Bacteremia during Open Septorhinoplasty

Background

In this study, we aimed at determining the incidence of bacteremia during septoplasty and open septorhinoplasty.

Methods

The study included 60 patients (30 septoplasties and 30 open septorhinoplasties). Preoperative nasal cultures from the nasal cavity and vestibule were taken by using swabs, and blood cultures were obtained from peripheral veins preoperatively, intraoperatively, and postoperatively. Blood cultures were evaluated by using the BACTEC method.

Results

Neither the blood cultures taken preoperatively nor those obtained postoperatively was positive for any organisms. On the other hand, although the bacterial growth was observed in only one of the blood cultures (3.3%) taken intraoperatively during septoplasty, it was observed in four blood cultures (13.3%) obtained intraoperatively during open septorhinoplasty.

Conclusion

Our data indicate that a transient bacteremia occurs during open septorhinoplasty. Although this bacteremia is transient and it has not led to any clinical manifestations in our patients, the possibility of bacteremia during this surgery should be kept in mind and necessary precautions should be taken preoperatively in patients with a high risk of cardiovascular infection.

Staphylococcus aureus bacteraemia and endocarditis - epidemiology and outcome: a review

PURPOSE

To review the epidemiology of Staphylococcus aureus bacteraemia (SAB) and endocarditis (SAE), and discuss the short- and long-term outcome.  Materials and methods: A literature review of the epidemiology of SAB and SAE.

RESULTS

The reported incidence of SAB in Western countries is 16-41/100,000 person-years. Increasing incidence has been observed in many regions, in Iceland by 27% during 1995-2008. The increase is believed to depend on changes in population risk factors and possibly better and more frequent utilization of diagnostic procedures. S. aureus is now the leading causes of infective endocarditis (IE) in many regions of the world. It accounts for 15-40% of all IE cases, and the majority of cases in people who inject drugs (PWID). Recently, the incidence of SAE in PWID in Stockholm, Sweden, was found to be 2.5/1000 person-years, with an in-hospital mortality of 2.5% in PWID as compared to 15% in non-drug users. The 30-day mortality associated with SAB amounts to 15-25% among adults in Western countries, but is lower in children (0-9%). Mortality associated with SAE is high (generally 20-30% in-hospital mortality), and symptomatic cerebral embolizations are common (12-35%). The 1-year mortality reported after SAB and SAE is 19-62% and reflects deaths from underlying diseases and complications caused by the infection. In a subset of SAE cases, valvular heart surgery is needed (15-45%), but active intravenous drug use seems to be a reason to refrain from surgery. Despite its importance, there are insufficient data on the optimal management of SAB and SAE, especially on the required duration of antibiotic therapy.  Conclusions: The epidemiology of SAB and SAE has been changing in the past decades. They still carry a substantial morbidity and mortality. Intensified studies on treatment are warranted for improving patient outcome.

Modeling Transmission of Methicillin-ResistantStaphylococcus AureusAmong Patients Admitted to a Hospital

Objective:

To determine the impact of the screening test, nursing workload, handwashing rates, and dependence of handwashing on risk level of patient visit on methicillin-resistantStaphylococcus aureus(MRSA) transmission among hospitalized patients.

Setting:

General medical ward.

Methods:

Monte Carlo simulation was used to model MRSA transmission (median rate per 1,000 patient-days). Visits by healthcare workers (HCWs) to patients were simulated, and MRSA was assumed to be transmitted among patients via HCWs.

Results:

The transmission rate was reduced from 0.89 to 0.56 by the combination of increasing the sensitivity of the screening test from 80% to 99% and being able to report results in 1 day instead of 4 days. Reducing the patient-to-nurse ratio from 4.3 in the day and 6.8 at night to 3.8 and 5.7, respectively, reduced the number of nosocomial infections from 0.89 to 0.85; reducing the ratio to 1 and 1, respectively, further reduced the number of nosocomial infections to 0.32. Increases in handwashing rates by 0%, 10%, and 20% for high-risk visits yielded reductions in nosocomial infections similar to those yielded by increases in handwashing rates for all visits (0.89, 0.36, and 0.24, respectively). Screening all patients for MRSA at admission reduced the transmission rate to 0.81 per 1,000 patient-days from 1.37 if no patients were screened.

Conclusion:

Within the ranges of parameters studied, the most effective strategies for reducing the rate of MRSA transmission were increasing the handwashing rates for visits involving contact with skin or bodily fluid and screening patients for MRSA at admission. (Infect Control Hosp Epidemiol 2005;26:607- 615)

Costs and Outcomes Among Hemodialysis-Dependent Patients With Methicillin-Resistant or Methicillin-SusceptibleStaphylococcus aureusBacteremia

Objective:

Comorbid conditions have complicated previous analyses of the consequences of methicillin resistance for costs and outcomes ofStaphylococcus aureusbacteremia. We compared costs and outcomes of methicillin resistance in patients withS. aureusbacteremia and a single chronic condition.

Design, Setting, and Patients:

We conducted a prospective cohort study of hemodialysis-dependent patients with end-stage renal disease andS. aureusbacteremia hospitalized between July 1996 and August 2001. We used propensity scores to reduce bias when comparing patients with methicillin-resistant (MRSA) and methicillin-susceptible (MSSA)S. aureusbacteremia. Outcome measures were resource use, direct medical costs, and clinical outcomes at 12 weeks after initial hospitalization.

Results:

Fifty-four patients (37.8%) had MRSA and 89 patients (62.2%) had MSSA. Compared with patients with MSSA bacteremia, patients with MRSA bacteremia were more likely to have acquired the infection while hospitalized for another condition (27.8% vs 12.4%;P= .02). To attribute all inpatient costs toS. aureusbacteremia, we limited the analysis to 105 patients admitted for suspectedS. aureusbacteremia from a community setting. Adjusted costs were higher for MRSA bacteremia for the initial hospitalization ($21,251 vs $13,978;P= .012) and after 12 weeks ($25,518 vs $17,354;P= .015). At 12 weeks, patients with MRSA bacteremia were more likely to die (adjusted odds ratio, 5.4; 95% confidence interval, 1.5 to 18.7) than were patients with MSSA bacteremia.

Conclusions:

Community-dwelling, hemodialysis-dependent patients hospitalized with MRSA bacteremia face a higher mortality risk, longer hospital stays, and higher inpatient costs than do patients with MSSA bacteremia.

Predictive Value of C-Reactive Protein (CRP) in Identifying Fatal Outcome and Deep Infections in Staphylococcus aureus Bacteremia

Introduction

Clear cut-off levels could aid clinicians in identifying patients with a risk of fatal outcomes or complications such as deep infection foci in Staphylococcus aureus bacteremia (SAB). Cut-off levels for widely used clinical follow-up parameters including serum C-reactive protein (CRP) levels and white blood cell counts (WBC) have not been previously studied.

Methods

430 adult SAB patients in Finland took part in prospective multicentre study in which their CRP levels and WBC counts were measured on the day of the positive blood culture, every other day during the first week, twice a week during hospitalization and at 30 days. Receiver operating characteristic (ROC) analysis was used to evaluate the prognostic value of CRP and WBC on the day of the positive blood culture and at days 4, 7, and 14 in predicting mortality and the presence of deep infections at 30 days. Adjusted hazard ratios (HR) for CRP level and WBC count cut-off values for mortality were calculated by the Cox regression analysis and adjusted odds ratios (OR) for cut-off values to predict the presence of deep infection by the binary logistic regression analysis.

