PandemicsPreventing Future Pandemics Starts with Recognizing Links between Human and Animal Health
The COVID-19 pandemic has demonstrated that zoonotic diseases – infections that pass from animals to humans – can present tremendous threats to global health. More than 70 percent of emerging and reemerging pathogens originate from animals.
The COVID-19 pandemic has demonstrated that zoonotic diseases – infections that pass from animals to humans – can present tremendous threats to global health. More than 70 percent of emerging and reemerging pathogens originate from animals. That probably includes the SARS CoV-2 virus, which scientists widely believe originated in bats.
There are still questions about specifically where the SARS-CoV-2 virus emerged. But experts across the globe agree that communities can take steps to reduce the risk of future spillovers. A key is for veterinarians, doctors and scientists to work together, recognizing how closely connected human health is with that of animals and of the habitats that we share – an approach known as One Health.
To prevent new pandemics, scientists need to identify specific locations where viruses are most likely to make the jump from animals to humans. In turn, this requires understanding how human behaviors – from deforestation to fossil fuel combustion to conflict to cultural activities – contribute to spillover risks.
We focus on global One Health research and education and epidemiology of infectious diseases, and we served on a science task force convened by the Harvard T.H. Chan School of Public Health and the Harvard Global Health Institute to evaluate current knowledge of how to prevent spillovers. The task force report noted that a recent analysis estimates the costs of addressing spillover at high-risk interfaces through One Health approaches and forest conservation at US$22 billion to $31 billion per year. These costs are dwarfed by the estimated global GDP loss of nearly $4 trillion in 2020 due to the COVID-19 pandemic.
In our view, coordinated investment based on a One Health approach is needed to initiate and sustain global prevention strategies and avoid the devastating costs of pandemic response.
Recognizing Risky Zones
Identifying high-risk areas for zoonotic spillover is challenging. People and wildlife move around a lot, and exposure may not lead immediately to infection or produce symptoms that clearly reflect exposure to pathogens.
But researchers can make predictions by combining data on human and livestock density with that on environmental conditions, such as deforestation and land use changes, that can enable pathogens to spread from wildlife to humans. For instance, there are areas in China, Indonesia, India and Bangladesh where development has fragmented forests and extended animal farming and human communities near the natural habitats of horseshoe bats. This group of bats, which includes more than 100 species, has been implicated as a reservoir for many coronaviruses.
