Cost-effectiveness of preoperative screening and eradication of Staphylococcus aureus carriage

Association of Staphylococcus aureus Bacterial Load and Colonization Sites With the Risk of Postoperative S. aureus Infection

Background

The independent effects of extranasal-only carriage, carriage at multiple bodily sites, or the bacterial load of colonizing Staphylococcus aureus (SA) on the risk of developing SA surgical site infections and postoperative bloodstream infections (SA SSI/BSIs) are unclear. We aimed to quantify these effects in this large prospective cohort study.

Methods

Surgical patients aged 18 years or older were screened for SA carriage in the nose, throat, or perineum within 30 days before surgery. SA carriers and noncarriers were enrolled in a prospective cohort study in a 2:1 ratio. Weighted multivariable Cox proportional hazard models were used to assess the independent associations between different measures of SA carriage and occurrence of SA SSI/BSI within 90 days after surgery.

Results

We enrolled 5004 patients in the study cohort; 3369 (67.3%) were SA carriers. 100 SA SSI/BSI events occurred during follow-up, and 86 (86%) of these events occurred in SA carriers. The number of colonized bodily sites (adjusted hazard ratio [aHR], 3.5-8.5) and an increasing SA bacterial load in the nose (aHR, 1.8-3.4) were associated with increased SA SSI/BSI risk. However, extranasal-only carriage was not independently associated with SA SSI/BSI (aHR, 1.5; 95% CI, 0.9-2.5).

Conclusions

Nasal SA carriage was associated with an increased risk of SA SSI/BSI and accounted for the majority of SA infections. Higher bacterial load, as well as SA colonization at multiple bodily sites, further increased this risk.

Economic evaluations of interventions to prevent and control health-care-associated infections: a systematic review

Almost 9 million health-care-associated infections have been estimated to occur each year in European hospitals and long-term care facilities, and these lead to an increase in morbidity, mortality, bed occupancy, and duration of hospital stay. The aim of this systematic review was to review the cost-effectiveness of interventions to limit the spread of health-care-associated infections), framed by WHO infection prevention and control core components. The Embase, National Health Service Economic Evaluation Database, Database of Abstracts of Reviews of Effects, Health Technology Assessment, Cinahl, Scopus, Pediatric Economic Database Evaluation, and Global Index Medicus databases, plus grey literature were searched for studies between Jan 1, 2009, and Aug 10, 2022. Studies were included if they reported interventions including hand hygiene, personal protective equipment, national-level or facility-level infection prevention and control programmes, education and training programmes, environmental cleaning, and surveillance. The British Medical Journal checklist was used to assess the quality of economic evaluations. 67 studies were included in the review. 25 studies evaluated methicillin-resistant Staphylococcus aureus outcomes. 31 studies evaluated screening strategies. The assessed studies that met the minimum quality criteria consisted of economic models. There was some evidence that hand hygiene, environmental cleaning, surveillance, and multimodal interventions were cost-effective. There were few or no studies investigating education and training, personal protective equipment or monitoring, and evaluation of interventions. This Review provides a map of cost-effectiveness data, so that policy makers and researchers can identify the relevant data and then assess the quality and generalisability for their setting.

The Burden of Surgical Site Infection at Hospital Universiti Sains Malaysia and Related Postoperative Outcomes: A Prospective Surveillance Study

Surgical site infections (SSIs) are the most common healthcare-associated infections that occur among surgical patients. Surgical site infections result in longer hospital stays, hospital readmissions, and higher death and morbidity rates. The current study was designed to highlight the importance of such surveillance studies in a Malaysian surgical population with a motive to evaluate and revise concurrent infection control and prevention policies by exploring the burden of surgical site infection and identifying its associated risk factors for future considerations. In this prospective observational cohort study, a total of 216 patients admitted to a surgical ward were identified and studied. Of these 216 patients, 142 elective procedures and 74 emergency procedures were included in the study, of which 13 patients (9.2%) undergoing elective procedures and 15 (20.3%) patients undergoing emergency procedures were SSI positive (OR: 2.5, p = 0.02). Among surgical site infections, 21 were superficial and 7 were deep incisional SSI. No case of organ/space SSI was identified. The time taken for SSIs to develop ranged from 2-17 days with a median of 6 days. Risk factors such as presence of comorbidities (p = 0.011), major co-existing medical diagnosis ≥2 (p = 0.02), and pre-existing infection (p = 0.027) were statistically significant. SSI-positive patients experienced an increase in the post-operative length of hospital stay. In the current population, it was seen that identifying patients who were at high risk of malnutrition via MUST and the NNIS risk index will help clinicians in identifying high risk patients and in managing their patients appropriately. Identifying patients who were at high risk of malnutrition will also improve postoperative outcomes considerably.

MRSA carriage among healthcare workers in a Vietnamese intensive care unit: a prospective cohort study

Background:

Little is known about the magnitude and patterns of methicillin-resistant Staphylococcus aureus (MRSA) carriage among intensive care unit (ICU) healthcare workers (HCWs), especially in lower-middle-income countries like Vietnam.