Results

The succumbing patients could be distinguished from the survivors, starting on day 4 after the positive blood culture, by higher CRP levels. Cut-off values of CRP for day 30 mortality in adjusted analysis, that significantly predicted fatal outcome were at day 4 CRP >103 mg/L with sensitivity of 77%, specificity of 55%, and HR of 3.5 (95% CI, 1.2–10.3; p = 0.024), at day 14 CRP >61 mg/L with a sensitivity of 82%, specificity of 80% and HR of 3.6 (95% CI, 1.1–10.3; p<0.039) and cut-off value of WBC at day 14 >8.6 x10⁹/L was prognostic with sensitivity of 77%, specificity of 78% and HR of 8.2 (95% CI, 2.9–23.1; p<0.0001). Cut-off values for deep infection in adjusted analysis were on the day of the positive blood culture CRP >108 mg/L with sensitivity of 77%, specificity of 60%, and HR of 2.6 (95% CI, 1.3–4.9; p = 0.005) and at day 14 CRP >22 mg/L with sensitivity of 59%, specificity of 68%, and HR of 3.9 (95% CI, 1.6–9.5; p = 0.003). The lack of decline of CRP in 14 days or during the second week were neither prognostic nor markers of deep infection focus.

Conclusions

CRP levels have potential for the early identification of SAB patients with a greater risk for death and deep infections.

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.

Risk factors for bloodstream infection in patients at a Brazilian hemodialysis center: a case-control study

BACKGROUND

Infection is the leading cause of morbidity and the second leading cause of mortality in patients on renal replacement therapy. The rates of bloodstream infection in hemodialysis patients vary according to the type of venous access used. Gram-positive bacteria are most frequently isolated in blood cultures of hemodialysis patients. This study evaluated risk factors for the development of bloodstream infections in patients undergoing hemodialysis.

METHODS

Risk factors associated with bloodstream infections in patients on hemodialysis were investigated using a case-control study conducted between January 2010 and June 2013. Chronic renal disease patients on hemodialysis who presented with positive blood cultures during the study were considered as cases. Controls were hemodialysis patients from the same institution who did not present with positive blood cultures during the study period. Data were collected from medical records. Logistic regression was used for statistical analysis.

RESULTS

There were 162 patients included in the study (81 cases and 81 controls). Gram-positive bacteria were isolated with the highest frequency (72%). In initial logistic regression analysis, variables were hypertension, peritoneal dialysis with previous treatment, type and time of current venous access, type of previous venous access, previous use of antimicrobials, and previous hospitalization related to bloodstream infections. Multiple regression analysis showed that the patients who had a central venous catheter had an 11.2-fold (CI 95%: 5.17-24.29) increased chance of developing bloodstream infections compared with patients who had an arteriovenous fistula for vascular access. Previous hospitalization increased the chance of developing bloodstream infections 6.6-fold (CI 95%: 1.9-23.09).

CONCLUSIONS

Infection prevention measures for bloodstream infections related to central venous catheter use should be intensified, as well as judicious use of this route for vascular access for hemodialysis. Reducing exposure to the hospital environment through admission could contribute to a reduction in bloodstream infections in this population.

Risk Factors and Costs Associated With Methicillin-Resistant Staphylococcus aureus Bloodstream Infections

Objectives:

To compare the cost of hospitalization of patients with methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) versus patients with methicillin-sensitive S. aureus (MSSA) BSI, controlling for severity of underlying illness; and to identify risk factors associated with MRSA BSI.

Design:

Retrospective case-control study based on medical chart review.

Setting:

A 640-bed, tertiary-care hospital in Seattle, Washington.

Patients:

All patients admitted to the hospital between January 1,1997, and December 31,1999, with S. aureus BSI confirmed by culture.

Results:

Twenty patients with MRSA BSI were compared with 40 patients with MSSA BSI. Univariate analysis identified 5 risk factors associated with MRSA BSI. Recent hospital admission (P = .006) and assisted living (P = .004) remained significant in a multivariate model. Costs were significantly higher per patient-day of hospitalization for MRSA BSI than for MSSA BSI ($5,878 vs $2,073; P = .003). When patients were stratified according to severity of illness as measured by the case mix index, a difference of $5,302 per patient-day was found between the two groups for all patients with a case mix index greater than 2(P<.001).

Conclusion:

These observations suggest that MRSA BSI significantly increases hospitalization costs compared with MSSA BSI, even when controlling for the severity of the patient's underlying illness. As MRSA BSI was also found to be significantly associated with a group of patients who have repeated hospitalizations, such infections contribute substantially to the increasing cost of medical care.

Comparison of Mortality Risk Associated With Bacteremia Due to Methicillin-Resistant and Methicillin-Susceptible Staphylococcus aureus

Objective.

To quantify the clinical impact of methicillin-resistance in Staphylococcus aureus causing infection complicated by bacteremia in adult patients, while controlling for the severity of patients' underlying illnesses.

Design.

Retrospective cohort study from October 1, 1995, through December 31, 2003.

Patients and Setting.

A total of 438 patients with S. aureus infection complicated by bacteremia from a single Veterans Affairs healthcare system.

Results.

We found that 193 (44%) of the 438 patients had methicillin-resistant S. aureus (MRSA) infection and 114 (26%) died of causes attributable to S. aureus infection within 90 days after the infection was identified. Patients with MRSA infection had a higher mortality risk, compared with patients with methicillin-susceptible S. aureus (MSSA) infections (relative risk, 1.7 [95% confidence interval, 1.3-2.4]; P < .01), except for patients with pneumonia (relative risk, 0.7 [95% confidence interval, 0.4-1.3]). Patients with MRSA infections were significantly older (P < .01), had more underlying diseases (P = .02), and were more likely to have severe sepsis in response to their infection (P < .01) compared with patients with MSSA bacteremia. Patients who died within 90 days after S. aureus infection was identified were significantly older (P < .01) and more likely to have severe sepsis (P < .01) and pneumonia (P = .01), compared with patients who survived. After adjusting for age as a confounder, comorbidities, and pneumonia as an effect modifier, S. aureus infection-related mortality remained significantly higher in patients with MRSA infection than in those with MSSA infection, among those without pneumonia (hazard ratio, 1.8 [95% confidence interval, 1.2-3.0]); P < .01.

Conclusions.

The results of this study suggest that patients with MRSA infections other than pneumonia have a higher mortality risk than patients with MSSA infections other than pneumonia, independent of the severity of patients' underlying illnesses.

Risk factors for mortality among patients with Staphylococcus aureus bacteremia: a single-centre retrospective cohort study

INTRODUCTION

Staphylococcus aureus bacteremia is associated with significant morbidity and mortality. Given the paucity of recent Canadian data, we estimated the mortality rate associated with S. aureus bacteremia in a tertiary care hospital and identified risk factors associated with mortality.

METHODS

We retrospectively reviewed the records of adults with S. aureus bacteremia admitted to a tertiary care centre in southwestern Ontario between 2008 and 2012. Cox regression analysis was used to evaluate associations between predictor variables and all-cause, in-hospital, and 90-day postdischarge mortality.

