You've probably read about MRSA, the so-called “super-bug” which has been on the rise over the past five years. MRSA, or Methicillin-Resistant Staphylococcus aureus is a kind of Staphylococcus aureus, a fairly common type of bacteria that has been causing skin and soft tissue infections for millennia. I see a lot of people with MRSA. It shows up in abscesses (we lance them and they go away), folliculitis (tiny pimples in the hair follicles, often resolved with hot soaks and antibacterial soap), or the skin infection known as impetigo (oral generic sulfamethoxazole is effective). As the Centers for Disease Control says:
“Almost all MRSA skin infections can be effectively treated by drainage of pus with or without antibiotics. More serious infections, such as pneumonia, bloodstream infections, or bone infections, are very rare in healthy people who get MRSA skin infections.”
How deadly is MRSA?
Section titled “How deadly is MRSA?”I have never seen anyone die from MRSA. However, statisticians tell us that MRSA kills about 18,000 or 19,000 people a year in the United States. (the figures are from 2005) How do we interpret this statistic? It's more than the 16,000 dead from AIDS that year, but less than 41,000 from automobile accidents, and far less than the 866,030 deaths from major cardiac disease (for more details of what carries us away, check out the CDC's National Vital Statistics Report, pages 31-34). Put another way, about .006 percent of the US population died of MRSA in 2005.
As a physician who has seen it and treated it, MRSA does not scare me. The most frightening thing about this bug is that we ourselves created it. With indiscriminate use of antibiotics, we encouraged the development and spread of these bacteria.
How to make a bad germ worse
Section titled “How to make a bad germ worse”Good germs
Section titled “Good germs”In last month's newsletter we talked about our intimate connection with the bacteria that live inside and around us. Just as the bacteria in our intestine depend upon us for life, so do we depend upon them. Here are just a few examples of what bacteria do for us. They synthesize biotin, a vitamin important for our hair and nails, and for proper regulation of blood sugar. They synthesize vitamin K, required for blood clotting. Bacteria enable us to obtain more energy from the food we eat by fermenting foods we cannot digest, then sharing the surplus with us. They protect us from harmful bacteria, by crowding them out.
We humans have benefited from our coexistence with certain bacteria for millennia.
Bad germs
Section titled “Bad germs”Of course, like any intimate relationship, this one can go bad. Not all bacteria are our friends. Some can cause infectious illness, have long ended human lives, and continue to do so. Before the discovery of antibiotics, diseases such as meningitis and tuberculosis were fatal. The discovery of antibiotics was a great breakthrough in medicine. Over the past fifty years, we've had antibiotics to fight infection. Now we hear that “Superbugs” such as MRSA foil these efforts.
The germs strike back!
Section titled “The germs strike back!”Just when we thought we had infections licked, some bacteria developed resistance to antibiotics that once killed them. We really shouldn't have been surprised. Bacteria fight one another, like all organisms, forever competing for resources and space on the planet. One method they use is chemical warfare. Bacteria synthesize compounds toxic to their enemies but not to themselves. For example, the Streptomyces genus of bacteria protect themselves using streptomycin, tetracyclines, neomycin, and many other compounds that we've copied for medical purposes. Fungi take part in this microscopic battle as well. Penicillin, for example, was first found in a bread mold, and used by that bread mold to stake out its territory. Antibiotic cephalosporins (Keflex) were discovered in a sewer, the product of another fungus.
Every war has offense and defense. Bacteria can synthesize and secrete compounds that destroy antibiotics, or they can make tiny "bilge pumps" in their cell membrane, and pump the antibiotics out before they do harm. Further, bacteria are promiscuous. They don't need to have a lasting relationship with individuals of the same species to mix and match DNA. They pass it around casually, even between different species.