Materials and methods:

A prospective cohort study was conducted on HCWs working in the adult ICU of the Hospital for Tropical Diseases in Vietnam between October 28 and December 20, 2019. These HCWs included physicians, nurses, and nursing assistants who were responsible for all essential medical activities and basic patient care. A questionnaire was used to collect participants’ information, including age, sex, profession, ICU working time, and underlying diseases. Hand and nasal swabs were collected weekly for 8 consecutive weeks for MRSA screening. Staphylococcal isolates were checked for catalase and coagulase and, for methicillin resistance using cefoxitin disk diffusion, then rechecked on the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Results:

Among 55 HCWs, 16 (29.1%) carried MRSA in their noses or hands. MRSA intermittent hand carriage was documented in 2 (3.6%) HCWs. Among 53 HCWs undertaking nasal swabs, 13 (24.5%) were MRSA persistent and 3 (5.6%) were intermittent carriers. The MRSA carriage rate was highest among nursing assistants (50%, 4/8). More HCWs with underlying diseases were found to be MRSA carriers (31.8%, 7/22) compared with those without comorbidities (27.3%, 9/33).

Conclusion:

MRSA carriage among HCWs is not rare. The findings highlight an urgent need to review and update the local infection prevention and control measures to prevent MRSA transmission from HCWs to patients.

Pre-surgical Nasal Decolonization of Staphylococcus aureus: A Health Technology Assessment

BACKGROUND

Staphylococcus aureus (S. aureus) is the most common cause of surgical site infections, and the nose is the most common site for S. aureus colonization. Pre-surgical (in the days prior to surgery) nasal decolonization of S. aureus may reduce the bacterial load and prevent the organisms from being transferred to the surgical site, thus reducing the risk of surgical site infection. We conducted a health technology assessment of nasal decolonization of S. aureus (including methicillin-susceptible and methicillin-resistant strains) with or without topical antiseptic body wash to prevent surgical site infection in patients undergoing scheduled surgery, which included an evaluation of effectiveness, safety, cost-effectiveness, the budget impact of publicly funding nasal decolonization of S. aureus, and patient preferences and values.

METHODS

We performed a systematic literature search of the clinical evidence to retrieve systematic reviews and selected and reported results from one review that was recent, of high quality, and relevant to our research question. We complemented the chosen systematic review with a literature search to identify randomized controlled trials published since the systematic review was published in 2019. We used the Risk of Bias in Systematic Reviews (ROBIS) tool to assess the risk of bias of each included systematic review and the Cochrane risk-of-bias tool for randomized controlled trials to assess the risk of bias of each included primary study. We assessed the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature search and conducted both cost-effectiveness and cost-utility analyses using a decision-tree model with a 1-year time horizon from the perspective of Ontario's Ministry of Health. We also analyzed the budget impact of publicly funding nasal decolonization of S. aureus in pre-surgical patients in Ontario. To contextualize the potential value of nasal decolonization, we spoke with people who had recently undergone surgery, some of whom had received nasal decolonization, and one family member of a person who had recently had surgery. We also engaged participants through an online survey.

RESULTS

We included one systematic review and three randomized controlled trials in the clinical evidence review. In universal decolonization, compared with placebo or no intervention, nasal mupirocin alone may result in little to no difference in the incidence of overall and S. aureus-related surgical site infections in pre-surgical patients undergoing orthopaedic, cardiothoracic, general, oncologic, gynaecologic, neurologic, or abdominal digestive surgeries, regardless of S. aureus carrier status (GRADE: Moderate to Very low). Compared with placebo, nasal mupirocin alone may result in little to no difference in the incidence of overall and S. aureus-related surgical site infections in pre-surgical patients who are S. aureus carriers undergoing cardiothoracic, vascular, orthopaedic, gastrointestinal, general, oncologic, gynaecologic, or neurologic surgery (GRADE: Moderate to Very low). In targeted decolonization, compared with placebo, nasal mupirocin combined with chlorhexidine body wash lowers the incidence of S. aureus-related surgical site infection (risk ratio: 0.32 [95% confidence interval: 0.16-0.62]) in pre-surgical patients who are S. aureus carriers undergoing cardiothoracic, vascular, orthopaedic, gastrointestinal, or general surgery (GRADE: High). Compared with no intervention, nasal mupirocin combined with chlorhexidine body wash in pre-surgical patients who are not S. aureus carriers undergoing orthopaedic surgery may have little to no effect on overall surgical site infection, but the evidence is very uncertain (GRADE: Very low). Most included studies did not separate methicillin-susceptible and methicillin-resistant strains of S. aureus. No significant antimicrobial resistance was identified in the evidence reviewed; however, the existing literature was not adequately powered and did not have sufficient follow-up time to evaluate antimicrobial resistance.Our economic evaluation found that universal nasal decolonization using mupirocin combined with chlorhexidine body wash is less costly and more effective than both targeted and no nasal decolonization. Compared with no nasal decolonization treatment, universal and targeted nasal decolonization using mupirocin combined with chlorhexidine body wash would prevent 32 and 22 S. aureus-related surgical site infections, respectively, per 10,000 patients. Universal nasal decolonization would lead to cost savings, whereas targeted nasal decolonization would increase the overall cost for the health care system since patients must first be screened for S. aureus carrier status before receiving nasal decolonization with mupirocin. The annual budget impact of publicly funding universal nasal decolonization in Ontario over the next 5 years ranges from a savings of $2.98 million in year 1 to a savings of $15.09 million in year 5. The annual budget impact of publicly funding targeted nasal decolonization ranges from an additional cost of $0.08 million in year 1 to an additional cost of $0.39 million in year 5.Our interview and survey respondents felt strongly about the value of preventing surgical site infections, and most favoured a universal approach.

