Topic 9.2 dives into a not-so-happy discussion of disease and deadly illness that have plagued society since the turn of the 20th century. The historical 'throughline' between 1900 and 2020 could not be more obvious, as we will discuss the flu pandemic of 1918 and Covid-19 of today. But we will also discuss the medical and scientific developments [breakthroughs] and the significant effects on populations around the world. However, this topic also covers how certain diseases impact societies that are struggling with poverty (malaria, tuberculosis, and cholera) while other diseases emerged as new epidemics and threats to the entire human populations (1918 influenza pandemic, Ebola, HIV/AIDS, and Covid-19.