farm ppe chick

The next pandemic may well begin on a farm, and a new report says countries should step up their fight against this growing risk.

“I think the warning lights are blinking red. This is an unprecedented time,” said Lonnie King, dean emeritus of the Ohio State College of Veterinary Medicine.

King chaired a task force that earlier this month published a report on zoonotic diseases for the Council for Agricultural Science and Technology. He discussed the findings in a Nov. 17 webinar.

Some 60% of human pathogens are zoonotic, meaning they jump from animals to humans. The worst of them are the horrors of history — plague, tuberculosis, influenza, measles, HIV, Ebola, SARS, COVID-19, possibly smallpox.

Zoonotic diseases cause an estimated 2.5 billion illnesses and 2.7 million deaths worldwide each year, according to the Centers for Disease Control and Prevention.

These diseases emerged as a major problem roughly 10,000 years ago when humans developed agriculture and began domesticating animals.

People had never before lived in such close proximity to animals — or to each other, as permanent settlements were replacing nomadic encampments. Both factors allowed zoonotic diseases to take off, King said.

These diseases continued to dog humans down the centuries, with the suffering ranging from sporadic illness to millions of deaths.

The toll of infectious diseases finally began to decline in the late 19th and early 20th centuries, when sanitation improved and antibiotics became available.

“It was even thought early in the 1970s that the era of infectious diseases (was) over. And that, of course, was very premature,” King said.

Since the 1980s, globalization and other factors have facilitated a resurgence of zoonotic diseases. In the past 30 years, deaths from infectious diseases have increased almost 60%, King said.

The risk factors are varied, but they are hallmarks of the modern economy.

Trade zips goods around the world, and the growing human population creates demand for increased livestock production.

Billions of people are taking international trips. Millions are migrating because of natural disasters, war and poverty — often landing in sprawling slums where crowded, unsanitary conditions are conducive to outbreaks.

Disease-carrying pests like ticks are being introduced to new regions, and climate change could intensify problems in ways not yet known.

The pathogens that are thriving today are generalists, able to infect multiple species and adapt to new conditions rapidly, King said.

COVID-19 has been found in 23 animal species, from deer and mink to lions and tigers, according to the World Organisation for Animal Health.

King is concerned because the many risk factors for a zoonotic pandemic all seem to be accelerating.

“Outbreaks could be more frequent and more consequential if the last chapter we write is not different,” King said.

Farmers On the Frontlines

That next chapter begins on the farm.

The ideal outcome, after all, is controlling diseases in swine, chickens and other animals before they jump to humans. Biosecurity, vaccination of animals and landscape changes could all help with this goal, King said.

Preventing an outbreak, he said, is much cheaper than responding to one — 2% of the estimated cost of dealing with the disease over 10 years, in the case of COVID-19. But that ounce of prevention isn’t free and can be hard to justify to the public.

“Prevention means, for example, that the next pandemic will be invisible,” said Bernadette Dunham, a report co-author and former director of the Food and Drug Administration’s Center for Veterinary Medicine.

The change in thinking shouldn’t end with prevention, according to the report.

Rather than thinking of animal-to-human disease spread as rare and a problem for distant lands, zoonotic diseases should be considered part of U.S. national security.

Given the speed that pathogens can be transported around the world today, “a threat anywhere is a threat everywhere,” King said.

The report also says zoonotic diseases should be tackled from a One Health perspective, which sees humans, animals and the environment as interconnected, not discrete fields of study.

Following this mindset, King said, agriculture and veterinary medicine should be included in discussions of human health.

Relatedly, animal health professionals should build relationships now with the people they would work with during an outbreak. That way a system of coordination does not need to be developed from scratch when a crisis comes.

The report also recommends increased disease surveillance. Data on which pathogens are active in a region help choose a response and may help predict where the next hot spots will be.

The U.S. and other wealthy countries already do extensive disease surveillance, but these systems are needed in low- and middle-income countries, King said.

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