CONCLUSIONS

Based on the best evidence available, decolonization of S. aureus using nasal mupirocin combined with chlorhexidine body wash prior to cardiothoracic, vascular, orthopaedic, gastrointestinal, or general surgery lowers the incidence of surgical site infection caused by S. aureus in patients who are S. aureus carriers (including methicillin-susceptible and methicillin-resistant strains) (i.e., targeted decolonization). However, nasal mupirocin alone may result in little to no difference in overall surgical site infections and S. aureus-related surgical site infections in pre-surgical patients prior to orthopaedic, cardiothoracic, general, oncologic, gynaecologic, neurologic, or abdominal digestive surgeries, regardless of their S. aureus carrier status (i.e., universal decolonization). No significant antimicrobial resistance was identified in the evidence reviewed.Compared with no nasal decolonization treatment, universal nasal decolonization with mupirocin combined with chlorhexidine body wash may reduce S. aureus-related surgical site infections and lead to cost savings. Targeted nasal decolonization with mupirocin combined with chlorhexidine body wash may also reduce S. aureus-related surgical site infections but increase the overall cost of treatment for the health care system. We estimate that publicly funding universal nasal decolonization using mupirocin combined with chlorhexidine body wash would result in a total cost savings of $45.08 million over the next 5 years, whereas publicly funding targeted nasal decolonization using mupirocin combined with chlorhexidine body wash would incur an additional cost of $1.17 million over the next 5 years.People undergoing surgery value treatments aimed at preventing surgical site infections.

Tales of the unexpected in antibiotic resistance

Since the 1990s few new antibiotics have become available; during the same period the appearance and spread of bacteria no longer susceptible to first- and second-line antibiotics has accelerated; indeed some bacterial infections untreatable with existing antibiotics. Control of antibiotic resistance is multifactorial, and includes restrictive antibiotic use and good infection control. The 2021 Lowbury lecture addresses three aspects of antibiotic resistance, with reference to the Netherlands, that illustrate the complexity of antibiotic resistance epidemiology. Initially selective decontamination of the digestive tract (SDD) was not adopted in the Netherlands because of concern about antibiotic resistance. However, three trials showed that SDD regimens, including 4 days of systemic cephalosporins, gave better clinical outcomes with no effect on antibiotic-resistant bacteria. Many predictions have been made about the impact of infections with antibiotic-resistant bacteria on human health. However, the situation is complex, because the risk factors for infection with multidrug-resistant bacteria are also risk factors for poor clinical outcome. A study in 8 Dutch hospitals estimated the mortality attributable to antibiotic resistance as close to zero. Concern about the emergence of resistance in Staphyloocccus aureus has limited the universal use of mupirocin to prevent surgical site infections. However, the risk may have been overstated, and universal decolonisation with mupirocin and chlorhexidine has now become standard of care in patients undergoing cardiothoracic or orthopaedic surgery in many Dutch hospitals. Prophylactic antibiotics can improve patient outcomes with acceptable risks of promoting resistance.

Individual decontamination measures reduce by two the incidence of surgical site infections in spinal surgery

BACKGROUND

In spinal surgery, incidence of surgical site infections (SSI) is estimated between 1 and 10%. It results in increased morbidity, mortality and cost of management. Individual Staphylococcus aureus (SA) decolonization has already proved efficiency to prevent those events in various surgical domains. The aim of this study was to evaluate a strategy of prevention of SSI and in particular the decolonization of the nasal carriage of SA by a protocol with Mupirocin application.

METHODS

We conducted a bicentric observational study on 5314 spinal surgery patients over a seven-year period. In both center, we compared periods before and after implementation of two measures: modification of antibioprophylaxis and staphylococcus decolonization. Homogeneity of the different samples of patients was assessed through measure of individual and surgical variables. We measured monthly incidence of SSI and evaluated its evolution in order to assess efficiency of these interventions.

RESULTS

The incidence of SSI decreased by half, from 7.3% to 3% at the Beaujon Hospital and from 8.3% to 3.9% at the Georges-Pompidou European Hospital (GPEH). We do not observe any significant decrease of SA rate in these SSI.

CONCLUSION

We believe that Staphylococcus aureus decolonization should be recommended in spinal surgery, and should be combined with an overall improvement of the quality of care.

The economic benefits of surgical site infection prevention in adults: a systematic review

BACKGROUND

Surgical site infections (SSIs) present a significant burden to healthcare and patients in terms of excess length of stay, distress, disability and death. SSI risk and the associated economic burden may be reduced through adherence to prevention guidelines although the irreducible minimum is unclear.

