The reason of Yunnan Province being an area with high frequency of HIV is complicated. One of the possible explanations is the special geographic location of Yunnan with miles of shared borders with several south-eastern Asia countries which lets HIV easily spread across borders.
Recently, the research group headed by Prof. ZHENG Yongtang from Kunming Institute of Zoology (KIZ) of Chinese Academy of Sciences discovered that Burmese long-distance truck drivers (LDTDs) may contribute to HIV-1 transmission along the China-Myanmar border.
This group has long been engaged in the epidemiology and molecular mechanisms research of HIV. Prof. ZHENG reported in 2012 (AIDS, 2012, 26:1121-1129) that although various HIV-1 recombinants with high frequencies have been found along China-Myanmar border, the specific types of recombinants between two sides of the border are significantly different. For instance, the injection drug users (IDUs) have been considered as the main reason of HIV-1 spreading. The recombinants of CRF01_AE are more likely occurred among the injection drug users (IDUs) in northern Myanmar rather than among those people in Dehong, Yunnan.
Ruili county of Dehong perfecture, as the major gateway for trade between China and Myanmar is a good example for high prevalence of diversified HIV-1 recombinants. Therefore, to understand the epidemiology of HIV at the China-Myanmar border is of great importance in controlling HIV spreading.
To identify the possible channels for HIV-1 cross-border spreading, Prof. ZHENG and his colleagues have casted their eyesight onto the long-distance truck drivers (LDTDs) due to the transient nature of their work. LDTDs have a comparatively high potential to be infected with HIV-1 and spread virus to other individuals in the area they travel.
This study hypothesized that Burmese LDTDs crossing the China-Myanmar border frequently may potentially be involved in the cross-border transmission of HIV, and contribute to the high prevalence of HIV-1 inter-subtype recombinants in this border region. From 2008 to 2010, based on the results obtained from 105 Burmese male LDTDs (65 participants self-reported the potential routes for HIV-1 infection including 59 via sexual contact, two via blood transfusion, two via sexual contact and/or transfusions, and two via sexual and/or IDU), diverse forms of HIV-1, including subtypes CRF01_AE (41.9%), C (8.6%), B (4.8%), CRF02_AG (1.0%), and inter-subtype recombinants, as well as dual infection, were all detected.
Phylogeographic analyses including multiple fragments was carried out and revealed that 77.8% LDTDs acquired HIV-1 infection in Yunnan, and the others in Myanmar. Both the C-related and CRF01_AE-related recombinants from these LDTDs appeared to have close genetic relationship with those from IDUs in Myanmar and Dehong.
These findings indicate that no matter where Burmese LDTDs acquired their infection, they have high potential to further spread the viruses to their wives and/or sexual partners in Myanmar and Yunnan. By suggesting that Burmese LDTDs may contribute to HIV-1 transmission along the China-Myanmar border, the result may provide some new perspectives for understanding the on-going generation and prevalence of HIV-1 recombinants in the border region.
