by Augusta Williams in the Department of Environmental Health Sciences, MPH ’15
Drs. Jeff Shaman and Stephen Morse spoke on the intersections between infectious disease and climate change in the third SEA of Thoughts luncheon held by the Students for Environmental Action (SEA) on November 10, 2014. The vivid conversation began with a discussion of the current and future states of the global climate, and then quickly shifted to how human health will be directly impacted by climate change. Drawing from their work analyzing the effect of infectious diseases on populations, such as the current Ebola outbreaks, Drs. Shaman and Morse informed us how the spread of disease is currently studied, and how global climate change will influence the modeling of future outbreaks.
Through their talk, we learned how human health has evolved in a steady climate, and that the climate change we are currently facing will have impacts on infectious disease transmission. For instance, changing temperatures or increased severe weather events – like floods or droughts – can alter the prevalence of infectious diseases in the areas effected. Depending on the baseline climate of a region, altered precipitation patterns can make the area more or less hospitable to disease vectors like mosquitoes, which can lead to outbreaks.
Currently, there are models to project future global climates. There are also models that forecast infectious diseases, like influenza. Given what we know about how climate change, there will be impacts on how disease is spread across regions. It is now about bridging these two areas, while also incorporating many other fields to assess the future state of health.
These models based on mathematical algorithms, that also consider past and present conditions, are not perfect. Like many other predictive tools, climate and disease models contain a lot of information that is just not known. Assumptions have to be made whenever entering parameters into a forecasting model, even though we know these assumptions cannot hold true all of the time. Different models assume different things: a health model may adopt that the transmission mechanism of the disease will stay the same in the future, whereas a climate model may state that the amount of incoming radiation from the sun will remain constant over the next century. These assumptions are essential to compute the complex calculations with any meaningful predictive skill.
As Dr. Shaman then described, it is important to find a balance between the trade offs of assuming too much and imposing too much, especially when we are considering the social, political, economic, and public health impacts.
I feel that there is a quality in public health students that allows us to identify with the investigative work of our field. Our honorable guests discussed the importance of the distinction between novel pathogens in new locations versus what is endemic to a region. They conversed about the differing public health concerns between Ebola emerging in West Africa and how malaria is endemic in the same region. You could feel the inspiration that was ignited by Drs. Shaman and Morse as they further shared stories about areas where there are people that have Ebola antibodies without a record of a past epidemic occurring in the area. Facts like this make us curious to solve the mystery.
I am intrigued by the detective work that is involved to investigate disease outbreaks, but feel that the interrogative aspects of analysis can sometimes get lost between exams and readings. Although disease epidemics are terrible, we should feel a sense of pride to be earning our Master of Public Health during a huge public health emergency like the Ebola outbreak in West Africa. We have learned many of the skills needed to apply our education in a practical setting to help those who need it most.
Now some of us have the opportunity to exercise these skills. Perhaps more importantly, we have been fortunate enough to have two experts provide advice and insight to how we can best apply ourselves to these situations in the future.
As future public health professionals, we were encouraged by Drs. Shaman and Morse to become resilient instead of reactionary. Their messages echoed each other when telling us that if we can work on increasing funding and support for the development of early warning systems, we might be able to someday prevent outbreaks, instead of simply responding to them.
Although the discussion of unequivocal climate change and its resultant impacts can seem like a endless uphill battle, this discussion made me hopeful. Knowing that I am entering a field where there is so much left to be discovered, and so many people to help, gives me purpose and drive. Knowing that more and more people are accepting climate change, and seeing how things like our health are directly impacted, makes me feel like there is positive momentum building from our constant efforts.
As we are already starting to see the effects of climate change – in the agricultural sector, in our health, in the economy, and in our day-to-day weather – the nature of the climate conversation is shifting in the right direction. Better late than never.