Intercontinental Dispersal of HIV-1 Subtype B Associated with Transmission among Men Who Have Sex with Men in Japan

Targeting HIV Prevention Based on Molecular Epidemiology Among Deeply Sampled Subnetworks of Men Who Have Sex With Men

“…Even though only 179 participants were enrolled, phylogenetic analysis identified clustering among 64% of all participants, despite a diversity of HIV-1 subtypes and CRFs. Although somewhat higher than in other studies, this level of clustering is consistent with deep sampling of the local network such as other MSM cohorts [3,5,[33][34][35][36][37], and the epidemic is relatively new with rapid transmission. This high rate of clustering allowed us to determine that the local network structure followed a "preferential attachment" model, similar to other networks among MSM [3,23].…”

The International Dimension of the U.S. HIV Transmission Network and Onward Transmission of HIV Recently Imported into the United States

“…The relevance of this finding can be seen in the recent work by Takebe et al, 4 who looked at international migration of HIV in Japanese MSM.…”

“…1,2 For example, phylogenetic approaches have demonstrated how HIV-1 subtype B migrated across Europe and East Asia. 3,4 Moreover, these approaches have documented the introduction and continuous spread of non-B subtypes and circulating recombinant forms (CRFs), for example, in France and the United Kingdom. 5,6 Importantly, international routes of HIV migration represent potential points of intervention to reduce the spread of the virus.…”

HIV-1 CRF01_AE and Subtype B Transmission Networks Crossover: A New AE/B Recombinant Identified in Japan

“…In Japan, the number of HIV/AIDS patients at the end of 2013 was 23,015, including 7,203 AIDS and 15,812 non-AIDS patients. 15 The major circulating HIV-1 subtype in Japan has been B, which is genetically related to the strain circulating in North America, 16,17 followed by AE, with prevalences of 87.9% and 8.4%, respectively. 18 These two strains have distinct epidemiological characteristics; B predominates in men who have sex with men (MSM), whereas AE is observed mostly in heterosexuals engaging in high-risk sex.…”