Conceived and designed the experiments: JW NW. Performed the experiments: GD ZZ. Analyzed the data: JW CZ. Wrote the paper: JW. A cross-sectional survey was conducted collecting information on demographics, sexual behavior, medical history, and drug use. Multivariate logistic regression model was used to examine associations between factors and HIV-1 infection.
Of FSWs who participated in this study, It is important to characterize the nature of trans-border transmission in order to gain a better understanding of the potential impact on the international HIV epidemic. Thomas L. Another survey[ 2 ] in the U. In a molecular-epidemiological survey[ 3 ], seven HIV-1 hypotypes were detected in the border areas of Yunnan, China, which may have been spread to Yunnan from the neighboring countries.
The factors of high prevalence in border areas are multiple, such as drug use, commercial sex and migration, thus, intensifying the potential risk of HIV transmission in these regions[ 5 — 11 ]. A systematic review of the studies conducted on the Indo- Nepal Border concluded that high prevalence of HIV was associated with male labour migrants and commercial sex at the border area[ 12 ].
With the development of commercial relationships between China and Vietnam, there are more and more people moving across the border of the two countries, including mobile female sex workers. Although many cases in the region were initially concentrated among injection drug users IDUs , sexual transmission has been playing an increasingly greater role since [ 14 ]. Hekou in Yunnan province is an important border-trade and tourist county on the Chinese-Vietnamese border with a population of ,, which has an estimated mobile population of 28,[ 15 ].
It has been reported that there is an underground sex industry in Hekou dominated by Vietnamese female migrants who have been serving locally as sex workers ever since Hekou was opened to the outside world in [ 16 ]. It has been estimated that there are over 1, FSWs in Hekou, including both Vietnamese and Chinese approximately[ 16 ].
