A double-blind, randomized, controlled trial of topical polysporin triple compound versus topical mupirocin for the eradication of colonization with methicillin-resistant Staphylococcus aureus in a complex continuing care population

Staphylococcus aureus colonisation and strategies for decolonisation

Staphylococcus aureus is a leading cause of death by infectious diseases worldwide. Treatment of S aureus infections is difficult due to widespread antibiotic resistance, necessitating alternative approaches and measures for prevention of infection. Because S aureus infections commonly arise from asymptomatic colonisation, decolonisation is considered a key approach for their prevention. Current decolonisation procedures include antibiotic-based and antiseptic-based eradication of S aureus from the nose and skin. However, despite the widespread implementation and partial success of such measures, S aureus infection rates remain worrisome, and resistance to decolonisation agents is on the rise. In this Review we outline the epidemiology and mechanisms of S aureus colonisation, describe how colonisation underlies infection, and discuss current and novel approaches for S aureus decolonisation, with a focus on the latest findings on probiotic strategies and the intestinal S aureus colonisation site.

Preventing healthcare-associated MRSA bacteremia: getting to the root of the problem

Introduction

Bloodstream infections caused by methicillin-resistant Staphylococcus aureus (MRSA) remain a major challenge in most countries worldwide.

Setting

We describe a quasi-experimental sequential intervention at Mater Dei Hospital, Malta, to reduce hyper-prevalence of healthcare-associated MRSA bacteremia (HA-MRSA-B).

Interventions

The hospital initiated a hand hygiene (HH) campaign in 2008 to improve alcohol hand rub (AHR) use. In 2011, this was followed by root cause analysis (RCA) of all HA-MRSA-B cases and finally universal MRSA admission screening in 2014. Change-point analysis was used to evaluate the impact of the interventions.

Results

The effect of the HH campaign became evident when AHR consumption reached 40 L/1000 occupied bed days (BD). RCAs identified intravascular devices as the likely risk factor in 83% of all HA-MRSA-B; specifically non-tunneled double-lumen hemodialysis catheters (36%), peripheral venous cannulas (25%), and central venous catheters (22%). Interventions to improve their management resulted in the greatest reduction of HA-MRSA-B rates. They were informed by the RCA findings and targeted behavior change through education, motivation, and system change. Universal MRSA admission screening provided the final decline in incidence. Each intervention affected HA-MRSA-B rates after a lag period of approximately 18-24 months. Overall, HA-MRSA-B incidence decreased from 1.72 cases/10000BD in 2008 to 0.18/10000BD in 2019; a reduction of almost 90%. Intravenous device interventions were also associated with a reduction of methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia rates.

Conclusions

Significant improvement in HA-MRSA-B is possible, even in highly endemic regions. It requires well-planned behavior change interventions which are compatible with local context and culture.

Nasal decolonization: What antimicrobials and antiseptics are most effective before surgery and in the ICU

BACKGROUND

Staphylococcus aureus colonization is a key risk factor for S. aureus infections in surgical patients and in hospitalized patients. Many studies have assessed various decolonization agents, protocols, and settings. This review summarizes key findings about nasal decolonization for 2 different patient populations: patients undergoing surgery and patients hospitalized in intensive care units.

METHODS

We reviewed major studies related to decolonization of patients colonized with S. aureus and who were either undergoing surgical procedures or were hospitalized in intensive care units. We focused on recent studies, particularly randomized controlled trials and robust quasi-experimental trials. We also reviewed select non-randomized trials when more rigorous trials were limited.

DISCUSSION/CONCLUSIONS

Mupirocin is the best-studied agent for decolonization. Its use reduces the risk of surgical site infection following orthopedic surgery (strongest data) and cardiac surgery. Mupirocin decolonization also reduces the incidence of S. aureus clinical cultures in the intensive care unit. Povidone-iodine is less well-studied. Current data suggest that it decreases the risk of surgical site infections after orthopedic surgical procedures. In contrast, povidone-iodine is less effective than mupirocin for reducing the incidence of S aureus clinical cultures in the intensive care unit. Both mupirocin and povidone-iodine have important limitations, highlighting the need for future decolonization research.