RESULTS

Of the 925 patients involved in the study, 196 (21.2%) died in hospital and 62 (6.7%) died within 90 days after discharge. Risk factors associated with in-hospital and all-cause mortality included age, sepsis (adjusted hazard ratio [adjusted HR] 1.49, 95% confidence interval [CI] 1.08-2.06, p = 0.02), admission to the intensive care unit (adjusted HR 3.78, 95% CI 2.85-5.02, p < 0.0001), hepatic failure (adjusted HR 3.36, 95% CI 1.91-5.90, p < 0.0001) and metastatic cancer (adjusted HR 2.58, 95% CI 1.77-3.75, p < 0.0001). Methicillin resistance, hepatic failure, cerebrovascular disease, chronic obstructive pulmonary disease and metastatic cancer were associated with postdischarge mortality.

INTERPRETATION

The all-cause mortality rate in our cohort was 27.9%. Identification of predictors of mortality may guide empiric therapy and provide prognostic clarity for patients with S. aureus bacteremia.

High cell-free DNA predicts fatal outcome among Staphylococcus aureus bacteraemia patients with intensive care unit treatment

Introduction

Among patients with bacteraemia or sepsis the plasma cell-free DNA (cf-DNA) biomarker has prognostic value and Pitt bacteraemia scores predict outcome. We evaluated the prognostic value of plasma cf-DNA in patients with Staphylococcus aureus bacteraemia (SAB) treated in the ICU or in the general ward.

Methods

418 adult patients with positive blood culture for S. aureus were prospectively followed for 90 days. SAB patients were grouped according to ICU treatment: 99 patients were treated in ICU within 7 days of documented SAB whereas 319 patients were managed outside ICU. Pitt bacteraemia scores were assessed at hospital arrival and cf-DNA was measured at days 3 and 5 from positive blood culture.

Results

SAB patients with high Pitt bacteraemia scores and ICU treatment presented higher cf-DNA values as compared to SAB patients with low Pitt bacteraemia scores and non-ICU treatment at both days 3 and 5. Among ICU patients cf-DNA >1.99 µg/ml at day 3 predicted death with a sensitivity of 67% and a specificity of 77% and had an AUC in receiver operating characteristic analysis of 0.71 (p<0.01). The cut-off cf-DNA >1.99 µg/ml value demonstrated a strong association to high Pitt bacteraemia scores (≥4 points) (p<0.000). After controlling for all prognostic markers, Pitt bacteraemia scores ≥4 points at hospital admission (OR 4.47, p<0.000) and day 3 cf-DNA (OR 3.56, p<0.001) were the strongest factors significantly predicting outcome in ICU patients. cf-DNA at day 5 did not predict fatal outcome.

Conclusion

High cf-DNA concentrations were observed among patients with high Pitt bacteraemia scores and ICU treatment. Pitt bacteraemia scores (≥4 points) and cf-DNA at day 3 from positive blood culture predicted death among SAB patients in ICU and were found to be independent prognostic markers. cf-DNA had no prognostic value among non-ICU patients.

Characteristics of invasive Staphylococcus aureus infections in three regions of Korea, 2009-2011: a multi-center cohort study

BACKGROUND

Despite the importance of invasive Staphylococcus aureus (ISA) infection, its overall burden in non-selected populations has only been defined in a small number of studies in Europe and North America. To define the characteristics of ISA infections in Korea, we conducted a multi-center cohort study to estimate population-based incidence rates.

METHODS

We conducted a multicenter prospective cohort study at nine university-affiliated active-surveillance core centers (ASCs) in three regions of Korea. To cover all available clinical microbiologic laboratories, we classified the laboratories in these regions into three groups according to their clinical environment as: 1) Nine ASCs, 2) Five major commercial laboratories and 3) Forty-four acute-care hospital-affiliated microbiology laboratories. We requested all the laboratories to report prospectively their numbers of cases of S. aureus isolated from normally sterile sites. Detailed clinical information was collected about the cases in the nine ASCs.

RESULTS

From 1 July 2009 to 30 June 2011, a total of 1,198 cases of ISA infection were identified at the nine ASCs, including 748 (62%) methicillin-resistant S. aureus (MRSA) infections. Most (81%) ISA infections were healthcare-associated (HCA): 653 (55%) hospital-onset and 322 (27%) community-onset. 223 (19%) were community-associated infections. The most common primary diagnosis was catheter-associated infection (225 cases, 19%). Respiratory tract infection (160, 13%), skin & soft tissue (152, 13%) and bone & joint infections (120, 10%) were also common. 30-day and 12-week mortality rates were 25.6% (262/1,024) and 36.5% (314/860), respectively. Complications, including metastatic infection within 12 weeks, occurred in 17.8% of ISA infections. The most common site of metastatic infection was the lung (9.8%, 84/860). Based on the total of 2,806 observed cases of ISA infection, estimated annual rates of ISA and invasive MRSA infections were 43.3 and 27.7 per 100,000 populations, respectively.

CONCLUSIONS

Our data provide important information about the clinical characteristics of ISA infections. We estimate that over 21,000 ISA infections and 13,000 invasive MRSA infections occurred in Korea in 2010.

Controlled multicenter evaluation of a bacteriophage-based method for rapid detection of Staphylococcus aureus in positive blood cultures

Staphylococci are a frequent cause of bloodstream infections (BSIs). Appropriate antibiotic treatment for BSIs may be delayed because conventional laboratory testing methods take 48 to 72 h to identify and characterize isolates from positive blood cultures. We evaluated a novel assay based on bacteriophage amplification that identifies Staphylococcus aureus and differentiates between methicillin-susceptible and methicillin-resistant S. aureus (MSSA and MRSA, respectively) in samples taken directly from signal-positive Bactec blood culture bottles within 24 h of positive signal, with results available within 5 h. The performance of the MicroPhage KeyPath MRSA/MSSA blood culture test was compared to conventional identification and susceptibility testing methods. At four sites, we collectively tested a total of 1,165 specimens, of which 1,116 were included in our analysis. Compared to standard methods, the KeyPath MRSA/MSSA blood culture test demonstrated a sensitivity, specificity, positive predictive value, and negative predictive value of 91.8%, 98.3%, 96.3%, and 96.1%, respectively, for correctly identifying S. aureus. Of those correctly identified as S. aureus (n = 334), 99.1% were correctly categorized as either MSSA or MRSA. Analysis of a subset of the data revealed that the KeyPath MRSA/MSSA blood culture test delivered results a median of 30 h sooner than conventional methods (a median of 46.9 h versus a median of 16.9 h). Although the sensitivity of the test in detecting S. aureus-positive samples is not high, its accuracy in determining methicillin resistance and susceptibility among positives is very high. These characteristics may enable earlier implementation of appropriate antibiotic treatment for many S. aureus BSI patients.

