From the Ebola to COVID-19, diseases caused by viruses have killed humans throughout history. Viruses are much older than human beings, possibly even older than the first cellular life. More than 600 ...

"The mortality rate is lower with swine flu, but it seems to be cropping up in a lot more different places." See photos of the outbreak in Mexico » Previous influenza pandemics have been deadly.

A year ago, Rwanda faced its first outbreak of Marburg virus. Dr. Tsion Firew remembers how scared she was — and how that ...