The Spanish Flu, caused by the Influenza A/H1N1 virus, is considered the disease that has killed the most humans in history.
Top Diseases by Death Toll
Based on historical data, here's a ranking of some of the deadliest diseases, according to the provided reference:
| Rank | Epidemics/Pandemics | Disease |
|---|---|---|
| 1 | Spanish flu | Influenza A/H1N1 |
| 2 | Plague of Justinian | Bubonic plague |
| 3 | Black Death | Bubonic plague |
| 4 | HIV/AIDS pandemic | HIV/AIDS |
As shown in the table, the Spanish Flu pandemic of 1918-1920 caused by the Influenza A/H1N1 virus, resulted in an extraordinarily high number of fatalities, surpassing even the notorious Bubonic plague outbreaks.
The reference lists it as rank one regarding the most deaths. This makes it the disease with the highest death toll in history.
The Bubonic plague, while responsible for the infamous Plague of Justinian and the Black Death, falls behind the Spanish Flu in terms of the overall number of deaths, although it caused significant devastation.
It's also important to note that while the HIV/AIDS pandemic has caused a large number of deaths, it is ranked fourth in terms of the most deadly diseases historically.