Timing of initiating glycopeptide therapy for methicillin-Resistant Staphylococcus aureus bacteremia: the impact on clinical outcome

When a Staphylococcus-like organism (SLO) is microscopically found in Gram staining of blood culture (BC) specimen, it seems reasonable to administrate a glycopeptide (GP) for empirical therapy. The paper investigates the risk factors for 14-day mortality in patients with methicillin-resistance Staphylococcus aureus bacteremia (MRSAB) and clarifies the impact of the timing for initiating GP therapy. A retrospective study identifies patients with MRSAB (endocarditis was excluded) between 2006 and 2009. Patients were categorized as receiving GP at the interval before a preliminary BC report indicating the growth of SLO and the onward 24 hours or receiving GP 24 h after a preliminary BC report indicating the growth of SLO. Total 339 patients were enrolled. There was no difference on the 14-day overall or infection-related mortality rates at the time to administer GP. Multivariate analysis disclosed pneumonia (OR = 4.47; of 95% CI; of 2.09–9.58; P < 0.01) and high APACHE II score (OR, 2.81, with 95% CI, 1.19–6.65; P = 0.02) were independent risk factors for infection-related mortality. The mortality rate did not decrease following administrating GP immediately after a preliminary BC indicating SLO growth. An additional research for the optimal timing for initiating GP treatment is warranted.

Healthcare-associated Staphylococcus aureus bloodstream infection: length of stay, attributable mortality, and additional direct costs

This study aimed to determine the excess length of stay, extra expenditures, and attributable mortality to healthcare-associated S. aureus bloodstream infection (BSI) at a teaching hospital in central Brazil. The study design was a matched (1:1) case-control. Cases were defined as patients >13 years old, with a healthcare-associated S. aureus BSI. Controls included patients without an S. aureus BSI, who were matched to cases by gender, age (± 7 years), morbidity, and underlying disease. Data were collected from medical records and from the Brazilian National Hospital Information System (Sistema de Informações Hospitalares do Sistema Único de Saúde - SIH/SUS). A Wilcoxon rank sum test was performed to compare length of stay and costs between cases and controls. Differences in mortality between cases and controls were compared using McNemar's tests. The Mantel-Haenzel stratified analysis was performed to compare invasive device utilization. Data analyses were conducted using Epi Info 6.0 and Statistical Package for Social Sciences (SPSS 13.0). 84 case-control pairs matched by gender, age, admission period, morbidity, and underlying disease were analyzed. The mean lengths of hospital stay were 48.3 and 16.2 days for cases and controls, respectively (p<0.01), yielding an excess hospital stay among cases of 32.1 days. The excess mortality among cases compared to controls that was attributable to S. aureus bloodstream infection was 45.2%. Cases had a higher risk of dying compared to controls (OR 7.3, 95% CI 3.1-21.1). Overall costs of hospitalization (SIH/SUS) reached US$ 123,065 for cases versus US$ 40,247 for controls (p<0.01). The cost of antimicrobial therapy was 6.7 fold higher for cases compared to controls. Healthcare-associated S. aureus BSI was associated with statistically significant increases in length of hospitalization, attributable mortality, and economic burden. Implementation of measures to minimize the risk of healthcare-associated bacterial infections is essential.

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.

Predictors of mortality in Staphylococcus aureus Bacteremia

Staphylococcus aureus bacteremia (SAB) is an important infection with an incidence rate ranging from 20 to 50 cases/100,000 population per year. Between 10% and 30% of these patients will die from SAB. Comparatively, this accounts for a greater number of deaths than for AIDS, tuberculosis, and viral hepatitis combined. Multiple factors influence outcomes for SAB patients. The most consistent predictor of mortality is age, with older patients being twice as likely to die. Except for the presence of comorbidities, the impacts of other host factors, including gender, ethnicity, socioeconomic status, and immune status, are unclear. Pathogen-host interactions, especially the presence of shock and the source of SAB, are strong predictors of outcomes. Although antibiotic resistance may be associated with increased mortality, questions remain as to whether this reflects pathogen-specific factors or poorer responses to antibiotic therapy, namely, vancomycin. Optimal management relies on starting appropriate antibiotics in a timely fashion, resulting in improved outcomes for certain patient subgroups. The roles of surgery and infectious disease consultations require further study. Although the rate of mortality from SAB is declining, it remains high. Future international collaborative studies are required to tease out the relative contributions of various factors to mortality, which would enable the optimization of SAB management and patient outcomes.

The impact of vancomycin susceptibility on treatment outcomes among patients with methicillin resistant Staphylococcus aureus bacteremia

Background

Management of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia remains a challenge. The emergence of MRSA strains with reduced vancomycin susceptibility complicates treatment.

Methods

A prospective cohort study (2005-2007) of patients with MRSA bacteremia treated with vancomycin was performed at an academic hospital. Vancomycin minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined for stored MRSA isolates. Cox regression analysis was performed to predict 28-day all-cause mortality.

Results

One hundred sixty-three patients with MRSA bacteremia were evaluated. One hundred twelve patients (68.7%) had bacteremia due to MRSA with a vancomycin MIC ≥ 2 ug/mL. Among strains with a vancomycin MIC ≥ 2 ug/mL, 10 isolates (8.9%) were vancomycin-intermediate S. aureus (VISA). Thirty-five patients (21.5%) died within 28 days after the diagnosis of MRSA bacteremia. Higher vancomycin MIC was not associated with mortality in this cohort [adjusted hazard ratio (aHR), 1.57; 95% confidence interval (CI), 0.73-3.37]. Vancomycin tolerance was observed in 4.3% (7/162) of isolates and was not associated with mortality (crude HR, 0.62; 95% CI, 0.08-4.50). Factors independently associated with mortality included higher age (aHR, 1.03; 95% CI 1.00-1.05), cirrhosis (aHR, 3.01; 95% CI, 1.24-7.30), and intensive care unit admission within 48 hours after the diagnosis of bacteremia (aHR, 5.99; 95% CI, 2.86-12.58).

Conclusions

Among patients with MRSA bacteremia treated with vancomycin, reduced vancomycin susceptibility and vancomycin tolerance were not associated with mortality after adjusting for patient factors. Patient factors including severity of illness and underlying co-morbidities were associated with the mortality.

Clinical significance of Staphylococcus aureus bacteriuria in a nationwide study of adults with S. aureus bacteraemia

OBJECTIVES

To evaluate the clinical significance of Staphylococcus aureus bacteriuria (SABU) in adults with S. aureus bacteraemia (SAB).

METHODS

All individuals ≥18 years old diagnosed with SAB in Iceland between December 1st 2003 and November 30th 2008 were retrospectively identified. Data was collected from medical records. Concomitant SABU was defined as growth of S. aureus in a urine sample taken within 24 h of the index blood culture.

RESULTS

SABU was seen in 27 of 166 (16.3%) SAB patients having urine cultured before administration of antibiotics, but after excluding those with SAB of urinary tract origin SABU was seen in 16 of 152 (10.5%). In this latter cohort SABU was independently associated with having endocarditis (RR 6.68; 95% CI 1.53-17.3) and admission to intensive-care unit (RR 2.84; 95% CI 1.25-4.44), while for having complicated SAB the RR was 1.56 (95% CI 0.96-1.80). No correlation was seen with mortality or relapse rates.

CONCLUSIONS

SABU appears to be secondary to SAB in some cases while it is the primary infection causing SAB in others. In patients with SAB of non-urinary tract origin SABU should probably be regarded as distant haematogenous seeding and a marker of deep tissue dissemination, thus affecting general management and treatment duration.

