For what reason are people at a higher risk for pandemics today than 100 years ago?

Risk is lower: Pandemics, viral or other illness that spreads and causes death and disease, HIV is a more recent example. Black plaque, yellow fever, polio and tuberculosis are other examples. Flu and food born illness continue to be health risks for pandemic spread today. Our health monitoring, tracking and therapies are so much better today that pandemics are much less risk now than 100 years ago. Be well.

Pluses and minuses: Smallpox has been eradicated. We have vaccines for yellow fever, Influenza & polio. But we also have the ability to rapidly spread infectious diseases because of rapid travel modes. Consider the Ebola epidemic- early outbreaks were contained in rural communities situated near jungles - it has now spread to a number of West African countries and outside of the continent of Africa.