Due to the special geographical location of the Myanmar-China border, and relatively high numbers of high-risk groups, including intravenous drug users (IDUs), commercial sex workers (CSWs), long-distance truck drivers (LDTDs), etc., this region has become one of the hardest-hit areas of HIV worldwide. Moreover, the constant and regular activities of these high-risk groups between China and Myanmar are increasing the bidirectional spreading of HIV between these two countries and are contributing to the genetic diversity of HIV-1.

Although there were many studies focusing on the subtypes of HIV-1, including CRF01_AE, B, C, and numerous unique recombinant forms (URFs), the majority of the HIV-1 URFs were identified through partial genomic sequences, but not by full-length or near full-length genomic sequences, even though the latter can provide much more genetic information for understanding HIV-1 genetic diversity.

Under these circumstances, with the support of the Australia HIV/AIDS Asia Regional Program (HAARP) and the Yunnan HAARP project, the research team of Prof ZHENG Yongtang from Kunming Institute of Zoology, CAS, reported a near full-length characterization of a novel HIV-1 CRF01_AE/B/C recombinant isolated from a long-distance truck driver in Northern Myanmar. According to Prof ZHENG, this so far considered most complicated HIV-1 chimera ever detected in Myanmar contains four CRF01_AE, six B segments, and five C segments separated by 14 breakpoints throughout its genome.

The description of the near full-length genomic sequence of this novel HIV-1 chimera is the first report after 12 years since the first report by Takebe Y in 2003 on AIDS. The results of this study not only provide sequence references to HIV-1 vaccine design, but more importantly, suggest the severe situation of ongoing inter-subtype recombination of HIV-1 in Myanmar. The main findings of this study have been published on AIDS Research and Human Retroviruses (http://online.liebertpub.com/doi/full/10.1089/aid.2015.0021).