Staphylococcus aureus nasal decolonization strategies: a review

Introduction: Staphylococcus aureus (S. aureus) infections are associated with increased morbidity, mortality and health-care costs. Persistent nasal carriage of S. aureus found in 10-30% of the general population, constitutes a risk factor for these infections. Nasal decolonization is one of the used strategies to prevent this risk in some situations. Areas covered: Mupirocin nasal ointment has been used for the nasal decolonization and prevention of staphylococcal infections in various settings like surgeries. However, rising rates of resistance to mupirocin require the development of new decolonization agents. In this review, we will discuss mupirocin, its origins, studies that proved its efficacy and the associated resistance, as well as other decolonization agents under investigation. Expert opinion: As some limitations exist to mupirocin use, further research for alternatives is encouraged. Some old approved antiseptics (chlorhexidine, povidone-iodine) or antibiotics (rifampicin, bacitracin) have been investigated for their efficacy in this indication. Other new agents (tea tree oil, retapamulin, LTX-109, XF-73, phages, lysostaphin, squalamine analogues, etc.) are being studied. Some of them are still in preclinical phases, and others have reached clinical trials, but further research is needed. Special interest should be given to single dose decolonization strategies and to molecules that do not select resistant strains.

Prior Staphylococcus Aureus Nasal Colonization: A Risk Factor for Surgical Site Infections Following Decolonization

INTRODUCTION

Staphylococcus aureus (S aureus) decolonization regimens are being used to mitigate the risk of surgical site infection (SSI). However, their efficacy is controversial, with mixed results reported in the literature.

METHODS

Before undergoing primary total knee arthroplasty (TKA), total hip arthroplasty (THA), or spinal fusion, 13,828 consecutive patients were screened for nasal S aureus and underwent a preoperative decolonization regimen. Infection rates of colonized and noncolonized patients were compared using unadjusted logistic regression. An adjusted regression analysis was performed to determine independent risk factors for SSI.

RESULTS

The rate of SSI in colonized patients was 4.35% compared with only 2.39% in noncolonized patients. In our TKA cohort, unadjusted logistic regression identified S aureus colonization to be a significant risk factor for SSI (odds ratio [OR], 2.9; P < 0.001). After controlling for other potential confounders including age, body mass index, tobacco use, and American Society of Anesthesiologists score, an SSI was 3.8 times more likely to develop in patients colonized with S aureus (OR, 3.8; P = 0.0025). The THA and spine colonized patients trended toward higher risk in both unadjusted and adjusted models; however, the results were not statistically significant.

DISCUSSION

The results of our study suggest that decolonization may not be fully protective against SSI. The risk of infection after decolonization is not lowered to the baseline of a noncolonized patient.

LEVEL OF EVIDENCE

Level IV.

Decolonization in Prevention of Health Care-Associated Infections

Colonization with health care-associated pathogens such as Staphylococcus aureus, enterococci, Gram-negative organisms, and Clostridium difficile is associated with increased risk of infection. Decolonization is an evidence-based intervention that can be used to prevent health care-associated infections (HAIs). This review evaluates agents used for nasal topical decolonization, topical (e.g., skin) decolonization, oral decolonization, and selective digestive or oropharyngeal decontamination. Although the majority of studies performed to date have focused on S. aureus decolonization, there is increasing interest in how to apply decolonization strategies to reduce infections due to Gram-negative organisms, especially those that are multidrug resistant. Nasal topical decolonization agents reviewed include mupirocin, bacitracin, retapamulin, povidone-iodine, alcohol-based nasal antiseptic, tea tree oil, photodynamic therapy, omiganan pentahydrochloride, and lysostaphin. Mupirocin is still the gold standard agent for S. aureus nasal decolonization, but there is concern about mupirocin resistance, and alternative agents are needed. Of the other nasal decolonization agents, large clinical trials are still needed to evaluate the effectiveness of retapamulin, povidone-iodine, alcohol-based nasal antiseptic, tea tree oil, omiganan pentahydrochloride, and lysostaphin. Given inferior outcomes and increased risk of allergic dermatitis, the use of bacitracin-containing compounds cannot be recommended as a decolonization strategy. Topical decolonization agents reviewed included chlorhexidine gluconate (CHG), hexachlorophane, povidone-iodine, triclosan, and sodium hypochlorite. Of these, CHG is the skin decolonization agent that has the strongest evidence base, and sodium hypochlorite can also be recommended. CHG is associated with prevention of infections due to Gram-positive and Gram-negative organisms as well as Candida. Conversely, triclosan use is discouraged, and topical decolonization with hexachlorophane and povidone-iodine cannot be recommended at this time. There is also evidence to support use of selective digestive decontamination and selective oropharyngeal decontamination, but additional studies are needed to assess resistance to these agents, especially selection for resistance among Gram-negative organisms. The strongest evidence for decolonization is for use among surgical patients as a strategy to prevent surgical site infections.