AIM

To evaluate the methods used to estimate the cost-effectiveness of prevention strategies for all SSIs.

METHODS

PubMed, Medline, CINAHL, and UK National Health Service Economic Evaluation Database were searched from inception to January 2020 to identify English language economic evaluation studies, embedded economic evaluations, and studies with some analysis in relation to cost and benefit in adult patients receiving surgical care in any setting. Risk of bias was assessed using two published checklists.

FINDINGS

Thirty-two studies involving 24,043 participants were included. Most studies evaluated SSI prevention in orthopaedic surgeries. Antibiotic prophylaxis, screening, treating, or decolonization of meticillin-resistant Staphylococcus aureus and surgical wound closure were the main methods evaluated. Methods ranged from cost-analyses to cost-effectiveness and cost-utility analyses. Synthesis of results was not possible due to heterogeneity. All studies reported some economic benefit associated with preventing SSI; however, measures of benefit were not reported consistently and the quality of studies was low to moderate. Limited evidence in relation to SSI impact on quality of life was identified.

CONCLUSION

Current evidence in relation to the economic benefits of SSI prevention is limited. Further robust studies that utilize sound economic and epidemiological methods are required to inform future investment decisions in SSI prevention.

Efficacy of silver nanoparticles against multidrug resistant clinical Staphylococcus aureus isolates from Nigeria

Multidrug resistant (MDR) S. aureus infections continue to account for excess mortality in hospital and community settings and constitute a rising global health problem. However, data on the efficacy and mechanism of actions of alternative solutions like silver nanoparticles in developing countries are lacking. This study investigated anti-staphylococcal activity of silver nanoparticles (AgNP) against local strains from Nigeria. A total 119 clinical isolates of S. aureus from five Nigerian laboratories categorized as MRSA (n = 52) and MSSA (n = 67) by PCR were studied. The MIC of AgNP produced by chemical reduction method and characterized by surface plasmon resonance absorbance and size equivalence by scanning electron microscopy was determined by microbroth dilution method. Its effect on protease activity and plasmids were also investigated. Baseline characteristics of the isolates revealed MDR phenotype of the isolates, carriage of diverse plasmids (15-32 kb) among the MDR MSSA, and mean extracellular protease activity of 24.8-55.7 U/mL. The chemically synthesized AgNP had a peak absorbance at 400 nm with a size equivalence of 4.58 nm. The MICs of AgNP against the isolates were 4.7 μg/mL and 4.9 μg/mL, respectively, for MRSA and MSSA (P > 0.05). The bactericidal effect of AgNP at 2.5-5 μg/mL on the MSSA and MRSA isolates was observed at 2.7-5.5 h post exposure in vitro. Further analysis revealed plasmid eviction in the MDR MSSA isolates exposed to 5 μg/mL AgNP and dose-dependent reduction in extracellular protease activity by 84.6-93.1%. Hemolysis of human erythrocytes by AgNP was not observed at the MIC range. Conclusion: This study revealed safety and efficacy of AgNP against clinical MDR S. aureus isolates from Nigeria, using plasmid eviction and protease inhibition as mechanisms of action.

Cost-effectiveness of pre-operative Staphylococcus aureus screening and decolonization

OBJECTIVE

We developed a decision analytic model to evaluate the impact of a preoperative Staphylococcus aureus decolonization bundle on surgical site infections (SSIs), health-care-associated costs (HCACs), and deaths due to SSI.

METHODS

Our model population comprised US adults undergoing elective surgery. We evaluated 3 self-administered preoperative strategies: (1) the standard of care (SOC) consisting of 2 disinfectant soap showers; (2) the "test-and-treat" strategy consisting of the decolonization bundle including chlorhexidine gluconate (CHG) soap, CHG mouth rinse, and mupirocin nasal ointment for 5 days) if S. aureus was found at any of 4 screened sites (nasal, throat, axillary, perianal area), otherwise the SOC; and (3) the "treat-all" strategy consisting of the decolonization bundle for all patients, without S. aureus screening. Model parameters were derived primarily from a randomized controlled trial that measured the efficacy of the decolonization bundle for eradicating S. aureus.

RESULTS

Under base-case assumptions, the treat-all strategy yielded the fewest SSIs and the lowest HCACs, followed by the test-and-treat strategy. In contrast, the SOC yielded the most SSIs and the highest HCACs. Consequently, relative to the SOC, the average savings per operation was $217 for the treat-all strategy and $123 for the test-and-treat strategy, and the average savings per per SSI prevented was $21,929 for the treat-all strategy and $15,166 for the test-and-treat strategy. All strategies were sensitive to the probability of acquiring an SSI and the increased risk if SSI if the patient was colonized with SA.

CONCLUSION

We predict that the treat-all strategy would be the most effective and cost-saving strategy for preventing SSIs. However, because this strategy might select more extensively for mupirocin-resistant S. aureus and cause more medication adverse effects than the test-and-treat approach or the SOC, additional studies are needed to define its comparative benefits and harms.

