COVID-19: Another Century, Another Pandemic

Tetsunori Koizumi, Director

“Nous sommes en guerre.” We don’t expect to hear these words, “We are at war,” coming from the leader of a country, except when it is actually involved in a war against another country. In fact, France is not involved in any war against another country in 2020. Yet, these are the words President Emmanuel Macron used—not once but multiple times—in his televised address to the French people on March 16 in which he announced a nationwide lockdown enforced by police. Why did President Macron use these words? It is because, as he put it, “The enemy is there,” and “The enemy is invisible and it requires our general mobilization.”

We all know by now what the enemy is that President Macron is referring to. It is the coronavirus that is spreading around the world, claiming many human victims. With patients infected with this novel virus found in well over 100 countries around the world, and with the number of deaths climbing every day, the World Health Organization (WHO) was compelled to issue a warning on March 11, saying that COVID-19, the name given to this novel virus, is a pandemic that threatens the lives of people all around the world. It actually took a few months before the WHO finally decided to use the word “pandemic” because initially COVID-19 was an epidemic that threatened the lives of people living in one region of a country when it started in Wuhan, China, in December 2019.

It was 2018, just two years ago, that we marked the centenary of what is now known as the Great Pandemic of 1918. What was initially a local outbreak of influenza among farmers in Haskell County, Kansas, the influenza spread worldwide from the US to France, to Spain, to countries on the African continent, and even to New Zealand, a country in the Southern hemisphere. Though estimates vary, some put the number of human lives lost in the Great Pandemic as high 100 million, or 5% of the world population at the time.

Like the Great Pandemic of 1918, which is believed to have started from hogs in rural Kansas, COVID-2019 is also believed to have started from animals—the live and slaughtered animals sold on the Wuhan seafood wholesale market. Scientists now know that a virus can jump across species from animals to humans. The 2013 outbreak of influenza, H7N9, in China is believed to have started from contact with birds. The 2013-2016 outbreaks of Ebola virus disease in West Africa are suspected to have started from contact with bats.

How a disease initially started becomes less of a concern once it begins to spread around the world and becomes a pandemic. Once a virus jumps from animals to humans, it begins to be transmitted from one human to another in a variety of ways. Hence, the key question in our fight against “the invisible enemy” like the coronavirus is whether we can figure out the transmission mechanism among humans.

History tells us many examples of human-to-human transmission of viral diseases. One well-known example to historians was the Smallpox brought over to the New World by Spaniards after the initial expedition by Columbus opened up the sea route from the Old World to the New World.1 It was in 1519 that Cortez landed on the coast of Mexico with 66 Spaniards. One slave infected with Smallpox who arrived in the following year from Spanish Cuba spread the virus, resulting in the death of nearly half of the Aztecs. A similar devastating effect on the native population also occurred with another Spanish expedition a decade later. Pizarro arrived on the coast of Peru in 1531 with 168 men. By then, Smallpox had wiped out much of the Inca population with the virus traveling overland from Mexico to Peru.

It does not take much imagination to see that human-to-human transmission of diseases is facilitated by the development of transportation networks, whether overland or over the seas. Smallpox outbreak known as the Plague of Antoninus that killed millions of Romans between 165 and 180 CE is an example of overland transmission due to the development of world trade routes by the Romans. On the other hand, Captain Cook’s expedition to the Pacific islands is another example of transmission of diseases by seafarers, similar to the Spanish expeditions. Smallpox did not reach Hawaii until 1853, but the population of Hawaii had already plunged from about half a million in 1779 when Captain Cook arrived to about 80,000.

We are now living in the age of global travels, with transportation networks covering the entire globe. Globalization of human activities, for business as well as for pleasure, facilitated by the development of global transportation networks has opened up many channels of human-to-human transmission of viral diseases. What is worrisome is the fact that most cases of transmission take the form of what researchers today call “stealth transmission” in which people without symptoms of a viral disease unwittingly spread the virus to people around them. This is certainly the case with the novel coronavirus that is spreading around the world.

Is the novel coronavirus the enemy to be conquered and destroyed, as President Macron suggests? While the threat to humans is real and needs to be dealt with, we also need to examine the question of how we have allowed it to spread all around the world in such a short period of time. This is so because, as Robert G. Webster, a world-renowned virologist, has already told us in a book published in 2018 that another pandemic like the Great Pandemic of 1918 with a deadly and disruptive impact on our lives is not only possible, it is also a matter of time.2

  1. For this and other examples of transmission of diseases in history, see: Diamond, Jared, Guns, Germs, and Steel: The fates of Human Societies, New York: WW. Norton, 1998, and McNeill, William H., Plagues and Peoples, New York: Anchor Books, 1976.
  2. Webster, Robert G., Flu Hunter: Unlocking the Secrets of a Virus, Otago: Otago University Press, 2018.