Environmental Impacts on Infectious Disease
Author : Nikil Naveel Chand (Umanand Prasad School of Medicine & Health Sciences Year 3 Student)
Environmental changes have had a huge impact on the reemergence of certain infectious diseases, mostly in countries with high biodiversity and unsolvable economic issues [1, 3]. It is widely accepted that human modification to the environment is the major driver for global environmental change. Emerging infectious disease are recognised as major global threats [2].
Some drivers include anthropogenic change’s (deforestation, mining oil extraction ,food production changes, urbanization) [2]. Urbanization has been responsible for a decline of biodiversity due to the fact that wildlife is unable to adapt,furthermore due to urbanisation there is aggregation of a large number of people and animals causing microorganism to jump species barriers and infecting humans [4].
One way in which climate change will affect the risk of diseases such as spread of ebola is by making new areas into suitable homes for disease-carrying species [5]. For example, if the trees that serve as reservoirs for fruits bats and also support the growth of eloba virus could grow in a new environment, the fruit bats would follow and reside in the new environment as well [3, 2]. Global warming isn’t the only environmental change that could increase disease risk. Clearance of the Amazon rainforest seems to be driving up the spread of malaria [3].
Irrevocable agriculture advances in frontier rainforest result in increasing rates of spices contact and a spillover transmission[5] .
Some example of environmental impacts on infectious diseases and their occuring rates are :
EL Nino (Papua New Guinea 2004) - decreased malaria incidence in PNG due to the lack of rainfall causing less places for Anopheles mosquitoes to breed ,thus leading to a smaller mosquito population leading to lower bite rates and ultimately to lower malaria cases [5].
Hurricane - leads to a higher number of malaria, chikungunya and zika cases being reported because in the hurricane season there is high amount of rainfall leading to the creation of many suitable places for mosquito to breed. Thus leading to a higher bite rates which results in a higher number of cases being reported [5].
Increase Temperature - Increased number of leishmaniasis cases due to the heightened movement of sandfly which acts as the vector for leishmaniasis [5].
Increased temperature - leads to a higher number of dengue fever cases being reported due to the stimulation of vectors gonotrophic cycle and female biting behavior [5].
Deforestation - lyme disease outbreak caused by a history of deforestation, and habitat fragmentation that causes increase in preference reservoir population infection and higher contact with infected vectors [.
In conclusion a education component should clearly present the anthropogenic driver of EID’s as not only ephemeral or present concern ,but establish the perception of them as long-term public health threats requiring improved public support from more effective environment protection or insurance practice at national and even international levels.
References
[1]. 4, R. C., Cho, R., 2, Idakwoji, J. A., & Radice, L. (2019, July 25). How Climate Change Is Exacerbating the Spread of Disease. Retrieved from https://blogs.ei.columbia.edu/2014/09/04/how-climate-change-is-exacerbating-the-spread-of-disease/#:~:text=Climate change will also affect,and more extreme weather events.
[2]. Climate change and human health - risks and responses. Summary. (2012, October 25). Retrieved from https://www.who.int/globalchange/summary/en/index5.html
[3]. Environmental Infectious Disease " Department of Environmental & Global Health " College of Public Health and Health Professions " University of Florida. (n.d.). Retrieved from https://egh.phhp.ufl.edu/research/environmental-infectious-disease
[4]. Nava, A., Shimabukuro, J. S., Chmura, A. A., & Luz, S. L. (2017, December 15). Impact of Global Environmental Changes on Infectious Disease Emergence with a Focus on Risks for Brazil. Retrieved from https://academic.oup.com/ilarjournal/article/58/3/393/4745724
[5]. Vaughan, A. (2019, October 15). How deadly disease outbreaks could worsen as the climate changes. Retrieved from https://www.newscientist.com/article/2219981-how-deadly-disease-outbreaks-could-worsen-as-the-climate-changes/