Recent Transmission Clustering of HIV-1 C and CRF17_BF Strains Characterized by NNRTI-Related Mutations among Newly Diagnosed Men in Central Italy.
BACKGROUND
Increased evidence of relevant HIV-1 epidemic transmission in European countries is being reported, with an increased circulation of non-B-subtypes. Here, we present two recent HIV-1 non-B transmission clusters characterized by NNRTI-related amino-acidic mutations among newly diagnosed HIV-1 infected men, living in Rome (Central-Italy).


METHODS
Pol and V3 sequences were available at the time of diagnosis for all individuals. Maximum-Likelihood and Bayesian phylogenetic-trees with bootstrap and Bayesian-probability supports defined transmission-clusters. HIV-1 drug-resistance and V3-tropism were also evaluated.


RESULTS
Among 534 new HIV-1 non-B cases, diagnosed from 2011 to 2014, in Central-Italy, 35 carried virus gathering in two distinct clusters, including 27 HIV-1 C and 8 CRF17_BF subtypes, respectively. Both clusters were centralized in Rome, and their origin was estimated to have been after 2007. All individuals within both clusters were males and 37.1% of them had been recently-infected. While C-cluster was entirely composed by Italian men-who-have-sex-with-men, with a median-age of 34 years (IQR:30-39), individuals in CRF17_BF-cluster were older, with a median-age of 51 years (IQR:48-59) and almost all reported sexual-contacts with men and women. All carried R5-tropic viruses, with evidence of atypical or resistance amino-acidic mutations related to NNRTI-drugs (K103Q in C-cluster, and K101E+E138K in CRF17_BF-cluster).


CONCLUSIONS
These two epidemiological clusters provided evidence of a strong and recent circulation of C and CRF17_BF strains in central Italy, characterized by NNRTI-related mutations among men engaging in high-risk behaviours. These findings underline the role of molecular epidemiology in identifying groups at increased risk of HIV-1 transmission, and in enhancing additional prevention efforts.
National Institute for Infectious Diseases L. Spallanzani-IRCCS, Rome, Italy.
Lavinia
L
Fabeni
University of Rome Tor Vergata, Rome, Italy.
Claudia
C
Alteri
National Institute for Infectious Diseases L. Spallanzani-IRCCS, Rome, Italy.
Nicoletta
N
Orchi
National Institute for Infectious Diseases L. Spallanzani-IRCCS, Rome, Italy.
Caterina
C
Gori
University of Rome Tor Vergata, Rome, Italy; University Hospital Tor Vergata, Rome, Italy.
Ada
A
Bertoli
National Institute for Infectious Diseases L. Spallanzani-IRCCS, Rome, Italy.
Federica
F
Forbici
S. Giovanni Addolorata Hospital, Division of Clinical Immunology, Rome, Italy.
Francesco
F
Montella
S.Andrea Hospital, Sapienza University of Rome, Rome, Italy.
Alfredo
A
Pennica
National Institute for Infectious Diseases L. Spallanzani-IRCCS, Rome, Italy.
Gabriella
G
De Carli
IRCSS San Gallicano, Rome, Italy.
Massimo
M
Giuliani
National Institute for Infectious Diseases L. Spallanzani-IRCCS, Rome, Italy.
Fabio
F
Continenza
National Institute for Infectious Diseases L. Spallanzani-IRCCS, Rome, Italy.
Carmela
C
Pinnetti
National Institute for Infectious Diseases L. Spallanzani-IRCCS, Rome, Italy.
Emanuele
E
Nicastri
University of Rome Tor Vergata, Rome, Italy.
Francesca
F
Ceccherini-Silberstein
Infectious Diseases Unit, Sapienza University, Polo Pontino, Latina, Italy.
Claudio Maria
CM
Mastroianni
National Institute for Infectious Diseases L. Spallanzani-IRCCS, Rome, Italy.
Enrico
E
Girardi
University Hospital Tor Vergata, Rome, Italy.
Massimo
M
Andreoni
National Institute for Infectious Diseases L. Spallanzani-IRCCS, Rome, Italy.
Andrea
A
Antinori
University of Rome Tor Vergata, Rome, Italy.
Maria Mercedes
MM
Santoro
National Institute for Infectious Diseases L. Spallanzani-IRCCS, Rome, Italy.
Carlo Federico
CF
Perno
D000328:Adult; D001483:Base Sequence; D019143:Evolution, Molecular; D005260:Female; D015658:HIV Infections / Q000453:epidemiology / Q000235:genetics* / Q000635:transmission; D015497:HIV-1 / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny