In a previous post I touched on the infection risk associated with surgical procedures in hospitals, and the very real health threat posed by surgical site infections (SSI’s). I’d like to revisit SSI’s (and will likely do so again in the future), since they represent the largest subset of hospital-acquired infections and are particularly related to Staphylococcus aureus and MRSA.
Because of the variety of surgical procedures out there, SSI’s encompass a wide range of both costs and severities. S. aureus/MRSA, which causes far more SSI’s than any other type of bacteria, can add thousands of dollars to the cost of care for a single patient even when considering just minor surgeries.1 In complicated major surgeries that cost can stretch into the hundreds of thousands.2 These costs include everything from extended hospital stays to extra procedures, medicines, and diagnostic tests. Even apart from the human suffering caused by SSI’s, there is major economic incentive to keep rates as low as possible.
While it may take days or weeks for a surgical incision site to fully heal, it is generally accepted among infection control specialists that the high risk periods for contracting an SSI are during surgery and within 24 hours of completion of the procedure. These are the times when bacteria can enter the body through the incision site, contaminating the inside of the wound or even entering the bloodstream. Amazingly, by about 24 hours post-surgery the incision has actually sealed itself by epithelialization to the point where bacteria can no longer penetrate. Thus, when dealing with SSI’s doctors are facing an extremely high risk, yet very short and well-defined, period in which to implement preventive measures.
Everyone knows the care that is taken in hospital operating rooms to ensure that all surfaces, equipment, instruments, and clothing are sterilized to prevent the introduction of bacteria during surgery. Even the surgeons and nurses don’t enter the room until they’ve changed, scrubbed thoroughly, and covered their bodies with gowns and gloves. So in such a careful environment, where is all this SSI-causing bacteria coming from? Increasing evidence is suggesting that the patients themselves are a major source of S. aureus/MRSA, and that so-called “self-infection” is a real issue when it comes to SSI’s.3, 4 It’s standard practice to disinfect the skin surface directly around the incision site before cutting, but that isn’t always where the problem comes from. If you’ve read past posts you’ll remember that the nose and other skin surfaces can harbor high concentrations of pathogenic bacteria such as MRSA. In light of this, what is truly unbelievable is that it is not standard practice to make sure bacteria from these “self” sources is eliminated prior to surgery! Elimination of bacteria from the patient’s body before surgery, generally known medically as “decolonization therapy”, is not only not considered to be standard of care….its actually rare in North American hospitals.
Decolonization therapy is a concept that is quite controversial among medical professionals. On one hand, some assert that there’s not enough supporting evidence that decolonization has a measurable impact on SSI rate. On the other hand, there are the well-informed and up-to-date healthcare providers who have examined more recent published studies and seen the convincing results supporting decolonization. At a recent international infection control conference that I attended, one of the keynote speakers began his discussion of decolonization therapy by questioning the audience as to why we are still asking ourselves 1990’s questions (ie. does decolonization reduce infection rate) in 2010? Seems like a reasonable question, especially when the current literature taken together shows that identification and decolonization of S. aureus/MRSA carriers before surgery results in a 40-60% reduction in SSI rates. Furthermore, these types of results are now being reported consistently across surgical specialties as diverse as cardiac,5 orthopedic, 6, and gastroenterology.7
The good news is that more and more hospitals are moving out of the 1990’s and implementing various levels of presurgical decolonization therapy. It’s probably a reasonable question these days to ask your doctor or nurse before surgery about what measures they will take to ensure that your own potential sources of S. aureus and/or MRSA won’t contaminate your incision and lead to an SSI. The challenge going forward will hopefully be one of introducing better decolonization therapies to stay on the cutting edge of widespread infection prevention initiatives.
1 Broex et al. (2009) Journal of Hospital Infection 72:193-201
2 Noskin et al. (2005) Archives of Internal Medicine 165:1756-1761
3 Davis et al. (2004) Clinical Infectious Diseases 39:776-782
4 von Eiff et al. (2001) New England Journal of Medicine 344(1):11-16
5 Walsh et al. (2011) Archives of Internal Medicine 171(1):68-73
6 Lee et al. (2010) Infection Control and Hospital Epidemiology 31(11):1130-1138
7 Dupeyron et al. (2006) Journal of Hospital Infection 63:385-392