Updated: April 15, 2020 at 11:19 p.m.

A Milken Institute School of Public Health researcher co-authored a study published Wednesday that examined how treating livestock with antibiotics negatively impacts human health and the economy.

The study – conducted through the Antimicrobial Resistance Action Center in the public health school – analyzed how antibiotics and other antimicrobial substances in animal agriculture degrade human health and increase medical treatment costs. The research team, on which occupational and environmental health professor Lance Price served, developed a model to quantify the “negative externalities,” or societal costs that are not properly reflected in market prices, of the use of antibiotics in livestock.

The study states that consuming animals that have been treated with antibiotics “significantly” heightens disease and mortality rates, prolongs hospital stays among people with bacterial infections and increases direct health care-related and indirect societal costs.

“Similar to antimicrobial use in humans, antimicrobial use in animal agriculture can promote antimicrobial resistance in animal and human pathogen populations, which imposes significant health and economic costs on society,” the study states.

The research group received a $3.1 million grant to study antibiotic usage in livestock in 2018, and the Biostatistics Center received an $18.6 million funding extension for antibiotic resistance research in January. The World Health Organization ranks antimicrobial resistance among the top ten threats to global health, according to a 2019 report.

The researchers analyzed broiler chickens raised in the United States that were treated with enrofloxacin, an antibiotic drug, to estimate how a bacterium commonly found in the species impacts societal costs, like health care and the number of people who develop or die from bacterial diseases.

The study found that one kilogram of enrofloxacin administered to chickens imposed $1,500 worth of negative effects on human society. The model’s estimates could provide guidance for policy interventions to address the “threat” of antibiotic resistance, according to the study.

“We hope that better understanding of the external costs of antimicrobial use in food animals will help to guide policy decisions aimed to balance the important societal functions of food animal production with the risks of antimicrobial resistance to society,” the study states.

This post has been updated to correct the following: 

The Hatchet previously reported that the Antibiotic Resistance Action Center received an $18.6 million grant. The Biostatistics Center received the grant. We regret this error.