[Undocumented immigrants: what do we know about their health?].

In Italy, immigrants represent a "fuzzy" set, to which it is difficult to apply dichotomous categories as a classification (i.e., regular/irregular, economic/forced, etcetera). These categories lose its meaning when used to study health phenomena. Rather, the epidemiological profile of such a heterogeneous population depends on the varying influence of health determinants in the life-course of migration. This article builds on those assumptions, and analyses the health of irregularly- staying immigrants by adopting a global approach to the migration phenomenon. The article aims at identifying cross-sectional elements of continuity and epidemiological dynamics in the different categories. Different factors, strictly interacting with each other, strongly influence the resulting picture. Specific push-factors primarily influence the starting phases ("healthy migrant effect") and the final stages of the migration process ("salmon effect"). These factors determine good health in these groups, but are also interwined with other dynamics, connected both with the social integration process ("exhausted migrant effect") and the relation with health services, which depends on the regional and local contexts of reference. Such dynamics have been thoroughly examined for "economic migrants" arriving on the Italian coasts. However, nowadays there is important evidence that the "healthy migrant effect" can be also applied to incoming international protection seekers, as demonstrated, for example, by the low prevalence of imported infectious diseases (including tuberculosis). Mental health deserves special attention and a particular final focus, for it is a topic still not adequately addressed, in spite of the high incidence of psychic problems, caused by violence endured either before or during the journey. In the framework of migration phenomena, health issues of irregularly staying immigrants stands hence as most vulnerable, due to the overlapping effects of departure and travel conditions, and of marginalization experienced by a wide group of them in the host Country. It is, therefore, essential to pursue a balanced management of this phenomenon - rich both in implications and in opportunities - by developing highly inclusive and evidence-based public policies.