Wednesday, April 1, 2020

The Major Pandemics thru History


The Plague of Athens was an epidemic that devastated the city of Athens during the second year of the Peloponnesian War in 430 BC. The plague returned twice more and killed 25% of the Athenian populationThe epidemic caused a massive migration from the Attic countryside into the city and resulted into an overpopulation. Due to the close quarters and poor hygiene, Athens proper became a breeding ground for the Plague and many citizens died, including the statesman  Pericles, Aspasia his wife, and his two sons.  

Some 30 pathogens have been implicated as having caused the plague but the most likely microbe according to Professor Durack of the University of Maryland was due to Rickettsial bacteria that can cause three different varieties of the disease we call typhus. According to historian Thucydides, the Athenian Plague came from Africa, Ebola and other hemorrhagic fever diseases are other distinct possibilities. (The Plague of Athens, paintng of Michiel Sweets c 1652-1654) 
In the year 541 AD, the Justinian Plague, spread thru most of the Byzantine Empire, and Western Europe including England and Ireland.  The pandemic that reappear several times until 750 AD resulted in the death of 25 to 100 million people a toll that represented 50% of Europe’s population in the first outbreak.  In 2013, researchers confirmed that the cause of the Justinian Plague was Yersinia pestis, the same bacterium responsible for the Black Death. 
The Black Death, also known as the Pestilence, the Great Bubonic Plague or the Plague, was the most devastating pandemic recorded in human history, resulting in the deaths of an estimated 200 million people in Eurasia, peaking in Europe from 1347 to 1351. The bacterium Yersinia Pestis which is known to cause several forms of the Plague such as the bubonic which is the most common, the pneumonic and others, is believed to have been the cause. 
The Black Death probably originated in Central Asia and via the Silk Road reached Crimea by 1343. From there, it was likely carried by the fleas living on rats that traveled on Genoese  merchant ships, spreading the Black Death throughout the Mediterranean Basin, and reaching the rest of Europe via the Italian Peninsula.  The plague arrived in Europe in October 1347, on 12 ships that docked at the port of Messina. People at the docks were met with a horrifying surprise: Most sailors aboard the ships were dead, and those still alive were gravely ill and covered in black boils that oozed blood and pus.  
The Black Death is estimated to have killed 30% to 60% of Europe's population.  In total, the plague may have reduced the world population from an estimated 475 million to 375 million in the 14th century. It took 200 years for Europe's population to recover to its previous level There were three more outbreaks of the plague in the 17th, 18th and 19th centuries that claimed an additional 15 million lives.  
The arrival of European conquerors and later immigrants into the Americas introduced new diseases to the indigenous populations who had no immunity to them.  As early as 1492 and later in 1836 through 1840 smallpox epidemics occurred.  Smallpox reached its height after the spring of 1837 when the steamboat, S.S. St. Peter, carried infected people and supplies into the Missouri Valley.  The death toll during the epidemic was approximately 17,000 people.  In the span of two years the Mandan Indian tribe was totally decimated.  During the epidemic white settlers and the army allegedly facilitated the spread of smallpox among unsuspecting Native Americans by giving them blankets that smallpox patients had used.  Although not scientifically documented it is likely one of the many genocides in human history. 
The Spanish flu an unusually deadly influenza pandemic lasted from January 1918 to December 1920.  It infected 500 million people—about a quarter of the world's population at the time and its death toll is estimated to have been anywhere from 17 million to 50 million.  WWI military censorship minimised reports of deaths among populations of waring nations while they were free to report from neutral Spain thus their stories created the false impression that Spain was the place the flu originated from and giving rise to the pandemic’s nickname Spanish flu.  A recent paper describes that the cities which were mostly affected by the flu experienced an economic decline with an 18% reduction of their economic output.  They authors suggest that the cities which intervened earlier and aggressively grew faster after the pandemic was over. 
(Soldiers with Spanish flu at hospital ward at Camp Funston)
Since its beginning in December 2019 in Wuhan city, in Hubei province of China, nearly 860,000 cases and 42,000 deaths due to Corona virus have been reported worldwide.  During this period, confirmed cases in select countries, are as listed in round numbers; US 190,000, Italy 105,000, China 82,000, Germany 71,000, France 52,000, Sweden 4,500, Greece 1,300, S. Korea 9,900 and Japan 2,000.  For those who are interested in a more detailed analysis please check the link Radiology Monthly but briefly as of today the death per million in the USA is 12, Italy’s is off the scale at 200, Germany’s is 10, Sweden’s is 18, Greece’s is 5, S. Korea’s is 3 and Japan’s is 0.5 which is remarkably low.  Most of the countries have instituted lockdowns, the Swedes and the Japanese are using social distancing and have not changed their way of living comparing to that before the pandemic. The Koreans and the Singaporeans are doing extensive testing.  The Taiwanese are advising hygienic measures with excellent results.  Those interested in more information about pandemics of the past two millennia please consult the following link.