[The plague of the third pandemic and its current remergence].

The reappearance of the plague in the 19th century, in what is generally referred to as the third pandemic, brought back painful memories of the great plague outbreaks of the past that had killed tens of millions of people. At the same time, this new pandemic opened the era of great discoveries, such as identification of the Yersinia pestis bacterium, of transmission vectors and the first effective treatments. With these advances it became possible to control a disease which had, because of progress in maritime transport, spread almost throughout the world.