The hidden cost of cheap hamburger
Section titled “The hidden cost of cheap hamburger”Here's the problem. When animals are raised on antibiotics, the bacteria in and on that animal tend to become resistant, even though the bacteria don't make the animal ill. Whatever bacteria are left when that animal gets to our table will travel through our intestine, gaily passing out DNA packets (called plasmids) to the bacteria in our own ecosystem, giving them the blueprints to resist certain antibiotics. Now our own bacteria have the means to destroy penicillin, or to pump out methicillin before it harms them. So if our usually benign bowel bacteria get into our tissues from diverticulitis, a urinary infection, surgery or trauma, the standard antibiotics are not going to work. This is just one way that careless use of antibiotics harms us.
The hidden cost of that unnecessary antibiotic prescription
Section titled “The hidden cost of that unnecessary antibiotic prescription”A frequent error in medical practice is the over-prescription of broad-spectrum drugs such as cephalexin (Keflex). A couple of decades ago, this drug was a good choice. It killed both staph and strep, and these are the common offenders in skin and soft tissue infections. Nowadays, though, cephalexin will not kill MRSA, so it is a lousy choice. It is also much more likely to disrupt the ecosystem in the intestines, leading to overgrowth of usually innocuous bacteria called Clostridium difficile. These bacteria, nicknamed “C diff”, can cause diarrhea that can last for years, or in someone weakened by other illness, can kill.
What to do
Section titled “What to do”Don't be frightened
Section titled “Don't be frightened”Your chances of succumbing to MRSA are miniscule. We all have to go sometime, but it probably won't be by MRSA. If you discover symptoms of MRSA, such as a skin infection or fever, call your doctor. This is almost always a treatable, curable disease.
Do be careful
Section titled “Do be careful”In every medical clinic, we use standard precautions, such as hand-washing and proper sterile procedures, as preventive measures. These are equivalent to the rules you have for fire in your home. You make sure that the candle is not sitting next to drapery, and you extinguish it before leaving the house.
The Standard Precautions:
Wash your hands often, especially before preparing food and after using the lavatory.
Cover your mouth when you cough.
Shower daily.
Keep skin infections covered.
Some people are colonized with MRSA, meaning they do not have an infection, but the bacterial lives quietly in their nose. If you carry MRSA in this way, or have an active infection, follow these guidelines (from the Tacoma-Pierce County Health Department) to prevent spread to your loved ones.
Help your doctor help you
Section titled “Help your doctor help you”Avoid unnecessary prescription antibiotics. If you have a bacterial infection, don't hesitate to accept an antibiotic. But if your doc says it's probably a virus, try not to tell her your friend had the same thing and her doctor gave her an antibiotic and the friend promptly improved. Your doctor may prescribe an antibiotic just to show she cares, but all you are doing is disturbing your own bacterial community.
If you do need antibiotic treatment for skin and soft tissue infections, the current reasonable, initial choice of antibiotics to cover MRSA would be trimethoprim/sulfamethoxazole (Septra, Bactrim), combined with penicillin to treat strep if present. Your doctor may also collect some material for culture, so that if the initial treatment isn't effective, he'll know what is.
Hot soaks for superficial skin and soft-tissue infections
I recommend hot soaks for skin infections. The heat increases blood flow and oxygen and speeds healing. For instructions, see our page on hot soaks.
Live long and prosper
Section titled “Live long and prosper”The good news is you've got a smart immune system. It is used to a bacterial environment and has learned to take advantage of it. Our immune system does not just blindly attack whatever it sees. Like an intelligent policeman, it evaluates risk. Some bacteria, as they pass down the gastrointestinal tract, are actively tolerated. Others do not arouse our immune system to inappropriate action, but do get the immune equivalent of a “keep moving” message¹. If we don't throw off our bacterial ecosystem by overuse of antibiotics, it should keep traffic moving along safely for the rest of our lives.
¹ This “keep moving” analogy comes from Good Germs, Bad Germs by Jessica Snyder Sachs.
For further reading
Section titled “For further reading”Good Germs, Bad Germs: Health and Survival in a Bacterial World. By Jessica Synder Sachs. Hill & Wang, 2007.
Why Dirt is Good: Five Ways to Make Germs Your Friends. By Mary Ruebush, Kaplan, 2009. Reviewed in the New York Times by Jane Brody on January 26, 2009.