Impact of infectious-disease specialist consultations on outcomes of Staphylococcus aureus bacteremia in a hospital with a low volume of patients with S. aureus bacteremia

Clinical and microbiological characteristics of Staphylococcus lugdunensis

PURPOSE OF REVIEW

This review provides an update on recent findings about the clinical and microbiological characteristics of Staphylococcus lugdunensis .

RECENT FINDINGS

European Committee on Antimicrobial Susceptibility Testing (EUCAST) and Clinical and Laboratory Standards Institute (CLSI) differ in their methodology and breakpoints for the detection of penicillin and oxacillin resistance in S. lugdunensis . The EUCAST method for beta-lactamase detection recommends a 1-unit penicillin disk and has demonstrated superior performance compared to the 10-unit penicillin disk recommended by CLSI. A similar outcome has been previously reported in Staphylococcus aureus. In addition, there is emerging oxacillin resistance in some geographical areas. Of particular concern is that oxacillin resistance in mecA positive isolates may not be reliably detected by current cefoxitin breakpoints.

SUMMARY

Coagulase negative staphylococci are now recognised as a heterogenous group of organisms that do not microbiologically or clinically behave the same way. The spectrum of clinical disease is species dependent and is particularly true for S. lugdunensis , which causes an array of clinical infections like that of S. aureus. Further studies are needed to assess the performance of phenotypic tests to detect resistance, to ensure that appropriate antimicrobial therapy is delivered to patients.

The Role of the Oral Immune System in Oropharyngeal Candidiasis-Facilitated Invasion and Dissemination of Staphylococcus aureus

Candida albicans and Staphylococcus aureus account for most invasive fungal and bacterial bloodstream infections (BSIs), respectively. However, the initial point of invasion responsible for S. aureus BSIs is often unclear. Recently, C. albicans has been proposed to mediate S. aureus invasion of immunocompromised hosts during co-colonization of oral mucosal surfaces. The status of the oral immune system crucially contributes to this process in two distinct ways: firstly, by allowing invasive C. albicans growth during dysfunction of extra-epithelial immunity, and secondly following invasion by some remaining function of intra-epithelial immunity. Immunocompromised individuals at risk of developing invasive oral C. albicans infections could, therefore, also be at risk of contracting concordant S. aureus BSIs. Considering the crucial contribution of both oral immune function and dysfunction, the aim of this review is to provide an overview of relevant aspects of intra and extra-epithelial oral immunity and discuss predominant immune deficiencies expected to facilitate C. albicans induced S. aureus BSIs.

Impact of a pharmacist-facilitated, evidence-based bundle initiative on Staphylococcus aureus bacteremia management

OBJECTIVE

To evaluate a pharmacist-facilitated evidence-based bundle (EBB) initiative with infectious disease consultation (IDC) for Staphylococcus aureus bacteremia (SAB).

METHODS

This was a before-and-after quasi-experimental study of adult patients with SAB before and after the pharmacist-facilitated EBB initiative, which included IDC, timely definitive antibiotics, source control, echocardiography, and repeat blood cultures.

RESULTS

Ninety and 111 patients were included in pre- and post-intervention cohorts, respectively. We observed significant increases in adherence to all 5 (4.4% vs 68.5%, P < 0.001) and 4 (10.0% vs 76.6%, P < 0.001) EBB elements. Time to definitive antibiotics (48 vs 16 hours, P < 0.001), time to IDC (43.5 vs 32 hours, P < 0.001), SAB duration (95 vs 66 hours, P = 0.009), persistent SAB (18.9% vs 9.0%, P = 0.041), and length of stay (14 vs 13 days, P = 0.027) also improved. No statistically significant differences for SAB-related readmission or all-cause mortality were observed.

CONCLUSIONS

Our pharmacist-facilitated SAB initiative was associated with improved EBB adherence and clinical outcomes.

The Effect of Insurance on Appropriate Hospital Discharge Antibiotics for Patients With Staphylococcus aureus Bacteremia

Background

Inappropriate antimicrobial therapy of Staphylococcus aureus bacteremia (SAB) is associated with worsened outcomes. The impact of insurance coverage on appropriate selection of antibiotics at discharge is poorly understood.

Methods

We used a retrospective cohort design to evaluate whether patients with SAB at a large academic medical center over 2 years were more likely to receive inappropriate discharge antibiotics, depending on their category of insurance. Insurance was classified as Medicare, Medicaid, commercial, and none. Logistic regression was used to determine the odds of being prescribed inappropriate discharge therapy.

