Tampering with Nature and the Rise of Pandemics


In recent memory, no disease has had such a vast effect on the entire human population as COVID-19 has. While diseases have come and gone, and others have come and stayed, what many of those have in common with the one currently ravishing the human population is that they originated in animals. Many have looked at the bat as the culprit of what is happening in the world, and countless memes have been circulated online making light of that idea; however, this oversimplification of the matter does a disservice to all. It is critical that people understand the larger implications at play, which have given rise to the current and previous pandemics.

Our relationship with nature is something that we need to examine to truly understand how pandemics come to be. Often we compartmentalize environmental issues and view them with a detached stance. For example, the burning of forests, and therefore, destruction of biodiversity and ecosystems taking place in South America and South–East Asia is of no concern to citizens here in Egypt. However, this is not true; what happens in one corner of the globe is going to reverberate around the world. Think of it as a domino effect.

Pathogens usually have bad reputations; they are recognized for causing infectious diseases, and they also give a bad reputation to the organisms that carry them. However, they do not always have a detrimental effect and are important in maintaining biodiversity and ecosystems. While pathogens can be harmful to some hosts, they can also be beneficial to others. It is all a delicate dance that occurs in nature; problems arise when humans interfere with it and commence to stomp on nature’s toes.

It is believed that the threat of disease outbreaks is higher in tropical regions, where forests and natural areas—previously untouched and rich with biodiversity—are altered. Human activities that alter the natural landscape can include: establishing settlements, livestock farming, oil and gas extraction, logging, mining, or plantation development. When these activities occur, it spells out the loss of biodiversity, as well as brings humans into increased contact with wildlife. This in turn gives rise to more opportunities where disease spillover can and does occur.

Not all pathogens have the potential to cause pandemics; some can transmit to people from animals, but that is where it stops, such as rabies. Others can be transmitted from an animal, but survive in human populations through human to human transmission. While some viruses have existed harmlessly and co-evolved with their host animals in nature, the threat is when humans become hosts for these previously harmless viruses. This can occur through the destruction of natural habitats and the handling and consumption of wildlife, which gives way to unpredictable consequences. What may have been a harmless pathogen in an animal, can easily turn deadly in a human.

Urbanization is one of the factors leading to deforestation and loss of biodiversity. It is estimated that over five billion people will be living in urban areas by 2030; land allocated to urbanization is projected to triple from those of the beginning of this millennia. It is to be expected that many of those newer urbanized areas will be in the Global South. In many underdeveloped areas with little resources, the repercussions of these expansions could prove problematic.

In 2015, WHO published “Connecting Global Priorities: Biodiversity and Human Health: A State of Knowledge Review” in which it was stated that, “urban demography presents variable socioeconomic trends, with a significant population globally (≥800 million people) residing in urban slums, with limited access to sustaining resources and sanitation”. This limited access to food and sanitation is an issue; not only is sanitation key to controlling and preventing disease outbreaks, but in remote areas where there is a lack of an available domestic food supply, people tend to turn to hunting and wildlife consumption. This increases the risk of a zoonotic disease spill-over; due to the nature of urban settings.

Indian Flying Fox Roosting near Bananas. Credit: Rajib Islam/www.eurekalert.org

Another reason for land-clearing and deforestation is the creation of pastures for livestock grazing and farming feed crops. Some of those areas are on the periphery of forests or wetlands where there is an increased chance of contact between the farmed animals, farm workers, and wildlife. The conditions of some livestock productions are a perfect setting for the spread of disease.

We have already witnessed many occurrences where livestock had to be culled to prevent the spread of diseases beyond our control. This is due to, according to the WHO publication, “high animal density, confined living quarters, and antimicrobial use” which has enabled “rapid pathogen spread and evolution, especially among genetically similar breeds or immune-suppressed animals”. Due to its potential role as an intermediary host for zoonotic disease transmission from wildlife to humans, the location of intensive livestock farming must be studied carefully.

There has already been instances where this unfortunate series of events took place when the Nipah virus made the jump from bats, to farmed pigs, and then to humans. Fruit bats of the Pteropodidae family are the natural host of the Nipah virus; in 1998, the first recognized outbreak of the Nipah virus took place in Malaysia, but it was in 1997 that the chain of events actually started.

