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The Global Influenza Pandemic of 1918-19 Influenza is caused by a virus that attacks mainly the upper respiratory tract – the nose, throat and bronchi and rarely also the lungs. The genetic makeup of influenza viruses allows for both major and minor genetic changes, making them immune to existing vaccines. Three times in the last century, the influenza viruses have undergone major genetic changes, resulting in global pandemics and large tolls in terms of both disease and deaths. The most infamous pandemic was “Spanish Flu” which affected large parts of the world population and is thought to have killed at least 40 million people in 1918-1919. More recently, two other influenza pandemics occurred in 1957 (“Asian influenza”) and 1968 (“Hong Kong influenza”) and caused significant morbidity and mortality globally.

"The Global Influenza Pandemic of 1918-19" is

Spanish flu

The principal reasons for the decline in the death rate after 1921 were increased levels of control over famines and epidemic diseases. The latter cause was perhaps the most important. The major epidemic diseases in the past were fevers of various sorts, plague, smallpox and cholera. But the single biggest epidemic was the influenza epidemic of 1918-19, which killed as many as 170 lakh people, or about 5% of the total population of India at that time. (Estimates of deaths vary, and some are much higher. Also known as ‘Spanish Flu’, the influenza pandemic was a global phenomenon