Dominoes on a table

Domino Effect of the African Swine Fever Outbreak

Meg StevensAnimal Health, Livestock diseases, Risk Communication

*African swine fever information on this site has been updated. Read the Updates on African Swine Fever article here.

What do you do when an uncontrolled virus is rapidly sweeping the world’s largest pork producer, killing millions of pigs? Furthermore, how do you make people who are removed from the problem care about it? China is currently trying to answer these questions as they experience an African swine fever (ASF) outbreak, a huge threat to national and international biosecurity. National economies, pharmaceutical companies, consumers, and pork producers are all being negatively affected by ASF. However, this outbreak can serve as a lesson in the importance of biosecurity and risk communication.

A Deadly Outbreak

ASF is a viral disease with a survival rate of nearly zero for pigs of all ages. The first case of ASF in China was detected in August of 2018. Since then, the virus has spread to all of the country’s provinces and regions. Over 140 African swine fever outbreaks were reported and over 1.16 million pigs culled as of July, 2019, but even more have been killed by the virus.

The outbreaks show no signs of slowing down, and the government has lost the equivalent of millions of U.S. dollars. Managing the outbreaks is complicated by the fact that the virus has no vaccine. Research efforts to find a vaccine have so far been unsuccessful, but the Chinese government has set aside 103,095,001 yuan ($15 million U.S.) to be used for vaccine research. While this is a positive step, it takes between 10 and 15 years for a vaccine to be developed, so an ASF vaccine won’t be available anytime soon.

Biggest Animal Disease Outbreak Ever

The situation in China is what Dirk Pfeiffer, a professor and veterinary epidemiologist living in Hong Kong, described as “the biggest animal disease outbreak ever.” (Zimmer, 2019). It is hard to find an exact number of pigs that have died so far. Pfeiffer estimates that anywhere between 10 and 40 percent of China’s pig population has been infected with ASF. There are suspicions that more outbreaks have occurred than have been confirmed by the government.

According to an April 22, 2019 article in the New York Times, farmers have admitted to not reporting signs of an outbreak in their own herds, because they didn’t think the government would do anything. Other farmers said they had reported outbreaks, but the government did not respond in a timely manner. As a result, dead pigs are being disposed of in roadside ditches and rivers, and the government is unable to make an accurate estimate of regional outbreaks and infections.

A Lack of Communication and Trust

The lack of reporting from farmers isn’t because of irresponsibility on their part; the farming community feels betrayed and distrustful of their government. Government officials have promised to compensate farmers’ losses by paying 1,237 yuan ($180 U.S.) per pig lost to ASF (Zhong, Tang, 2019). However, several farmers have claimed that when they reported their losses, authorities failed to confirm the outbreak; farmers suspect that the authorities simply don’t want to reimburse them for their losses. The combination of farmers not reporting outbreaks and the government failing to confirm the outbreaks has allowed the virus to continue spreading. It has also strained the Chinese government’s relationship with the farming community.

The lack of trust and regular communication between farmers and the Chinese government is one of the reasons why the ASF outbreak has spread, and continues to spread so rapidly. New hygiene requirements have been created, but with no one enforcing them, farmers aren’t observing the new rules. There hasn’t been any formal education on the early signs of ASF, so many farmers don’t realize they have an outbreak in their herd until it’s too late. With diseases like ASF, prevention is key. But without adequate communication between government and farmers, that prevention is complicated and difficult.

The ASF outbreak is obviously affecting China’s pork producers. Some pig farmers who lost their entire herds have abandoned swine completely in favor of other agricultural products. One farmer said he and his wife started farming strawberries as a safer alternative. (Zhong, Tang, 2019). This could be good news for producers in other countries; if China produces less pork, there could be an opportunity for other producers to sell more and make more money.

Global Impacts

All of this sounds like a bad situation, but why should we care? China is thousands of miles away from the United States, and their problems seem to be their own. How would a virus that does not affect humans, but is killing millions of pigs on a far-away continent affect Americans? There are several ways the ASF outbreak could impact the U.S. (and other countries). China is the largest pork producer in the world; the country is home to more than 50 percent of the world’s pig population. If China continues to lose millions of pigs, we will start to see a global shortage of pork.

China’s stock of live pigs has dropped 20 percent since 2018 and is continuing to fall. They have been supplementing their own stocks with frozen pork products but may end up buying live pigs from the U.S., Canada, and/or Europe.

