Abstract

Infectious disease epidemics occur within dynamic systems and environments that shape risk and, ultimately, the spread of infectious diseases. Gay men and other men who have sex with men (MSM) are disproportionately impacted by HIV everywhere in the world. Several emerging trends present risks for sustained or increased HIV acquisition and transmission, and the growth of global travel in the context of emerging online platforms for social/sexual networking is discussed here. Four factors associated with travel that could potentiate HIV transmission are highlighted: different patterns of sexual risk behaviours during travel; the growth of online tools to meet sex partners more efficiently; the global heterogeneity of HIV strains; and the potential for diassortative mixing of men from high- and low-HIV prevalence areas. Prevention tools and services must rise to these challenges, and innovative mobile applications and programs have played, and will continue to play, an important role in supporting MSM at risk for or living with HIV during their periods of travel.