The medical world has certainly come far in the last few hundred years. Vaccines and immunology have turned once-dangerous diseases like the Black Plague into treatable conditions, and, despite millions of deaths that have been reported in the past, there are now very rare instances of such diseases taking hold.
But there are a select few viruses around the world that still claim the lives of many people. Their case fatality rates are among the highest of any virus, and most of them cannot be treated. So, which ones top the list? Click on to find out.