Peri-Operative Nasal Eradication Therapy Prevents Staphylococcus aureus Surgical Site Infections in Aortoiliac Surgery

BACKGROUND

Surgical site infections (SSIs) cause considerable morbidity and deaths among patients undergoing vascular surgery. Pre-operative screening and subsequent treatment of nasal Staphylococcus aureus carriers with mupirocin and chlorhexidine reduces the risk of SSIs in cardiothoracic and orthopedic surgery. The aim of this study was to investigate the effect of this screen-and-treat strategy on the development of SSI in patients undergoing aortoiliac surgery.

METHODS

A prospective study was performed that enrolled an intervention cohort comprising all patients undergoing aortoiliac surgery from February 2013 to December 2016. Before surgery, patients were screened for S. aureus nasal carriage and, if positive, were treated with mupirocin nasal ointment and chlorhexidine body washes. The presence of SSI was recorded on the basis of the criteria of the U.S. Centers for Disease Control and Prevention. A historic control group was used, consisting of aortoiliac surgery patients in 2010 who tested positive for S. aureus but received no treatment.

RESULTS

A total of 374 patients in the study cohort were screened of whom 75 (20.1%) tested positive for S. aureus. Of these patients, 68 were given eradication therapy. In the 2010 cohort, 22 patients (15.7%) were positive. The incidence of S. aureus infection was 0 of 75 in the treatment group versus 3 of 22 (13.6%) in the control group (p = 0.021). Both the 30-day mortality rate (1.3% vs. 13.6%; p = 0.035) and the rate of re-interventions (12.0% vs. 31.8%) were significantly lower in the treated group.

CONCLUSION

We conclude that S. aureus nasal screening and eradication with mupirocin and chlorhexidine reduces S. aureus SSI and its complications after aortoiliac surgery.

Thirteen-year experience with universal Staphylococcus aureus nasal decolonization prior to cardiac surgery: a quasi-experimental study

INTRODUCTION

Sternal wound infection (SWI) after cardiac surgery is a severe complication. Among preventive measures, pre-operative decolonization of nasal carriage of Staphylococcus aureus has recently been shown to be beneficial. This quasi-experimental study assessed the effect of decolonization on the incidence of S. aureus-associated SWI based on 19 years of prospective surveillance.

METHODS

Segmented negative binomial regression was used to analyse the change over time in the incidence of S. aureus mediastinitis requiring re-operation after cardiac surgery in a French university hospital between 1996 and 2014. Universal nasal decolonization with mupirocin was introduced in December 2001. The association between pre-operative nasal carriage and SWI due to S. aureus was analysed between 2006 and 2012.

RESULTS

Among 17,261 patients who underwent a cardiac surgical procedure, 565 developed SWI (3.3%), which was caused by S. aureus in 181 cases (1%). The incidence of mediastinitis caused by S. aureus decreased significantly over the study period (1.43% in 1996-2001 vs 0.61% and 0.64% in 2002-2005 and 2006-2014, respectively; P<0.001). In segmented analysis, there was a significant break in 2002, corresponding to the introduction of decolonization. Despite this intervention, pre-operative nasal carriage remained a significant risk factor for S. aureus mediastinitis (adjusted odds ratio 2.2; 95% confidence interval 1.2-4.2), as were obesity, critical pre-operative status, coronary artery bypass grafting (CABG), and combined surgery with valve replacement and CABG.

CONCLUSION

Universal nasal decolonization before cardiac surgery was effective in decreasing the incidence of mediastinitis caused by S. aureus. Nasal carriage of S. aureus remained a risk factor for S. aureus-associated SWI.

Systematic review of a patient care bundle in reducing staphylococcal infections in cardiac and orthopaedic surgery

Surgical site infections (SSIs) are serious adverse events hindering surgical patients' recovery. In Australia and New Zealand, SSIs are a huge burden to patients and healthcare systems. A bundled approach, including pre-theatre nasal and/or skin decolonization has been used to reduce the risk of staphylococcal infection. The aim of this review is to assess the effectiveness of the bundle in preventing SSIs for cardiac and orthopaedic surgeries. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Published literature was searched in PubMed, Embase and Cochrane Library of Systematic reviews. Identified articles were selected and extracted based on a priori defined Population-Intervention-Comparator-Outcome and eligibility criteria. Data of randomized controlled trials (RCTs) and comparative observational studies were synthesized by meta-analyses. Quality appraisal tools were used to assess the evidence quality. The review included six RCTs and 19 observational studies. The bundled treatment regimens varied substantially across all studies. RCTs showed a trend of Staphylococcus aureus SSIs reduction due to the bundle (relative risk = 0.59, 95% confidence interval (CI) = 0.33, 1.06) with moderate heterogeneity. Observational studies showed statistically significant reduction in all-cause and S. aureus SSIs, with 51% (95% CI = 0.41, 0.59) and 47% (95% CI = 0.35, 0.65), respectively. No publication biases were detected. SSIs in major cardiac and orthopaedic surgeries can be effectively reduced by approximately 50% with a pre-theatre patient care bundle approach.

