Written by Ethan Thio
Edited by Ishaani Khatri
Assessing a problem requires a holistic analysis — evaluating each and every possible consequence regardless of how obvious or logical they may seem. In the case of climate change, the oft-ignored consequences may be just as devastating as those we are intimately aware of. In the journal Neglected Tropical Diseases, a part of the Public Library of Science, a study titled “Global expansion and redistribution of Aedes-borne virus transmission risk with climate change,” tackles how climate change will increase the spread of mosquito-borne diseases around the world.  The core reality behind this research and its conclusions is relatively simple: mosquito activity and viral transmission of mosquito-borne diseases occur at an optimal temperature, and climate change will raise temperatures in more parts of the world to enter these optimal temperature ranges.
The researchers utilized a mechanistic model that uses predicted temperature to forecast viral transmission of diseases such as dengue fever. The results of this model served as the basis of the researchers’ conclusion: that these mosquito-borne diseases will now be an issue at higher latitudes and elevations. These new areas of exposure are uniquely vulnerable, as these unexposed populations are especially predisposed to explosive outbreaks of these diseases as they lack immunity or experience with these diseases.
Furthermore, risks abound when considering how long the potential for transmission may persist. Regions where these diseases are already seasonal concerns, such as south Asia and sub-Saharan Africa, are predicted to have rising temperatures that will render all seasons within the optimal range for disease transmission, making these diseases a year-round public health concern. As such, climate change presents a dual threat in regards to mosquito-borne diseases: increasing the areas that will be vulnerable to contagion while simultaneously increasing the time at which already affected areas must contend with these diseases.
However, the shift may not be entirely negative. The authors also found that rising temperatures in the tropics will render some seasons too hot for optimal mosquito-borne disease transmission. But as a whole, the risks of new areas affected by these diseases for a longer period of time is a serious consequence that cannot be ignored, as the researchers predict that nearly a billion people may be threatened by exposure to these diseases over the next century.
Mosquito-borne illnesses are incredibly dangerous. From dengue fever to the Zika virus, these diseases are primary concerns of public health preparedness, and can be lethal., the risks of new outbreaks and longer seasons of vulnerability make climate change more than simply an issue of rising sea levels or melting glaciers. Climate change and the rising temperatures that accompany it will directly cause the spread of mosquito-borne diseases, and this reality should only increase the urgency surrounding efforts to address climate change. Our cities, our livelihoods, and now our health, depend on it.
Ryan SJ, Carlson CJ, Mordecai EA, Johnson LR (2019) Global expansion and redistribution of Aedes-borne virus transmission risk with climate change. PLoS Negl Trop Dis 13(3): e0007213. https://doi.org/10.1371/journal.pntd.0007213
Gene editing wipes out mosquitoes in the lab. (2018, September 24). Retrieved April 20, 2019, from https://www.bbc.com/news/science-environment-45628905