Catheter-related bloodstream infection in end-stage kidney disease: a Canadian narrative review

Purpose of the review

Patients with end-stage renal disease (ESRD) are at a high risk of bacterial infection. We reviewed publications on risk factors, prevention, and treatment paradigms, as well as outcomes associated with bacterial infection in end-stage kidney disease. We focused in particular on studies conducted in Canada where rates of haemodialysis catheter use are high.

Sources of information

We included original research articles in English text identified from MEDLINE using search terms ‘chronic kidney failure’, ‘renal dialysis’, or ‘chronic renal insufficiency’, and ‘bacterial infection’. We focused on articles with Canadian study populations and included comparisons to international standards and outcomes where possible.

Findings

Bacterial infections in this setting are most commonly due to Gram-positive skin flora, particularly Staphylococcus, with methicillin-resistant Staphylococcus aureus (MRSA) carrying a poorer prognosis. Interventions that may decrease mortality from sepsis include a collaborative care model that includes a nephrology team, an infectious disease specialist, and use of standardized care bundles that adhere to proven quality-of-care indicators. Decreased infectious mortality may be achieved by ensuring appropriate antibiotic selection and dosing as well as avoiding catheter salvage attempts. Reduction in bloodstream infection (BSI) incidence has been observed with the use of tPA catheter-locking solutions and the use of mupirocin or polysporin as a topical agent at the catheter exit site, as well as implementing standarized hygiene protocols during catheter use.

Limitations

There has been a paucity of randomized controlled trials of prevention and treatment strategies for catheter-related BSIs in haemodialysis. Some past trials have been limited by lack of blinding and short duration of follow-up. Microbiological epidemiology, although well characterized, may vary by region and treatment centre.

Implications

With the high prevalence of catheter use in Canadian haemodialysis units, further studies on long-term treatment and preventative strategies for BSI are warranted.

Randomized, placebo-controlled, double-blind clinical trial to evaluate the efficacy of polyhexanide for topical decolonization of MRSA carriers

OBJECTIVES

The objective of this study was to evaluate the efficacy of polyhexanide (Prontoderm(®)) in eliminating MRSA carriage.

METHODS

In a 1900 bed teaching hospital, MRSA-colonized patients were randomized into a double-blind, placebo-controlled superiority trial between January 2011 and July 2014. Patients were treated with either polyhexanide or placebo applied to the anterior nares (thrice daily) and skin (once daily) for 10 days. The primary outcome was MRSA decolonization at day 28 (D28) after the end of treatment assessed by ITT responder and PP analyses (microbiological follow-up ± 7 days and topical treatment ≥ 5 days). Secondary outcomes included safety, emergence of resistance and MRSA genotype changes. Registered trial number ISRCTN02288276.

RESULTS

Of 2590 patients screened, 146 (polyhexanide group, 71; placebo group, 75) were included. ITT analysis showed that 24/71 (33.8%) patients in the polyhexanide group versus 22/75 (29.3%) in the placebo group were MRSA-free at D28 (risk difference, 4.5%; 95% CI, -10.6% to 19.5%; P = 0.56). PP analysis confirmed the results with 19/53 (35.8%) decolonized polyhexanide-treated patients versus 17/56 (30.4%) in the placebo arm (risk difference, 5.5%; 95% CI, -12.2% to 23%; P = 0.54). Nine serious adverse events occurred in the polyhexanide group versus 12 in the placebo group; none was attributable to study medication. Emergence of polyhexanide resistance or cross-resistance between polyhexanide and chlorhexidine was not observed. No case of exogenous recolonization by a genotypically different MRSA strain was documented.

CONCLUSIONS

This study suggests that under real-life conditions, a single polyhexanide decolonization course is not effective in eradicating MRSA carriage.