Decolonization of Staphylococcus aureus carriage

Staphylococcus aureus nasal colonization is a well-known independent risk factor for infection caused by this bacterium. Screening and decolonization of carriers have been proven effective in reducing S. aureus infections in some populations. However, a gap remains between what has been proven effective and what is currently done. We aimed to summarize recommendations and current knowledge of S. aureus decolonization to answer the following questions: Why? For whom? How? When? And what are the perspectives?

Is it worth screening elective orthopaedic patients for carriage of Staphylococcus aureus? A part-retrospective case-control study in a Scottish hospital

BACKGROUND

With recent focus on methicillin-resistant Staphylococcus aureus (MRSA) screening, methicillin-susceptible S. aureus (MSSA) has been overlooked. MSSA infections are costly and debilitating in orthopaedic surgery.

METHODS

We broadened MRSA screening to include MSSA for elective orthopaedic patients. Preoperative decolonisation was offered if appropriate. Elective and trauma patients were audited for staphylococcal infection during 2 6-month periods (A: January to June 2013 MRSA screening; B: January to June 2014 MRSA and MSSA screening). Trauma patients are not screened presurgery and provided a control. MSSA screening costs of a modelled cohort of 500 elective patients were offset by changes in number and costs of MSSA infections to demonstrate the change in total health service costs.

FINDINGS

Trauma patients showed similar infection rates during both periods (p=1). In period A, 4 (1.72%) and 15 (6.47%) of 232 elective patients suffered superficial and deep MSSA infections, respectively, with 6 superficial (2%) and 1 deep (0.3%) infection among 307 elective patients during period B. For any MSSA infection, risk ratios were 0.95 (95% CI 0.41 to 2.23) for trauma and 0.28 (95% CI 0.12 to 0.65) for elective patients (period B vs period A). For deep MSSA infections, risk ratios were 0.58 (95% CI 0.20 to 1.67) for trauma and 0.05 (95% CI 0.01 to 0.36) for elective patients (p=0.011). There were 29.12 fewer deep infections in the modelled cohort of 500 patients, with a cost reduction of £831 678 for 500 patients screened.

CONCLUSIONS

MSSA screening for elective orthopaedic patients may reduce the risk of deep postoperative MSSA infection with associated cost-benefits.

Evaluation of Staphylococcus aureus Eradication Therapy in Vascular Surgery

INTRODUCTION

Surgical site infections (SSI) are a serious complication in vascular surgery which may lead to severe morbidity and mortality. Staphylococcus aureus nasal carriage is associated with increased risk for development of SSIs in central vascular surgery. The risk for SSI can be reduced by perioperative eradication of S. aureus carriage in cardiothoracic and orthopedic surgery. This study analyzes the relation between S. aureus eradication therapy and SSI in a vascular surgery population.

METHODS

A prospective cohort study was performed, including all patients undergoing vascular surgery between February 2013 and April 2015. Patients were screened for S. aureus nasal carriage and, when tested positive, were subsequently treated with eradication therapy. The presence of SSI was recorded based on criteria of the CDC. The control group consisted of a cohort of vascular surgery patients in 2010, who were screened, but received no treatment.

RESULTS

A total of 444 patients were screened. 104 nasal swabs were positive for S. aureus, these patients were included in the intervention group. 204 patients were screened in the 2010 cohort. 51 tested positive and were included in the control group. The incidence of S. aureus infection was 5 out of 51 (9.8%) in the control group versus 3 out of 104 in the eradication group (2.2%; 95% confidence interval 0.02-1.39; P = 0.13). A subgroup analysis showed that the incidence of S. aureus infection was 3 out of 23 (13.0%) in the control group in central reconstructive surgery versus 0 out of 44 in the intervention group (P = 0.074). The reduction of infection pressure by S. aureus was stronger than the reduction of infection pressure by other pathogens (exact maximum likelihood estimation; OR = 0.0724; 95% CI: 0.001-0.98; p = 0.0475).

CONCLUSION

S. aureus eradication therapy reduces the infection pressure of S. aureus, resulting in a reduction of SSIs caused by S. aureus.

Complications Related to the Endoscopic Endonasal Transsphenoidal Approach for Nonfunctioning Pituitary Macroadenomas in 300 Consecutive Patients

OBJECTIVE

To analyze complications of endoscopic transsphenoidal surgery (ETS) for nonfunctioning pituitary macroadenomas (NFPAs).

METHODS

A retrospective study of 300 NFPAs was performed. Complications and factors that could influence these complications were analyzed.

RESULTS

Visual and pituitary functions worsened in 2.4% and 13.7% of cases, respectively. Postoperative diabetes insipidus was permanent in 6.2% of cases. Postoperative meningitis occurred in 3.3% of patients. Meningitis was strongly associated with intraoperative cerebrospinal fluid (CSF) leaks (P = 0.01), postoperative CSF leaks (P = 0.0001), and operation times longer than 1 hour (P = 0.023). Detection of Staphylococcus aureus and preoperative treatment with mupirocin in the nostrils did not impact the occurrence of meningitis. Two patients with meningitis died (unique causes of death). Postoperative CSF leaks occurred in 2.7% of cases and were associated with intraoperative CSF leaks (P = 0.007) and permanent diabetes insipidus (P = 0.028). The rate of CSF leak decreased from 4% to 0.8% (P = 0.048) after we moved from a soft to hard reconstruction of the sella. The rate of postoperative epistaxis decreased from 6.7% to 1.25% after we stopped using monopolar coagulation (P = 0.013).

