Growing resistance

Bacteria that don’t respond to antibiotics are spreading while FDA fails to ban their use in livestock

Courtesy of Resistance

The World Health Organization statement on the matter reads like the setup to a sci-fi horror film — a once hypothetical problem has now become a major threat to public health. And no, we’re not talking about Ebola flying home on airplanes. We’re talking about the bacteria brought home in the chicken, beef and pork you buy at the grocery store, and the increasing presence of antibiotic resistant bacteria you may be bringing home along with it.

Antibiotic resistance “is no longer a prediction for the future, it is happening right now in every region of the world and has the potential to affect anyone, of any age, in any country,” according to the World Health Organization.

As our use of antibiotics has spread, so has the ability of bacteria to develop a resistance to them. Using antibiotics can kill off all the bacteria related to an illness, and leave a few drug resistant bacteria and none of the good bacteria that previously protected the body.

An infection from drug resistant bacteria that doesn’t respond to standard treatment can lead to longer illnesses, higher costs for health care and a greater risk of death. Drug resistant infections can, according to the World Health Organization, undermine the successes of modern medicine, compromising now accepted medical procedures, organ transplants, chemotherapy and other major surgeries among them.

“Without urgent, coordinated action by many stakeholders, the world is headed for a post-antibiotic era, in which common infections and minor injuries which have been treatable for decades can once again kill,” Dr Keiji Fukuda, World Health Organization’s assistant directorgeneral for health security, said in an April press release accompanying a report on the spread of antibiotic resistance among infections caused by bacteria, as well as parasites including malaria, viruses including HIV and fungi.

“Effective antibiotics have been one of the pillars allowing us to live longer, live healthier and benefit from modern medicine,” Fukuda continued. “Unless we take significant actions to improve efforts to prevent infections and also change how we produce, prescribe and use antibiotics, the world will lose more and more of these global public health goods and the implications will be devastating.”

The U.S. Centers for Disease Control and Prevention have confirmed cases of resistant bacteria in 47 states, including Colorado. Two million people develop antibiotic resistant infections each year and at least 23,000 die as a result of these infections, though that number is likely underreported. These infections occur in two places — at hospitals during procedures or in the community, often through the food supply. Though most of the deaths happen to patients who contract those infections in hospitals and nursing homes, most of the infections happen outside healthcare facilities in the community. Between January and June of 2013, 63 patients in Colorado were found to have resistant bacteria, according to the Colorado Department of Public Health and Environment.

Scientists have known that antibiotic resistance could become a problem since the dawn of antibiotics. Alexander Fleming, who discovered penicillin, cautioned in his Nobel Prize for Medicine acceptance speech that the irresponsible use of antibiotics could breed resistant strains of infection — and that those irresponsible users would be morally responsible for the deaths they incurred through the spread of resistant infections.

But the bacteria that cause infections, and the, as Fleming would say, morally responsible parties, are tough to trace. It’s only recently that the average state health department might have the equipment to conduct tests to confirm that two samples of bacteria from two patients came from the same source. Scientists are only just now beginning to be able to tie all the pieces together, particularly when those pieces cross disciplines from microbiology to food production. We are only just now able to find, for example, that the bacteria found in a person’s stool is very similar to the bacteria found on chicken in the grocery store where that person shops.

In the 1950s, researchers discovered that giving food animals small, constant doses of antibiotics speeds their growth by somewhere between 5 percent and 20 percent. Entire flocks and herds are now fed small doses of antibiotics for an extended period of time, in a use of the drug approved by the U.S. Food and Drug Administration. Between 70 percent and 80 percent of all the antibiotics sold in the U.S. annually are going to livestock herds.

By the 1970s, researchers were beginning to connect the use of antibiotics in the livestock industry with increasing antibiotic resistant infections. Animals fed antibiotics develop resistant bacteria in their guts. That drug resistant bacteria can remain on the meat and spread to humans who handle or consume that meat, or can be transferred through fertilizer that contains drug-resistant bacteria and is used on food crops.

