Global Health Threat Seen in Overuse of Antibiotics on Chinese Pig Farms

BEIJING â€" As Europe continues to recoil at the “horseburger” scandal, focusing minds on the risks in long food-production chains, a new study has found that high use of antibiotics in Chinese pig farms is producing antibiotic-resistant genes that pose “a potential worldwide human health risk.”

The “unchecked” use of antibiotics in Chinese farms poses risks that “may spread worldwide through manure and fertilizer run-off,” according to an article in The Conversation, a journal funded by more than a dozen Australian universities.

The article cited a study by eight scientists from China and the United States published in the journal PNAS, or the Proceedings of the National Academy of Science of the United States of Aerica.

The Chinese researchers, from the Chinese Academy of Sciences, and their colleagues from Michigan State University analyzed manure from three commercial pig farms in China. They compared the results to manure from pigs never fed antibiotics and soil from “a pristine forest,” also in China, the Conversation article said.

The result: They found 149 “unique” antibiotic-resistant genes in the commercial farm manure, three times more than in the control samples.

In the language of science: “Antibiotic resistance genes (ARGs) are emerging contaminants posing a potential worldwide human health risk,” the researchers wrote in an abstract.

“Intensive animal husbandry is believed to be a major contributor to the increased environmental burden of ARGs. Despite the volume of antibiotics used in China, little information is available regarding the corresponding ARGs associated with animal farms,” t! hey wrote.

The genes can be spread via microbes in manure, compost or the soil, as these enter rivers, leach into underground water, are transported by the wind or human travel, or in agricultural products such as gardening compost, they said.

It was unclear from the study if the resistance had created superbugs, germs that are resistant to a combination of antibiotics, a co-author, Timothy Johnson, said, according to The Conversation.

China is the world’s biggest producer and consumer of antibiotics in the world, with at least 46 percent of antibiotics being used in livestock, The Conversation said.

Professor Matthew Cooper of the University of Queensland’s Institute for Molecular Bioscience told The Conversation that the paper had quantified this type of resistance evolution in Chinese pigs for the first time.

Professor Cooper said that more transparent reporting measures for antibiotics use were needed in both China and India. The European Union has banned the use of antbiotics as growth promoters, and the United States and Australia have been banning more classes of antibiotics, but a global framework is needed, he said.

“Animals get transported between countries, as do people. Infectious disease is no longer a national issue, it’s a global issue,” Professor Cooper said.