MRSA: Superbug

The medical community has failed to contain it. Science has failed to develop new drugs to treat it. MRSA is “the most frightening epidemic since AIDS.”

Staphculture
A culture of Staphyloccocus aureus.

“It was my intent to scare people,” admits veteran medical writer Maryn McKenna, speaking about why she wrote “Superbug: The Fatal Menace of MRSA” (Free Press), her recently-released book about medicine’s war on methicillin-resistant Staphyloccocus aureus. “But I’m finding that it’s a little too scary,” she continues, clearly troubled that her effort to highlight the latest developments has the potential to make readers paranoid, not to mention paralyzed by fear. After reading “Superbug,” it’s easy to see why McKenna—referred to by colleagues as “scary disease girl” during her days covering the Centers for Disease Control for the Atlanta-Journal Constitution—is concerned about the fear factor.

For one, MRSA is no longer confined to hospitals. The pathogen is now out in the community-at-large, so even the strongest and healthiest individuals may find themselves afflicted, suddenly overcome by hideous infections that require emergency intervention. And thanks to antibiotic resistance there are only one or two drugs that are still effective against the most serious strains, so MRSA is often fatal. Never mind the fact that those lucky enough to survive a serious MRSA infection often find that it recurs again and again, causing (more) life-altering physical, emotional and financial pain.

With all this in mind, I spoke with McKenna—a contributing writer at the Center for Infectious Disease Research and Policy at the University of Minnesota—about how science and medicine has failed to fully address MRSA, and what will need to be done to get the epidemic under control.

Why don’t we start by defining MRSA?

Most people who have heard the acronym don’t actually know what it is. People tend to pronounce it as if it’s a word, whereas physicians tend to say: M-R-S-A. The S.A. part stands for Staphyloccocus aureus, which is a bacterium that is incredibly common. Regular drug-sensitive staph lives on the skin and in the nostrils of about one-third of the population. It’s one of our oldest evolutionary companions, and it’s sophisticated in that it lives with us without making us sick. Ever since staph was identified back in the late 19th century we’ve known that if it gets from the outside of the body to the inside [through a cut or wound, for instance] it can make you ferociously sick. Even after the beginning of the antibiotic era, staph remained a formidable opponent.

Then in the late 1950s staph became massively resistant to penicillin and caused a worldwide pandemic. Methicillin [the “M” part of MRSA] was the first of the drugs invented to counter that. Methicillin has the same structure as penicillin, along with some extra stuff attached that pharmaceutical chemists believed would keep staph from becoming resistant to it—and did … for 11 months. That started a game of microbiological leapfrog that we’ve been locked in ever since.

At this point, methicillin-resistant staph is common enough that in 2004 it was estimated that 1.5 percent of the population—about 4.4 million people—walk around with it.

How does one “pick up” MRSA?

No one has done a good study to figure out why people become colonized. But it can survive on skin and also on surfaces in the environment, so the places you can get it are varied, including shaking hands with someone or touching a surface that a carrier has also touched. In hospitals, health care workers carry it from the environment to a patient or from one patient to another. MRSA also causes a lot of infections among people who have lots of skin-to-skin contact, like athletes.

It sounds as if there’s no sure way to protect yourself. 

Unfortunately, that’s probably true. And not only is the prevalence of MRSA in the population rising, new strains are emerging. It’s causing new illnesses and syndromes that it didn’t used to, like necrotizing fasciitis [flesh-eating disease], while also picking up additional resistance factors.

Why hasn’t MRSA received more attention in the media?  

I would like to know the answer to that myself. I think the reason MRSA has snuck up on us has to do with the fact that it keeps finding new ecological niches to live in. First it was a hospital bug, and medicine thought it knew what was going on with MRSA attacking people in intensive care units, burn units and cancer wards. You can argue whether or not medicine took it seriously enough even there. I think the record shows it did not, because it’s a problem that hospitals are still coming to grips with.

Staph’s next major evolutionary leap—the start of the second overlapping epidemic—came when it began causing illness in people who were not already ill. This epidemic started taking place outside the walls of hospitals; that’s why it’s called community staph. But intensivists don’t talk to primary care physicians, and they don’t read the same journals or go to the same meetings, so there was a lot of skepticism about whether it was really happening and how serious it was.

Now MRSA has emerged again in a slightly different genetic way among farm animals and has started expressing itself in people who have close contact with these animals. Again, veterinarians don’t read the same journals or go to the same meetings [as doctors that treat humans]. So there is a lot of skepticism about livestock-associated MRSA and how serious it is. All of this is complicated by the commercial and political interests involved, but to my eyes it looks similar to the pushback from the first to the second epidemic.

What kind of resources have the Centers for Disease Control allocated to fighting MRSA?

If you look at the organizational chart for the Centers for Disease Control—which I know pretty well because I covered the CDC for 11 years and wrote a book about it—MRSA exists in a unit that is way off on the side of the chart. The biggest part of the CDC is the part that fights infectious diseases; that’s the part that gets the most money. But MRSA is in the branch that deals with hospital-associated infections. Organizationally, the CDC is still dealing with MRSA as a hospital thing, even though it hasn’t been hospital-only since the late 1990s. I’m not saying they aren’t paying attention to the community and livestock epidemics, but the organization of their efforts hasn’t kept up with the changes in the epidemic.

What are some of the challenges in diagnosing MRSA?

The biggest challenge is being aware that you are supposed to look for it in the first place. There are plenty of physicians who haven’t gotten the message that MRSA is out in the community. ER doctors and dermatologists get it but a lot of primary care doctors—especially those who have been in practice for a while—haven’t gotten the message. We don’t have very good mechanisms for getting information out to the vast, disseminated mass of doctors.

