hey ricardo what is the worst virus you have come across?

Question: hey ricardo what is the worst virus you have come across?
- Keywords:
  virus
Asked by guyguyington to Toby, Ricardo on 12 Mar 2020.
- Ricardo Sanchez answered on 12 Mar 2020:
  
  It would be difficult to select just one. I believe yellow fever is quite dangerous as not may people pay attention to it anymore.

Question: hey ricardo what is the worst virus you have come across?