We’ve all had several bouts of influenza or the flu, which causes headaches, runny nose, cough and muscle pain. This viral infection is self-limiting, with severe illness lasting for two to three days and most people recovering within a week after using non-prescription medicines for fever and pain.
It’s not considered a serious illness because it rarely causes hospitalisation in healthy people and kills causing complications and co-infections and aggravating existing illnesses. The cause of death is rarely recorded as influenza. It kills up to 650,000 people every year, estimates the World Health Organisation, with most deaths occurring from pneumonia, heart or brain inflammation and circulatory shock from organs not getting enough blood or oxygen.
2018 marks the 100th anniversary of 1918 influenza pandemic popularly known as “Spanish flu”, which infected an estimated 500 million people worldwide — about one-third of the planet’s then population — and killed between 20 million to 50 million people, including in India. The only decade in which India’s population did not register a decadal growth is 1910-1920, according to the Census of India, with experts attributing the reversal in population growth to increased deaths from the flu.