The growing threat of emerging infectious diseases
COVID-19, monkeypox, dengue fever. Headlines today leave no doubt that new viral diseases will continue to appear and threaten our health. Infectious diseases are emerging at a greater rate than ever before, resulting from global changes over the last century that favor disease transmission coupled with better technologies to diagnose and detect the diseases. Global social-ecological changes include rampant deforestation in highly biodiverse tropical regions, warming temperatures and more frequent extreme climate events, and the rapid global movement of people and viruses. This scenario is ideal for the emergence of diseases, as the increasing contact between people, animals and viruses increases the likelihood of new and old viruses being transmitted from animals to people, and vice versa.
Climate change and deforestation (land use change) are shifting the geographic distribution of people, animals, viruses, and disease vectors like mosquitoes. We are now witnessing dengue fever outbreaks in places previously too cool for mosquito-borne disease transmission, such as mid-elevation areas in the tropical Andes or cities in the temperate Southern Cone of South America, like Córdoba, Argentina. As species migrate and move into new geographic locations, they come into contact with many more species.
A recent study predicted that these geographic shifts would result in over 300,000 ‘first encounters’ between mammal species, doubling the current rate of encounters. As new mammals come into contact, it is more likely that viruses can jump between species, including people. The authors found that these new encounters are most likely to occur in mountainous tropical regions with high biodiversity and high human population density. They also found that bats are one of the most critical mammal species to spread new viral diseases due to their unique ability to fly long distances.
Notably, the current and future burden of endemic and emerging viral diseases is not equally shared across wealthy and less wealthy countries. The so-called Global South is most impacted by disease outbreaks and lacks equitable access to vaccines and other public health solutions, as painfully apparent during the COVID-19 pandemic. Colonial legacies have left profoundly entrenched poverty, social inequalities, and weak governance, increasing the population of highly vulnerable people. However, global health research and funding priorities continue to be driven by the Global North.
Building the capacity of the health sector to respond to the next pandemic
Doctors, nurses, and frontline public health practitioners are now faced with responding to this increasingly complex public health scenario. The traditional biomedical model – reviewing the patient, identifying physical symptoms, and recommending medical treatment – is no longer sufficient. The WHO and other global health actors have proposed integrated approaches like One Health, which brings together human health, animal health, and environmental health, and Planetary Health, which focuses on “addressing the impacts of human disruptions to Earth’s natural systems on human health and all life on Earth”. These approaches conceive health as the outcome of interconnected social and ecological systems. And yet, most medical schools and public health programs are not preparing their workforce to make this paradigm leap.
Clinical and public health solutions to emerging infectious diseases must be addressed in the context of rapidly changing, interconnected social and ecological systems. An essential first step is to build the capacity of the health sector to understand and respond to these changes. To respond to this need, the Global Consortium on Climate & Health Education (GCCHE) has established a rapidly growing global network of health professions schools, health societies, and regional health organizations to “create a global climate-ready health sector, prepared to mobilize and lead health promotion and response in the era of climate change, while restoring the health of the planet”.
In April 2022, the Inter-American Institute for Global Change Research (IAI), the Pan American Health Organization, and the GCCHE partnered to launch a virtual course entitled “Climate & Health Responders for Latin America.” The response was overwhelmingly positive. Over five weeks, over 1500 people from across the Americas and beyond participated in live sessions with experts from Latin America. Similar courses were conducted in North America and the Caribbean, reaching thousands of professionals across the Americas.
This course revealed the high demand for climate & health training from diverse sectors, including government ministries, academia, and civil society. Some Ministries of Health reported that this course allowed them to address their training needs as part of their commitment to the UNFCCC international climate change agreement. To continue to support this effort, a regional (Americas) community of practice will be launched in September 2022. A virtual platform will bring together policy practitioners, researchers, and civil society to share knowledge and best practices to combat emerging infectious diseases and other health issues affected by climate and the environment.
Co-designing solutions through equitable transdisciplinary partnerships
Fundamentally, a One Health or Planetary Health approach requires a shift in how scientists, health professionals, and civil society work together. Equitable collaborations and trusting partnerships are essential, built by partners committed to a long-term engagement process. Health practitioners, civil society, and stakeholders from other key sectors should identify their communities’ priorities and solutions. Professionals and scientists from diverse disciplines can work with these partners to co-design evidence-based solutions for their communities. This transdisciplinary approach is a best practice to develop tools and information that can be used by the health sector to make informed decisions about how, when and where to intervene to prevent an epidemic.
Solutions include improved surveillance systems to detect emerging disease threats, new vaccines and therapeutics, innovations to control mosquito-borne diseases, and early warning systems to predict disease outbreaks. This requires a long-term funding commitment from the most significant global health funders, like Wellcome Trust and the Gates Foundation, to support One Health teams led by investigators in the Global South.
This also requires training for early career researchers and practitioners in collaborative leadership skills such as listening, facilitation, diplomacy, communication, and personal self-reflection. Addressing emerging infectious diseases requires a radical transformation of the systemic oppressions – colonialism, racism, sexism, classism – that continue to shape how we work together and the health of our current and future generations.