Increasing use of antibiotics in livestock undermines effectiveness of antimicrobials in humans

For about a billion poor people, livestock are essential to survival,” said Tim Robinson, principal scientist from the International Livestock Research Institute. “They are raising their livestock in extensive, backyard systems on the whole and do not use antibiotics as growth promoters or in disease prevention. They use them when their livestock are sick and will take a disproportionately high share of the consequences as effective drugs become more costly and less available in treating their livestock and themselves when they become sick.”

Having reliable global data is essential for scientists and policymakers to both measure the extent of the problem and assess potential solutions, said lead author Thomas Van Boeckel, a Fulbright research scholar in Princeton’s Department of Ecology and Evolutionary Biology.

An important limiting factor in carrying out this first inventory of antibiotic consumption in animals was the lack of ‘modeling-ready’ data on veterinary antibiotic sales in many countries,” Van Boeckel said. “Sometimes these data are simply not collected because of lack of veterinary surveillance programs, but sometimes the barriers are more political and or legislative. With this work we hope to trigger a momentum and show how useful such data could be to inform the design of global concerted policies against antimicrobial resistance.”

Antibiotic resistance is a dangerous and growing global public health threat that isn’t showing any signs of slowing down,” Laxminarayan said. “Our findings advance our understanding of the consequences of the rampant growth of livestock antibiotic use and its effects on human health — a crucial step towards addressing the problem of resistance.”

The release notes that in addition to Laxminarayan, Robinson and Van Boeckel, the research was conducted by Bryan Grenfell, the Kathryn Briger and Sarah Fenton Professor of Ecology and Evolutionary Biology and Public Affairs at the Woodrow Wilson School of Public and International Affairs; and Simon Levin, the George M. Moffett Professor of Biology and professor of ecology and evolutionary biology. In addition, two scholars from the Center for Disease Dynamics, Economics and Policy in Washington, D.C., were involved as well as Marius Gilbert from the Université Libre de Bruxelles.

The research was funded through the U.S. Department of Homeland Security; the Organization for Economic Co-operation and Development; the Bill and Melinda Gates Foundation; the RAPIDD Program; the National Institutes of Health Fogarty International Center; and the Princeton University Grand Challenges Program.

— Read more in Thomas P. Van Boeckela et al., “Global trends in antimicrobial use in food animals,” Proceedings of the National Academy of Sciences (18 February 2015) (doi: 10.1073/pnas.1503141112)