CONCLUSIONS

ETS permits a wide view, allowing good conditions for a satisfactory resection in the majority of NFPAs. Some pitfalls of endoscopy can lead to complications that improve with modification of the operative technique (i.e., CSF leak and postoperative epistaxis). This study confirms an acceptable rate of complications associated with ETS.

Prevention of Surgical Site Infections: Decontamination With Mupirocin Based on Preoperative Screening for Staphylococcus aureus Carriers or Universal Decontamination?

Perioperative decolonization of Staphylococcus aureus nasal carriers with mupirocin together with chlorhexidine body washing reduces the incidence of S. aureus surgical site infection. A targeted strategy, applied in S. aureus carriers only, is costly, and implementation may reduce effectiveness. Universal decolonization is more cost-effective but increases exposure of noncarriers to mupirocin and the risk of resistance to mupirocin in staphylococci. High-level mupirocin resistance in S. aureus can emerge through horizontal gene transfer originating from coagulase-negative staphylococci (CoNS) and through clonal transmission. The current evidence on the occurrence of high-level mupirocin resistance in S. aureus and CoNS, in combination with the results of mathematical modeling, strongly suggests that the increased selection of high-level mupirocin resistance in CoNS does not constitute an important risk for high-level mupirocin resistance in S. aureus. Compared with a targeted strategy, universal decolonization seems associated with an equally low risk of mupirocin resistance in S. aureus.

Economic features of antibiotic resistance: the case of methicillin-resistant Staphylococcus aureus

This paper analyses and updates the economic information regarding methicillin-resistant Staphylococcus aureus (MRSA), including information that has been previously reviewed by other authors, and new information, for the purpose of facilitating health management and clinical decisions. The analysed articles reveal great disparity in the economic burden on MRSA patients; this is mainly due to the diversity of the designs of the studies, as well as the variability of the patients and the differences in health care systems. Regarding prophylactic strategies, the studies do not provide conclusive results that could unambiguously orientate health management. The studies addressing treatments noted that linezolid seems to be a cost-effective treatment for MRSA, mostly because it is associated with a shorter length of stay (LOS) in hospital. However, important variables such as antimicrobial susceptibility, infection type and resistance emergence should be included in these analyses before a conclusion is reached regarding which treatment is the best (most efficient). The reviewed studies found that rapid MRSA detection, using molecular techniques, is an efficient technique to control MRSA. As a general conclusion, the management of MRSA infections implicates important economic costs for hospitals, as they result in higher direct costs and longer LOS than those related to methicillin-susceptible S. aureus (MSSA) patients or MRSA-free patients; there is wide variability in those increased costs, depending on different variables. Moreover, the research reveals a lack of studies on other related topics, such as the economic implications of changes in MRSA epidemiology (community patients and lineages associated with farm animals).

Acquisition of high-level mupirocin resistance in CoNS following nasal decolonization with mupirocin

OBJECTIVES

The association between mupirocin use and plasmid-based high-level resistance development mediated through mupA in CoNS has not been quantified. We determined acquisition of mupirocin resistance in Staphylococcus aureus and CoNS in surgery patients treated peri-operatively with mupirocin.

PATIENTS AND METHODS

Patients admitted for surgery were treated with nasal mupirocin ointment and chlorhexidine soap for 5 days, irrespective of S. aureus carrier status. Nasal swabs were obtained before decolonization (T1) and 4 days after surgery (T2) and were inoculated onto agars containing 8 mg/L mupirocin. Staphylococci were identified by MALDI-TOF MS and mupirocin resistance was confirmed by Etest.

RESULTS

Among 1578 surgical patients, 936 (59%) had nasal swabs obtained at T1 and T2; 192 (21%) patients carried mupirocin-resistant CoNS at T1 and 406 (43%) at T2 (P<0.001). Of 744 patients not colonized at T1, 277 acquired resistance (37%), corresponding to an acquisition rate of 7.4/100 patient days at risk. In all, 588 (97%) of 607 mupirocin-resistant CoNS had an MIC >256 mg/L (high level) and 381 of 383 (99.5%) were mupA positive. No acquisition of mupirocin resistance was observed in S. aureus.

CONCLUSIONS

Acquisition of mupirocin resistance following decolonization was widespread in CoNS and absent in S. aureus. As almost all isolates harboured the mupA gene, monitoring resistance development in S. aureus when decolonization strategies containing mupirocin are used is recommended.

Staphylococcus aureus screening and decolonization in orthopaedic surgery and reduction of surgical site infections

BACKGROUND

Staphylococcus aureus is the most common organism responsible for orthopaedic surgical site infections (SSIs). Patients who are carriers for methicillin-sensitive S. aureus or methicillin-resistant S. aureus (MRSA) have a higher likelihood of having invasive S. aureus infections. Although some have advocated screening for S. aureus and decolonizing it is unclear whether these efforts reduce SSIs.

