Global Restrictions on Farm Antibiotics Needed to Fight Superbugs, Report Says

A new report calls for a concerted global effort, not just localized changes.

Dec 8 2015, 10:55pm

There's no denying the link between the overuse of antibiotics on farm animals and the development of antibiotic resistance, according to a new report commissioned by UK Prime Minister David Cameron, and fighting back will require a global effort.

The Review on Antimicrobial Resistance is a UK government funded project, chaired by the former head of economic research for Goldman Sachs, Jim O'Neill, researching the causes of, risks of, and possible solutions to antibiotic resistance. The group kicked things off last year with a grim report estimating that, by 2050, antibiotic resistance could account for 10 million deaths annually worldwide if left unchecked. In its latest report, the group is firm in its conclusion that the science shows overusing antibiotics on the farm impacts the development of antibiotic resistant bugs.

"There is no doubt though that prolonged exposure to antibiotics creates ideal conditions for the cultivation of drug resistance; and there is evidence to show that this can increase the localized prevalence of antibiotic-resistant bacteria very significantly," the report reads, noting it reviewed stacks of published, peer-reviewed scientific literature on the topic. Of 139 studies, 100 found evidence of a link between antibiotic consumption in animals and antibiotic resistance.

"I find it staggering that in many countries most of the consumption of antibiotics is in animals, rather than humans," said O'Neill in a press release. "This creates a big resistance risk for everyone, which was highlighted by the recent Chinese finding of resistance to colistin—an important last-resort antibiotic which has been used extensively in animals."

Medically-important antibiotics (i.e. antibiotics that we use to treat humans, as opposed to other antibiotics we only use on animals) are widely used in agriculture around the world both to prevent disease and as a growth promoter to help livestock fatten up, rather than when the animal is already sick. And overusing antibiotics, whether in humans or animals, makes it easier for bacteria to become resistant to those drugs.

The Review's proposed solution: change the rules over when and how much medically-important antibiotics can be administered to livestock, not just in the UK, but around the world. The report suggests using the example set by Denmark, which limits antibiotics to a maximum of 50 milligrams per kilogram of livestock in the country. In the UK, the average is slightly higher—an average of 62 mg/kg in 2013, the most recent year, according to the European Medicines Agency. But the numbers vary around the world from as low as 4 mg/kg of meat produced in Norway to as high as 400 mg/kg in Cyprus.

"Denmark has combined low use with being one of the largest exporters of pork in the world," it reads. "Reducing levels of use to that of Denmark may be a good starting point for such a target."

How far do Denmark's limits differ from the levels of antibiotics used on farm animals in the US? We don't actually know. One 2007 report estimated US producers used as much as 250 to 300 milligrams of antibiotics per kilogram of meat produced, but the Food and Drug Administration only releases numbers on the percentage of total antibiotics that are sold to agriculture every year (it hovers around 70 to 80 percent), but either doesn't track or doesn't release how much is actually being used per pound of meat. And the US government has been slow to adopt major changes to the way antibiotics are used on the farm.

But change is not impossible: Earlier this year California passed the strictest farm antibiotic laws in the country, making it illegal to use medically-important antibiotics on a farm animal unless it is already sick, is at serious risk of an infection, or needs antibiotics ahead of a surgery or medical procedure. Though this might be a bit extreme for the palates of some lawmakers, it's clear that some kind of limitations need to be put in place if we hope to fight back against the terrifying specter of the post-antibiotic world predicted by the World Health Organization.

"The continued use of antibiotics in agriculture for non-therapeutic uses such as disease prevention and growth promotion cannot be sustained if we expect antibiotics to continue to be medically effective for humans in the future," said Congresswoman Louise Slaughter in a press release. Slaughter has spent the past 16 years trying to pass a law banning the use of medically-important antibiotics on farm animals.

"The new report by Lord O'Neill makes clear what many of us have known for years: antibiotic resistance is now a global problem which will require a global response," she added.