Results

A total of 273 SAB patients met inclusion criteria, with 14.3% receiving inappropriate discharge therapy. In the unadjusted model, there was 2-fold increased odds of being prescribed inappropriate therapy for Medicare, Medicaid, and no insurance, compared with commercial insurance, respectively (odds ratio [OR], 2.08; 95% CI, 1.39–3.13). After controlling for discharge with nursing assistance and infectious diseases (ID) consult, there were 1.6-fold increased odds (OR, 1.57; 95% CI, 0.998–2.53; P = .064) of being prescribed inappropriate therapy for Medicare, Medicaid, and no insurance, compared with commercial insurance, respectively. We found that being discharged home without nursing assistance resulted in 4-fold increased odds of being prescribed inappropriate therapy (OR, 4.16; 95% CI, 1.77–9.77; P < .01), and failing to consult an ID team resulted in 59-fold increased odds of being prescribed inappropriate therapy (OR, 59.2; 95% CI, 11.4–306.9; P < .001).

Conclusions

We found strong evidence that noncommercial insurance, discharging without nursing assistance, and failure to consult ID are risk factors for being prescribed inappropriate antimicrobial therapy for SAB upon hospital discharge.

Impact of infectious diseases consultation as a part of an antifungal stewardship programme on candidemia outcome in an Italian tertiary-care, University hospital

Candidemia is a major cause of in-hospital mortality. Antifungal stewardship programme (AFSP) providing infectious diseases consultation (IDC) might improve the outcome. We evaluate the impact on candidemia mortality of IDC as part of AFSP restricting the use of all antifungals with exception of fluconazole. We retrospectively reviewed the charts of patients with documented candidemia in our hospital during the period 2012-2014 evaluating the impact of several variables on 30-days in-hospital mortality. We reviewed data on 276 patients with documented candidemia: 200 (72%) were treated without IDC and 76 (28%) with IDC. In the group without IDC, 52 patients (26%) received no antifungal therapy. Antifungals used for treating candidemia were (no IDC/IDC): azoles (74%/42%); echinocandins (0%/46%); liposomal and lipidic complex amphotericin B (0%/12%). The 30-day in-hospital mortality was respectively (no IDC/IDC) 37% vs. 20% (p = 0.011). The multivariate analysis confirmed IDC as independent factor protecting from death (OR 0.511, 95% CI 0.251-0.994; p = 0.046), together with fungemia due to non-albicans Candida (OR 0.565, 95% CI 0.327-0.977; p = 0.042). Age >65 years was associated with a higher risk of death (OR 1.989, 95% CI 1.055-3.895; p = 0.038). The additional cost for the use of echinocandins driven by IDC in the study period was €207,000. IDC, as a part of a restrictive front-end antimicrobial stewardship programme (ASP), providing a timely right choice of antifungal therapy, increases the cost of antifungal drugs but might be a contributing protective factor from mortality due to candidemia. Efforts to increase the number of IDC in patients with candidemia seems to be warranted.

Infectious diseases consultation improves key performance metrics in the management of Staphylococcus aureus bacteremia: A multicentre cohort study

BACKGROUND

Staphylococcus aureus bacteremia (SAB) is associated with significant morbidity and mortality. We sought to identify factors associated with infectious diseases consultation (IDC) and understand how IDC associates with SAB patient management and outcomes.

METHODS

A multicentre retrospective study was performed between 2012 and 2014 in a large Canadian Health Zone in order to determine factors associated with IDC and performance of key quality of care determinants in SAB management and clinical outcomes. Factors subject to quality of care determinants were established a priori and studied for associations with IDC and 30-day all-cause mortality using multivariable analysis.

RESULTS

Of 961 SAB episodes experienced by 892 adult patients, 605 episodes received an IDC. Patients receiving IDC were more likely to have prosthetic valves and joints and to have community-acquired and known sources of SAB, but increasing age decreased IDC occurrence. IDC was the strongest independent predictor for quality of care performance metrics, including repeat blood cultures and echocardiography. Mortality at 30 days was 20% in the cohort, and protective factors included IDC, achievement of source control, targeted therapy within 48 hours, and follow-up blood cultures but not the performance of echocardiography.

