Environmental change as enabler for disease transmission
March 2020: The spread of emerging infectious disease can be amplified by climate change and habitat loss. Environmental change is altering human-wildlife interactions which can accelerate the spread and intensity of disease outbreaks. It is recommended to treat disease outbreaks as symptoms of environmental degradation instead of isolated incidents.
Information
The world continues to grapple with the fallouts from the novel coronavirus (COVID-19). While outbreaks of new infectious diseases are typically seen as isolated events, recent evidence highlights the risk of animal borne diseases being catalysed by environmental change. Climate change and globalisation alter the way animals and humans interact - removing and altering animals’ habitats which changes how they live, where they live, what they eat and their presence in human food supply chains. In addition, 35% more people live in urban areas compared to 50 years ago, increasing population density in cities and accelerating the spread of diseases. Urban areas offer new habitats and/or food sources for certain wildlife, potentially transforming urban spaces into vectors for evolving diseases.
Implications and opportunities
It is too soon to say if this has been a factor for COVID-19, however epidemiologists have warned that the spread and evolution of infectious disease can be accelerated by climate change and changing environmental habitats. This process is further amplified by international travel and accelerated spread and/or adverse impacts amongst vulnerable groups. People living in deprived areas, particularly deprived urban areas, are more likely to be exposed to waste and unsanitary conditions. In addition, these groups may also have weaker immune systems due to poor nutrition and exposure to air pollution. These changes lead to significant socio-economic impacts from emerging infectious diseases on a global scale. Costs of treatment and lost productivity can lead to an increase in global poverty which in turn will expose more people to emerging infectious diseases. Experts recommend that governments recognise how infectious diseases are not isolated events, but are rather symptoms of changing environments and ecosystem disruptions which provide new opportunities for diseases to emerge. Further, only 10% of the world’s pathogens are currently documented and additional research in this area could inform which animals may be carriers and how humans interact with these species. Lastly, improving sanitation, waste disposal, pest control and improved understanding of people’s interactions with the environment can contribute to the management of disease outbreaks.
Limitations
The evidence base correlating disease outbreak to climate change or habitat loss is not yet strong and further research is required to substantiate the views. Additional research will be required to establish a clear link and formulate practical recommendations to manage future outbreaks. These papers do not yet incorporate detailed analysis of the COVID-19 pandemic.
Sources
Benton, T., (2020). Coronavirus: Why are we catching more diseases from animals? Retrieved from: https://www.bbc.co.uk/news/health-51237225
Brooks, D.,R., Hoberg, E.,P., Boeger, W.,P., (2019). The Stockholm Paradigm: Climate Change and Emerging Disease. Chicago: Chicago University Press.