The XXI Meeting Scientific of Spanish Society of Epidemiology (S.E.E.) is held jointly with the conference of the International Epidemiological Association (I.E.A.) European Federation. The chosen motto for both meetings is: "Epidemiology: Development and Equity".

In preceding meetings of the Spanish Epidemiology Society reference was made to the capacity of the Epidemiology as a discipline to directly participate in the social process of improving life conditions of the population. In recent years, the magnitude of social and economic changes has been highly impressive, however. The choice of the motto arises from the need to define the role that Epidemiology should play and the answers it can offer when facing the challenges emerging in a constantly evolving society:

­ How does economic and social development influence morbidity and mortality patterns in today's society? Does it affect different countries, social classes and gender in the same way?

­ Is equity a relevant category in the distribution of health and disease?

­ Is Epidemiology a "pure and aseptic" science whose only aim is to explain the events related to the health-disease imbalance taking place in the community or rather a discipline involved in the social process?

At a point in human history in which infectious diseases are re-emerging in some European countries with decaying health systems and the prevalence of chronic diseases is rapidly expanding in others, according to the spectacular social and economic transformations and longer life expectancy, it is necessary to look for answers and strategies to address those challenges.

In the face of a global society that produces increasing poverty, war and social conflict, desperate migrations, deep changes in the ecosystem, elimination or decreasing of public health systems, Equity can be the answer.

Can Epidemiology, from its perspective, with its possibilities and limitations contribute to equitable global development?

To look for answer to these questions, we welcome all to Toledo.