli
AU  - Vanni Borghi
AU  - Francesco Montella
AU  - Alfredo Pennica
AU  - Miriam Lichtner
AU  - Enrico Girardi
AU  - Massimo Andreoni
AU  - Cristina Mussini
AU  - Andrea Antinori
AU  - Francesca Ceccherini-Silberstein
AU  - Carlo Federico Perno
AU  - Maria Mercedes Santoro
ED  - ,
TI  - Characterisation of HIV-1 molecular transmission clusters among newly diagnosed individuals infected with non-B subtypes in Italy
AID  - 10.1136/sextrans-2019-054017
DP  - 2019 Dec 01
TA  - Sexually Transmitted Infections
PG  - 619--625
VI  - 95
IP  - 8
4099  - http://sti.bmj.com/content/95/8/619.short
4100  - http://sti.bmj.com/content/95/8/619.full
SO  - Sex Transm Infect2019 Dec 01; 95
AB  - Objective We evaluated the characteristics of HIV-1 molecular transmission clusters (MTCs) in 1890 newly diagnosed individuals infected with non-B subtypes between 2005 and 2017 in Italy.Methods Phylogenetic analyses were performed on pol sequences to characterise subtypes/circulating recombinant forms and identify MTCs. MTCs were divided into small (SMTCs, 2–3 sequences), medium (MMTCs, 4–9 sequences) and large (LMTCs, ≥10 sequences). Factors associated with MTCs were evaluated using logistic regression analysis.Results 145 MTCs were identified and involved 666 individuals (35.2%); 319 of them (16.9%) were included in 13 LMTCs, 111 (5.9%) in 20 MMTCs and 236 (12.5%) in 112 SMTCs. Compared with individuals out of MTCs, individuals involved in MTCs were prevalently Italian (72.7% vs 30.9%, p<0.001), male (82.9% vs 62.3%, p<0.001) and men who have sex with men (MSM) (43.5% vs 14.5%, p<0.001). Individuals in MTCs were also younger (median (IQR) years: 41 (35–49) vs 43 (36–51), p<0.001) and had higher CD4 cell count in comparison with individuals out of MTCs (median (IQR): 109/L: 0.4 (0.265–0.587) vs 0.246 (0.082–0.417), p<0.001). The viral load remained stable between the two groups (median (IQR) log10 copies/mL: 4.8 (4.2–5.5) vs 5.0 (4.3–5.5), p=0.87). Logistic regression confirmed that certain factors such as being MSM, of Italian origin, younger age and higher CD4 cell count were significantly associated with MTCs.Conclusions Our findings show that HIV-1 newly diagnosed individuals infected with non-B subtypes are involved in several MTCs in Italy. These MTCs include mainly Italians and MSM and highlight the complex phenomenon characterising the HIV-1 spread. This is important especially in view of monitoring the HIV epidemic and guiding the public health response.