Preventing spread of viruses from animals to humans would cost just 5% of the losses they cause, report says | science and technology


The ongoing Covid-19 pandemic is far from a unique event. Ebola, MERS, Zika, bird flu… Viral pathogens are spreading through the human population at an increasingly rapid rate, causing increasingly severe and widespread global epidemics. Over the past 50 years, an average of 3.3 million people have died each year from animal-derived viruses – a figure calculated before Covid and which was already on the rise. Not enough is being done to stop this overflow – that’s according to a study by around 20 experts, who also offer a formula so lawmakers can see it’s worth trying.

It would be an extraordinarily profitable investment: a complete and comprehensive plan to stop the spread of these viruses from wildlife to humans would cost no more than 5% of the losses they cause each year. “Spending just five cents on the dollar can help prevent the next tsunami of lives lost to pandemics by taking cost-effective actions that stop the wave from emerging, instead of paying trillions to pick up the pieces,” said through a press release Aaron Bernstein, Harvard researcher and lead author of the study, which was published in Scientists progress.

An ever-larger and ever-more-connected human population constantly creates more opportunities for viruses to spread once they establish themselves among human populations, says another study co-author, Andy Dobson of the Princeton University. “This strongly suggests that we need to focus more on preventing the passage of pathogens than on stopping their spread once they have established themselves,” Dobson says via email with EL PAÍS. “The impact of Covid-19 on the economies and death rates of many countries illustrates that prevention is significantly more effective than cure.”

This team of experts offers a conservative estimate that the world spends around €300 billion due to deaths and around €185 billion in direct economic losses due to emerging zoonotic diseases. And this despite the fact, as the authors admit, that they are not able to integrate all the factors given the difficulty of estimating the psychological impact, the school burden of an entire generation and the additional costs caused by the delay in medical care due to the pandemic.

Slaughtered bats at a market in Indonesia.University of California Davis

To cope with these colossal figures, the investment in effective preventive measures that would limit infection in humans with these diseases would, according to the researchers, be around 18 billion euros. This figure would at least halve the number of deaths. “The net annual cost of putting mechanisms in place to significantly reduce the risk of spread is consistently lower than the average annual cost of outbreaks,” Dobson says via email. “There are ongoing economic and environmental benefits to putting mechanisms in place that reduce fallout rates.” “Even a 1% reduction in the risk of emergence of viral zoonoses would be cost-effective,” the study says.

According to the survey, there are three main mechanisms that allow pathogens to spread to human populations: tropical deforestation, which is closely linked to animal husbandry and agricultural intensification; wildlife trade; and the lack of resources to detect these viruses before the health emergency sets in. And this is where we must act. “Viruses are being detected in humans at a roughly even rate of two new species per year,” the study warns, adding, “Humanity needs a global virus discovery project if we are to prevent future pandemics”.

We need to focus more on preventing the passage of pathogens than stopping their spread once they have established themselves.

Andy Dobson of Princeton University

“Resources spent on reducing deforestation are an investment to prevent future epidemics, but also to mitigate current threats, such as malaria and respiratory diseases associated with forest burning,” said Marcia Castro, professor of demography at Andelot and chair of the Department of Global Health and Population at Harvard Chan School, in the aforementioned press release. “These investments in prevention are beneficial for human health, the environment and economic development,” she added. Additionally, a multitude of jobs may be created in various fields as the global economy is reconfigured due to the pandemic.

The report begins by criticizing that leaders and policy makers “only take action after humans have gotten sick.” “We strongly disagree,” the authors state. They argue that the spread of viruses from animals to humans is the primary source of pandemic risk. “Therefore, our failure to consider downplaying the fallout in influential conversations about preventing the next pandemic puzzles us.” Specifically, the report challenges the Global Preparedness Monitoring Board, a joint initiative of the World Bank and the World Health Organization (WHO), which was created after the Ebola outbreak. Its reports and strategies do not mention how to prevent overflows.

In this context, one of the most important measures to be taken is to hire many more people in the veterinary field, since they have an essential role as “guardians” of the appearance of new diseases. And, as the study points out, they have been among the main advocates of the concept of “One Health”, which integrates human and animal well-being in general, and infectious diseases in particular. However, they are rare, especially in countries and regions most at risk. “A country with few veterinarians, many reservoir species, and many people who consume or trade wildlife will be at greater risk from zoonoses,” the authors state.

Scientists study the spread of viruses in animals such as bats.
Scientists study the spread of viruses in animals such as bats.Gianluca Battista

Virologist Marion Koopmans, who was part of the mission to find the origin of the Covid-19 pandemic in Wuhan, China, believes that this work is an “interesting argument for focusing more on real prevention: trying to reduce outbreaks at their origin”. given that the majority of pandemic preparedness initiatives “are focused on detecting human disease, but that is putting the cart before the horse”. However, his colleague Alina Chan, who defends the possibility that SARS-CoV-2 escaped from a laboratory, criticizes the fact that in the past these specialists carried out research in an opaque way and today do not explain exactly how they will work to improve the security and transparency of virus discovery work.

“Solving these problems primarily requires political will and international collaboration and cooperation,” says Dobson. According to this specialist, “increasing the number of trained veterinary personnel around the world will significantly increase the productivity of global agriculture and the establishment of a global database on viral diversity will allow faster development of tests and vaccines for future epidemics”.

As Michael Leavitt, then US Secretary of Health and Human Services, said in 2007: “Anything we do before a pandemic will sound alarmist. Everything we do afterwards will seem inadequate to us. Besides the fact that they serve to put lessons learned into action.


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