Study Finds Bidirectional Animal–Human Antimicrobial Resistance

In a study published this week, scientists uncovered a bidirectional link between antimicrobial resistance in humans and food-producing animals for the first time. Researchers from the London School of Hygiene & Tropical Medicine (LSHTM) observed that increased antimicrobial resistance in animals was linked to the use of antibiotics in humans, while the same was true for animal consumption of antibiotics and antimicrobial resistance in humans.

The study used multivariable regression and antimicrobial resistance (AMR) data from 2018 to determine that human and animal antibiotic consumption was linked to bidirectional increases in AMR. Results from the team’s model showed a small positive correlation (OR, 1.05; 95% CI, 1.01–1.09) between human consumption of carbapenems and cephalosporin antibiotics and AMR in food-producing animals like cattle, pigs, and chickens. 

"To the best of our knowledge, our study is the first to identify these bidirectional animal–human associations globally," the authors wrote. "Retained significance of bidirectionality at this scale, and after adjusting for other covariates, contributes important evidence to the One Health paradigm."

The One Health paradigm is an approach to public health that recognizes the connectedness of animal and human well-being and both groups’ shared environment. According to the CDC, changes in land use and the activities of humans and animals have contributed to the emergence of new zoonotic diseases.

One Health also encourages interdisciplinary collaboration between experts to understand better the relationships between humans, animals, and the environment and improve the response to and control of potential problems arising from these changing relationships.

"Designing interventions around this holistic picture of resistance will be essential in tackling what has rapidly become one of the biggest threats to global health," said senior author Laith Yakob, PhD. "Going forward, we recommend tighter country policies and regulations on antibiotic use and prescription among animals and humans, as well as improved governance, transparency, and accountability, particularly among countries with the highest disease burdens."

The danger of these AMR infections is evident, and nearly 1.27 million people die globally every year because of antibiotic-resistant microbes. Despite the risk AMR poses, corporations and the United States healthcare system are not yet incentivized to direct their resources toward the issue. Pharmaceutical companies see the development of new antibiotics as a losing venture, while some prescribing entities continue to overprescribe the products contributing to the AMR crisis.

The Department of Health and Human Services is trying to shoulder the burden in the United States, already pledging up to $300 million to combat AMR using the Antibiotic-Resistant Bacteria Biopharmaceutical Accelerator.