This work examines a few of the epidemics affecting the world population in the early 21st century, analyzing the social, political, and scientific stakes.

Despite scientific progress and the developpment of public health standards, diseases known to us for centuries continue to wreak havoc (cholera, malaria), while new ones capable of swift dissemination emerge (AIDS, SARS). Since the late 20th century, the possibility of a truly global pandemic has given rise to a feeling of vulnerability, reigniting fears of returning to an age when humanity was unable to check their spread. Why have these diseases returned, and become epidemics? How can we fight them?