''The Spanish Flu'' of 1918 - the most dreaded pandemic - A brief look

Spanish Flu  of 1918 bshm.org.uk

An electron micrograph showing recreated 1918 influenza virionsen.wikipedia.org

Barring many facts related to mode of transmission and time of activity,  one can  see some similarity between  the Spanish Flu  of 1918 and pandemic Covid-19 that is strangling the countries across the globe  right now.  Modern analysis of Spanish flu of 1918 has shown  that the virus is particularly deadly because it triggers a ''cytokine storm'' (overreaction of the body's immune system). Because of it  20% died a very unpleasant death  and in fast-progressing cases, mortality was caused  primarily from pneumonia, by virus-induced lung consolidation. In the case of Covid-19, if the virus, once inside the human body remains there untreated,  ultimately it will reduce the efficiency of lungs causing death. It transmits in clusters and the  easy targets  are people in crowded places.

the Spanish flu, 1918  www.tes.com

The first of two pandemics caused by the H1N1(airborne avian virus) influenza virus, the Spanish flu, the deadly one that was active from January 1918 to December 1920 infected about a quarter of the world's population at that point of  time and it left behind a trail of countless deaths, pain and sufferings, and further shattered the world economy.  The exact death toll of the Spanish Flu is a subject of debate and it is as low as 17 million people and possibly as high as 50 to may be 100 million. It is one of the  deadliest  epidemics in human history that turned the world upside down. The second deadliest one was the Swine Flu in 2009.  Much deadlier  second wave of  Spanish Flu  - 1918 pandemic  had a hold on the world for some time and those most at risk were the sick and elderly; as for  younger, healthier people, they  recovered easily. Toward 1919, the virus developed less lethal strains and cases dropped slowly.

The Spanish flu .bbc.com

The Spanish flu impacted many parts of the globe and since it happened during WWI,  maintaining morale among soldiers in the war front was the first priority of the warring countries.  So, World War I censors recommended minimized early reports of illness and mortality in Germany, the United Kingdom, France, and the United States.  As for the source of the virus, in 1917 itself UK  military pathologists concerned about high mortality rate among young adults, postulated that  the overcrowded medical camps and hospitals  provided  ideal sites for transmission of a respiratory virus. The hospital treated  soldiers in tens of thousands   during the war every day.  The place was home to a piggery, and poultry  and the food supplies came from surrounding villages. The British team postulated that a significant ''precursor virus,'' harbored in birds, mutated and then migrated to pigs kept near the front. It is obvious the virus had been around for sometime even before 1918 and the military  soldiers had been carrying it without their knowledge. Later, it turned out to be a pandemic. A 2003  American medical report said that 1918 outbreak  happened in  Haskell County, Kansas. Some reports pointed that the flu first originated in China and later transmitted to other countries like the US. Chinese researchers deny  such reports.   
Given below are some important facts of Spanish Flu of 1918:
01.  The shocking fact is  Spanish flu killed more people in 24 weeks than HIV/AIDS killed in 24 years and the black death lasted for a long time.  
02.  In this  pandemic young adults were killed in large number.  
03.  During the period between 1918–1919, 99% of  deaths in the U.S. occurred in people under 65, and nearly half of deaths were in young adults 20 to 40 years old.
04.  Like wise death was quite common among pregnant women because the virus could weaken the respiratory system.  
05. Yet another noticeable fact is in 1918 adults above 70 had a sort of partial protection against the Spanish flu because of exposure to the Russian flu Pandemic of 1899-90. 
06. Another strange fact was this influenza was worse in winter and widespread in  the summer and autumn (in the Northern Hemisphere).
07 .The 1918 flu spread rapidly, killing 25 million people in just the first six months.
08. Over crowding, mass gathering and social contacts accelerated the spread of this influenza.
09. During the war time (WWI), troop movements, mass medical camps further triggered the spread. So, death rate can be attributed to crowding in military camps and urban environments, as well as poor nutrition and sanitation, which suffered during wartime.
10. The 1918 pandemic came to be dubbed the Spanish flu not because it originated there but because ''Spain''  remained  neutral in the war and so reported freely on the outbreak.
11. The U.S. and other countries at war   did not want the soldiers and others  to know about the  severity of the disease; reason: it might damage  their morale.
12. Some  Historians now believe  this air-bone avian virus most probably originated near Fort Riley, Kansas, in March 1918. Its place of origin is still debatable.  
13. Death in the initial wave first half of 1918 was  relatively low; highest death rate in the second wave October through December; More lethal than the first but less so than the 2nd was the third wave - spring of 1919. 
14. Most victims were certain ethnic groups who had no previous exposure to the flu. example Native American Indians. 
15.  No specific anti-viral therapies were available during the 1918 flu.