Importance of appropriate empirical antibiotic therapy for methicillin-resistant Staphylococcus aureus bacteraemia

OBJECTIVES

To document the effects of appropriate and inappropriate empirical antibiotic therapy on mortality in a cohort of patients with bacteraemia due to methicillin-resistant Staphylococcus aureus (MRSA) and to summarize effects with previous studies.

METHODS

In the retrospective cohort study, episodes of clinically significant MRSA bacteraemia during a 15 year period were included. Polymicrobial episodes were excluded unless MRSA was isolated in more than one bottle and co-pathogens were given appropriate empirical antibiotic treatment. Appropriate empirical treatment was defined as matching in vitro susceptibility and started within 48 h of blood-culture taking, except for single aminoglycosides or rifampicin. We assessed univariate and multivariate associations between appropriate empirical therapy and 30 day all-cause mortality. Multivariable analysis was conducted using backward stepwise logistic regression. We reviewed all studies assessing the effects of appropriate empirical antibiotic treatment on mortality for MRSA infections and compiled adjusted odds ratios (ORs) using a random effects meta-analysis.

RESULTS

Five hundred and ten episodes of MRSA bacteraemia were included. There were no cases of community-acquired infection. The 30 day mortality was 43.9% (224/510) and was stable throughout the study period. Mortality was significantly higher among patients receiving inappropriate (168/342, 49.1%) compared with those receiving appropriate (56/168, 33.3%) empirical antibiotic treatment, P = 0.001. In the adjusted analysis the OR was 2.15 [95% confidence interval (CI) 1.34-3.46]. Pooling of six studies using adequate methodology for the adjusted analysis resulted in an OR of 1.98 (95% CI 1.62-2.44).

CONCLUSIONS

Appropriate empirical antibiotic treatment has a significant survival benefit in MRSA bacteraemia. Treatment guidelines should consider this benefit.

Genetic polymorphism of the C-reactive protein (CRP) gene and a deep infection focus determine maximal serum CRP level in Staphylococcus aureus bacteremia

C-reactive protein (CRP) is widely used in early detection of sepsis or organ dysfunction. Several single nucleotide polymorphisms (SNPs) in the CRP gene are shown to be associated with variability of basal CRP. To clarify the effect of these SNPs to CRP response in systemic infections, we compared genetic and clinical data on patients with Staphylococcus aureus bacteremia (SAB). Six SNPs in the CRP gene region (rs2794521, rs30912449, rs1800947, rs1130864, rs1205 and rs3093075) were genotyped in 145 patients and analyzed for associations with CRP and various clinical outcomes. We found that the rare minor A-allele of triallelic SNP rs30912449 (C > T > A) and presence of a deep infection focus were strongly associated to the higher maximal CRP during the first week of SAB. Median of the maximal CRP in patients who had the A-minor allele was 282 mg/L (interquartile range [IQR, defined as the difference between the third quartile and the first quartile], 169 mg/L) but only 179 mg/L (IQR, 148 mg/L) in patients without this allele (P = 0.004), and CRP in patients who had deep infection focus was higher 208 mg/L (IQR, 147 mg/L) than in other patients 114 mg/L (IQR, 121 mg/l) (P < 0.0001). Mortality, degree of leucocytosis, time to defervescence or number of deep infections were not affected by CRP gene SNPs. The maximal CRP during the first week in SAB was partly determined by variation in the CRP gene and partly by presence of deep infection focus. This finding suggests cautiousness in interpreting exceptionally high CRPs from SAB patients and comparison between patients.

Nasopharyngeal colonization with methicillin-resistant staphylococcus aureus and mortality among patients in an intensive care unit

Nasopharyngeal colonization with Methicillin-resistant Staphylococcus aureus (MRSA) is common in critically ill patients, but its effect on patient prognosis is not fully elucidated. A retrospective cohort study was carried out enrolling 122 patients from an intensive care unit who were screened weekly for nasopharyngeal colonization with MRSA. The outcomes of interest were: general mortality and mortality by infection. Several exposure variables (severity of illness, procedures, intercurrences and MRSA nasopharyngeal colonization) were analyzed through univariate and multivariable models. Factors significantly associated with mortality in general or due to infection were: APACHE II and lung disease. The performance of surgery predicted favorable outcomes. MRSA colonization did not predict mortality in general (OR=1.02; 95%CI=0.35-3.00; p=0.97) or by infectious causes (OR=0.96; 95%CI=0.33-2.89; p=0.96). The results suggest that, in the absence of severity of illness factors, colonization with MRSA is not associated with unfavorable outcomes.

Mortality of S. aureus bacteremia and infectious diseases specialist consultation--a study of 521 patients in Germany

OBJECTIVES

To evaluate the relationship between mortality of bloodstream infection due to Staphylococcus aureus and infectious diseases specialist consultation and other factors potentially associated with outcomes.

METHODS

A 6-year cohort study was conducted at a 1600-bed university hospital. Consecutive adult patients with S. aureus bacteremia were assessed using a standardised data collection and review form. A new infectious diseases service increased its consultations for S. aureus bacteremia from 33% of cases in 2002 to >80% in 2007. Infectious disease consultation and other factors potentially associated with in-hospital mortality were analysed by multivariate logistic regression.

RESULTS

A total of 521 patients were studied. All-cause in-hospital mortality was 22%, 90-day mortality was 32%. Factors significantly associated with in-hospital mortality in multivariate analysis were ICU admission (OR 5.8, CI 3.5-9.7), MRSA (OR 2.6, CI 1.4-4.9), age >/=60 years (OR 2.4, CI 1.4-4.2), a diagnosis of endocarditis (OR 2.8, CI 1.4-5.7), a non-fatal underlying disease/comorbidity according to the McCabe classification (OR 0.2, CI 0.1-0.4), and infectious disease specialist consultation (OR 0.6, CI 0.4-1.0).

CONCLUSIONS

These data suggest that outcome of S. aureus bacteremia may be improved by an expert consultation service.

Clinical and economic burden of antimicrobial resistance

Knowledge of the clinical and economic impact of antimicrobial resistance is useful to influence programs and behavior in healthcare facilities, to guide policy makers and funding agencies, to define the prognosis of individual patients and to stimulate interest in developing new antimicrobial agents and therapies. There are a variety of important issues that must be considered when designing or interpreting studies into the clinical and economic outcomes associated with antimicrobial resistance. One of the most misunderstood issues is how to measure cost appropriately. Although imperfect, existing data show that there is an association between antimicrobial resistance in Staphylococcus aureus, enterococci and Gram-negative bacilli and increases in mortality, morbidity, length of hospitalization and cost of healthcare. Patients with infections due to antimicrobial-resistant organisms have higher costs (US $6,000-30,000) than do patients with infections due to antimicrobial-susceptible organisms; the difference in cost is even greater when patients infected with antimicrobial-resistant organisms are compared with patients without infection. Given limited budgets, knowledge of the clinical and economic impact of antibiotic-resistant bacterial infections, coupled with the benefits of specific interventions targeted to reduce these infections, will allow for optimal control and improved patient safety. In this review, the authors discuss a variety of important issues that must be considered when designing or interpreting studies of the clinical and economic outcomes associated with antimicrobial resistance. Representative literature is reviewed regarding the associations between antimicrobial resistance in specific pathogens and adverse outcomes, including increased mortality, length of hospital stay and cost.

