Infectious agents with high mortality rates tend to weed themselves out of the population. There’s a sweet spot for infectious disease; prolific enough to pass themselves on, not so prolific as to kill their host before they got the opportunity. Additionally, there’s a strong negative feedback to particularly nasty disease in the form of quarantine.
A much bigger risk to my mind actually comes from healthcare, which can push that sweet spot further into the “mortal peril” section. Healthcare provokes an arms race with infectious agents; the better we are at treating disease and keeping it from killing people, the more dangerous an infectious agent can be and still successfully propagate.
Infectious agents with high mortality rates tend to weed themselves out of the population. There’s a sweet spot for infectious disease; prolific enough to pass themselves on, not so prolific as to kill their host before they got the opportunity. Additionally, there’s a strong negative feedback to particularly nasty disease in the form of quarantine.
A much bigger risk to my mind actually comes from healthcare, which can push that sweet spot further into the “mortal peril” section. Healthcare provokes an arms race with infectious agents; the better we are at treating disease and keeping it from killing people, the more dangerous an infectious agent can be and still successfully propagate.