This news item disturbed even me. It is one thing to contemplate economic doomsday, which always leaves the hope of rebuilding. But, a biological doomsday is different, especially if it is microbiologically caused. It hits you from within where you can’t defend yourself.
The Black Death, which once devastated the European population, may be making a comeback, in a mutated form, which is airborne, that is spread by coughing etc. from person to person, and not just by fleas:
https://www.shtfplan.com/experts/air-travel-could-spread-plague-as-health-officials-warn-nine-countries_10262017
http://edition.cnn.com/2017/10/25/health/madagascar-pneumonic-plague-outbreak/index.html