“There’s not one paper that I could cite as ‘Read this and you’ll understand the clear smoking gun link between antibiotic use on farms and resistance in humans,’ but the cumulative effect of the hundreds of studies out there is pretty overwhelming,” says Dr. Dimitri Drekonja, assistant professor of medicine at the University of Minnesota in the infectious disease section and a member of the public health committee for the Infectious Diseases Society of America. “When antibiotic use of any sort, whether it’s in humans or animals, goes up, we do see more resistance to that drug — and sometimes not just to that drug, sometimes to other drugs because mechanisms travel … and then as antibiotic use goes down, we typically see resistance go down.”

Some of the more convincing studies into that issue, he says, come from countries with more stringent rules about antibiotics than are in the U.S. Take Australia. The country has never approved the use of certain antibiotics often used in America with poultry, where there’s also been a high rate of resistant salmonella, one of the most common organisms found in poultry. In Australia, the percentage of resistant salmonella is negligible.

Most of the time, those antibiotic resistant bacteria get into humans through the food supply. Processing livestock to become the meat on a dinner plate isn’t a sterile process, and even the best practices in the kitchen — like using a separate, glass cutting board that’s only for meat — don’t prevent the spread of bacteria.

The Centers for Disease Control have declared the use of antibiotics to promote growth in food-producing animals unnecessary and said that to address the growing health threat of resistant bacteria, the practice should be phased out.

The U.S. Food and Drug Administration (FDA) states on its website about antimicrobial resistance that “Because all uses of antimicrobial drugs, in both humans and animals, contribute to the development of antimicrobial resistance, it is important to use these drugs only when medically necessary. Governments around the world consider antimicrobial-resistant bacteria a major threat to public health. Illnesses caused by drug-resistant strains of bacteria are more likely to be potentially fatal when the medicines used to treat them are rendered less effective.”

The FDA took the first step in reducing the use of antibiotics in food animals in December by issuing a call for drug companies to remove increased growth as an approved use on the label for some antibiotics, including penicillin.

The measure was challenged as insufficient, but was upheld in the New York state court that saw its challenge, despite one judge noting that the FDA has essentially acknowledged the practice as one that threatens human health, but declined to ban it.

On June 30, the FDA announced that all 26 drugmakers affected by the policy had committed to participating in the voluntary program.

The withdrawal of the indication of using those drugs for growth is essentially a ban — drugs can’t be used for a treatment that isn’t approved by the FDA. Anyone using those antibiotics for growth promotion would be breaking the law, but there’s a question of enforcement. Livestock could be fed the same dose of the same antibiotic at the same intervals as disease prevention, which is still an approved indication.

“Ideally if everyone follows the rules, this will result in a decrease in antibiotic use and this should result in a decrease in resistance,” says Dr. Drekonja. “It’s hard to know for sure because we do not have a national speedometer of how much antibiotic we’re using, and we also don’t have sort of a national dashboard indicator of here is our sum total of antibiotic resistance. If we had such a thing, it would be great to watch one dial go down and hopefully see a corresponding drop in the other dial, and that would be really nice and simple, but unfortunately we don’t have that.”

Colorado is one of 10 states in which the Centers for Disease Control are conducting surveillance for this issue. The Boulder County health department isn’t charged with monitoring or addressing the issue, so they don’t.

“We’re able to track diseases that are on a state-mandated list and in Boulder County, antibiotic resistant infections are not something that’s reportable,” says Dr. Bernadette Albanese, medical officer with Boulder County Public Health.

The Colorado Department of Public Health and Environment just began tracking antibiotic resistant infections a year and a half ago, and staff says it’s too soon to report a trend on that data.

Two bills are currently in Congress that would provide more regulatory oversight. They’re not expected to budge before the end of the session.

What antibiotic resistant bacteria and the Ebola virus have in common comes back to a question of globalization.

“The world is ridiculously small these days. The antibiotic practices that go on on a farm or the sanitation practices that go on somewhere where they’re growing raspberries in Honduras, a day later those raspberries are on an airplane and a day later they’re sitting in front of you in a grocery store, and whatever sanitation equipment was like in Honduras is now highly relevant to your health,” Dr. Drekonja says. “It’s kind of amazing how much stuff gets moved around in the world and when it gets moved, it brings a little bit of potential disease with it in terms of, there are very few things that are sterile, they all have bacteria, viruses, fungi on them. For the most part, our host defenses handle them quite well, but there’s always the possibility.”