There are approximately 231.5 million international migrants. Combined with some 740 million internal migrants, this means that there are about 1 billion people on the move at any given time. Migration can place people in situations of heightened vulnerability to HIV, and has been identified in certain regions as an independent risk factor for HIV (3–5). In a majority of countries, undocumented migrants face complex obstacles, such as a lack of access to health-care services or social protection. Social exclusion also leaves migrants highly vulnerable to HIV.
