Covid-19, Food Systems, and Wild Animals

The Reset the Table essay series is published weekly, describing today’s challenges to global food security and proposing U.S. government responses.

The most important food system lesson from Covid-19 is the origin of the virus itself. The pathogen came originally, in all likelihood, from contact with wild animals, transmitted and amplified through a traditional food market in Wuhan, China. This is only the latest in a deadly sequence of high-profile pathogens that originated in wild animals, including HIV, Ebola, SARS, MERS, the avian flu (H5N1), and swine flu (H1N1). When high-risk wild animals—such as waterfowl, bats, or chimpanzees—are not adequately segregated from people seeking food, or from domestic food animals such as pigs or chickens, disease often spreads. Zoonotic diseases associated with livestock production cause more than 2 million deaths a year in the developing world.

Covid-19 is telling us to remove high-risk, wild animals from markets where people buy food and to separate the animals we raise for food from wild animals. This obviously means tighter regulations on bushmeat hunting in Africa as well as on wet markets in Asia, but it also means moving the developing world toward more bio-secure livestock production systems. This will require new local rules, closer global coordination, new investments, and also new research.

Until recently, most efforts to control the marketing of wild animals were designed to protect endangered species, but our own species is also one of those facing danger. The so-called “wet markets” in Asia that sell freshly killed or live animals, often including wild animals, are key transmission points that allow animal diseases to jump into the human population. Steve Osofsky, a professor of wildlife health and health policy at Cornell, describes the threat from such markets this way:

If you’re a virus whose ‘goal’ is to spread, you couldn’t really design a better system to aid and abet a pandemic, particularly in dense urban centers. You have species that simply never would have run into each other under natural conditions, all packed together, bodily fluids mixing, and then people come into the equation. Pathogens are meeting species that they’ve never met before, creating perfect opportunities for viral jumps—including ones that lead to humans and can create the type of situation we’re in now.

Closing wet markets is not the answer in Asia, since so many low-income citizens depend on them. In January 2020, China closed the market in Wuhan where Covid-19 was thought to have emerged, but local demand caused the stalls to begin reopening in April.

A better strategy in these markets is to restrict the selling of high-risk wild animals, such as the pangolins suspected of transmitting the Covid-19 virus from bats to humans in Wuhan in 2019. At the time, pangolins enjoyed official protection in China, but an estimated 195,000 of these animals were nonetheless trafficked illegally in 2019. In June 2020, China decided to upgrade the protection of native pangolins up to the same protection level enjoyed by giant pandas.

Farming high-demand but high-risk wild animals in bio-secure environments would be another strategy, and China itself has as many as 20,000 wildlife breeding farms. Unfortunately, these operations are sometimes used to “launder” wild animals that have been illegally poached.

“By 2050, livestock herds will be 20 percent larger in Asia and 185 percent larger in Africa. To make this expansion safe, Asians and Africans will have to increase biosecurity by moving more of their pigs and poultry indoors.”

Africa is also struggling to make the hunting and selling of wild animals safe. In regions like the Congo Basin, bushmeat is an important source of dietary protein, often providing more product than domesticated animals. The most notable zoonotic diseases transmitted from bushmeat to humans in Africa have included HIV, originally from chimpanzees, and multiple outbreaks of Ebola. After the 2014 Ebola outbreak, which took over 10,000 lives, governments in West Africa launched campaigns to reduce bushmeat consumption, but the volume of sales soon bounced back.

Consumer demand for animal protein is projected to continue growing in both Asia and Africa in the years ahead as population and income continue to increase. Indeed, increased consumption of animal protein is essential for nutrition for millions in developing countries, particularly women and children. By 2050, livestock herds will be 20 percent larger in Asia and 185 percent larger in Africa. To make this expansion safe, Asians and Africans will have to increase biosecurity by moving more of their pigs and poultry indoors. This will increase productivity along with safety, and Europe’s experience shows that animal welfare need not be compromised by confinement.

Regulations in Europe require more space for the animals, more daylight, less noise, and less antibiotic use. Pigs must even be given objects to manipulate, like toys, to fight boredom. These more stringent European regulations have proved to be affordable; in fact, Europe currently raises twice as many pigs as the United States, which has rules that are far less strict. Introducing more animal confinement into the developing world will be the only safe way to meet growing urban demand for animal products while segregating people and food animals from high-risk wild animals. 