CONCLUSIONS

There were significant gaps between the treatments and investigations that patients actually received for SAB and what is considered the optimal management of their condition. IDC is associated with improved attainment of targeted SAB quality of care determinants and reduced mortality rates. Based on our findings, we propose a policy of mandatory IDC for all cases of SAB to improve patient management and outcomes.

Impact of an Unsolicited, Standardized Form-Based Antimicrobial Stewardship Intervention to Improve Guideline Adherence in the Management of Staphylococcus aureus Bacteremia

Background

Antimicrobial stewardship programs (ASPs) improve Staphylococcus aureus bacteremia (SAB) management. The objective of the current study was to evaluate the effect of unsolicited prospective audit and feedback (PAF) using a standardized SAB bundle form on the management of SAB.

Methods

Multicenter, pre-post quasi-experimental study of inpatients with SAB. The ASP developed an evidence-based SAB management bundle that included recommendations for infectious diseases consultation, blood culture clearance, appropriate empiric and definitive therapy, echocardiography, adequate treatment duration, and source control where applicable. ASP pharmacists performed PAF using a standardized form outlining bundle components. The primary outcome was bundle component adherence. Secondary outcomes were length of stay, 30-day readmission rate, and in-hospital and 30-day mortality rates.

Results

A total of 199 patients were included (preintervention group, 62; intervention group, 137). Bundle implementation with PAF resulted in significant improvements in infectious diseases consultation (56.5% in preintervention vs 93.4% in intervention group), appropriate definitive antibiotic therapy (83.9% vs 99.3%), ordering echocardiography (72.6% vs 95.6%), and adequate treatment duration (87.0% vs 100%) (all P < .001). Overall bundle adherence increased by 43.8% (P < .001). Readmission and 30-day mortality rates decreased, but this difference did not reach statistical significance.

Conclusions

Unsolicited PAF using a standardized SAB management bundle significantly improved adherence to evidence-based recommendations. This simple yet effective ASP-driven intervention can ensure consistent management of a highly morbid infection.

An Automated, Pharmacist-Driven Initiative Improves Quality of Care for Staphylococcus aureus Bacteremia

Background

Infectious diseases (ID) consultation and antimicrobial stewardship intervention have been shown to improve the management of Staphylococcus aureus bacteremia (SAB). As the workload of antimicrobial stewardship programs (ASPs) continues to increase, ASPs must find a way to maximize the efficiency of the program while optimizing patient outcomes. The objective of this study was to evaluate the impact of incorporating health informatics into the management of SAB via a pharmacist-driven initiative.

Methods

Retrospective, single-center quasi-experimental study of hospitalized patients with SAB. During the intervention period, pharmacists were alerted to patients with SAB via a patient scoring tool integrated into the electronic medical record. Pharmacists utilized the scoring tool and the institution's evidence-based practice guideline to make standardized recommendations to promote adherence to SAB quality-of-care measures and encourage ID consultation. The primary outcome was overall compliance along with adherence to individual quality-of-care components. Secondary clinical outcomes were also analyzed.

Results

In sum, 84 patients were identified for study inclusion, 45 in the pre-intervention and 39 in the intervention group. As a whole, all 4 quality-of-care components for the management of SAB were significantly more frequently adhered to in the intervention group (68.9% vs 92.3%; P = .008). The incidence of ID consult improved significantly by almost 20% in the intervention group (75.6% vs 94.9%, P = .015). No statistically significant differences in duration of bacteremia, length-of-stay, infection-related length-of-stay, or readmission were observed between the groups. The incidence of all-cause mortality was 6-fold higher in the pre- intervention group compared to the intervention group (15.6% vs 2.6%, P = .063).

Conclusion

An automated, pharmacist-driven intervention for the management of patients with SAB demonstrated a significant improvement in patients receiving an ID consult, targeted antimicrobial therapy, and adherence to all SAB quality-of-care measures. As antimicrobial stewardship becomes a mandatory aspect of healthcare in all hospitals in the United States, ASPs will be forced to find ways to provide more efficient, impactful, disease state-based patient care. Our study provides the framework for and data to support this intervention in one of the most clinically important infectious diseases.

Current Status and Survival Impact of Infectious Disease Consultation for Multidrug-Resistant Bacteremia in Ventilated Patients: A Single-Center Experience in Korea

Background

We evaluated the current status and survival impact of infectious disease consultation (IDC) in ventilated patients with multidrug-resistant (MDR) bacteremia.