Treatment of severe infections caused by Staphylococcus aureus: a change in the vancomycin paradigm?

Staphylococcus aureus is a frequent agent of serious intensive care unit infections with high associated mortality rates. Resistance to methicillin is frequent, exceeding 50% in many countries, and for these strains, vancomycin is the agent of choice. Resistance to this drug is now frequent for Enterococcus, but low rates are reported for S. aureus. Nonetheless, treatment failures with vancomycin for infections caused by strains considered susceptible have been reported during recent years. This article aims to review the possible explanations for this phenomenon, which is challenging the old paradigm of S. aureus infections and vancomycin use.

Analysis of vancomycin use and associated risk factors in a university teaching hospital: a prospective cohort study

Background

Vancomycin use is considered inappropriate in most hospitals. A particular concern is the recent emergence of S. aureus with decreased susceptibility to vancomycin, making it important to reduce overall exposure to vancomycin to minimize the incidence of VRE (vancomycin-resistant enterococci). The aim of this work was to analyze the use of vancomycin and the risk factors associated with inappropriate treatment.

Methods

A prospective survey was conducted on all patients receiving vancomycin between 1^st March 2002 and 30^th September 2002 in a university-school hospital. Appropriateness of vancomycin use was assessed, according to the criteria established by the Centers for Disease Control and Prevention (CDC), at two time points: first, at the beginning of therapy, and second, continuing after 72 hours.

Results

A total of 557 patients received vancomycin. Three hundred seventy-four (67.1%) were under 60 years old, 374 (67.1%) had prolonged stays (>two weeks) in hospital, and 455 (81.7%) were in the intensive care unit (ICU). Two hundred sixty-three patients (47.2%) had some invasive device. In 324 (58.2%) patients the duration of vancomycin treatment was up to two weeks. Vancomycin was inappropriately used in 65.7% during the first 24 hours and in 67% at the 72 hours point according to CDC criteria [4]. The inappropriateness of vancomycin use during the first 24 hours was related to: patients aged less than 60 (OR 1.7; CI 95% 1.1–2.5), non-ICU patients (OR 1.5; CI 95% 1.0–2.4) and patients without neutropenia (OR 7.5; CI 95% 2.4–22.7). At 72 hours, the inappropriateness of vancomycin use was related to: patients aged less than 60 (OR 1.5; CI 95% 1.0–2.3), non-ICU patients (OR 1.7; CI 95% 1.1–2.7) and patients without neutropenia (OR 8.0; CI 95% 2.6–24.3).

Conclusion

Vancomycin was abused. Patients aged less than 60, non-ICU patients and those who did not present neutropenia were the principal groups at risk of inappropriate use.

Clinical features of head and neck cancer patients with methicillin-resistant Staphylococcus aureus

CONCLUSIONS

The risk factors for methicillin-resistant Staphylococcus aureus (MRSA) detection in head and neck cancer patients are the duration of hospitalization, intravenous hyperalimentation, prior antibiotic use, and the coexistence of other pathogens.

OBJECTIVES

To shed light on the clinical characteristics of MRSA-positive inpatients with head and neck cancers. The secondary goal was to evaluate risk factors for MRSA detection in comparison with methicillin-sensitive S. aureus (MSSA).

PATIENTS AND METHODS

Sixty-one consecutive inpatients with head and neck cancers with S. aureus detection were analyzed based on their medical records. The antimicrobial susceptibility of isolated S. aureus was tested by the broth microdilution method.

RESULTS

MRSA and MSSA were detected in 46 (75.4%) and 15 (24.6%) of the 61 patients, respectively. There was no significant difference in the male/female ratio, age, primary site, comorbidity, cancer stage, cancer treatment, or 5-year survival rate between the MRSA and MSSA groups. Compared with the MSSA group, the MRSA group had significantly longer hospitalization periods and intervals between admission and MRSA detection, as well as significantly greater likelihood of intravenous hyperalimentation, prior antibiotic use, and co-isolation of other pathogens. Isolated strains of MRSA were thoroughly sensitive to vancomycin and arbekacin and moderately sensitive to minocycline.

The relationship between antimicrobial resistance and patient outcomes: mortality, length of hospital stay, and health care costs

There is an association between the development of antimicrobial resistance in Staphylococcus aureus, enterococci, and gram-negative bacilli and increases in mortality, morbidity, length of hospitalization, and cost of health care. For many patients, inadequate or delayed therapy and severe underlying disease are primarily responsible for the adverse outcomes of infections caused by antimicrobial-resistant organisms. Patients with infections due to antimicrobial-resistant organisms have higher costs (approximately 6,000-30,000 dollars) than do patients with infections due to antimicrobial-susceptible organisms; the difference in cost is even greater when patients infected with antimicrobial-resistant organisms are compared with patients without infection. Strategies to prevent nosocomial emergence and spread of antimicrobial-resistant organisms are essential.

Microbial pattern and antimicrobial resistance, a surgeon's perspective: retrospective study in surgical wards and seven intensive-care units in two university hospitals in Cairo, Egypt

OBJECTIVES

Significant morbidity and mortality in surgical practice is due to infection with resistant pathogens. Data from Egyptian hospitals may reflect a peculiar pattern.

METHODS

Retrospective study of antimicrobial susceptibility of 1,064 isolates from patients in surgical zones and intensive-care units (ICUs) in the largest 2 hospitals in Cairo in 2003.

RESULTS

The infection rate in surgical wards was 0.41%, mostly surgical site infections. Cardiothoracic wards showed higher rates (0.52%). In ICUs, the infection rate was 6.51%, the majority were respiratory. The highest resistance rate was shown by Staphylococcus aureus (23.8%), Pseudomonas (14.9%) and Escherichia coli (10.48%). Enterococci and Citrobacter had rates below 1%. Pseudomonas aeruginosa had the highest resistance rate with third-generation cephalosporins (Cef3) and the lowest with imipenem, while for Enterobacter and Klebsiella it was highest with Cef3 and lowest with imipenem. E. coli showed the highest rate with quinolone 2 and Cef3, but there was no resistance to imipenem. Acinetobacter demonstrated the highest resistance rate with quinolone 2 and the lowest with fourth-generation cephalosporins (Cef4), while for methicillin-resistant S. aureus it was 60%. All enterococci were sensitive to vancomycin.

CONCLUSION

The study provides meaningful data on a high antimicrobial resistance in Egypt. Failure of hospital hygiene and overuse of antibiotics are considered responsible.