In Malaysia’s neighboring country Indonesia, a significantly large area of a rainforest was burned to make way for agriculture. The bats that resided in this area no longer could find sustenance since the trees no longer produced the fruit it used to feed on. This led some of the fruit bats to migrate to Malaysia where some settled in orchards near a pig farm; soon after, pigs residing in the area started falling sick, and in 1998, the Nipah outbreak emerged in humans. The WHO publication states that “human infections resulted from direct contact with sick pigs or their contaminated tissues. Transmission is thought to have occurred via unprotected exposure to secretions from the pigs, or unprotected contact with the tissue of a sick animal”.  Since that first outbreak, others have occurred in places, such as Bangladesh, India, and Singapore.

It is believed that the virus jumped from bats to pigs through the consumption of fruit contaminated with bat saliva from a fruit tee. Due to the nature of the pig farm conditions—including a high volume of pigs packed together closely—it created ideal conditions for the disease to be transmitted from pigs to humans that worked closely tending to the pigs. This led to an encephalitis and respiratory disease in humans, causing over 100 deaths. The Nipah virus is currently on the WHO top ten viruses in terms of priority for research due to its epidemic potential.

Who is the Culprit?

Seems like bats are quite the reservoir for deadly viruses, but if we examine why disease spillovers keep happening, it is either because bats have been displaced from their natural habitats of rich forests or they have been harvested and ended up finding their way into a wet market. In both cases, it is human interference and environmental mismanagement that is the culprit. These animals are extremely important to the ecosystem since they help pollinate more than 500 plant species, as well as keep insect populations in check, which in turn play an important role in disease control. For example, they eat mosquitoes which helps reduce the spread of malaria. Due to our mishandling, they end up causing great damage; not only to human health, but disease outbreaks cause economic damage as well.

The Nipah virus outbreak “was estimated to cost USD 550–650 million in South–East Asia, including costs incurred for control measures, the financial impact to swine industry, and loss of employment”, according to WHO. The Nipah virus is not the only one that has cost us a lot of money; every disease outbreak has a great detrimental effect on the health of our economies. From MERS, SARS, Zika, bird flu (Avian), swine flu, and of course COVID-19, all have had similar financial impact.

In an article for the World Economic Forum website, Jeremy Schwab states that “significantly reducing transmission of new diseases from tropical forests would cost, globally, between USD 22.2–30.7 billion each year” and “the COVID-19 pandemic will likely end up costing between USD 8.1–15.8 trillion globally—roughly 500 times as costly as what it would take to invest in proposed preventive measures.” It then seems as a no brainer to prioritize preventive measures starting now to avoid another global catastrophe, such as the one we are living in! It is only a matter of time until a new disease comes and steals the spotlight, “every year, two new viruses are estimated to transfer from animals to humans,” Schwab adds.

As Andy MacDonald, disease ecologist at the Earth Research Institute of the University of California, Santa Barbara, has said “it is pretty well established that deforestation can be a strong driver of infectious disease transmission . . . It is a numbers game: The more we degrade and clear forest habitats, the more likely it is that we are going to find ourselves in these situations where epidemics of infectious diseases occur”.

While preventive measures, such as slowing down deforestation and putting a stop to wildlife trade and consumption, are important, these measures will not work unless the issue is looked at as a whole. Any plan needs to be holistic; it needs to include considerations for why deforestation is occurring in the first place. There are economic and cultural factors at play, many people depend on hunting and trading in wild animals for their livelihoods. These issues must be factored into any preventive plan that is to be put in place by governments and the global community for it to have lasting and beneficial effects.

Time and time again, nature has shown us how interconnected we all are. How we went from patient zero in China, to suddenly, the whole world being under lockdown, should serve as a poignant example of that. An event in a far-away place does not exempt us from feeling the consequences of said event. It would behoove us to take note of the lesson nature is teaching us at this moment and act accordingly.










The article was first published in print in SCIplanet, Winter and Spring 2021 issue.

Cover Image: miro.medium.com

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