@maxdancona,
Then you likely know you are wrong.
Marburg, along with all 5 strains of ebola have a 90% potential mortality rating.
Marburg has a higher fatality rate, but has yet to spread sufficiently to qualify its average.
Smallpox doesn't exist anymore (Outside certain labs).
None of the others are viruses.
We are discussing VIRAL diseases btw - Thought that was self-evident.
Otherwise Heart disease would top the list.