Impact to the Dairy Industry

Perhaps unexpectedly, the ASF outbreak impacts the dairy industry as well. Chinese pigs consume whey and lactose, produced by American dairy producers. As herd sizes decrease in China, the demand for whey and lactose from the U.S. also decreases, and American dairy producers are losing a good source of income. Because China’s swine industry is such a major consumer of dry whey products, as demand goes down, global prices for these products are also dropping, leaving dairy producers to lose profit.

Heparin Availability May be Affected

Another global consequence is the production of the blood thinner heparin. Heparin is used in veterinary and human medicine to prevent blood from clotting. For example, when a human or animal is given an I.V., the blood clots. Heparin prevents the clotting so that the medicine in the I.V. can enter the bloodstream. The active ingredient in heparin is taken from the mucous membranes of pig intestines; because China has most of the world’s pig population, they also account for 80 percent of the international heparin supply. Without China’s pigs to harvest heparin’s active ingredient, heparin availability will decrease, and the price will increase.

Communicating About Risk During a Crisis

On a larger scale, the situation in China demonstrates why biosecurity and risk communication are so crucial. An outbreak like this could be controlled or at least minimized, through education and implementation of better biosecurity practices. The fundamental issue at the heart of this outbreak isn’t scientific, it’s about poor communication to stakeholders. Without significant effort the relationship between farmers and the government will continue to falter, and the ASF outbreak will continue to spread. As the outbreak spreads, the global ramifications will increase.

Economies, industries, and individuals will suffer as a result of this outbreak. A disease like ASF, which spreads rapidly and for which there is no cure, is never truly isolated to one area. Even if the virus itself remains contained on one continent, its effects will be global.


Zhong, R. & Tang, A. (2019, April 22). A Vicious, Untreatable Killer Leaves China Guessing. New York Times. Retrieved from

Zimmer, K. (2019, June 24). Scientists Race to Build Vaccine for African Swine Fever. The Scientist. Retrieved from

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About the Author

Meg Stevens

Meg Stevens was an Animal Science major and Wildlife Biology/English double minor at the University of Vermont (UVM). Her interest in working with animals led to volunteering and organizing fundraisers for local animal shelters, and creation of pet health awareness campaigns. Meg was a marketing intern for LivingWell, a department at UVM devoted to mental health outreach. She managed their social media pages, creates website content, and designs promotional materials for LivingWell and affiliate events and programs. Meg worked as an intern for Julie M. Smith, DVM, PhD, in the UVM Animal and Veterinary Sciences Department, and wrote blog posts and online content related to agricultural biosecurity. Meg is interested in pursuing a career related to animal health or conservation, and finding a way to combine her marketing and communications skills with her passion for animals and wildlife.

About the Editor

Joanna Cummings

Joanna Cummings received a Bachelor of Science in Horticulture from The Pennsylvania State University (PSU), with a specialization in vegetable crop and greenhouse production. At PSU, she was a research technician on no-tillage vegetable crop experiments, and a greenhouse assistant in the All-American Selections Research Gardens. Her career in the agriculture industry includes field research, work with dairy and vegetable farms, and as a greenhouse manager, estate gardener, landscaping and market garden entrepreneur. She transitioned to the science communication field after receiving a master of science degree in environmental communications from Antioch University New England. At Antioch, Joanna was a field botany laboratory teaching assistant, manager of the herbarium, and editor of the department's student newsletter, Notes and Niches. She currently works with Research Professor Julie M. Smith as a communications professional in the University of Vermont Animal and Veterinary Sciences Department. She is the webmaster for the Healthy Farms Healthy Agriculture website.

About the Editor

Dr. Julie Smith

Dr. Julie Smith is a research professor at the University of Vermont. Julie received her B.S. in biological sciences, D.V.M., and Ph.D. in animal nutrition at Cornell University. Since 2002, she has applied her veterinary background to programs in the areas of herd health, calf and heifer management, and agricultural emergency management. She has taught courses in animal welfare, calf biology and management, and ABCs of biosecurity to undergraduates, mostly in the Department of Animal and Veterinary Sciences. As a veterinarian and spouse of a dairy farmer, Julie is well aware of the animal health and well-being concerns of dairy animals. Julie has conducted trainings for Extension educators, livestock producers, and community members on the risks posed by a range of animal diseases, whether they already exist in the United States, exist outside of the United States, or pose a risk to both animal and human health. In all cases, she emphasizes the importance of awareness and prevention. In addition, she has led a number of projects on biosecurity and emergency disease preparedness.