A viral social media photo purports that a pandemic has occurred every 100 years in 1720, 1820, 1920 and 2020.
Although history records that disease outbreaks have happened during those periods, not all such outbreaks were actually pandemics and not all have occurred exactly in the years indicated. Furthermore, the occurrence of other pandemics within the period indicated demystifies the pattern of a pandemic only every 100 years. There is also no basis to prove such patterned occurrences.
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Yet another theory surrounding the coronavirus pandemic is a claim that it is part of a pattern of pandemics every 100 years. A photo of an Instagram post indicates that a theory proposes the occurrence of pandemics every 100 years. The post further exemplifies a 1720 plague, an 1820 cholera outbreak, a 1920 Spanish flu and the 2020 coronavirus pandemic as proof of the theory.
The photo, which appears to be an extract from a print publication on January 26, 2020, is captioned; “1720 Plague, 1820 Cholera Outbreak, 1920 Spanish Flu, 2020 Chinese Coronavirus- What’s happening?”
It further reads; “There is a theory that every 100 years a pandemic happens. At first glance, nothing seems strange, but the accuracy with which these events take place is scary.”
The photo has also been shared on Twitter and Facebook.
Verification
All Google Reverse image searches indicate that the photo is only associated with similar claims appearing on different platforms on the Internet. None of the searches shows the original source of the publication.
However, all the outbreaks listed, and their corresponding years were verified.
The case of the 1720 plague
The 1720 plague, also referred to as The Great Plague of Marseille, can not be considered a pandemic, contrary to what the post states. Both the World Health Organisation and the Centres for Disease Control define a pandemic as a worldwide spread of a disease usually affecting a large number of people. However, the 1720 plague, which lasted from1720 to 1723, occurred in the city of Marseille and did not affect people beyond France.
The plague is recorded to have been caused by fleas on plague-infected rodents from a docked ship in Marseille and killed an estimated number of 100,000 people in that city and surrounding provinces.
The case of the 1820 Cholera outbreak
The Cholera outbreak first occurred in India in 1817 and lasted till 1824. The year 1820, therefore, is a period in which the outbreak lasted, not when it first occurred. However, 1820 is when it started becoming a pandemic, as it spread from India to affect and kill people in other parts of the world which makes the claim partly true.
According to historical accounts, this first Cholera pandemic spread throughout India to modern-day Myanmar and Sri-Lanka in 1817, then in 1820, it spread to Thailand, Indonesia, Sri-Lanka and China. In 1821, it affected Europe, modern-day Turkey, Syria and South Russia. And in 1822, Japan was also affected.
The 1817 Cholera pandemic is recorded to be the first Cholera pandemic among seven Cholera pandemics that have occurred.
The case of the 1920 Spanish flu
The claim of the 1920 Spanish flu shows inaccuracies in dates.
The influenza occurred in 1918 and lasted till 1920. This contradicts the claim stating that the pandemic occurred in 1920; rather, it ended in 1920. The Centre for Disease Control indicates that the flu spread worldwide, thereby becoming a pandemic between 1918 and 1919. The flu spread from Europe, America and parts of Asia to other parts of the world.
The flu, which was caused by an H1N1 virus is recorded to be the worst pandemic in recent history, affecting about one-third of the world’s population and killing an estimated 50 million people worldwide.
The case of the 2020 ‘Chinese Coronavirus’
The novel Coronavirus, Covid-19 was first reported in 2019 in China and was considered a pandemic in 2020 by the WHO, as it spread from China to affect and kill people around the world.
No correlation whatsoever
Not only does the post inaccurately characterise the Plague as a pandemic, as well as show discrepancies in the dating of the occurrence of the Spanish flu, it also ignores other pandemics that have occurred before 1720 and within the 1720 -2020 year period. The occurrence of other pandemics consequently distorts the pattern of the 100-year occurrence of pandemics to show that pandemics have happened over the years in no specific pattern.
Furthermore, some health experts have stated that although some viruses are seasonal, and some epidemics are also cyclical, the Covid-19, as a new virus, is unpredictable, and there is also no basis to prove that pandemics happen every 100 years.
Conclusion
The claim that a pandemic happens every 100 years is only partly true. Although all the outbreaks listed have occurred in history, the claim wrongly characterises the plague as a pandemic and inaccurately dates the Spanish flu pandemic. The claim also neglects other pandemics that have happened within the period indicated, which show that pandemics have happened over the years in non-cyclical order. Some health experts have also stated that there is no basis to prove the occurrence of pandemics every 100 years.
