MRSA: The Basics For The Layperson

My grandmother ended up with an MRSA toe infection and to give my parents a good understanding of what to worry about and, more importantly, what not to worry about, I wrote this "mini-article" and thought it would be useful for those of you worrying about this up and coming infection.

MRSA, or Methicillin Resistant Staph Aureus, has unfortunately become the norm of skin infections. For the past few years In the ER we've been treating almost all of our skin infections empirically for MRSA, since in that time we've seen it increasing in frequency, so that more than 50% of our skin infections are now due to it. It's become endemic and there's not much you can do to prevent it these days. Don't get too worried yet, though, it usually doesn't make you too sick as long as it's treated, and often times people will have just an isolated infection.

Interestingly, despite our increasingly germophobic culture, using UV-irradiated toothbrushes, largely unnecessary hand sanitizer gels, and the ubiquitous antibacterial soap, we are unfortunately beginning to generate a place for these products, with ever-increasing virulence of viruses and bacteria and a continuing rise in resistance against traditional antibiotics.
These hypersanitation products have not been traditionally necessary, since the human immune system, along with skin anatomy and a commensualistic relationship with "friendly" bacteria, have been enough to fight off the majority of invasive skin infections fairly well. Bacteria, however, are resourceful. They are highly adaptable to environmental pressure, and since they multiply at logarithmic rates, doubling a colony size in as little as 10 minutes time, the opportunity for mutation and the induction of "resistance genes" and other advantageous traits is significant.

The rampant use of antibiotics for agriculture has likely been one of the biggest evolutionary pressures for modern bacteria, with MRSA being cultured in higher rates in factory farm workers than in the general population and resistant E. coli strains being found in various human food products. This has been an interesting biologic process that has significantly increased human disease and has been due in large part to politics and economics rather than common sense and forward thinking. Michael Pollan's book, "The Omnivore's Dilemma", details the whole sordid tale - basically, in the early part of the century, as farmers got better at growing things, due to cheap fuel oil, advances in machinery, petroleum-based fertilizers and pesticides, and other improvements in technology, crop yields increased, generating a huge grain surplus in the 1930's, driving the price of grain to almost nothing. With all that extra corn, we figured out that we could use the surplus super-cheap grain to feed cattle, the cattle grow quickly and chubbily (the marbling us Americans all like), but at the cost of their health. A ruminant's stomach has evolved to eat grass, not corn, so feeding cows grain causes liver infections, bloat, and sometimes death in 30% or more of grain-fed cattle if not treated with antibiotics. This is one of the main reasons I'm trying to decrease red meat intake and when I do eat it, stick to grass-fed beef (besides the 10-fold increase in resource use to produce meat over vegetables, and the cruel factory farming techniques used in the industry today). The point is, because of the grain use, we're using inordinate and otherwise unnecessary quantities of antibiotics to treat whole herds of cows, and we're seeing an increase in microbial resistance and thereby an increase in human disease as a result.

I've come to think of antibiotic resistance as an unending race of technology vs. nature. We will never eradicate disease, and the very act of fighting it pressures it towards resistance. Fighting it too hard leads to more resistance, but not fighting it enough increases human morbidity and mortality. I suppose the answer is informed but cautious prudence in the use of antibiotics.

So what do you do about it? Aside from any political action or dietary change, what happens if you or a loved one gets MRSA? If you end up colonized with MRSA, all it means is that the normal Staph bacteria on your skin are now a bit tougher and more opportunistic, so it becomes easier to get skin infections, infected hair follicles, boils, abscesses, and other tasty low-level infections. Sometimes it can progress to worse problems, but if lesions are drained early, the proper antibiotics are given when needed (Bactrim, a sulfa drug, or a combination of clindamycin and rifampin is best right now where we are, but resistance profiles vary significantly depending on where you live). The biggest mistake I see practitioners make is to give antibiotics instead of draining an abscess. Once you get the pus out (I know, it's pretty nasty, but welcome to my world), it usually starts to improve fairly quickly and often actually doesn't need antibiotics at all. So, if you start to get big zits or boils, you actually need to try to "pop" them and allow them to drain. Sometime heating pads or moist heat will help draw a developing abscess to the surface of the skin where it can drain. When we have to incise them, we actually leave a packing in for a few days so that it can start to heal from the inside out, otherwise they seal themselves up and continue to fester. Once you start seeing recurrent MRSA in the household, it's probably a good idea to have everyone use intranasal Bactoban ointment in the nose, three times a day, for 5 days - this is because a common place for MRSA colonization is the nose. I would probably give the bathrooms a good once-over with some disinfectant, chlorhexidine kills MRSA and we use it in the hospital, but I'll have to check to see if it's available to the general public.

After all that, the message is: don't worry too much, just keep an eye out and take care of infections when they come along.

image from giantmicrobes.com