Course and outcome of Staphylococcus aureus bacteraemia: a retrospective analysis of 308 episodes in a Swiss tertiary-care centre

Staphylococcus aureus bacteraemia (SAB) is associated with substantial morbidity and mortality worldwide. The charts of adult patients with SAB who were hospitalised in a Swiss tertiary-care centre between 1998 and 2002 were studied retrospectively. In total, 308 episodes of SAB were included: 2% were caused by methicillin-resistant strains; 49% were community-acquired; and 51% were nosocomial. Bacteraemia without focus was the most common type of community-acquired SAB (52%), whereas intravenous catheter-related infection predominated (61%) among nosocomial episodes of SAB. An infectious diseases (ID) specialist was consulted in 82% of all cases; 83% received appropriate antibiotic treatment within 24 h of obtaining blood cultures. Overall hospital-associated mortality was 20%. Community-acquired SAB was associated independently with a higher mortality rate than nosocomial SAB (26% vs. 13%; p 0.009). Independent risk-factors for a fatal outcome were age (p < 0.001), immunosuppression (p 0.007), alcoholism (p < 0.001), haemodialysis (p 0.03), acute renal failure (p < 0.001) and septic shock (p < 0.001). Consultation with an ID specialist was associated with a better outcome in univariate analysis (p < 0.001). Compared with a previous retrospective analysis performed at the same institution between 1980 and 1986, there was a 140% increase in community-acquired SAB, a 60% increase in catheter-related SAB, and a 14% reduction in mortality. In conclusion, mortality in patients with SAB remained high, despite effective antibiotic therapy. Patients with community-acquired SAB were twice as likely to die as patients with nosocomial SAB. Consultation with an ID specialist may reduce mortality in patients with SAB.

Community-onset healthcare-associated MRSA bacteraemia in a district general hospital

Methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia is associated with significant mortality and morbidity. This retrospective study involved 76 episodes over four years in a district general hospital in the UK. Twenty-eight of these episodes (36.8%) occurred within 72 h of admission. All of these, however, had risk factors for MRSA acquisition and were classified as healthcare-associated bacteraemias. The mortality rates (all causes) at seven days and three months were 31.5% and 53.4%, respectively. Ten patients died before targeted therapy could be commenced. All patients in the study had multiple comorbidities, and pneumonia was a common diagnosis. Previous antibiotics, increased age, admission on surgical wards/intensive care units, and the presence of central venous cannulae and urinary catheters were risk factors for infection. In 48.7% of episodes, patients were not known to be colonized with MRSA prior to their bacteraemia. Empirical targeted therapy should be given to patients with risk factors for MRSA and staphylococci in blood cultures pending susceptibility results. Increased use of screening may also be required to reduce transmission and increase the likelihood of appropriate empirical antimicrobial therapy. Eradication of MRSA from carriers in the community should be considered to reduce the number of community-onset healthcare-associated bacteraemias.

Outcome of inappropriate empirical antibiotic therapy in patients with Staphylococcus aureus bacteraemia: analytical strategy using propensity scores

Patients with Staphylococcus aureus bacteraemia (SAB) who received either inappropriate or appropriate empirical therapy were compared by using two risk stratification models: (1) a cohort study using a propensity score to adjust for confounding by empirical treatment assignment; and (2) a propensity-matched case-control study. Inappropriate empirical therapy was modelled on the basis of patient characteristics, and included in the multivariate model to adjust for confounding. For case-matching analysis, patients with inappropriate empirical therapy (cases) were matched to those with appropriate empirical therapy (controls) on the basis of the propensity score (within 0.03 on a scale of 0-1). In total, 238 patients with SAB were enrolled in the cohort study. Characteristics associated with inappropriate empirical therapy were methicillin resistance, underlying haematological malignancy, no history of colonisation with methicillin-resistant S. aureus, and a long hospital stay before SAB. These variables were included in the propensity score, which had an area under the receiver operating characteristics curve of 85%. In the cohort study, SAB-related mortality was 39% (45/117) for inappropriate empirical therapy vs. 28% (34/121) for appropriate empirical therapy (odds ratio (OR) 1.60; 95% CI 0.93-2.76). After adjustment for independent predictors for mortality and the propensity score, inappropriate empirical therapy was not associated with mortality (adjusted OR 1.39; 95% CI 0.62-3.15). In the matched case-control study (50 pairs), SAB-related mortality was 32% (16/50) for inappropriate empirical therapy and 28% (14/50) for appropriate empirical therapy (McNemar's test; p 0.85; OR 1.15; 95% CI 0.51-2.64). In conclusion, inappropriate empirical therapy resulted in only a slight tendency towards increased mortality in patients with SAB.

Levofloxacin does not decrease mortality in Staphylococcus aureus bacteraemia when added to the standard treatment: a prospective and randomized clinical trial of 381 patients

OBJECTIVES

To study whether levofloxacin, added to standard treatment, could reduce the high mortality and complication rates in Staphylococcus aureus bacteraemia.

DESIGN

A prospective randomized multicentre trial from January 2000 to August 2002.

SETTING

Thirteen tertiary care or university hospitals in Finland.

SUBJECTS

Three hundred and eighty-one adult patients with S. aureus bacteraemia. Patients with meningitis, and those with fluoroquinolone- or methicillin-resistant S. aureus were excluded.

INTERVENTIONS

Standard treatment (mostly semisynthetic penicillin) (n = 190) or that combined with levofloxacin (n = 191). Supplementary rifampicin was recommended if deep infection was suspected.

MAIN OUTCOME MEASURES

Primary end-points were mortality at 28 days and at 3 months. Clinical and laboratory parameters were analysed as secondary end-points.

RESULTS

Adding levofloxacin to the standard treatment offered no survival benefit. Case fatality rates were 14% in both groups at 28 days, and 21% in the standard treatment and 18% in the levofloxacin group at 3 months. Levofloxacin combination did not differ from the standard treatment in the number of complications, time to defervescence, decrease in serum C-reactive protein concentration or length of antibiotic treatment. Deep infection was found in 84% of patients within 1 week following randomization with no difference between the treatment groups. At 3 months, the case fatality rate for patients with deep infection was 17% amongst those who received rifampicin versus 38% for those without rifampicin (P < 0.001, odds ratio = 3.06, 95% confidence intervals = 1.69-5.54).

CONCLUSIONS

Levofloxacin combined with standard treatment in S. aureus bacteraemia did not decrease mortality or the incidence of deep infections, nor did it speed up recovery. Interestingly, deep infections in S. aureus bacteraemia appeared to be more common than previously reported.

Improving adherence to hand hygiene among health care workers

Increased adherence to hand hygiene is widely acknowledged to be the most important way of reducing infections in health care facilities. Despite evidence of benefit, adherence to hand hygiene among health care professionals remains low. Several behavioral and organizational theories have been proposed to explain this. As a whole, the success of interventions to improve adherence to hand hygiene among health care professionals has been limited. Recent data suggest that a multifaceted intervention, including the use of feedback, education, the introduction of alcohol-based hand wash, and visual reminders, may increase adherence to hand-hygiene recommendations. Although the "active ingredient" of such an intervention is unknown, there is evidence that the use of feedback may be the key to increasing adherence. In this article, we review the theoretical basis for interventions and provide an overview of the evidence for interventions. Coherent and methodologically sound research is required to better understand the factors contributing to hand-hygiene behavior among health care professionals.

Prevention and control of antimicrobial-resistant infections in intensive care patients

OBJECTIVE

To review the literature summarizing important aspects of infection control in the critical care setting and to provide recommendations to reduce infections with resistant bacteria in the intensive care unit.

DATA SOURCE

Computer searches of MEDLINE, EMBASE, and the Cochrane Library.

DATA

The frequency of antibiotic-resistant, health care-associated infections has increased every year for the past 2 decades. Infections with antibiotic-resistant organisms have been linked to increases in morbidity, length of hospitalization, increased healthcare costs, and increased mortality. A comprehensive approach is necessary to prevent antimicrobial resistance in ICUs. This includes (1) preventing infections; (2) diagnosing and treating infections appropriately; (3) using antimicrobials wisely; and (4) preventing transmission.

