Biodiversity and its implications on COVID-19 and future pandemics

July 27, 2020

Biodiversity and its implications on COVID-19 and future pandemics

By: Diego Steed, B.Sc. student

The outbreak of the corona virus (“COVID-19”) and subsequent quarantine imposed by most nations, has provided a brief insight into what happens on the planet when factories close and the populace stays inside. For one, there is a marked reduction in emissions and pollution in metropolitan areas. This has been illustrated in two popular maps that circulated the web a few weeks into the quarantine. Using data from NASA the European Space Agency, the maps show a significant drop in atmospheric nitrogen dioxide over East Asia and the Po Valley, Northern Italy, compared to concentrations in 2019. 

Alongside these maps are images taken by local media of swans, fish, and dolphins returning to the canals of Venice for the first time in ages.  The media was eager to exclaim that the pandemic appeared to have a silver lining!  In doing so, they ignored the questions of there possibly being a deeper and negative underlying root connection between the quarantine and the environment. The sudden admiration for nature in its authentic form is ironic considering that the systematic destruction and fragmentation of environments was likely a contributing factor to the onset of the COVID-19 pandemic.

The United Nations (UN) reports that since the 1970s, 75% of the planet’s terrestrial environment has been either destroyed or fragmented by rapid development and urbanization which lead to habitat loss. An important issue associated with habitat loss is that interactions between people and wildlife grow. This increases the probability of transmission of zoonotic emerging infectious diseases (EIDs) which, as the UN and the Centers for Disease Control and Prevention (CDC) report, are the cause of more than 2.7 million deaths globally per year.

Dr. Kate Jones, Chair of Ecology and Biodiversity at University College London (UCL), and her research team, identified 335 EIDs between 1994 and 2004, 60% of which were zoonotic in origin. They found a clear correlation between areas of fragmentation and the transmission of zoonotic diseases.  Fragmentation and development also lower local biodiversity which causes an amplification effect. “Simpler systems get an amplification effect” Dr. Jones explains “Destroying landscapes, and the species you are left with are the ones humans get diseases from”. This knowledge led experts from the World Health Organization to predict that an EID would have the potential to put an ever globalized and interconnected world into a health crisis.

Dr. Jones also warns against an increase in ‘spill over’, the rate of disease transmission from one species to another due to proximity.  Due to development and fragmentation, organisms are becoming more confined in their habitats and, as a result, interact more often. A molecular study published in the journal Nature Medicine led by Dr. Kristian Andersen (2020), identified the South-East Asian pangolin as an intermediate vector of COVID-19 between bats and humans.  Human encroachment on habitat likely caused bats to come in closer contact with pangolins, facilitating transmission of the virus. Infected pangolins in turn were brought to wet food markets and possibly transmitted COVID-19 to humans.

COVID-19 is not the first instance of a zoonotic disease leading to an outbreak and is likely far from being the last. Ebola virus, SARS-MERS, and bird flu are examples of zoonotic diseases that preceded COVID-19 and are a part of the increasing trend in EIDs.  Unfortunately, environmental destruction has not only led to the biodiversity crisis but to a new era of affliction by zoonotic pandemics on humanity.

The true silver lining of the current pandemic is not the ‘returning’ swans to Venice, who were actually local inhabitants more photogenic when not surrounded by boats, but the opportunity to use the knowledge on the origins and causes of COVID-19.  Looking to the root causes of a lack in biodiversity and habitable environment; taking a step toward preventing the next pandemic involves sustaining large biodiverse ecosystems as a buffer to reduce rates of spillover and the transfer of EIDs to humans.

 

References

Anderson, R. M., & May, R. M. (1986). The invasion, persistence and spread of infectious diseases within animal and plant communities. Philosophical Transactions of the Royal Society of London. B, Biological Sciences, 314(1167), 533–570. https://www.nature.com/articles/s41591-020-0820-9

Coronavirus: Lockdowns continue to suppress European pollution. BBC. (2020, March 27). Retrieved from: https://www.bbc.com/news/science-environment-52065140

Jones, K., Patel, N., Levy, M. et al. (2008). Global trends in emerging infectious diseases. Nature 451, 990–993. https://www.nature.com/articles/nature06536

The coronavirus pandemic in five powerful charts. Nature. (2020, March 18).  Retrieved from https://www.nature.com/articles/d41586-020-00758-2

UN Report: Nature's Dangerous Decline 'Unprecedented'; Species Extinction Rates 'Accelerating' - United Nations Sustainable Development. (2019, May 6). Retrieved from https://www.un.org/sustainabledevelopment/blog/2019/05/nature-decline-unprecedented-report/

World Health Organization: Prioritizing diseases for research and development in emergency contexts. (n.d.). Retrieved from https://www.who.int/activities/prioritizing-diseases-for-research-and-development-in-emergency-contexts

Zoonotic Diseases. CDC. (2017, July 14). Retrieved from https://www.cdc.gov/onehealth/basics/zoonotic-diseases.html