However, migration may also affect psychological and physical health as a result of confl ict, famine, poverty, and the insuffi cient cultural or economic integration of migrants within their new home society. It may contribute to the spread of infectious diseases across borders ( Figure 1 ). The recent epidemic of SARS was a classic example of an infectious disease propagated through the movement of people across borders; it required attention from the original site to control migration (quarantine) as well as vigilance by secondary sites to protect their populations ( Figure  2 ) [4] . For these and other reasons, the International Organization for Migration is increasingly concerned with migratory patterns and their health consequences in a globalizing world (for an illustration of the emerging confl ict of ideas, see http:⁄⁄www.iom. int and http:⁄⁄www.noborder.org/ iom/index.php).