Methods

One hundred sixty-one consecutive patients from a single tertiary care hospital were enrolled over a 5-year period. Patients with at least one of the following six MDR bacteremias were included: methicillin-resistant Staphylococcus aureus, extended-spectrum β-lactamase-producing gram-negative bacteria (Escherichia coli and Klebsiella pneumonia), carbapenem-resistant gram-negative rods (Acinetobacter baumannii and Pseudomonas aeruginosa), and vancomycin-resistant Enterococcus faecium.

Results

Median patient age was 66 years (range, 18 to 95), and 57.8% of subjects were male. The 28-day mortality after the day of blood culture was 52.2%. An IDC was requested for 96 patients based on a positive blood culture (59.6%). Patients without IDC had significantly higher rate of hemato-oncologic diseases as a comorbidity (36.9% vs. 11.5%, P < 0.001). Patients without an IDC had higher Acute Physiology and Chronic Health Evaluation (APACHE) II score (median, 20; range, 8 to 38 vs. median, 16; range, 5 to 34, P < 0.001) and Sequential Organ Failure Assessment (SOFA) score (median, 9; range, 2 to 17 vs. median, 7; range, 2 to 20; P = 0.020) on the day of blood culture and a higher 28-day mortality rate (72.3% vs. 38.5%, P < 0.001). In patients with SOFA ≥9 (cut-off level based on Youden's index) on the day of blood culture and gram-negative bacteremia, IDC was also significantly associated with lower 28-day mortality (hazard ratio [HR], 0.298; 95% confidence interval [CI], 0.167 to 0.532 and HR, 0.180; 95% CI, 0.097 to 0.333; all P < 0.001) based on multivariate Cox regression analysis.

Conclusions

An IDC for MDR bacteremia was requested less often for ventilated patients with greater disease severity and higher 28-day mortality after blood was drawn. In patients with SOFA ≥9 on the day of blood culture and gram-negative bacteremia, IDC was associated with improved 28-day survival after blood draw for culture.

18F-FDG PET/CT Optimizes Treatment in Staphylococcus Aureus Bacteremia and Is Associated with Reduced Mortality

Metastatic infection is an important complication of Staphylococcus aureus bacteremia (SAB). Early diagnosis of metastatic infection is crucial, because specific treatment is required. However, metastatic infection can be asymptomatic and difficult to detect. In this study, we investigated the role of ¹⁸F-FDG PET/CT in patients with SAB for detection of metastatic infection and its consequences for treatment and outcome. Methods: All patients with SAB at Radboud University Medical Center were included between January 2013 and April 2016. Clinical data and results of ¹⁸F-FDG PET/CT and other imaging techniques, including echocardiography, were collected. Primary outcomes were newly diagnosed metastatic infection by ¹⁸F-FDG PET/CT, subsequent treatment modifications, and patient outcome. Results: A total of 184 patients were included, and ¹⁸F-FDG PET/CT was performed in 105 patients, of whom 99 had a high-risk bacteremia. ¹⁸F-FDG PET/CT detected metastatic infectious foci in 73.7% of these high-risk patients. In 71.2% of patients with metastatic infection, no signs and symptoms suggesting metastatic complications were present before ¹⁸F-FDG PET/CT was performed. ¹⁸F-FDG PET/CT led to a total of 104 treatment modifications in 74 patients. Three-month mortality was higher in high-risk bacteremia patients without ¹⁸F-FDG PET/CT performed than in those in whom ¹⁸F-FDG PET/CT was performed (32.7% vs. 12.4%, P = 0.003). In multivariate analysis, ¹⁸F-FDG PET/CT was the only factor independently associated with reduced mortality (P = 0.005; odds ratio, 0.204; 95% confidence interval, 0.066-0.624). A higher comorbidity score was independently associated with increased mortality (P = 0.003; odds ratio, 1.254; 95% confidence interval, 1.078-1.457). Conclusion:¹⁸F-FDG PET/CT is a valuable technique for early detection of metastatic infectious foci, often leading to treatment modification. Performing ¹⁸F-FDG PET/CT is associated with significantly reduced 3-mo mortality.

