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Fact-checked

Why Did So Many of the World’s Pigs Get Sick Last Year?

There is a cruel irony in the fact that 2019 was the Year of the Pig, according to the Chinese zodiac.

In the worst such case on record, African swine fever has devastated the world's domestic pig population, leading to the deaths of approximately 220 million pigs in China alone. Experts have estimated that a quarter of the global pig population may have died in 2019, either as a direct or indirect result of the disease.

The world's pig population has been decimated by the spread of African swine fever.

China is the world's largest pork producer and home to roughly half of all pigs. While millions of the deaths were caused by the disease itself (the fatality rate among pigs is nearly 100 percent), farmers were also compelled to kill many more animals in the hope of containing the infection.

The African swine fever virus is believed to have originated in sub-Saharan Africa, spread east through Europe and into Russia, China, and much of East Asia. Although sanitation controls and other means of prevention have been undertaken, no commercially-available vaccine currently exists, although some experimental trials are currently underway.

A closer look at African swine fever:

As of 2020, African swine fever has never been detected in North America; the United States has eradicated classical swine fever as well.

People are not susceptible to African swine fever or classical swine fever.

African swine fever and classical swine fever should not be confused with swine influenza (swine flu), which has many strains. Occasionally, a swine-origin virus such as H1N1 can be spread among humans through droplets in the air, which is what occurred in the 2009 "swine flu" pandemic.