Hidden and mobile: A web-based study of migration patterns of men who have sex with men in China

Abstract

Background. Men who have sex with men (MSM) are highly vulnerable to human immunodeficiency virus (HIV) infection and more likely to migrate due to widespread stigma and discrimination in China. Their mobility complicates estimation of local MSM population sizes and the provision of HIV services, and may also contribute to the spread of HIV. Methods. Between 1 January 2008 and 31 December 2012, the visits of all individuals to the largest Chinese MSM dating website were recorded. After a predesigned de-identification procedure by the website, we analyzed Internet Protocol addresses for migration patterns. Migrants were defined as individuals who were away from their registered residence for >6 months in the last 12 months. Results. The website contained data on 794 912 MSM eligible for the study, of which 34.5% were migrants. The median age was 26 years (range, 18-61 years), and 85.5% were unmarried. Compared with nonmigrant MSM, migrants were less likely to be married to a woman (8.6% vs 13.5%; P