Burmese injecting drug users in Yunnan play a pivotal role in the cross-border transmission of HIV-1 in the China-Myanmar border region

Abstract

Injecting drug users (IDUs) are the major risk group for HIV-1 infection in the China-Myanmar border area. There are a large number of Burmese IDUs living in Yunnan (Yunnan-mIDUs) who might be associated with the cross-border transmission of HIV-1. From 2010 to 2013, 617 Yunnan-mIDUs were recruited from three counties of Yunnan, 19.0% of whom were detected to be HIV-1 positive by serological testing. Partial HIV-1 p17, pol, vif-env, and env genes were amplified from the positive samples and were sequenced. Phylogenetic and HIV-1 subtyping analyses revealed that HIV-1 recombinant forms (RFs), including RF_BC (36.4%), RF_01BC (26.1%), RF_01C (9.1%) and RF_01B (1.1%), were predominant among this cohort. Of the identified HIV-1 strains, 14.8%, 9.1% and 3.4% belonged to subtype C, CRF01_AE and subtype B, respectively. Transmission cluster analysis showed that sequences from the Yunnan-mIDUs formed transmission clusters not only with those from Burmese IDUs but also with those from Chinese IDUs, indicating that Yunnan-mIDUs might acquire HIV-1 infection from or spread HIV-1 to both Burmese and Chinese IDUs. Phylogeographic analyses revealed three cross-border transmission patterns associated with Yunnan-mIDUs, in which Yunnan-mIDUs served as the crucial nodes linking the Burmese and Chinese IDUs. These results suggest that Yunnan-mIDUs are a potential viral reservoir for the diffusion of HIV-1 in Yunnan and play a pivotal role in the bidirectional cross-border transmission of HIV-1 in the China-Myanmar border region. More intervention efforts that focus on Yunnan-mIDUs are recommended in Yunnan’s campaign against HIV/AIDS.

<p>HIV-1 Drug Resistance in ART-Naïve Individuals in Myanmar</p>

“…Although Burmese and Chinese individuals were less inclined to share some high-risk behaviors (eg, IDU) each other, 31 Burmese individuals staying in Yunnan were significantly associated with the dissemination of HIV-1 across the China-Myanmar border region. 29,45 The finding that some TCs of HIV-1 drug resistance were formed by Burmese individuals staying in Myanmar and Yunnan, China, further highlighted the bridge role of Burmese individuals staying in Yunnan in the dissemination of HIV-drug -resistance strains across the China-Myanmar border region. Yunnan government is enlarging ART coverage for Burmese individuals staying in Yunnan.…”

“…40 Some SDRMs, including Figure 4 Maximum likelihood tree of the drug-resistance sequences among ART-naïve individuals in the China-Myanmar border region. The sequences from the Burmese IDUs, 28,33,34 Burmese LDTDs, 30 the Burmese staying in Yunnan 29,32 and newly diagnosed HIV-1 infections in Dehong, Yunnan province 37,38 are highlighted by green spots, green triangles, green diamonds and red stars, respectively. Mutations associated with resistance to PI, NRTI and NNRTI are indicated with magenta, red and blue, respectively.…”

“…43 Our previous studies reported a bidirectional crossborder transmission of HIV-1 between Myanmar and China and demonstrated that Burmese LDTDs and Burmese IDUs staying in Yunnan played a crucial role in this cross-border transmission. 29,30,44 In this study, we identified some transmission clusters formed by HIV-1 drugresistant strains in the China-Myanmar border region. Although Burmese and Chinese individuals were less inclined to share some high-risk behaviors (eg, IDU) each other, 31 Burmese individuals staying in Yunnan were significantly associated with the dissemination of HIV-1 across the China-Myanmar border region.…”

“…To explore whether there was a cross-border transmission of the HIV-1 resistant virus among ART-naïve individuals of the China-Myanmar border region, the drug-resistance mutation sequences among ART-naïve individuals from Dehong, Yunnan province, China were downloaded. 29,32,37,38 After aligning with reference sequences and resistance sequences generated in this study, ML phylogenetic analysis and transmission cluster analysis were performed as described above.…”

“…27 Our previous studies showed that northern Myanmar had a high prevalence of HIV-1 recombinants and demonstrated that Burmese long-distance truck drivers (LDTDs) and injection drug users (IDUs) staying in Yunnan could form transmission clusters with local IDUs and contribute to the crossborder transmission of HIV-1 and other viruses between Myanmar and China. [28][29][30][31] In particular, a high prevalence (12.8%) of HIV-1 TDR was detected among ART-naïve Burmese travelers entering Yunnan, China via Dehong ports during 2003 to 2012, 32 implying a cross-border transmission risk of HIV-1 drug resistance. 13 Whether the cross-border activities of these high-risk Burmese groups of IDUs and LDTDs drive the cross-border transmission of HIV-1 drug resistance via transmission links with local counterparts needs to be determined.…”