In the past, the epidemic of Acquired Immune Deficiency Syndrome (AIDS) was not conceived originally as a public health problem, and was attributed instead to individuals enacting social roles related to lifestyles considered as transgressions from hegemonic sexuality (heterosexual, reproductive and monogamous). The epidemiological analysis was upheld by clinical notions which reinforced the stigma of population groups historically discriminated, such as homosexuals and the Afro-American population. The study of the epidemic based on the concept of risk gave rice to the category of groups at risk, so that the phenomenon was explained from a moral point of view, as it also became apparent that the deaths associated with AIDS were a consequence of sexual preferences. This then impeded the analysis of the epidemic from the standpoint of the structural components of public health. Once it was possible to isolate and identify the Human Immune Deficiency virus (HIV) as the causal agent of AIDS, the epidemiology ceased referring to risk groups and incorporated the notion of risk practices. Even though, in the beginning potential infection with HIV by means of bodily fluids, such as blood, semen, and uterine cervical fluid was recognized, the clinical discourse still reinforced the stigmatization of infected people. The only innovation was the invention of the sexual worker as a new likely victim of the epidemic. At this moment, epidemiology recognizes the importance of speaking about contexts of risk instead of groups or practices at risk. Notwithstanding, the global dynamics of the epidemic tends to reinforce the idea that migrants are a new group at risk. This implies going backwards in the conceptual thinking of HIV/AIDS because it suggests that migrants are a new hazard for public health, just like homosexuals and commercial sex workers. The mobile populations play a role in the transmission of HIV, especially in regions where international borders are shared between countries with unequal economies. For this, it is necessary to consider that the infections of HIV exist in cultural, political, and economical contexts. In this kind of regions, the epidemic can not be analyzed thinking of migrants as the responsible actors in the prevalence growth. The human traffic and the sexual aggressions, for example, are social phenomena linked to the structural conditions of the geographical stations of the mobile populations. In addition, it is necessary to consider that the worldwide dynamics of poverty and migration are produced as a result of disintegration of rural economies (disasters, wars, structural poverty). The relation between migration and poverty can be focused as that of contexts of sexual violence and discrimination. This point of view allows for the exploration of the conditions of HIV/STD infection among persons whose dignity is less respected. The relationship between international clandestine migration and HIV/AIDS has been studied scarcely. With the aim of proposing a different epistemological focus for this problem, in this article we reflect on the possibility of analyzing the notion of vulnerability placing it in a category which takes into account the historical, cultural, social and economic contexts. We propose to analyze vulnerability as a condition that may be transformed in space and time, and that is socially diverse because of this. From this, it follows that vulnerability is acquired in the process of interaction between migrants and the societies through which they move in transit. In this sense, vulnerability can be expressed as a way of being and living, linked to social roles and the course of the personal lives of the people who accompany migrants at the time of their territorial migration. Thus vulnerability is modified according to the historical and social conditions of their places of origin, the places they pass through, and the places of their destination, but also varies according to age, sex, education and social norms which direct sexual identity, as well as the reasons migrants have for displacing themselves. This perspective also permits us to observe that in ethnographic terms, vulnerability can be studied by taking into account the social capital of the clandestine migrant which, when translated into terms of their access to social networks in the places of origin, transit and destination, may either bring them nearer to or further away from situations of isolation, depression and sexual violence. The concept of vulnerability that we propose allows for the explanation of the ruralization of the HIV/AIDS epidemic as a phenomenon related to four socio-historic aspects: poverty, disintegration of agricultural zones, sexual violence and clandestine migration to the United States. We also suggest to include the fact that the HIV/AIDS epidemic occurs in contexts where the violation of human rights is associated with sexual aggression, which can also cause new HIV/STD. For this reason, the impact of poverty acquires a specific influence on this process presenting itself as the way of life of the migrant who transfers him-herself without documents and without authorization and who is especially fragile because he/she faces circumstances in which he/she has no social power. We thus consider that in order to understand in depth the phenomenon concerning the vulnerability of populations who move without legal papers, it is necessary to include both the life histories of the individuals and a study of the social context in which these take place, as a mean of analyzing their vulnerability. The objective of this essay consists in demonstrating the instrumental potential of the concept of vulnerability and its methodological implications for the study of international clandestine migration, as well as sexual aggressions as indicators of violation of human rights and infection with HIV/STD, respectively.
