Identification of a Novel HIV-1 Circulating Recombinant Form (CRF184_BC) Among Heterosexual Populations Along the China–Myanmar Border Region

The China–Myanmar border region is recognized as a hotspot for the emergence of HIV-1 recombinant forms. This study identified a novel HIV-1 circulating recombinant form (CRF) in this area, designated CRF184_BC. Near-full-length genome sequences were obtained from four individuals infected through heterosexual contact: one Chinese individual and three Burmese individuals. These sequences formed a distinct monophyletic clade with strong bootstrap support, separate from all known subtypes/CRFs. Recombination analysis revealed a conserved mosaic structure comprising four subtype C segments and three subtype B segments: I C (790–2897), II B (2898–3208), III C (3209–5983), IV B (5984–6435), V C (6436–8821), VI B (8822–8969), and VII C (8970–9468). Bayesian Markov chain Monte Carlo analysis indicated that CRF184_BC emerged between the mid-2000s and the early 2010s. Identifying emerging CRFs highlights the ongoing dynamic evolution of HIV-1 in this region and emphasizes the need for enhanced molecular surveillance to inform effective public health strategies and vaccine development efforts.