stengel.mycpanel.princeton.edu/

Above image: A cytokine storm is an ''overproduction of immune cells and their activating compounds (cytokines), which, in a flu infection, is often associated with a surge of activated immune cells into the lungs. The resulting lung inflammation and fluid buildup can lead to respiratory distress and can be contaminated by a secondary bacterial pneumonia -- often enhancing the mortality in patients''..(https://www.sciencedaily.com/releases/2014/02/140227142250.html)  ..........................................
Normally, most influenza outbreaks disproportionately kill the very young and the very old, with a higher survival rate for those in between,  But, the  chilling fact about  the Spanish flu is it caused higher mortality rate than projected among young adults.  Medical researchers came up  with possible explanations for the high mortality rate among young adults in the 1918 pandemic. Some were of the view the virus turned deadly because  it triggered  a cytokine storm. (see the image above).
 However, a 2007 analysis of medical  reports on the early pandemic published in medical   journals from the active period observed that   the viral infection was no more aggressive than previous influenza strains.The influencing factors in this case  were  undernourishment, overcrowded medical camps and hospitals, and poor hygiene. They caused bacterial super infection that resulted in the  death of most of the victims, typically after a somewhat prolonged death bed.
In the past decades various studies have been undertaken as to the  total death toll of 1918 Spanish flue. A 1991 estimate says the pandemic killed 25–39 million people. However, a 2005 estimate put death toll at probably 50 million (less than 3% of the global population), and possibly as high as 100 million (more than 5%). A clear estimate is not yet available.   As for India that was ruled by the Raj 12-17 million people died ( about 5% of the population).  The death toll in India's British-ruled districts was 13.88 million About China, the estimates are at variance and on an average it was more than 1.5 million people.

dailyastorian.com

How did the Spanish flu spread?   From which country the flu had begun to spread  still remains controversial. However, based on data from Austrian archives  scientist mentioned that the influenza began to spread from Austria in 1917. The British researchers

believe that it began in the USA in 1918  The transmission of this virus was a quick one. If  an infected person sneezes or coughs, more than half a million virus particles  are out in the air invisible and can catch those nearby.  This dangerous flu became a pandemic soon because of increased mutation, easy transmission  through  close social  contact, mass gathering,  massive troop movements of World War I, crowded medical camps, hospitals, etc.  The viral became lethal during the war time as the hosts - soldiers, it is speculated, burdened by stress of  facing enemy lines and chemical attacks  and mal-nourishment. The sustained virus weakened their immunity system and made them   susceptible to diseases.Yet another important factor that promoted transmission  of virus in many parts of the globe was  travel.  With better development of  modern transportation systems in air, sea land, etc the soldiers, sailors, and civilian  had easy access to them and they became carriers of  the disease.
The following are the casualty reports in other countries: Iran: High mortality rat;  about  between 902,400 and 2,431,000, or 8% to 22% of the total population died;  Japan: 23 million people were affected,  at least 390,000  died; The Dutch East Indies (now Indonesia): about 1.5 million death a population of  30 million people;    USA:  About 28% of the population of 105 million became infected, and 500,000 to 675,000 died (0.48 to 0.64 percent of the population); death was widespread among native American Indians. Entire Inuit and Alaskan Native village communities died in Alaska; Canada: 50,000 died; Brazil: 300,000 died,
We in India, like other countries,  are going through a tough time, a period of uncertainty, anxiety and weakened economy  and the present total lock down, it is likely,  may go beyond April 14.  We, as responsible citizens, must obey the orders of state and central governments and trust the precautionary measures being taken by them. In the present context, with no proper medication available  for corona virus, only precaution is social distancing and self-imposed isolation   Try to shun lousy politicians who make capital out of Corona virus pandemic for their publicity. Our administrators have to tackle many problems on many fronts. For them and the medical fraternity it is a horrendous time  to be on duty beyond their capacity.  Let us all pray  and follow the govt. regulations with patience to tackle  the present emergency. Positively, we will see a silver line in the cloud in the near future.
https://en.wikipedia.org/wiki/Spanish_flu

https://www.modernhealthcare.com/article/20180922/NEWS/309229988/data-points-1918-spanish-flu-hits-centennial-virus-killed-50-million-worldwide
https://bshm.org.uk/the-spanish-influenza-pandemic-of-1918-19/
https://timesofindia.indiatimes.com/india/why-covid-19-is-nothing-like-the-deadly-spanish-flu/articleshow/74623053.cms 
https:www.sciencedaily.com/releases/2014/02//140227142250.htmstengel.mycpanel.princeton.edu/