How is MRSA treated?

How you treat MRSA and the Meta strategies you think about for deploying drugs is a lesson in the limitations of technology. In our market structure it takes about 10 years and a billion dollars to get a new drug on the market. Bacteria have a new generation every 20 minutes. So it’s not hard to see how it outpaces us.

For the most serious MRSA infections there are now only one or two drugs that work, and the one that everyone thinks of as the drug of last resort is vancomycin. It’s the go-to drug for really serious MRSA infections, but it has limitations and bacteria are becoming resistant to it. Researchers have been trying to come up with new drugs, and in a clinical trial sense vancomycin is the drug that they are judged against. No one has come up with anything better; they have mostly come up with drugs that are different but equally effective. Every drug has some difficulty to it; it doesn’t work in a certain organ system or it can only be delivered in a certain way. And there are people for whom drugs just don’t work anymore.

The good news—if there is any good news—is that for some manifestations of MRSA, older drugs that haven’t been used for a long time may work. But these older drugs are all off patent, and drug companies are not likely to fund trials of a drug from which they are not going to make money. That’s why the National Institutes of Health recently stepped up and put money towards looking at these older drugs.

What can individuals do to reduce their chance of getting a MRSA infection?

There are things that people can do to protect themselves. Some are simple, like washing your hands a ton. People should use hand sanitizers, preferably ones that don’t have antibacterial components, because that just makes the problem worse. People should not buy antibacterial cutting boards and antibacterial toys for their children because that increases antibiotic resistance in the environment.

There are also a lot of cases associated with gyms, so one of the things primary care doctors advise is to be sure to amp up your hygiene right after you work out—shower right away and change your clothes. I think we should probably force kids to shower after gym class. That was a trauma for me at school, and I don’t see why kids should be spared now.

What do we have to do as a society to limit the number of infections?

We have to harass people in healthcare to be really good about hygiene because hospital hygiene is in a much worse state than people understand. In terms of the livestock-associated epidemic, it is probably a good idea to buy organic or antibiotic-free meat, because if this bug is on a piece of meat and you handle it you are potentially adding it to your personal flora and to your kitchen environment.

There are bigger things that we have to do as well, the first of which is to be counting this better. Only a few states have mandated MRSA reporting, and we still allow hospitals to duck out from really robust reporting. Peter Pronovost [co-author of “Safe Patients, Smart Hospitals”] has said if the federal government made hospital infections mandatorily public, the consumers of America would rise up and demand change.

Can you explain the connection between MRSA and pets?

Cats and dogs don’t generally get the human strain; they get other strains that have evolved to live in them. But they can harbor Staphyloccocus aureus without any harm to them. What usually happens is that you have someone with a community-associated infection and they pass that strain to their pet. It doesn’t make them sick and they don’t become permanently colonized, but they hang onto it just long enough to outlast a course of antibiotics. It’s one of the factors that cause people to have recurrent MRSA infections. It hangs out in the animal just long enough to be passed back to the human after the antibiotics are done.

Which countries have done the best job of controlling MRSA?

The countries that have done a good job are significantly different from the U.S. in terms of how they organize their health care. They use both carrots and sticks and are able to exert a great deal of compulsion over antibiotic use, particularly in hospitals. We probably need to do that; antibiotics overuse and misuse in both humans and animals keeps driving the epidemic of antibiotic resistance.

The Netherlands is really good at keeping MRSA out of hospitals through “search and destroy,” which is now being practiced in some parts of the U.S. [The assumption is that every patient, doctor, nurse and staff member is colonized until proven clean, and anyone suspected of carrying MRSA is checked before being admitted.] The biggest healthcare system that is doing it in the U.S. is the Veterans Administration, which is kind of like a single payer healthcare system. It’s not patchwork the way our private healthcare is patchwork.

Norway—a single payer system—has done a very good job of antibiotic stewardship, which involves taking extant antibiotics and withdrawing them from circulation so the bacteria do not experience them. The idea is to save them for some future date. So there are models out there, but none are in societies as politically or culturally complex as the United States.

Where are we at in terms of development of a MRSA vaccine?

There have been several sets of trials of MRSA vaccines and in every case they have failed at Phase II or III. But there is still a lot of interest in a vaccine in the drug development community.

However, assume that we had a staph vaccine. Then what happens? Who would we give it to? People going into surgery? Women who are going to deliver? People going into intensive care? Those would be places where you could be pretty sure of having a targeted impact on hospital-associated infections. But what about community infections? Does that mean we would give it to all kids who play sports?

Meanwhile, we are becoming a society that doesn’t believe in vaccines anymore. Lots of people have objections to vaccination, variously clad as concerns about autism, or belief in personal autonomy, or religious or quasi religious objections.

Despite its seriousness, [MRSA] is not something that most people are that concerned about. It has become this enormous problem without raising broad social concern. If there is no broad social concern, are people going to believe in the necessity of taking a vaccine? Probably not.

They might begin to feel differently as more and more people are infected—and affected.

The thing that gets lost is that people don’t realize how devastating MRSA is. It’s not just the people who die. People’s lives are forever changed. The wife of the morning drive-time radio host I profile in chapter three [who went in for a bowel resection to treat diverticulitis, which led to recurring MRSA and a pulmonary embolism], developed a MRSA infection too, as well as irritable bowel syndrome, which caused her to lose 100 pounds. As for him, he’s now had eight surgeries and 12 hernias. He’s still in his fifties, but for the rest of his life can’t pick up anything bigger than a lunchbox. 

Official Web site for Maryn McKenna’s “Superbug: The Fatal Menace of MRSA”

See also:
Rising Plague