Next pandemic could come from pigs at county or state fair

A researcher takes a 'snout out' sample at a fair.
(Photo by Maddie McGarvey, The New York Times)

A state or county fair can be all sorts of fun, but when there are pig shows, there's often swine flu, and the next pandemic could start there. "But there is real risk in our own backyards — and barnyards. Since 2011, there have been more confirmed human cases of swine flu in the United States than anywhere else in the world," reports Emily Anthes of The New York Times. "Outbreaks of zoonotic diseases, which can spread between animals and humans, have become more frequent in recent decades, and animal pathogens will continue spilling over into human populations in the years ahead. . . . Most have been linked to agricultural shows and fairs."

Americans often see pandemics as something that comes into the country and not something that happens here. But considering the number of swine cases in the U.S., the next pandemic could as easily come from within. "Although flu is often mild in pigs, the animals are renowned for giving rise to novel flu variants. In 2009, one of these new variants, which originated in pigs in Mexico, set off a pandemic that killed at least 150,000 people, according to estimates from the Centers for Disease Control and Prevention," Anthes writes. "Dr. Andrew Bowman, a molecular epidemiologist at Ohio State University and his colleagues have been documenting the dangers and seeking ways to make swine shows safer. Meaningfully reducing the risks will require looking past the pigs to creatures on the other side of the spillover equation. What needs to change, Dr. Bowman said, 'is an awful lot of human behavior.'”

Anthes notes, "Pigs play a key role in the evolution of influenza. They can be infected by swine, bird and human flu viruses simultaneously, serving as mixing vessels in which different strains can reshuffle their genetic material, yielding new versions of the virus. When the 2009 swine flu pandemic hit, influenza surveillance in pigs was limited. [Bowman] began swabbing pigs at swine shows, ultimately uncovering a national network of events that resulted in human infections in a predictable annual cycle. Starting every spring, regional and national 'jackpot' shows, which attract serious swine competitors, bring together pigs from far-flung farms, causing new flu variants to spread across the country."

"Over the years that followed, the researchers worked to identify what made these shows risky. They found that although most fairs had hand-sanitation stations, few had signs explaining how to use them — and almost no one did," Anthes writes. Researchers also found that fair "line-ups" where pigs are one behind speeds transmission. "The researchers, who have shared their findings with show organizers and health officials, say they have seen some changes, with many shows moving away from mandatory mass weigh-in. . . . Still, some health recommendations, such as the advice to avoid eating or drinking around the animals, have been a tough sell. For many families, some of whom bring crockpots into the barn with them, sharing a meal at a show is a way of building community. . . . It is hard to determine how effective the team’s efforts have been overall; the surveillance is still fairly new, and some flu seasons are naturally worse than others." Bowman told Anthes: “But I think we have moved the needle. . . .There is change happening.”