The globalization of economies in the last 25 years has greatly increased b
oth the number of people on the move and the rapidity of their movement, an
d has brought attention to global disparities in health determinants and to
the health of migrant populations themselves. Differences in epidemiologic
al disease risk (prevalence gaps) may have negative, neutral, or positive h
ealth consequences for the migrant or receiving population. Population mobi
lity represents a growing challenge to the development of public health pro
grams and legislative policies to prevent the importation of disease, and t
o promote and protect the health of migrants and the local, receiving popul
ation. The inability to detect and contain imported disease threats at nati
onal borders requires a shift in immigration, quarantine, and public health
approaches to health and mobile populations. A new paradigm is needed to f
acilitate che development of policies and programs to address the health co
nsequences of population mobility.