When is a new global epidemic going to strike? At a time when new viruses are emerging at an unprecedented rate, and as Ebola is claiming lives in West Africa, this in-depth investigation examines this invisible threat.

In the space of 60 years, over 350 new infectious diseases have appeared, including SARS, H1N1, H5N1 and Ebola. The emergence of viruses seems to be speeding up. Experts are unanimously wondering: when will a new world-wide epidemic strike? The Plague, the Spanish flu, smallpox, AIDS - history has undergone infectious episodes that have decimated populations. But what is the state of research today? Are we better prepared?

This film traces 3 particularly threatening viruses: the H7N9 flu virus in Asia; the Mers-CoV virus, related to SARS, which is active in the Middle East; and the Ebola virus, which is striking terror in West Africa.

Also available in French: Épidémies, la menace invisible