The Top 20 Deadliest Diseases in the World

 Spanish Flu Between 1918-19: 50-100 Million dead

The 1918 flu pandemic (commonly referred to as the Spanish flu) was a category 5 influenza pandemic caused by an unusually severe and deadly Influenza A virus strain of subtype H1N1. Many of its victims were healthy young adults, in contrast to most influenza outbreaks which predominantly affect juvenile, elderly, or otherwise weakened patients. The Spanish flu pandemic lasted from 1918 to 1919, spreading even to the Arctic and remote Pacific islands. While older estimates put the number of killed at 40–50 million people, current estimates are that 50 million to 100 million people worldwide died, possibly more than that taken by the Black Death. This extraordinary toll resulted from the extremely high infection rate of up to 50% and the extreme severity of the symptoms, suspected to be caused by cytokine storms. Between 2 and 20% of those infected by Spanish flu died, as opposed to the normal flu epidemic mortality rate of 0.1%. In some remote Inuit villages, mortality rates of nearly 100% were recorded.