In late march of the year 1918, during the fourth year of the First World war, the entirety of Europe was surprised by an event that killed a tremendous number of soldiers and civilians. The cause of such deaths was not violence but a disease widely known as “the Spanish Flu”. This disease single handedly infected ⅓ of the whole human population and killed three times more people than the ongoing Great War in a year. The first wave swept across Europe in mere months, and when the war ended and the new year of 1919 began, the second wave of infections started. The disease that started in the European region reached the United States, and then went to Asian and African regions rapidly. The pandemic was active until winter came in 1920. Eventually killing at least 500 million people, the Spanish Flu is remembered as the deadliest pandemic of the 20th century.
So why was the Spanish Flu so deadly? There are few factors which gave the pandemic its lethal and destructive power. First of all, the virus that caused the Spanish Flu Pandemic, The H1N1 virus was airborne. Most airborne diseases are very infectious and are considered to be the most difficult type of contagious diseases to control, because it is spread through the most common medium in the world: air. The H1N1 virus in 1918 was one of them. It was just as infectious as the virus SARS-COV-2, a virus which caused the current COVID-19 outbreak. Shown with the value called “R-nought” value, which shows the infectiousness of the virus with a format R-n, (higher the n, more infectious the virus), SARS-CoV-2 has an R-nought value of R-2.2, while the H1N1 virus which caused the Spanish Flu pandemic has R-1.8. Considering the massive medical development since 1918 to the current times, the H1N1 virus could easily transfer and infect through the population just as, or maybe better than SARS-Cov-2. Also when the first wave of Spanish flu pandemic hit Europe, it was during the last year of the First world war. Countries sent troops overseas in large numbers and many combatants had to fight and live in very small and unhygienic places such as trenches. These conditions made them a good host for the H1N1 virus.
The modern understanding of a virus that causes the infectious disease is that most times if the virus is very infectious, it’s not lethal enough to kill the host in large numbers as it will eventually kill the virus prior to its spread if it does. But for the H1N1 virus in 1918, this was not the case. It was both very infectious and lethal. When infected, the virus created normal symptoms of the common flu, but there was one big difference: it could develop the Cytokine Release Syndrome(CRS). Also known as the name ‘Cytokine Storm’. The CRS occurs when the pathogen enters the body that has an unhealthy or incomplete immune system. Cytokines are chemicals that act as alarms that warn phagocytes that infections are happening in the body it leads them to the organ that infections are happening to stop it. When CRS triggers, cytokine is released without any control, calling up too many phagocytes, which again releases more cytokine, creating a chain reaction. When the immune system is healthy it senses the problem and injects another type of cytokine called Anti-flammable Cytokine to stop the release of normal cytokine and restore the immune system to work in track. However, when the immune system is unhealthy, the body cannot control the release of cytokine in the body and phagocytes arriving at a certain point of the body starts to attack normal cells, eventually killing the tissue, then the organ, then the body system, and then the body itself. It was deadly when the Spanish flu pandemic hit, as the whole world was full of populations that had wounds and injuries, tuberculosis and other infectious diseases, and lack of enough nutrients due to the First world war and other factors.
Lastly, the governments and regimes during the Spanish flu Pandemic could not respond successfully to it due to several reasons such as war effort, underdeveloped technology, and lack of infrastructure. The infection of the H1N1 was first reported in Europe in March 1918 just after the unit of the US Army arrived in France from the states, carrying the disease. This was during the time period when the Western front had one of it’s biggest campaigns, the Spring offensive of 1918. Many units and combatants had to move around the frontline due to planned offensive. Soon the disease spread to every single unit in the western front, but armies did not prepare themselves against the outbreak since they feared that it would affect their war efforts in a negative way and they thought that it would end just like any other ‘trench flu’ occurred during the last 4 years of war. A single month later, it started to kill more military personnel than the war itself. Units around the frontline could start to do something to stop, or at least slow down, the infection when the war was at its ending phase from the summer of 1918. They created a series of quarantine rules for overseas troops, supplied surgical masks and alcoholic beverages to troops, but it did not work well. Eventually 41% of the US Navy personnel, 37% of US Army personnel, 32% of Canadian Army personnel, and about 30% of the British Army personnel were infected by the H1N1, and 4~20% of them got killed by the H1N1 till the cease fire on November 11th 1918.
After the war got into its ending phase from the summer of 1918, a high number of cases appeared in many homefront societies due to returning troops from the theater of war. When countries realised the outbreak in civilian society, they locked up theaters, markets, squares and most other public places. Civilians were forced to wear masks. Infected people were ordered to quarantine themselves in their houses until the medical service arrived. Police forces arrested people who broke the rules of social distancing. However, these acts did not function properly in many countries. Countries such as the United States and France still opened Schools for student and military camps for recruits, creating a good incubator for the virus. Many medical personnels around the world were already infected by the virus due to lack of protection, leading to numerous deaths. By the summer of 1919, there were not even enough doctors to fill up the hospitals, and medical students had to work as part-time doctors to fill up the gap.
Lastly, medicine overuse was a problem. During the Spanish Flu pandemic, doctors used Aspirin to help the patients as it was the only available drugs for them. It seemed to work out well when Aspirin was properly dosed by helping patients cease their symptoms, thus giving the body more control over the immune system. However doctors used too much of it. In modern days Aspirin could not be used more than 4 grams per day, but doctors in 1919 used more than 30 grams per day. This caused Aspirin poisoning: its symptoms include hyperventilation and fluid build-up in the patient’s lung. When layered with the Symptoms of the H1N1 virus, these poisonings became very critical to the patient’s health. More than 11~20% of all Spanish Flu deaths in western countries were known to have Aspirin poisoning.
With these critical symptoms and conditions, the H1N1 virus eventually killed at least 500 million people worldwide: 3~5% of the whole European population and 1~3% of the whole Asian population were killed by the H1N1 virus.