The efficacy of the direct clinical intervention for infectious diseases by a pediatric infectious disease specialist in the pediatric ward of a tertiary medical facility without a pediatric antimicrobial stewardship program

Antimicrobial stewardship programs (ASPs) have been introduced in most hospital complexes; however, they are not always useful for pediatric patients. The aim of this study is to investigate the efficacy of direct clinical intervention for infectious diseases by a pediatric infectious disease specialist in a tertiary medical facility without pediatric ASP. This retrospective study included 1,821 patients who were hospitalized in the pediatric ward of a large metropolitan hospital from 2010 to 2015. The clinical course, the use of intravenous antimicrobial agents and the results of a microbiological analysis were compared between the period after the beginning of direct intervention by the specialist (post-intervention period) and the previous period (pre-intervention period). In the post-intervention period, the proportion of the patients who received intravenous antimicrobial agents, the number of antimicrobial agents used for each episode, and the proportion of episodes in which an antimicrobial agent was re-administrated were significantly lower (P = 0.006, P = 0.004, P = 0.036, respectively), and the duration of antimicrobial treatment was significantly shorter (P < 0.001). In addition, narrower spectrum antimicrobial agents were used, and the incidence of meropenem-sensitive Pseudomonas aeruginosa significantly increased (P = 0.037) in the post-intervention period. There was no change of mortality between the two periods. Direct clinical intervention by a pediatric infectious diseases specialist is useful for the treatment of infectious diseases in the pediatric ward of a tertiary medical facility without a pediatric ASP. The creation of a pediatric ASP is recommended in hospital complexes.

Prognostic impact of hyperglycemia at onset of methicillin-sensitive Staphylococcus aureus bacteraemia

Previous reports have associated hyperglycemia to poor outcome among aged and comorbid Staphylococcus aureus bacteraemia (SAB) patients. However, the prognostic impact of hyperglycemia in SAB irrespective of age and underlying conditions including a diagnosis of diabetes has received little attention. The objective here was to evaluate the prognostic relevance of hyperglycemia at onset of methicillin-sensitive SAB (MS-SAB). It was a retrospective study of MS-SAB patients. Blood glucose was measured within 24 h of positive blood cultures. The patient cohort was analyzed en bloc and by categorization according to age, underlying conditions and a diagnosis of diabetes. Altogether 161 patients were identified. High initial blood glucose levels were observed among diabetics (p < 0.001), patients with deep infections (p < 0.05) and poor outcome at 28- or 90-days (p < 0.05). Receiver operating characteristics presented the glucose cut-off level of 7.2 mmol/L as a significant predictor of mortality with an area under the curve of 0.63 (95% CI 0.52-0.75, p < 0.05). Blood glucose ≥7.2 mmol/L connected to higher 28- (9 vs. 20%, p < 0.05) and 90-day (14 vs. 29%, p < 0.01) mortality. In Cox proportional hazard regression the blood glucose cut-off value of 7.2 mmol/L significantly predicted 90-day mortality (HR, 2.12; 95% CI, 1.01-4.46; p < 0.05). Among young and healthy non-diabetics the negative prognostic impact of high glucose was further accentuated (HR 7.46, p < 0.05). High glucose levels had no prognostic impact among diabetics. Hyperglycemia at SAB onset may associate to poor outcome. The negative prognostic impact is accentuated among young and healthy non-diabetics.

Impact of Infectious Diseases Consultation on Clinical Outcomes of Patients with Staphylococcus aureus Bacteremia in a Community Health System

Staphylococcus aureus bacteremia (SAB) causes high rates of morbidity and death. Several studies in academic health settings have demonstrated that consultations from infectious diseases specialists improve the quality of care and clinical outcomes for SAB. Few data that describe the impact in resource-limited settings such as community hospitals are available. This retrospective cohort study evaluated the adherence to quality-of-care indicators and the clinical outcomes for SAB in a five-hospital community health system (range of 95 to 272 available beds per hospital), for patients with versus without infectious diseases consultation (IDC). IDC was provided if requested by the attending physician. The primary outcome was the incidence of treatment failure, defined as 30-day in-hospital death or 90-day SAB recurrence. Other outcomes included adherence to quality-of-care indicators. A total of 473 adult patients with SAB were included, with 369 (78%) receiving IDC. We identified substantial differences in baseline characteristics between the IDC group and the no-IDC group, including greater incidences of complicated bacteremia and intravenous drug users in the IDC group, with similar rates of severe illness (measured by Pitt bacteremia scores). Adherence to quality-of-care indicators was greater for patients with IDC (P < 0.001). After adjustment for other predicting variables, IDC was associated with a lower rate of treatment failure (adjusted odds ratio, 0.42 [95% confidence interval, 0.20 to 0.86]; P = 0.018). IDC provided better quality of care and better clinical outcomes for patients with SAB who were treated at small, resource-limited, community hospitals.

