The current disease load is only a part of the problem.2 New diseases are continually emerging, with Covid-19 being the most dramatic recent example, as humans come into contact with novel pathogens and global transport networks facilitate their rapid spread. Environmental degradation is a potential contributor to this emergence through human infiltration and destruction of natural habitats for increased trading of wildlife and intensive livestock farming, among other activities.
Alongside this, warming temperatures and other climatic shifts are forecast to move vector organisms, such as mosquitoes and ticks, into new regions.3 This will intensify disease pressure on communities that are already struggling with other stressors. Thawing of Arctic permafrost due to climate change represents another potential source of new and dangerous diseases.4
Given the difficulty of addressing these underlying factors in the short term, our overall aim should be to move from treating and managing disease outbreaks to preventing or at least detecting spillover events early, and containing them. There are many specialised areas of infectious disease science — such as accelerated vaccine development, and genetic sequencing in pursuit of vector control technologies — in which considerable progress remains to be made. There is a tantalising prospect of preventing future pandemics before they take hold.
Doing this will entail tackling infectious diseases in their broader context as part of a social-ecological system: for example, understanding when diseases are likely to spread from wild animals to humans as a result of environmental changes that are in turn influenced by social, economic and political trends; or understanding when socioeconomic conditions promote the spread of infections such as cholera. The complementary banners of One Health and Planetary Health offer frameworks to understand disease in this way.
Selection of GESDA best reads and further key reports
In 2015, The Lancet published a set of policy responses discussing how to protect public health in an era of climate change.5 In 2022, Carlson et al provided evidence of climate change's effects on cross-species viral transmission.6 Lerner and Berg provided a useful comparison of One Health, EcoHealth and Planetary Health in 2017,7 and the One Health High-Level Expert Panel published a new definition of One Health in 2022.8 A useful set of studies of global parasite diversity was published in 2021,9 and a 2020 overview of the history of disease vector mitigation argued for a return to a more thorough, evidence-based approach.10