QUESTIONS/PURPOSES

The purposes of this study were to determine (1) whether S. aureus screening and decolonization reduce SSIs in orthopaedic patients and (2) if implementing this protocol is cost-effective.

METHODS

Studies for this systematic review were identified by searching PubMed, which includes MEDLINE (1946-present), EMBASE.com (1974-present), and the Cochrane Library's (John Wiley & Sons) Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects (DARE), Health Technology Assessment Database (HTAD), and the NHS Economic Evaluation Database (NHSEED). Comprehensive literature searches were developed using EMTREE, MeSH, and keywords for each of the search concepts of decolonization, MRSA, and orthopedics/orthopedic surgery. Studies published before 1968 were excluded. We analyzed 19 studies examining the ability of the decolonization protocol to reduce SSIs and 10 studies detailing the cost-effectiveness of S. aureus screening and decolonization.

RESULTS

All 19 studies showed a reduction in SSIs or wound complications by instituting a S. aureus screening and decolonization protocol in elective orthopaedic (total joints, spine, and sports) and trauma patients. The S. aureus screening and decolonization protocol also saved costs in orthopaedic patients when comparing the costs of screening and decolonization with the reduction of SSIs.

CONCLUSIONS

Preoperative screening and decolonization of S. aureus in orthopaedic patients is a cost-effective means to reduce SSIs.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I-IV studies. See the Guidelines for Authors for a complete description of levels of evidence.

Reduced costs for Staphylococcus aureus carriers treated prophylactically with mupirocin and chlorhexidine in cardiothoracic and orthopaedic surgery

BACKGROUND

A multi centre double-blind randomised-controlled trial (M-RCT), carried out in the Netherlands in 2005-2007, showed that hospitalised patients with S. aureus nasal carriage who were treated prophylactically with mupirocin nasal ointment and chlorhexidine gluconate medicated soap (MUP-CHX), had a significantly lower risk of health-care associated S. aureus infections than patients receiving placebo (3.4% vs. 7.7%, RR 0.42, 95% CI 0.23-0.75). The objective of the present study was to determine whether treatment of patients undergoing elective cardiothoracic or orthopaedic surgery with MUP-CHX (screen-and-treat strategy) affected the costs of patient care.

METHODS

We compared hospital costs of patients undergoing cardiothoracic or orthopaedic surgery (n=415) in one of the participating centres of the M-RCT. Data from the 'Planning and Control' department were used to calculate total hospital costs of the patients. Total costs were calculated including nursing days, costs of surgery, costs for laboratory and radiological tests, functional assessments and other costs. Costs for personnel, materials and overhead were also included. Mean costs in the two treatment arms were compared using the t-test for equality of means (two-tailed). Subgroup analysis was performed for cardiothoracic and orthopaedic patients.

RESULTS

An investigator-blinded analysis revealed that costs of care in the treatment arm (MUP-CHX, n=210) were on average €1911 lower per patient than costs of care in the placebo arm (n=205) (€8602 vs. €10513, p=0.01). Subgroup analysis showed that MUP-CHX treated cardiothoracic patients cost €2841 less (n=280, €9628 vs €12469, p=0.006) and orthopaedic patients €955 less than non-treated patients (n=135, €6097 vs €7052, p=0.05).

CONCLUSIONS

In conclusion, in patients undergoing cardiothoracic or orthopaedic surgery, screening for S. aureus nasal carriage and treating carriers with MUP-CHX results in a substantial reduction of hospital costs.

Evaluation of Staphylococcus aureus nasal carriage screening before vascular surgery

INTRODUCTION

Staphylococcus aureus is the most important pathogen in the development of surgical site infections (SSI). Patients who carry S. aureus in the nose are at increased risk for the development of SSI in cardiothoracic and orthopedic surgery. In these populations it has been shown that the risk for SSI can be substantially reduced by eradicating S. aureus carriage. For vascular surgery the relation between nasal carriage and surgical site infections has not been clearly investigated. For this reason we performed this study to analyze the relation between S. aureus nasal carriage and SSI in our vascular surgery population.

METHODS

A prospective cohort study was undertaken, including all patients undergoing vascular surgery between January first 2010 and December 31th 2010. Before surgery patients were screened for S. aureus nasal carriage using a PCR technique. The presence of SSI was recorded based on criteria of the CDC.

RESULTS

Screening was performed in 224. Of those, 55 (24.5%) were positive, 159 (71.0%) were negative and 10 (4.5%) were inconclusive. In the screened vascular population 4 S. aureus SSI occurred in the 55 carriers compared with 6 in 159 non-carriers (p=0.24). A stratified analysis revealed a 10-fold increased risk in nasal carriers undergoing central reconstruction surgery (3 S. aureus SSI in 20 procedures versus 1 in 65 procedures in non-carriers, p=0.039).

DISCUSSION

In patients undergoing central reconstruction surgery nasals carriers are at increased risk for the development of S. aureus SSI. These patients will probably benefit from perioperative treatment to eradicate nasal carriage.