The Impact of Infectious Disease Specialist Consultation for Staphylococcus aureus Bloodstream Infections: A Systematic Review

Staphylococcus aureus is a common cause of severe bloodstream infection. We performed a systematic review to assess whether consultation with infectious disease specialists decreased all-cause mortality or rate of complications of S aureus bloodstream infections. The review also assessed parameters associated with the quality of management of the infection. We searched for eligible studies in PubMed, Embase, Scopus, and clinical trials.gov as well as the references of included studies. We identified 22 observational studies and 1 study protocol for a randomized trial. A meta-analysis was not performed because of the high risk of bias in the included studies. The outcomes are reported in a narrative review. Most included studies reported survival benefit, in the adjusted analysis. Recommended management strategies were carried out significantly more often among patients seen by an infectious disease specialist. Trials, such as cluster-randomized controlled trials, can more validly assess the studies at low risk of bias.

Should all adjunctive corticosteroid therapy be avoided in the management of hemodynamically stabile Staphylococcus aureus bacteremia?

The purpose of this study was to examine the prognostic impact of corticosteroids in hemodynamically stabile Staphylococcus aureus bacteremia (SAB). There were 361 hemodynamically stabile methicillin-sensitive SAB patients with prospective follow-up and grouping according to time-point, dose and indication for corticosteroid therapy. To enable analyses without external interfering corticosteroid therapy all patients with corticosteroid therapy equivalent to prednisone >10 mg/day for ≥1 month prior to positive blood culture results were excluded. Twenty-five percent (92) of patients received corticosteroid therapy of which 11 % (40) had therapy initiated within 1 week (early initiation) and 9 % (31) had therapy initiated 2-4 weeks after (delayed initiation) positive blood culture. Twenty-one patients (6 %) had corticosteroid initiated after 4 weeks and were not included in the analyses. A total of 55 % (51/92) received a weekly prednisone dose >100 mg. Patients with early initiated corticosteroid therapy had higher mortality compared to patients treated without corticosteroid therapy at 28 days (20 % vs. 7 %) (OR, 3.11; 95%CI, 1.27-7.65; p < 0.05) and at 90 days (30 % vs. 10 %) (OR, 4.01; 95%CI, 1.82-8.81; p < 0.001). Considering all prognostic markers, early initiated corticosteroid therapy predicted 28-day (HR, 3.75; 95%CI, 1.60-8.79; p = 0.002) and 90-day (HR, 3.10; 95%CI, 1.50-6.39; p = 0.002) mortality in Cox proportional hazards regression analysis. When including only patients receiving early initiated corticosteroid therapy with prednisone ≥100 mg/week the negative prognostic impact on 28-day mortality was accentuated (HR 4.8, p = 0.001). Corticosteroid therapy initiation after 1 week of positive blood cultures had no independent prognostic impact. Early initiation of corticosteroid therapy may be associate to increased mortality in hemodynamically stabile SAB.

Infectious disease consultation for Staphylococcus aureus bacteremia - A systematic review and meta-analysis

OBJECTIVE

Mortality and morbidity of Staphylococcus aureus bacteremia (SAB) still remains considerably high. We aimed to evaluate the impact of infectious disease consultation (IDC) on the management and outcomes of patients with SAB.

METHODS

We systematically searched 3 publication databases from inception to 31st May 2015 and reference lists of identified primary studies.

RESULTS

Our search returned 2874 reports, of which 18 fulfilled the inclusion criteria, accounting for 5337 patients. Overall 30-day mortality was 19.95% [95% CI 14.37-27.02] with a significant difference in favour of the IDC group (12.39% vs 26.07%) with a relative risk (RR) of 0.53 [95% CI 0.43-0.65]. 90-day mortality and relapse risk for SAB were also reduced significantly with RRs of 0.77 [95% CI 0.64-0.92] and 0.62 [95% CI 0.39-0.99], respectively. Both, the appropriateness of antistaphylococcal agent and treatment duration was improved by IDC (RR 1.14 [95% CI 1.08-1.20] and 1.85 [95% CI 1.39-2.46], respectively). Follow-up blood cultures and echocardiography were performed more frequently following IDC (RR 1.35 [95% CI 1.25-1.46] and 1.98 [95% CI 1.66-2.37], respectively).

CONCLUSIONS

Evidence-based clinical management enforced by IDC may improve outcome of patients with SAB. Well-designed cluster-randomized controlled trials are needed to confirm this finding from observational studies.

Staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management

Staphylococcus aureus is a major human pathogen that causes a wide range of clinical infections. It is a leading cause of bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device-related infections. This review comprehensively covers the epidemiology, pathophysiology, clinical manifestations, and management of each of these clinical entities. The past 2 decades have witnessed two clear shifts in the epidemiology of S. aureus infections: first, a growing number of health care-associated infections, particularly seen in infective endocarditis and prosthetic device infections, and second, an epidemic of community-associated skin and soft tissue infections driven by strains with certain virulence factors and resistance to β-lactam antibiotics. In reviewing the literature to support management strategies for these clinical manifestations, we also highlight the paucity of high-quality evidence for many key clinical questions.

Bacteremia, Sepsis, and Infective Endocarditis Associated with Staphylococcus aureus

Bacteremia and infective endocarditis (IE) are important causes of morbidity and mortality associated with Staphylococcus aureus infections. Increasing exposure to healthcare, invasive procedures, and prosthetic implants has been associated with a rising incidence of S. aureus bacteremia (SAB) and IE since the late twentieth century. S. aureus is now the most common cause of bacteremia and IE in industrialized nations worldwide and is associated with excess mortality when compared to other pathogens. Central tenets of management include identification of complicated bacteremia, eradicating foci of infection, and, for many, prolonged antimicrobial therapy. Evolving multidrug resistance and limited therapeutic options highlight the many unanswered clinical questions and urgent need for further high-quality clinical research.

Clinical management of Staphylococcus aureus bacteremia: a review

IMPORTANCE

Several management strategies may improve outcomes in patients with Staphylococcus aureus bacteremia.

OBJECTIVES

To review evidence of management strategies for S. aureus bacteremia to determine whether transesophageal echocardiography is necessary in all adult cases and what is the optimal antibiotic therapy for methicillin-resistant S. aureus (MRSA) bacteremia.

EVIDENCE REVIEW

A PubMed search from inception through May 2014 was performed to identify studies addressing the role of transesophageal echocardiography in S. aureus bacteremia. A second search of PubMed, EMBASE, and the Cochrane Library from January 1990 through May 2014 was performed to find studies addressing antibiotic treatment for MRSA bacteremia. Studies reporting outcomes from antibiotic therapy for MRSA bacteremia were included. All searches, which were limited to English and focused on adults, were augmented by review of bibliographic references from included studies. The quality of evidence was assessed using the Grades of Recommendation, Assessment, Development and Evaluation system with consensus of independent evaluations by at least 2 of the authors.

FINDINGS

In 9 studies with a total of 4050 patients, use of transesophageal echocardiography was associated with higher rates of a diagnosis of endocarditis (14%-28%) compared with transthoracic echocardiography (2%-15%). In 4 studies, clinical or transthoracic echocardiography findings did not predict subsequent transesophageal echocardiography findings of endocarditis. Five studies identified clinical or transthoracic echocardiography characteristics associated with low risk of endocarditis (negative predictive values from 93% to 100%). Characteristics associated with a low risk of endocarditis include absence of a permanent intracardiac device, sterile follow-up blood cultures within 4 days after the initial set, no hemodialysis dependence, nosocomial acquisition of S. aureus bacteremia, absence of secondary foci of infection, and no clinical signs of infective endocarditis. Of 81 studies of antibiotic therapy for MRSA bacteremia, only 1 high-quality trial was identified. In that study of 246 patients with S. aureus bacteremia, daptomycin was not inferior to vancomycin or an antistaphylococcal penicillin, each in combination with low-dose, short-course gentamicin (clinical success rate, 44.2% [53/120] vs 41.7% [48/115]; absolute difference, 2.4% [95% CI, -10.2% to 15.1%]).

CONCLUSIONS AND RELEVANCE

All adult patients with S. aureus bacteremia should undergo echocardiography. Characteristics of low-risk patients with S. aureus bacteremia for whom transesophageal echocardiography can be safely avoided have been identified. Vancomycin and daptomycin are the first-line antibiotic choices for MRSA bacteremia. Well-designed studies to address the management of S. aureus bacteremia are needed.

