Deadliest pandemics the world has witnessed in the past

London suffered a lot in the 17th century. In 1665, it witnessed the outbreak of the Bubonic Plague. It was also known as the Black Death as it had once hit the population in the 14th century. The plague had started in China and spread quickly to Europe. Whole communities were destroyed and there was nobody left to bury the bodies. It killed over 200 million people. It was said to be transmitted through rats.

The 1918 influenza pandemic, also known as Spanish flu, originated somewhere in northern China and infected over 500 million people around the world. The pandemic was caused by the H1NI influenza virus. Historians believe that the pandemic killed 50 to 100 million people, making it one of the deadliest epidemics in human history. It claimed more lives than World War 1 which wrapped up almost at the same time. There was nothing 'Spanish' about this pandemic except that Spain being neutral in the war, reported openly about the flu, while other countries downplayed it.

The Asian flu spread in the late 1950s and killed over 2 million people. It slowed down later after a vaccine was introduced in 1957. The second wave of H2N2 was again witnessed in 1958 and became part of the regular wave of the seasonal flu. In 1968, the H2N2 Asian flu disappeared. It is also believed to have gone extinct.

The flu pandemic of 1968 originated in Hong Kong. The pandemic is also known as the Hong Kong flu. The Hong Kong Flu was the third pandemic flu outbreak to occur in the 20th century. It was caused by  influenza A virus (H3N2). The virus claimed over one million people worldwide.

The 2009 flu pandemic, also known as swine flu, was an influenza epidemic that started in 2009 in the US. The virus was first detected in US and spread quickly across the world. According to the CDC (Centre for Disease Control and Prevention) up to 575,400 people died worldwide between April 12, 2009, and April 10, 2010. There were a total number of 60.8 million cases, 274,304 hospitalisations and 12,469 deaths in the US due to the virus outbreak.While the flu pandemic officially ended on August 10, 2010, the H1N1 virus still exists and circulates as a seasonal flu, causing illness, deaths and hospitalisation worldwide.