The speed at which COVID-19 is overwhelming health care facilities worldwide necessitates a fresh look at how we approach disease risk management — one that takes a one-health approach to disease prevention and mitigation. We know it is most likely that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes COVID-19, originated from an animal host. While leading wildlife health experts think that the ancestral host of the coronavirus was likely a bat, the intermediate host that allowed the virus to jump into people in Wuhan, China, is not known. What is clear, however, is that habitat destruction, as well as wildlife trafficking and poaching, are increasing our exposure to both known and novel pathogens.
A one-health approach to managing human health is needed now more than ever to address the full range of disease risk factors, from individual human behaviors to the environmental settings in which people reside. Through a one-health approach, risk levels can be identified for each hazard and their interactions so that appropriate management measures can be applied in targeted geographies to mitigate the impact of outbreaks and prevent future ones from occurring.
“The World Health Organization considers control of water-related disease one of its highest priority health security issues for the Western Pacific, where I am based in Fiji.”
For the COVID-19 pandemic, in the short-term, there needs to be critical focus on individual behavior in terms of handwashing and social distancing, as well as up-scaling health system response capacities for testing and treatment. But long-term management of coronavirus disease outbreaks, as well as other diseases emerging from animals, will require major policy changes, which at the very least should include bans on markets selling wildlife, where live and dead animals are sold for consumption, and on wildlife trade. In this regard, China and Vietnam have taken commendable steps by directing their governments to draft directives that would prohibit trade and consumption of wild animals.
Yet COVID-19 is not the only disease for which a one-health approach to management is important. Globally, waterborne diseases kill more children than AIDS, malaria, and measles combined. The World Health Organization considers control of water-related disease one of its highest priority health security issues for the Western Pacific, where I am based in Fiji. Outbreaks of water-related disease are common in Fiji, amplified by factors related to climate change, land use, poor coverage of improved sanitation facilities, and changing social conditions.
Control of water-related disease globally will undoubtedly require improved health surveillance systems and vaccination campaigns where appropriate. However, a one-health approach that also addresses the environmental foundations of health within the scale of a watershed may revolutionize prevention of water-related disease, particularly in rural, developing countries where people do not have routine access to health care.
“Around the world, development activities such as logging, mining, road-building, and agricultural expansion have decimated forests and wetlands, compromising their natural flood control and water purification functions that protect water quality and human health.”
A watershed is a geographic space defined by ridges that separate waters flowing to different rivers, basins or seas, and includes all of the people and habitats within. Over a decade ago in Fiji, we started noticing peaks of water-related bacterial diseases, such as typhoid fever and leptospirosis (another disease arising from animal hosts), two months or so after major flooding events from tropical cyclones or prolonged heavy rainfall. Moreover, the incidence of disease anecdotally appeared to be greater in watersheds that were highly altered through forest clearing, grazing and damming of the waterways.
In 2012, the Fiji Government hosted a typhoid task force meeting to identify solutions to the increasing frequency and severity of outbreaks. Myself and my colleague Aaron Jenkins, who was then running the Wetlands International — Oceania office, sat on the fringe trying to get the ear of anyone who would listen to us sound the alarm of the potential environmental risk factors for typhoid. The meeting resolutions largely focused on typical epidemiological measures for prevention, including improved hygiene, and response, such as carrier detection and vaccination.
Not satisfied with the lack of attention to potential environmental risk factors, Aaron initiated new research that uncovered key measures of environmental condition, such as fragmentation of forests along waterways and amount of highly erodible soil in watersheds, that were associated with typhoid incidence. To us, this wasn’t surprising. Around the world, development activities such as logging, mining, road-building and agricultural expansion have decimated forests and wetlands, compromising their natural flood control and water purification functions that protect water quality and human health.
We have taken this knowledge into the design of a pro-active, systems management approach through implementation of the Watershed Interventions for Systems Health in Fiji (WISH Fiji) project. WISH Fiji is bringing together environmental and public health experts, scientists and engineers, from academia, government and civil society to assess the degree of risk of contracting water-related disease from environmental, infrastructural and sociological factors present in five watersheds in Fiji where there have been documented outbreaks.
“WISH Fiji is bringing together environmental and public health experts, scientists and engineers, from academia, government and civil society.”
Through this solutions-oriented approach, we are identifying targeted management actions, at landscape to household to individual scales, that can optimize disease risk reduction while also providing benefits for the environment and biodiversity. In the meantime, we are working closely with the Ministry of Health and Medical Services to improve capacity for disease surveillance.
A watershed management approach is not going to be the solution for all diseases. But the idea of incorporating environmental considerations into disease management through a one-health approach, such as banning wildlife trade to combat pandemics like COVID-19, is going to be essential in a world going through rapid global change.