The impact of infectious disease specialists on antibiotic prescribing in hospitals

Given the current bacterial resistance crisis, antimicrobial stewardship programmes are of the utmost importance. We present a narrative review of the impact of infectious disease specialists (IDSs) on the quality and quantity of antibiotic use in acute-care hospitals, and discuss the main factors that could limit the efficacy of IDS recommendations. A total of 31 studies were included in this review, with a wide range of infections, hospital settings, and types of antibiotic prescription. Seven of 31 studies were randomized controlled trials, before/after controlled studies, or before/after uncontrolled studies with interrupted time-series analysis. In almost all studies, IDS intervention was associated with a significant improvement in the appropriateness of antibiotic prescribing as compared with prescriptions without any IDS input, and with decreased antibiotic consumption. Variability in the antibiotic prescribing practices of IDSs, informal (curbside) consultations and the involvement of junior IDSs are among the factors that could have an impact on the efficacy of IDS recommendations and on compliance rates, and deserve further investigation. We also discuss possible drawbacks of IDSs in acute-care hospitals that are rarely reported in the published literature. Overall, IDSs are valuable to antimicrobial stewardship programmes in hospitals, but their impact depends on many human and organizational factors.

Impact of infectious diseases consultation on the management of Staphylococcus aureus bacteraemia in children

OBJECTIVES

Infectious diseases consultation (IDC) in adults with Staphylococcus aureus bacteraemia (SAB) has been shown to improve management and outcome. The aim of this study was to evaluate the impact of IDC on the management of SAB in children.

STUDY DESIGN

Observational cohort study of children with SAB.

SETTING

Cambridge University Hospitals National Health Service (NHS) Foundation Trust, a large acute NHS Trust in the UK.

PARTICIPANTS

All children with SAB admitted to the Cambridge University Hospitals NHS Foundation Trust between 16 July 2006 and 31 December 2012.

METHODS

Children with SAB between 2006 and 31 October 2009 were managed by routine clinical care (pre-IDC group) and data were collected retrospectively by case notes review. An IDC service for SAB was introduced in November 2009. All children with SAB were reviewed regularly and data were collected prospectively (IDC group) until 31 December 2012. Baseline characteristics, quality metrics and outcome were compared between the pre-IDC group and IDC group.

RESULTS

There were 66 episodes of SAB in 63 children-28 patients (30 episodes) in the pre-IDC group, and 35 patients (36 episodes) in the IDC group. The median age was 3.4 years (IQR 0.2-10.7 years). Patients in the IDC group were more likely to have echocardiography performed, a removable focus of infection identified and to receive a longer course of intravenous antimicrobial therapy. There were no differences in total duration of antibiotic therapy, duration of hospital admission or outcome at 30 or 90 days following onset of SAB.

CONCLUSIONS

IDC resulted in improvements in the investigation and management of SAB in children.

Telephone consultation cannot replace bedside infectious disease consultation in the management of Staphylococcus aureus Bacteremia

BACKGROUND

Infectious disease specialist (IDS) consultation improves the outcome of Staphylococcus aureus bacteremia (SAB). Although telephone consultations constitute a substantial part of IDS consultations, their impact on treatment outcome lacks evaluation.

METHODS

We retrospectively followed 342 SAB episodes with 90-day follow-up, excluding 5 methicillin-resistant S. aureus SAB cases. Patients were grouped according to bedside, telephone, or no IDS consultation within the first week. Patients with fatal outcome within 3 days after onset of SAB were excluded to allow for the possibility of death occurring before IDS consultation.

RESULTS

Seventy-two percent of patients received bedside, 18% telephone, and 10% no IDS consultation. Patients with bedside consultation were less often treated in an intensive care unit during the first 3 days compared to those with telephone consultation (odds ratio [OR], 0.53; 95% confidence interval [CI], .29-.97; P = .037; 21% vs 34%), with no other initial differences between these groups. Patients with bedside consultation more often had deep infection foci localized as compared to patients with telephone consultation (OR, 3.11; 95% CI, 1.74-5.57; P < .0001; 78% vs 53%). Patients with bedside consultation had lower mortality than patients with telephone consultation at 7 days (OR, 0.09; 95% CI, .02-.49; P = .001; 1% vs 8%), at 28 days (OR, 0.27; 95% CI, .11-.65; P = .002; 5% vs 16%) and at 90 days (OR, 0.25; 95% CI, .13-.51; P < .0001; 9% vs 29%). Considering all prognostic markers, 90-day mortality for telephone-consultation patients was higher (OR, 2.31; CI, 95% 1.22-4.38; P = .01) as compared to bedside consultation.

CONCLUSIONS

Telephone IDS consultation is inferior to bedside IDS consultation.