It is now all but beyond living memory - but a century ago our ancestors were battling a flu pandemic which is now regarded as the most severe in recent history.
Spanish Flu is estimated to have caused something of the order of 50 million fatalities worldwide, with nearly a quarter of a million in Britain alone.
Like most facets of the disease facts about Spanish Flu are extremely difficult to pin down. The pandemic, which almost certainly did not start in Spain, is considered to have run from January 1918 through until 1920, although it may have started earlier. Estimates suggest that the illness could have caused anywhere between 17 million and 100 million deaths.
What is certainly true is that it reached its peak in 1918 as the First World War was grinding to its bloody end and it has been suggested that the high mortality levels were more readily accepted coming as they did on top of the tens of thousands casualties caused by the conflict.
It is thought that the illness gained its name because Spain was not involved in the war and was not subject to censorship, unlike Britain and Germany where the condition was rife.
There is evidence that Spanish Flu may have started in an army camp in America or a British army camp in France, with the presence of a large number of people, together with animals, living in close proximity to each other contributing to the eruption of the flu strain and its spread aided by the mass movement of large numbers of troops.
It has also been suggested that the flu element of the condition was little different to more common types of influenza and that the huge casualty numbers were caused by bacterial infections coming on top of the flu and made worse by the poor hygiene and malnourishment of the period.
A variant of the H1N1 strain which caused Spanish flu also caused the swine flu outbreak of 2009, one of a series of illnesses to hit world populations over the last century. There was also the “Hong Kong” flu pandemic of 1968, bird flu, swine flu, Severe Acute Respiratory Syndrome (SARS) and now the coronavirus.
Pandemics are nothing new and the once-thriving town of Huntingdon was ripped apart by the Black Death bubonic plague pandemic which left a quarter of the town uninhabited and three of its churches in disuse because of the dwindling population.
Huntingdon’s charter from 1363 says the town was “so weakened by mortal pestilence and other calamities” that it was unable to pay its taxes. The Black Death is thought to have claimed the lives of anywhere between 25 and 60 per cent of the population nationally.
However, historians think Huntingdon may have been exaggerating the impact of the Black Death to avoid paying taxes as a result of a downturn in local trade.
And in 1665 people living in the Derbyshire village of Eyam put themselves into quarantine because of an outbreak of bubonic plague, knowing full-well what the result would be, with only around a quarter of the population surviving the 14 month quarantine.
The coronavirus (Covid-19) first emerged in China at the start of the year. Since then, hundreds of thousands of people worldwide have been infected and there have been more than 24,000 deaths. The source of the coronavirus is believed to be a The virus started in a place called Wuhan which sold both dead and live animals, including fish and birds.
This mixing of livestock allowed the viruses to jump from animals to humans, probably due to poor hygiene standards. The livestock were also densely packed together which allowed the disease to spread.
The original source of the virus is thought to have been bats. There were no bats being sold at the Wuhan market so it is not clear how it mutated and spread in the way it did.
Coronaviruses usually only affect animals, but have been known to jump species to humans, until now, they have not been too problematic and have caused cold and flu-like symptoms.
The issue with Covid-19 is that it is closely related to severe acute respiratory syndrome (Sars) which swept around the world in 2002/2003.
The Government says only go outside for food, health reasons or work (but only if you cannot work from home); stay 2 metres (6ft) away from other peopl; wash your hands as soon as you get home.
You can spread the virus even if you don’t have symptoms.
More information at: www.gov.uk/coronavirus.