Updated: Jul 16, 2020
Crowds, Pathogens and Overpopulation
“When there is noise and crowds, there is trouble; When everything is silent and perfect, There is just perfection and nothing To fill the air."
- Dejan Stojanovic
It is certainly easier to find a needle in a haystack than it is to meet someone who has never had a hard time looking for Wally. Indeed, I remember in my childhood, spending hours on end looking for that cosmopolitan and scrawny little figure, but cursing the old gods and the new, for making that chore so arduous.
"Why would Wally choose to go into places with so many people?" I would desperately interrogate my parents. For all one knows, it could have been his choice to spend the last few decades mingling with those hordes of anonymous faces, although it is more likely that he had no choice altogether.
Recently, I've found one book of Where's Wally and decided to flip it through. After that initial feeling of reminiscence had dissipated, I started to notice a pattern. Every single illustration was bursting at the seams with humans. Could it be that my mind, already conditioned to pick up scenes of crowdedness - was seeing what it wanted to see? Or could it be that Martin Handford (Wally's illustrator), has perhaps been trying to warn us about overpopulation all along?
Regardless of Handford's intentions, anyone who looks at his work is hard-pressed not to find a suggestive hint of too many people in one location. Personally, I have begun to find the artwork somewhat disconcerting. Something about a scenario thouroughly dominated by a single species. Although it doesn't end there.
The discernible congestion, acting as the facilitator for transmissible diseases that gorge on the availability of human hosts, is all too disquieting. This at a time of forced quarantines and self-isolation due to the rapid spread of Covid-19. When we look at such renderings of reality, one can't help but wonder if these unchecked expansions of population density aren't just playing right into the pathogen's - microscopic - 'hands'.
As Covid-19 takes advantage of a globalized, interconnected and full world, I also took the opportunity to share some thoughts with a colleague from Singapore. We briefly discussed the - possible - role of human overpopulation in enhancing the transmissibility of the disease.
Of course, epidemics were among the initial "positive checks" postulated by Malthus (1798) that lead to a shorter lifespan, and since then, the link between population density and the severity of the impact of a given pathogen has been well substantiated (Langerlöf, 2003; Hu, Nigmatulina & Eckhoff, 2013; Sommerfeld, 2003; Diamond, 1998). As Dr. Peter Daszak, a disease ecologist affirms in Scientific American (2013):
"There's a strong correlation between the risk of pandemic and human population density. We've done the math and we've proved it."
As we exchanged virtual words, we touched on the lack of publicity that human density - hence overpopulation - was receiving by the official public health bodies, such as the World Health Organization (WHO) or the Centre for Disease Control (CDC). Despite their invaluable work during this crisis, the association between the growth of the human population and the transmissibility of infectious diseases isn't being made any clearer with the media and the general public.
Naturally, at a time like this, the priority is in putting out the many epidemiological fires arising throughout the world and attempting to prevent many others from emerging, therefore, one might argue that emphasizing the role of overpopulation amidst a public health emergency won't get us anywhere, since the harm (7.7 billion humans in March 2020) has already been done. Obviously, there is some truth in such reasoning, and even if it is just an intellectual exercise at this point, we should still conduct that experiment.
At a time like this, those of us in the overpopulation sphere are compeled to accentuate the role that a bloated human population has in aggravating the spread of infectious diseases, as it is the case of professor of agriculture and environmental sciences, Ambt Anoruo, who writes in How does population size affect a pandemic and social distancing? (2020):
"Scientists and scholars have demonstrated with nonhuman organisms that every space has a limit to its carrying capacity to support a species or organism but [they] are still divided if this concept is applied to humans. This brings me to the coronavirus issue, its transmission and spread among humans and how quickly it became a pandemic.
Imagine that when the population was about 4 billion in 1975, nobody outside China, the origin of the disease, could have heard about coronavirus because natural social distancing could have stopped the disease. Even if the virus escaped China, it could have run into natural distancing due to human population density per unit of land."
This much is true. If less people are inhabiting a certain place, that makes it harder to form new chains of transmission as well as maintaining them active (e.g. by having less instances of mass gatherings) (Tam et al. 2012). Nevertheless, we should resist the temptation of condensing the blame around population density, as other factors appear, in this early stage of the pandemic at least, to counter the adverse effects of human crowdedness.
For instance, a country like Singapore is at the top of the chart (third highest) regarding population density, with roughly 8,109 individuals per square kilometer (World Population Review, 2020), and despite being relatively close to the origin of the disease, meaning that contagion began in January (Duddu, 2020), it reports 385 total infections. The 18th of March witnessed a spike in cases, the highest number of daily cases since the disease has been tracked, with the majority being imported (Min, 2020).
