Overcoming the Disadvantages of Topical Antibiotics is Necessary to Achieve Universal DecolonizationBy
Disinfecting the skin prior to surgery has long been a standard of care. Whether with iodine, chlorhexidine washes or other antiseptic surfactants, reducing the bacterial load on the skin surface has been established as an important mechanism to control the rate of post-surgical infection. The nose, which is a warm, moist environment ideal for bacterial growth, however had been difficult to decolonize.
Up to 30% of patients are carriers of Staph aureus. Colonization rates of the serious antibiotic resistant version of Staph aureus, known as MRSAid (one of the 3 major superbugs), range from 2% in Canada to 80% in Shanghai. Ordinarily, these pathogens do not impact patients until they are weakened by illness or surgery. Post-surgical infection is a risk for patients colonized with this pathogens and therefore has led to the need for removing or reducing the bacterial load carried around by these patients just prior to surgery.
In several studies, the nose has been identified as the key reservoir of Staph aureus and MRSA, representing 40% of the bacteria load in one small area. Because the nose is not washed on a regular basis, unlike other body parts, Staph aureus can easily flourish in the nose and become a source of contamination for other body parts. Because of delicate mucosal tissue and the presence of cilia in the nose, the antiseptic washes used for hardier skin surfaces are not appropriate for use in the nose. Instead, nasal decolonization has been done by topical antibiotics such as mupirocin.
Topical antibiotics have 3 significant disadvantages that have resulted in many infection control experts rejecting pre-surgical nasal decolonization protocols. With sub-optimal patient compliance, infection control experts fear the resulting antibiotic resistance formation brought about by sub-optimal doses of antibiotics that occur when patients stop mid-way through their antibiotic treatments. Poor patient compliance, despite advisories about the severity of MRSA and Staph aureus infections, is the leading disadvantage of antibiotics.
The problem is the inconvenience and unpleasantness of antibiotic creams in the nose. Patients are known to dislike the Vaseline™-type viscosity of mupirocin and often do not comply with the 3 times a day for 5 days treatment protocol. Incomplete doses of antibiotics leads then to antibiotic resistance which in turn adds to, not subtracts from, the risks already present with patients colonized with Staph. This is the primary reason why many hospitals have not opted for nasal decolonization protocols despite the 30-40% reductions in surgical site infection rates demonstrated in clinical trials.
The second disadvantage of antibiotics is the time required to decolonize. On average, decolonization using topical antibiotics requires about 5 days which implies that patients need to be screened and identified early enough for the efficacy of antibiotics to kick in.
The third disadvantage of antibiotics, however, is the inconvenience to patients and the costs to the health care system to culture for and identify Staph aureus and MRSA carriers. Because of antibiotic resistance concerns, only carriers of Staph and MRSA are given nasal decolonization therapy. New rapid diagnosis technologies have emerged, but prior to Photodisinfection, there was little acceptance of these rapid diagnostics because antibiotics, the decolonization remedy, still required 5 days treatment for effect. The saving of 2-3 days prior to a 5 day treatment protocol did not justify, to many, the additional cost of same-day rapid diagnosis.
Technologies that overcome the disadvantages of topical antibiotics and allow for universal nasal decolonization are going to play an important role in health care associated infection control. These technologies must not generate resistance, must be safe for all surgical patients, even if they are not carriers of Staph aureus or MRSA. Finally, these technologies need to be easy to use, easy for patients to tolerate and fit well into the pre-operative work flow.