RALEIGH – A wide-ranging review of scientific papers and reports evaluated 46 proposed ‘win-win’ solutions to reducing the human burden of infectious diseases and advancing conservation goals, which can now be explored on a publicly accessible website. The study highlights diverse and widespread bright spots where there may be opportunities to protect human and ecosystem health at the same time.
Nearly 30 researchers from the United States and overseas conducted the study, which appears in The Lancet Planetary Health. The interdisciplinary team consisted of academic researchers, practitioners from governmental and non-profit organizations, and veterinarians.
Skylar Hopkins, an assistant professor of applied ecology at NC State and corresponding author of the study, said the interdisciplinary group worked on this synthesis for four years. They carefully searched the existing scientific literature for possible solutions, and then developed a new method to determine whether a given “win-win” solution is safe, feasible and cost-effective. They found that the solutions have different proofs of success; some already have strong support and others are ripe for further study.
“We like to think of these solutions as options on a bespoke menu. To choose and design a solution that meets your needs, you need a lot of information. As such, we provide an evidence summary for each solution,” Hopkins said. “We also created a decision-making process that anyone can follow, allowing researchers and decision-makers to design their own solutions or evaluate whether an existing solution will work in their situation.”
But Hopkins said evaluating some of the possible solutions isn’t easy.
“Sometimes the evidence for a possible solution has been conflicting,” Hopkins said. “One study would suggest that one intervention would reduce the burden of human disease, and another study would suggest that the same intervention would increase the burden of human disease. Possible solutions could also have trade-offs or side effects if the intervention was good for some people but not for others.” The team needed to develop a way to quantify evidence diversity, consistency and applicability to deal with these complications.
The list of 46 solutions shows just one with “high” evidence for both positive impacts on human health and conservation: vaccinating dogs to reduce transmission of rabies to wildlife and humans. Some of the solutions focus on domestic cats and dogs as disease reservoirs.
“Some of the 46 proposed solutions will be implemented on a large scale by national or international governments. Others can be done on a small scale, even by individuals. Every time you vaccinate your pets or raise your kitten to walk on a leash rather than roam unsupervised, implement one of these solutions,” Hopkins said.
The working group was funded by the Science for Nature and People Partnership after some team members spent years studying human schistosomiasis in Africa – a debilitating disease caused by contact with water contaminated with snail parasites. The snail population exploded when a river was dammed and shrimp, which eat the snails, could not migrate. The possible solution? Put the shrimp back in the river.
The team went looking for other examples of potential win-win solutions, but wasn’t sure if they would find many or few other examples. They found that the 46 potential solutions covered six of the world’s seven continents – all except Antarctica – and included many of the world’s most important known pathogens and methods of disease transmission. The solutions also address most of the world’s most pressing environmental problems, including land-use change due to agriculture, urbanization, resource depletion and invasive species.
Twenty-seven of the solutions focus on conservation efforts that have also had human health benefits; Many involve the management of species such as the snail parasite that contaminated village water sources.
Six of the solutions involved public health interventions that also had conservation benefits.
“People often ask what my favorite solution is,” Hopkins said, “and it’s hard to choose! But I am always impressed by the programs that aim to increase access to health care, education and livelihood opportunities for people living near protected forests, marine reserves or other biodiversity hotspots. When these communities have more control over their well-being, they can use resources more sustainably, slowing rates of deforestation and ocean degradation.”
Thirteen of the solutions are not specific to human health or nature conservation, but touch on both sectors. Replacing wood-burning stoves with cleaner stoves is proposed to reduce deforestation and smoke-related diseases, the researchers say.
“Policymakers are looking for ways to simultaneously advance multiple Sustainable Development Goals, such as ‘ensure health and well-being for all’ and ‘sustain life on land and underwater.’ This is important work, but it can feel abstract or intangible. We hope this study brings those efforts to life with real-world examples,” Hopkins said.