On the other hand, Portugal has a population density of 111/km2 (101th place on the chart); infections were detected much later, (26th of February), and as of the 2nd of April, 9,034 cases have been reported (DGS, 2020; Silva, 2020), with an exponential curve resembling population growth during the 20th century (images below).
Contrary to Singapore, Portugal is still in the early stages of the propagation of the disease, mirroring a scene observed throughout Europe, leading WHO to declare the continent as the new epicenter of COVID-19 (CIDRAP, 2020). Additionally, more than a third of reported cases in Singapore have recovered and they have two fatalities, while Portugal has 64 recoveries and already 209 deaths (Bing, 2020).
Evidently, population density isn't the only factor to take into account in this epidemiological analysis, although it can be a strong predictor. Nonetheless, it is still intellectually captivating to ponder on such a downright contrast between the two countries (or others such as Hong Kong or Macau, which are also in the top 5 most densely populated) (World Population Review, 2020; Bing, 2020).
For one thing, there is an abysmal variation in sociological behavior between the West and the East. Indeed, as the WHO elevated COVID-19 to a pandemic status on the 11th of March, the Portuguese population flocked to the beaches with a sudden rise in temperature. They ignored the advice of the government and the public health administration to remain in quarantine and maintain social distancing (Lopes, 2020). Universities and schools had initiated lockdowns to contain the spread of the virus two days before, instructing students to remain indoors, however, as one can testify, these warnings were virtually ignored.
Moreover, by examining the curve of cases reported above, we can see that by the 11th of March, Portugal was undergoing a phase that could be described as a silent but deadly "calm before the storm." At the time, people were still feeling a false sense of security and complacency towards the spread of the disease, and within a couple of days, reported infections skyrocketed. By the 12th, access to the beaches was being interdicted (Ramos & Moreira, 2020), and by the 18th, the government approved its declaration of a state of emergency (Chaíca & Ferreira, 2020). A week can be a very long time in an epidemiological emergency.
On the other end of Eurasia, Singapore, Hong Kong, and Macau all managed to get the upper hand (so far) and reduce transmissibility, despite their proximity to the 'ground zero' of the virus, and really elevated population densities. Did their inhabitants have access to more information? Unlikely, as in Portugal, everyone became aware of the emergence of the disease back in late December, or at least in January, when news about infections became routine. To this extent, there is an element that can probably explain the discrepancy in the numbers and the sociological response, and that's memory.
It was just in 2003 that South East Asia was being hit by the severe acute respiratory syndrome (SARS-CoV) outbreak (Chew, 2020; Peckham, 2016). SARS swept through these countries leaving a trail of death and fear behind it, but also caution, vigilance, and lessons learned (Beaubien, 2020). It shouldn't be far-fetched to argue that having such an episode (and others such as Dengue fever in Singapore in 2005 or the H1N1 pandemic in 2009) fresh in the memory of its denizens, allowed them to build some precautionary antibodies in response to COVID-19.
In other words, the collective response to the early warnings echoed from China, mutated the practices of individuals throughout South East Asia. To point out, I'm not talking about following the more basic salutary behaviors, such as washing one's hands regularly, sneezing into the elbow, or wearing protective masks in public gatherings. From what I could gather through my Singaporean colleague, her fellow citizens have assimilated so scrupulously these practices that they implement them on their daily routines, with or without WHO's 'call to arms.'
Under these circumstances, what certainly turned the tables on the chains of transmission was, perchance, that people self-isolated or went into voluntary quarentines, without the advice of national or supranational public health bodies. While in Portugal, people thought it would be a good idea to get a tan in early March, in Singapore, they avoided mass gatherings and initiated their social distancing much earlier. This was a decisive bet.
Of course, this isn't the end of the story. For instance, South Korea appears as a ray of hope having witnessed a sharp decline of cases recently. These were only made possible by the most far-reaching and ordered testing program in the world, mixed with extensive efforts to isolate those deemed infected, and trace anyone who might have been in contact with them (Normile, 2020).
Unfortunately, South Korea's public health prowess isn't universal, meaning that there are a lot of countries that will be severely impacted by the virus, with experts sharing their concern about the fate of the African continent (Nordling, 2020). At the same time, Africa appears to be spared in the climate suitability front, as the model below shows a diminished ecological niche for the Coronavirus throughout most of the continent and the climatological year (Araújo & Naimi, 2020). The model appears to indicate that in terms of climate suitability, the virus is deemed to spread much more easily throughout the global North, than the South. However, this is probably where the good news end for those countries.
