We describe an outbreak of subtype G among injecting drug users (IDU) in northern Italy newly infected with HIV. We analysed pol gene sequences from samples of 139 individuals from different risk groups. Non-B subtypes were more frequently detected among IDU than in homosexual or heterosexual contacts. All G subtypes but one were found among IDU. The phylogenetic analysis indicated that the outbreak was of monophyletic origin and was caused by HIV-1 strains similar to those from western Africa.
aEpidemiology Unit Department of Infectious, Parasite and Immune-mediated Diseases, Istituto Superiore di Sanità, Rome, Italy
bDepartment of Pathology, Immunology and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, Florida, USA
cMRC Pathogen Bioinformatics Unit South African National Bioinformatics Institute, UWC, Cape Town, South Africa
dOspedale Amedeo di Savoia, Turin, Italy
eDepartment of Infectious and Tropical Diseases, Università di Milano, Milan, Italy
fPoliclinico ‘Agostino Gemelli’ Università Cattolica Roma, Rome, Italy
gOspedale ‘S. Gallicano’, Rome, Italy.
Received 7 January, 2007
Accepted 31 January, 2007