Does the nose know? An update on MRSA decolonization strategies

Colonization with methicillin-resistant Staphylococcus aureus (MRSA) is an important step in the pathogenesis of active infection and is a key factor in the epidemiology of MRSA infection. Decolonization of patients found to have MRSA carriage may be of value in certain patient populations, especially those undergoing elective surgery. However, the most commonly used agent for decolonization, mupirocin, comes with a considerable risk of resistance if widely employed. Recent studies of other novel agents for decolonization show promise, but further research is necessary. This review focuses on the pathogenesis from MRSA colonization to infection, identifies the risk factors for colonization, and summarizes decolonization strategies, including novel approaches that may have a role in decreasing MRSA disease burden.

Relation between nasal carriage of Staphylococcus aureus and surgical site infection in orthopedic surgery: the role of nasal contamination. A systematic literature review and meta-analysis

Staphylococcus aureus is the pathogen most frequently implicated in infection on orthopedic hardware; various strategies are deployed to limit the risk of transmission and surgical infection.

OBJECTIVES

The present study is based on a meta-analysis assessing firstly the relationship between nasal carriage of S. aureus and the development of osteo-articular infection and secondly current methods of decolonization.

RESULTS

The meta-analysis showed increased risk of surgical site infection in case of nasal carriage of S. aureus: OR=5.92, 95% CI [1.15-30.39]; P=0.033. For cross-transmission, a scientifically proven reduction in surgical site S. aureus levels is ensured by associated mupirocin and 2% chlorhexidine antiseptic solution in subjects with positive nasal screening results for all surgical procedures taken together; the reduction was not, however, significant in the orthopedic surgery subgroup. The meta-analysis confirmed these findings: OR=0.60, 95% CI [0.34-1.06]; P=0.08.

CONCLUSION

The literature review confirmed that nasal carriage of S. aureus is a major risk factor for surgical site infection. The efficacy of eradication could not be demonstrated for orthopedic surgery as samples were too small. The positive trend found, however, should encourage further studies with sufficient power and risk/benefit should meanwhile be assessed on a case-by-case basis.

LEVEL OF EVIDENCE

Level 2. Meta-analysis.

Dose-ranging study to assess the application of intranasal 2% mupirocin calcium ointment to eradicate Staphylococcus aureus nasal colonization

BACKGROUND

Mupirocin nasal ointment may be prescribed for decolonization prior to surgical procedures, especially for carriers of methicillin-resistant Staphylococcus aureus (MRSA). The approved regimen for decolonization of S. aureus from the anterior nares is twice daily for 5 d (10 doses). We performed a two-center, randomized, open-label study to compare the utility of six and 10 doses for decolonization of S. aureus.

METHODS

Patients expecting to undergo surgery were screened for S. aureus nasal carriage approximately three weeks prior to the procedure. Those found to be positive were offered enrollment in the study. In the first arm (n=41), patients were randomized to receive 2, 3, or 5 d (six or 10 doses) of treatment prior to their operation. Their anterior nares were swabbed for culture and S. aureus polymerase chain reaction (PCR) during the decolonization therapy period as well as for four weeks after surgery. In the second arm (n=60), all patients were given 5 d (10 doses) of nasal mupirocin treatment, and the patient's anterior nares were swabbed for culture and S. aureus PCR for four weeks after surgery. Data from six of the patients were excluded from analysis because of failure to submit swabs after operation. All S. aureus isolates were tested for susceptibility to mupirocin and the presence of the mecA gene to detect MRSA.

RESULTS

In Arm 1, 16 patients received 10 doses of mupirocin, 18 received six doses (twice daily for 3 d), and 7 received six doses (thrice daily for 2 d). In the second arm, all patients received 10 doses of mupirocin (twice a day for 5 d). Overall, 89.5% patients who received 10 doses of mupirocin remained decolonized for at least four weeks after surgery versus 68.0% of patients who received six doses (p=0.016). There was no difference between arms 1 and 2 for those given mupirocin twice daily for 5 d.

CONCLUSION

The ten-dose regimen is superior to any six-dose regimen for de-colonizing S. aureus from the anterior nares of patients and for maintaining the decolonized state for at least four weeks after therapy.