Emerging Viruses: How They Get from Animals to You

Today we are experiencing a widely publicized outbreak of a newly discovered zoonotic disease, the Wuhan Coronavirus. A zoonotic virus is a virus that previously infected animals and has gone through a transition to infecting humans. This virus has appeared close in proximity to a previous outbreak of a SARS virus back in 2015. The previous host of SARS was never determined but it is certain that the outbreak was caused by an interaction that is not typical, such as a human eating exotic bushmeat or interacting with a species not normally interacted with. 

The Problem is Growing

As the world is increasingly altered by human development, especially in third world countries, these types of outbreaks will only become more and more prevalent. In the last 30 years we’ve had more outbreaks of emerging zoonotic diseases than we have as humans in the last 300 years. This trend is synonymous with the rapid rate of expansion and development over the last few decades. As urban sprawl continues outward, there will be increasing interaction between humans and the surrounding wildlife. Urban sprawl encourages the eating of bushmeat and the fragmentation of native habitats of the wildlife. 

As the environment changes, many species are not going to be well adapted, especially to harsh or barren conditions. As pollution, sprawl, and poaching have continually increased throughout recent history, the extinction rate of species has been keeping pace. All species are affected by their own slew of pathogens that have coevolved throughout the millennia. When a species goes extinct, their pathogens can either adapt to a new host or also go extinct. Viruses and bacteria have a very high mutation rate that allows them the possibility of producing favorable traits for transmission to a new host species. In other words, if a species goes extinct then all of their bugs will try to infect something else. 

Possibly the Greatest Extinction Event in History

At this very moment, we are in the middle of the 6th mass extinction event in the earth’s history. This is termed the Holocene extinction and is due to the rise of humanity. The current rate of extinction is up to 1000 times greater than previous extinction rates. 

Previously, this was due to humans eating other apex predators and disrupting food webs. As predators are taken out of their ecosystem, the entirety of the system is thrown off. Generally, this allows for population blooms of consumers that overgraze to the detriment of the primary producers in the ecosystem. If this occurs, the system goes through a cycle of consumer population blooms and falls as the food supply runs out. Many examples exist in the USA. The white tail deer population has been blooming and falling since the removal of wolves and cougars. The overgrazing has led to the stagnation of new growth in many forests since as long ago as the 1920s. Humans have been forced to step in and control the population with a hunting season in order to maintain the balance of the forest. 

Currently, ocean devastation, deforestation, increasing consumption per capita, and human population growth are the driving factors of the extinction event. The ocean has been decimated from its previous abundance through overfishing and massive pollution. Humans are consuming more than ever before which requires more land than ever before, which displaces more animal species and increases the chances that a disease from one of the displaced or endangered species will become infectious to humans. Human population sizes are growing, which means that as they do, humans will have more interaction with unusual animal species than ever before. And then we will have outbreaks such as the one we are currently facing. 

Triangle of interactions

The triangle of interactions between domesticated animals, humans and wildlife/bushmeat becomes increasingly important as the human population size increases. As the previous environment is encroached, the risk of transmission from wildlife to domestic animals and/or humans increases. This is a very large issue in the coming future as more diseases begin to infect our food supply and humans themselves. The effects will be far reaching and are guaranteed to make life more difficult. All humans and countries on the planet will be affected by the threatening emergence of zoonotic diseases. As time moves forward, the need for active, unbiased news such as Newtrals will only become greater. 

Mechanism for Emerging Viruses

This is just one aspect of the larger problem — climate change. As we learn more and more, the widespread effects and issues that we will face are multifaceted and far reaching. They concern a great many industries including the real estate, food production, construction, fishing, energy, and medical industries. Even more so, a great number of people will be directly affected by changes in their immediate environment. These changes include but are not limited to changes in biodiversity or biodensity in the surrounding environment, changes in water level, increased range for pests i.e. mosquitoes, decreased range for seasonally dependent species such as migratory birds or species that require specific conditions i.e. bears, and compositional changes in forested regions and grasslands.