But aren’t confined livestock systems a source of disease? They can be if procedures are lax, but well-managed, bio-secure barns are also one of the best ways to stop the spread of deadly pathogens. This is why the Dutch government, earlier this year, ordered all poultry in the Netherlands to be moved indoors following an outbreak of bird flu in Germany.

Moving pigs indoors also helps contain zoonotic disease. Tapeworm parasites were not eliminated from the meat supply in Europe and North America until traditional pig rearing was replaced by confinement systems. The incidence of trichinosis from pork in the United States was reduced by 85 percent between the 1940s and 1980s, once infections could be better controlled inside barns. Dr. Rodney Baker, a former president of the American Association of Swine Veterinarians, has said “By bringing the animals indoors and creating biosecurity, we’ve truly eliminated about 15 diseases and parasites we had back to the 1980s.”

This kind of biosecurity is still missing on too many pig farms in China. A disastrous outbreak of African swine fever in 2018 eventually led to a 50 percent reduction in China’s hog herd, which was the largest in the world. It is worrisome that China’s pig farms are now harboring a new strain of the H1N1 swine flu virus, one that has already infected humans. When an earlier H1N1 pathogen spread around the world in 2009, it killed about 285,000 people before morphing into a seasonal flu.

“We need to reframe the zoonotic disease problem as a food system problem, and then invest in better means to segregate high-risk animals in the developing world from humans and human food. The focus should be on affordable, productive, humane, and bio-secure livestock facilities.”

What policy steps might the United States take to reduce threats of new zoonotic diseases coming through food systems? Pathogens cross national borders easily, so global cooperation will be essential. A key institution is the World Health Organization (WHO), which works with the Food and Agriculture Organization (FAO) and the World Organization for Animal Health (OIE) to operate a Global Early Warning System for Major Animal Diseases (GLEWS). In its own national interest, the United States should end its recent feud with the WHO and rejoin as a full partner in such cooperative efforts. Greater support should also be provided to the Convention on International Trade in Endangered Species (CITES), which monitors wildlife trade. CITES is seriously underfunded, with a net global budget of just $6 million, so greater investment is required to monitor animals that are high risk as well as endangered. The United Nations Environment Program (UNEP) also has a role to play, since slowing incursions into forests is another good way to reduce dangerous interactions between humans seeking food and wild animals.

More urgently, we need to reframe the zoonotic disease problem as a food system problem, and then invest in better means to segregate high-risk animals in the developing world from humans and human food. The focus should be on affordable, productive, humane, and bio-secure livestock facilities. Research to support such efforts is being done by the International Livestock Research Institute (ILRI), part of the CGIAR international agricultural research system. The CGIAR recently expanded its vision to address human health risks from food systems, including zoonotic diseases as well as simple food contamination, and it even created a new cross-disciplinary research program in 2013 named Agriculture For Nutrition and Health (A4NH) with a mandate to address such problems. A wide-ranging CGIAR reorganization plan, one that failed to anticipate Covid-19, now threatens progress in these areas.

The U.S. government contributes $107 million annually to the CGIAR system, more than any other single donor (China contributes less than $1 million). The United States should use its leverage to insist on more research to understand interactions between human food systems and high-risk wild animals, and on ways to improve the biosecurity of livestock systems in developing countries. The CGIAR is globally positioned to lead in this important job, and the U.S. government should be mobilizing broad multi-donor support to make sure it happens. 

Scrambling to find new vaccines or treatments after every fresh pathogen outbreak is treadmill we should want to avoid. A better path is to invest in food systems that deliver nutrition safely to consumers and that have enough biosecurity to block zoonotic spread in the first place. 

Robert Paarlberg is an associate professor in the Sustainability Science Program at the Harvard Kennedy School and at Weatherhead Center for International Affairs. This essay is drawn in part from his new book, Resetting the Table: Straight Talk About the Food We Grow and Eat, to be published by Alfred A. Knopf in February 2021.

Commentary is produced by the Center for Strategic and International Studies (CSIS), a private, tax-exempt institution focusing on international public policy issues. Its research is nonpartisan and nonproprietary. CSIS does not take specific policy positions. Accordingly, all views, positions, and conclusions expressed in this publication should be understood to be solely those of the author(s).

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Robert Paarlberg

Associate Professor, Sustainability Science Program, Harvard Kennedy School and Associate, Harvard Weatherhead Center for International Affairs