Spanish flu
The Spanish flu pandemic of 1918, considered the deadliest in history, infected an estimated 500 million people worldwide and killed up to 50 million people. This was in the wake of the first world war. The flu was first uncovered in Europe, the United States and some parts of Asia before immediately spreading around the world. Within a short period of seven months, it had wreaked havoc as there were no effective vaccines to treat it. Bodies were found piled up in makeshift morgues in many parts of the world, according to History.
