The spread of an infectious disease depends much on the environmental contexts at the time of its emergence. In today’s world of international globalization, emerging infectious diseases have many opportunities to spread on the global scale. A number of these opportunities result from the shortening of distance between disease vectors and humankind. Normally, humans and certain disease-carrying species wouldn’t come into contact with one another. Certain poorer communities are forced to go deep into the jungle to hunt for ‘jungle meat’, due to a lack of resources to acquire food elsewhere. Exposure to jungle meat provides an opportunity for emerging pathogens to jump species into humans (Glandon, 2022). Additionally, as deforestation continues (resulting from land development), groups of animals continue to be pushed out of their living spaces. This also leads to novel animals intermingling with humans, providing another opportunity for diseases to jump species (Morand & Lajaunie, 2021).
Global interconnectedness and increased international travel mean that individuals infected with a novel emerging disease are more likely to spread it to other nations, leading to global pandemics such as COVID-19. This most recent pandemic isn’t the first-time international travel led to the spread of infectious disease in new localities. Minnesota saw an increase in malaria between 1988-1998 resulting from Minnesota natives returning home from travel as well as immigrants arriving from malaria endemic localities. In WWII, dengue fever arrived via vector mosquitos on transport ships to the United States (Friis, 2019).
Another upstream factor that leads to a closer proximity between disease vectors and humans is poverty. Individuals in poverty live with significantly fewer resources, leading to poorer sanitation practices. Crowded living spaces alongside the lack of proper sanitation creates optimal breeding grounds for certain disease-carrying pests. Rats (and rodent fleas), for instance, were the vector carrying Yersinia pestis during the time of the Plague (Friis, 2019). Poor sanitation practices within cramped living quarters of those in poverty is sadly still problematic today. Homeless shelters in Grand Rapids tend to be overcrowded and unsafe, leading to many homeless individuals living in “tent cities”. These homeless encampments have poor access to clean water or toilets, providing a breeding ground for any new infectious disease to spread rapidly. A large homeless encampment in Grand Rapids was cleared in 2020 in response to fears about the spread of COVID in the community. Sadly, this led to a number of homeless individuals dispersing out into smaller encampments, possibly dispersing COVID into the community, and certainly perpetuating inequitable health outcomes in those individuals (Krantz, 2020).
There are a number of public health interventions that could be utilized in order to reduce the chances of yet another global pandemic. Some of these interventions would also be beneficial to communities that suffer from inequitable poorer health outcomes. Jungle meat hunting could be reduced by the provision of food and other resources to those specific communities in need. Decreasing deforestation would not only protect the distance between humans and disease-carrying animals, it would also contribute to the lessening of the impact of climate change. More locally, individuals in poverty would benefit greatly with the provision of clean water, toilets, affordable/cheap living spaces, etc. The surrounding community itself would benefit from the decrease in risk of disease outbreaks coming from those living situations as well.
Friis, R. H. (2019). Essentials of Environmental Health (3rd ed.). Jones & Bartlett Learning.
Glandon, R. (2022). Following are major factors influence emergence of infectious diseases [D2L Mod 10 Lecture].
Kransz, M. (2020). Emotions high as Grand Rapids cracks down on homeless encampments. mLive. https://www.mlive.com/news/grand-rapids/2020/12/emotions-high-as-grand-rapids-cracks-down-on-homeless-encampments.html
Morand, S., Lajaunie, C. (2021). Outbreaks of Vector-Borne and Zoonotic Diseases Are Associated With Changes in Forest Cover and Oil Palm Expansion at Global Scale. Front. Vet. Sci. https://doi.org/10.3389/fvets.2021.661063