Why 20’s is a cursed year for disease outbreaks?

Throughout the history the twenties has been hit by major disease outbreaks and epidemics

1520

Smallpox was an unknown disease not only in Mexico, but in the Americas, before the arrival of Europeans

The native people of Mexico experienced an Smallpox epidemic disease in the wake of European conquest (Figure 1), beginning with the smallpox epidemic of 1519 to1520 when 5 million to 8 million people perished.

1620

Algiers lost 30,000–50,000 to it in 1620–21 as a result of second epidemic of Blackdeath

1720

The Great Plague of Marseille was the last of the significant European outbreaks of bubonic plague. Arriving in Marseille, France in 1720, the disease killed a total of 100,000 people: 50,000 in the city during the next two years and another 50,000 to the north in surrounding provinces and towns.

1820

By 1820, cholera had spread to Thailand, Indonesia (killing 100,000 people on the island of Java alone) and the Philippines. From Thailand and Indonesia, the diseasemade its way to China in 1820 and Japan in 1822 by way of infected people on ships. It also spread beyond Asia.

1920

Between 1918 and 1920 a disturbingly deadly outbreak of influenza tore across the globe, infecting over a third of the world’s population and ending the lives of 20–50 million people.

The Spanish flu, also known as the 1918 influenza pandemic, was an unusually deadly influenza pandemic caused by the H1N1 influenza A virus. Lasting from February 1918 to April 1920, it infected 500 million people — about a third of the world’s population at the time — in four successive waves.

2020

The Wuhan Corona virus outbreak threatens to become a major epidemic already in 2020. It was first reported from Wuhan, China, on 31 December 2019 with more than 10K cases as of Feb 10.

WHO publishes frequent updates every day here: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/situation-reports/