It was back in the mid-2000s that experts were telling the world it was not a case of “if” but “when” a pandemic would hit the world.
In the spring of 2009, a pandemic of a new type of influenza did actually occur, but it was, thankfully, not highly virulent. Ten years on, our world has had to resort to archaic restrictions on outings just months after group pneumonia cases caused by the novel coronavirus were first reported in China. Many would surely agree by now that the world underestimated the threat of an infectious disease.
Humankind has a long history of battling infectious diseases. Traces of smallpox were found in a mummy in ancient Egypt, and in the 14th century Europe was ravaged by the Black Death, also known simply as the Plague. There were pandemics both before and after this, too.
The most recent, truly devastating pandemic was the Spanish flu a century ago, which killed tens of millions of people across the world.
— A crisis triggered by optimism
At the time of the Spanish flu, people were moving about due to trade and World War I. The proliferation of infectious diseases has a large impact on society — just as the Plague is said to have resulted in a loss of Church authority at the time.
The appearance of antibiotics and vaccines produced hope that humankind had defeated disease. The former were used as a trump card against bacteria, and the latter against viruses, and this led to the eradication of smallpox in 1980.
Sadly, however, neither proved to be a universal cure, and disease once again stalks our world. From the 1970s onward, countries saw the emergence of Ebola, AIDS, bovine spongiform encephalopathy (mad cow disease), Lassa fever and other new illnesses, one after another. In the meantime, malaria, tuberculosis and other existing illnesses have retained their deadly power.
It was a quarter century ago that the World Health Organization sounded the alarm over new and re-emerging infectious diseases, warning that our undue optimism could lead us to crisis.
Posing a particular threat to public health are zoonoses, infectious diseases caused by pathogens that have jumped from animals to humans. New, recombined types of influenza such as bird and swine flu have spread among humans. West Nile fever is a virus carried by birds and transmitted by mosquitoes. And Ebola, SARS and MERS, as well as SARS-CoV-2 — the scientific name for the novel coronavirus — are thought to originate from viruses found in bats.
Three-quarters of new infectious diseases, in fact, come from pathogens found in animals, and we cannot say that the emergence of the latest coronavirus came as a surprise.
What then, has caused zoonoses to spread? One factor is the exploding human population.
In 1950, the world’s population stood at 2.5 billion people. There are now 7.7 billion. In line with this population increase, forests have been cut down and nature has been destroyed to make way for farmland, increasing opportunities for animals and humans to come into contact with each other.
Due to changes in eating habits and poverty, there are people who use wild animals as a food source. And that has increased the risk of infections jumping from animals to people.
— Human activity holds the key
The effects of urbanization and globalization cannot be overlooked.
In the past, pathogens that escaped from the natural world had merely been endemic. But now, with extensive land and air routes spanning the globe, huge numbers of people are able to move from one place to another very quickly, and viruses can now spread across the world in an instant.
A prime example of this is the Ebola virus, which wreaked havoc in the Democratic Republic of the Congo and various countries in West Africa. Previously, serious outbreaks had occurred only sporadically in small villages, but now they cross borders and reach cities.
Mass livestock farming to support urban populations also increases the risk. This was seen with avian flu. And due to the progression of global warming, there is great concern over tropical infectious diseases like dengue spreading to temperate zones.
The novel coronavirus that quickly spread across the world from a single region of China is indeed a consequence of such composite risk factors. Human activity has heightened the risk of infections with pathogens from animals.
Pandemics smoke out various problems produced by modern society, from population explosions to those relating to industrialization, urbanization, environmental destruction, climate change, global warming, and poverty resulting from disparity.
The extended fight against the novel coronavirus provides an opportunity for us to rethink such issues, which are common to the world. We hope the wisdom of humankind can come together so we can overcome this battle.