On Christmas Day 1948, scientist Thomas H. Jukes checked the results of an experiment with chicken feed — he noticed that chicks who were fed small amounts of antibiotics gained more weight than those who were not. Jukes was one of a number of scientists conducting experiments to find an inexpensive feed for livestock to compensate for the market losses following WWII, and he thought he had stumbled upon a possible solution. According to journalist and Schuster Institute of Investigative Journalism fellow Maryn McKenna, Jukes’ discovery caused a massive upheaval in the system of raising livestock as well as “a profound human health threat that would sweep the world.”

When McKenna first heard about the use of antibiotics on healthy animals, she was “perplexed,” and, having recently finished writing a book on the antibiotic-resistant bacteria MRSA, decided to learn more about the subject. The result was her book “Big Chicken,” in which McKenna discusses “how we came to give antibiotics routinely to most of the meat animals on the planet.” McKenna presented the tale at a Feb. 26 forum, followed by a Q&A.

McKenna began her presentation with the history of antibiotics, starting from Alexander Fleming’s invention of penicillin in 1943. She stated that “antibiotics were a miracle and a shock,” and emphasized their role in allowing soldiers “to survive … grave infections that would otherwise have killed them in horrible [and] lingering ways, saving them in days, sometimes in hours.” The country went into an antibiotic fever; seemingly every disease could be cured with these new miracle drugs. 

In 1947, however, trouble struck in the form of antibiotic-resistant staph, McKenna said. This new strain of the disease presented a problem never seen before, and medical professionals struggled with finding a cure. America had now faced its first bout of antibiotic-resistant bacteria, but with Jukes’ discovery of antibiotics as growth promoters in healthy animals, the nation soon forgot about the problem. “Within five years, farmers went from using no antibiotics … to giving [their animals] 500,000 pounds [of them] per year,” McKenna stated. 

The potential dangers of the skyrocketing use of antibiotics were not, however, without warning. “Just three years before Jukes made his experiment,” McKenna explained, “Alexander Fleming, the father of penicillin, … warned that using doses of antibiotics that were too small to cure an infection would encourage resistant bacteria to arise.” 

McKenna elaborated, “When we give an antibiotic to a sick human, or to a sick animal, … we are balancing that risk of resistance against the benefit of curing an infection. But when we use antibiotics when an animal is not sick, we shift the balance almost entirely over to risk, and that’s what we do when we give antibiotics routinely to the animals that provide the protein that we eat.”

People across the globe soon felt the negative effects of antibiotic use on livestock. McKenna stated that several outbreaks of antibiotic-resistant foodborne illnesses occurred, killing dozens across the U.S. and UK. In response, in 1971, the UK restricted the use of antibiotics in animals, but the U.S. failed to do the same. The powerful agriculture lobby stopped congressional hearings on antibiotic usage policies, and, McKenna explained, instead of acting to prevent the damaging aftermath of antibiotic resistance, the U.S. decided to “put antibiotics out into the farm environment, and wait to see what happens.”

The results of America’s lack of controls, McKenna stated, led to the spread of antibiotic-resistant bacteria far from farms and their workers. Drug-resistant salmonella outbreaks in 2013 and 2014 sickened hundreds in 29 states and Puerto Rico; the origin was one California chicken plant. 

McKenna added that other countries have also felt the ills of antibiotic-resistant epidemics. In 2004, the Netherlands had an outbreak of MRSA originating from pig farms, and in 2015, pork from Chinese farms carrying bacteria resistant to the last-resort drug Colistin afflicted people around the globe.

With many common antibiotics now too risky to use, it is expected that pharmaceutical companies will research new drugs. McKenna said, “We always assumed that however bad the resistance might get, there would always be another drug.” However, according to McKenna, these companies have largely stopped making new drugs, as the process is expensive and often takes over a decade from developing the drug until getting approval by the Food and Drug Administration.

The developing world is now facing its own problems with antibiotic usage in livestock, McKenna stated. As middle classes emerge in these countries, demand for protein goes up, and so does the use of antibiotics. The large increase in antibiotic usage and lax regulations, McKenna stressed, will only magnify the issue of antibiotic resistance.

“Whether we realize it or not,” McKenna said, “by our overindulgence in antibiotics in medicine and in agriculture, we have brought ourselves to the edge of a post-antibiotic world, which is a world in which we would lose most of what we think of as modern medicine. … I think we do not realize how close we are to being in that much danger.”

However, McKenna declared, the tide is turning in a positive direction. China has preventively banned the use of the antibiotic Colistin. In the U.S., poultry companies such as Purdue, Cargill and Tyson no longer feed antibiotics to their chickens, and in January 2017, the Obama Administration banned the use of growth promoters in agriculture.

To end her presentation, McKenna quoted the microbiologist Joshua Lederberg, saying, “There is nowhere in the world from which we are remote.” If we change our ways, McKenna concluded, we may have time to stop the bugs from overtaking the drugs.