If I mentioned before that Southeast Asian countries managed to control the abrupt diffusion of the epidemic, despite their heightened population densities, as I see it, their model of practices is essentially endemic to their cultures and absent from mostly the rest of the world. Furthermore, the aggressive measures taken by China (which many have deemed extreme and authoritarian) have definitely changed the course of the disease nationally and abroad (Kupferschmidt & Cohen, 2020).
Do all countries have the capacity to synchronously move an entire population in the same direction and with the necessary celerity (I have borrowed the term 'crowd control' from security forces to describe this capability)? The answer is most likely no, as history suggests a divide between the more individualistic Western mindset to more collectivism in the East (Triandis, Brislin & Hui, 1988; Singelis, Triandis, Bhawuk & Gelfand, 1995; Triandis, 2018).
Although Africa is usually described as 'communitarian' (Metz, 2014), the lack of infrastructure, specialized medical class and equipment, and robust governments will create a 'ticking time bomb' (Nordling, 2020). On top of this, and possibly even more critical, is their rapid population growth combined with an already vulnerable exposure to climate risks and food insecurity. If the East's collectivism provided them with the necessary ingredients to enact the necessary crowd control protocols and cancel out their extremely inflated population densities, I fear that Africa, particularly, will become the next battleground against COVID-19, as they fight against multiple interconnected failures.
Furthermore, as countries are waking up to the seriousness of the COVID-19 pandemic, it is interesting to notice how the populations are quickly surrendering a multitude of rights and liberties to regain some sort of control over this invisible threat. As borders close, as national emergency status is declared and people attempt to find a safe sanctuary in their homes, they also expect their governments to protect them and solve the situation, so that normality might be recovered. Still, there is the possibility that people willingly forego their freedoms but the expected results are not met. If and when that happens, democratic and autocratic rule might be eroded to the point of collapse, and anarchy ensues.
In any event, we might have a chance to contain the spread of the disease if we emulate the procedures applied by countries such as South Korea, however, if we descend into disorder and rioting, that will only surely elevate the death count.
Lastly, we go full circle and end with the link of overpopulation and disease outbreaks. We've already established the connection between population density and the spread of pathogens, although I haven't mentioned the continuous population growth and what can be expected. It must be remembered that projections put roughly 10 billion humans on this Earth in about thirty years. As Bahar Gholipour wrote for Scientific American (2013):
"The sheer number of people, their interactions with animals and ecosystems, and the increase in international trade and travel are all factors that will likely change how infectious diseases emerge."
It should become clear to all that more people will inevitably result into an expansion of all economic activity, including those that magnify the proliferation of zoonoses (Swift, Hunter, Lees & Bell, 2007), particularly 'wildlife' (Safina, 2020) and 'wet markets' (Chen, 2020). More people will definitely translate into an increase in the demand of these types of medieval outlets if we don't use this crisis to at least change direction and effectively outlaw these sort of establishments since a global demographic policy still seems to be too far-off.
Alternatively, population growth will mean the gradual invasion of natural areas to settle, transmogrify or seize materials and resources. Many of these areas might be reservoirs of diseases unknown to humans, or the contact between an expanding population with native wildlife might lead to the infection of biodiversity, which in turn aggravates the odds of the emergence of an infectious disease (Jones et al. 2008; Daszak, Cunningham & Hyatt, 2001; Rodier et al. 1995; Zell, 2004). As Geoffrey Holland asserts in an interview for MAHB (2020):
"To the extent that people are moving into forested areas or areas where they're more in contact with animals or insect vectors, simply because they're looking for places to live. We have an intrusion into areas where people might not have been trying to live before, into ecological zones. Also, global warming is having an impact on disease distribution. Secondly, people have to feed themselves and their children. In Sub Saharan Africa a major source of protein is what's called bushmeat, the hunting of wildlife. Exposure to wild animals as food is part of the problem."
Anyway, if I haven't made myself clear, the blame is not on the side of wildlife for standing in the way of a burgeoning human population. As several zoologists have told CNN (Walsh & Cotovio, 2020):
"The destruction of natural habitats, coupled with the huge number of fast-moving people now on Earth -- has enabled diseases that were once locked away in nature to cross into people fast.
We are increasing transport of animals -- for medicine, for pets, for food -- at a scale that we have never done before. Bats [the possible source of the virus] are being shipped or held in markets, in close proximity to other animals or humans.
We are also destroying their habitats into landscapes that are more human-dominated. Animals are mixing in weird ways that have never happened before. Spillovers from wild animals will have occurred historically, but the person who would have been infected would probably have died or recovered before coming into contact with a large number of other people in a town or in a city."
All things considered, I leave you with a 'Where's Wally' Coronavirus parody edition, and unlike Wally, I urge everyone to stay home even if the streets and beaches are deserted. Stay safe.