CONCLUSIONS

The reservoirs for antibiotic-resistant organisms are colonized patients, and the vectors are often healthcare workers. This places an enormous responsibility on healthcare providers to protect their patients. Clinicians must recognize the importance of adhering to the recommendations in the Centers for Disease Control's Campaign to Prevent Antimicrobial Resistance in the healthcare setting.

A comparison of clinical features and mortality among methicillin-resistant and methicillin-sensitive strains of Staphylococcus aureus endocarditis

Our objective was to assess the clinical factors that would reliably distinguish methicillin-resistant S. aureus (MRSA) from methicillin-susceptible S. aureus (MSSA) endocarditis. A retrospective cohort study of clinical features and mortality in patients with MRSA and MSSA endocarditis between March 1986 and March 2004 was performed in a 750-bed, tertiary care teaching hospital. A total of 32 patients (10 MRSA [31.3%] vs 22 MSSA [68.7%]) were evaluated. Their mean age and sex ratio (male/female) were as follows: 30.8 +/- 16.0 vs 24.4 +/- 19.6 years old and 6/4 vs 13/9, for MRSA and MSSA infective endocarditis (IE), respectively. Univariate and multivariate analyses revealed that persistent bacteremia was significantly more prevalent in MRSA IE (OR, 10.0 [1.480- 67.552]; p, 0.018). There was a higher mortality trend for MRSA IE (50.0%) than for MSSA IE (9.1%) (p=0.019). However, persistent bacteremia was not associated with higher mortality (p > 0.05). These results indicate that if persistent bacteremia is documented, the likelihood of MRSA endocarditis should be viewed as high, and the patient's anti- staphylococcal therapy should be prolonged and/or changed to a more "potent" regimen.

Cannula-associated Staphylococcus aureus bacteraemia: outcome in relation to treatment

BACKGROUND

Despite the frequency of cannula-associated Staphylococcus aureus bacteraemia (CASAB) there is uncertainty regarding the duration of treatment required.

AIM

To determine the relationship between the duration and type of treatment for CASAB and subsequent relapse with deep-seated S. aureus infection.

METHODS

We prospectively studied 276 patients with CASAB. Patients were followed for at least 8 weeks after completion of antibiotic treatment. Initial and subsequent isolates of S. aureus were compared using molecular methods to determine strain similarity.

RESULTS

Initial mortality was 9% (26 of 276) and a complicating focus of infection presented during initial treatment in 6% (15 of 250) of the survivors. There were nine relapses of deep-seated infection from the strain causing the original infection. Relapses were equally common following peripheral CASAB and central CASAB. There was no relationship between the duration of treatment and the rate of relapse of deep-seated infection (P = 0.24). This observation held true regardless of whether the duration of treatment was analysed as < or = 7 versus > or = 8, < or =10 versus > or =11, or < or=14 versus > or =15 days (P = 0.62, 0.87 and 0.16, respectively).

CONCLUSION

Episodes of peripheral CASAB pose an equal risk of relapse to central cannula-related episodes. Although further studies are needed to determine the optimal treatment of CASAB, our study strongly suggests that more than 14 days treatment is excessive for most patients who respond promptly to cannula removal and antibiotic treatment.

Risk factors for hematogenous complications of intravascular catheter-associated Staphylococcus aureus bacteremia

BACKGROUND

The role of both host and pathogen characteristics in hematogenous seeding following Staphylococcus aureus bacteremia is incompletely understood.

METHODS

Consecutive patients with intravascular catheter-associated Staphylococcus aureus bacteremia were prospectively recruited over a 91-month period. The corresponding bloodstream isolates were examined for the presence of 35 putative virulence determinants. Patient and bacterial characteristics associated with the development of hematogenous complications (HCs) (i.e., septic arthritis, vertebral osteomyelitis, or endocarditis) were defined.

RESULTS

HC occurred in 42 (13%) of 324 patients. Patient characteristics at diagnosis that were associated with HC included community onset (relative risk [RR], 2.25; 95% confidence interval [CI], 1.24-4.07; P=.007), increased symptom duration (odds ratio for each day, 1.14; 95% CI, 1.06-1.2; P<.001), presence of a long-term intravascular catheter or noncatheter prosthesis (RR, 4.02; 95% CI, 1.74-9.27; P<.001), hemodialysis dependence (RR, 3.84; 95% CI, 2.08-7.10; P<.001), and higher APACHE II score (P=.02). Bacterial characteristics included sea (RR, 2.03; 95% CI, 1.16-3.55; P=.011) and methicillin-resistant S. aureus (MRSA) (RR, 2.09; 95% CI, 1.19-3.67; P=.015). Subsequent failure to remove a catheter was also associated with HC (RR, 2.28; 95% CI, 1.22-4.27; P=.011). On multivariable analysis, symptom duration, hemodialysis dependence, presence of a long-term intravascular catheter or a noncatheter device, and infection with MRSA remained significantly associated with HC.

CONCLUSIONS

This investigation identifies 4 host- and pathogen-related risk factors for hematogenous bacterial seeding and reaffirms the importance of prompt catheter removal.

Effect of granulocyte colony-stimulating factor in experimental methicillin resistant Staphylococcus aureus sepsis

Background

Methicillin resistant Staphylococcus aureus (MRSA) is the leading pathogenic cause of nosocomial infections, especially in bacteraemia and sepsis. The essential therapy for MRSA infection is glycopeptides. Therapeutic failure can be seen with this therapy and the mortality is still high. The aim of this study was to evaluate the additional effect of G-CSF on the traditional antibiotic treatment in an experimental MRSA sepsis.

Methods

Experimental sepsis was performed in mice by intraperitoneal injection of MRSA isolate. Inoculum dose was estimated as 6 × 10⁹/ml. Mice were randomised for the study into four group; control group (not receive any therapy), G-CSF group (1000 ng/daily, subcutaneously for 3 d), antibiotic group (vancomycin 25 or 50 mg/kg intraperitoneally every 12 hours for 7 d), and vancomycin+G-CSF group (at the same concentrations and duration). Autopsy was done within one hour after mice died. If mice was still alive at the end of seventh day, they were sacrificed, and autopsy was done. In all groups, the effect of G-CSF therapy on the survival, the number of the MRSA colonies in the lung, liver, heart, spleen, and peritoneal cultures, the histopathology of the lung, liver, heart and spleen was investigated.

Results

One hundred and six mice were used. There were no significant differences in survival rates and bacterial eradication in G-CSF group compared with control group, and also in antibiotic +G-CSF group compared with antibiotic alone group. These parameters were all significantly different in antibiotic alone group compared with control group. Histopathologically, inflammation of the lung and liver were significantly reduced in vancomycin (25 mg/kg)+G-CSF and vancomycin (50 mg/kg)+G-CSF subgroups, respectively (p < 0.01). The histopathological inflammation of the other organs was not significantly different in antibiotic+G-CSF group compared with antibiotic group and, also G-CSF group compared with control group.

Conclusion

G-CSF treatment had no additional effect on survival and bacterial eradication in MRSA sepsis in nonneutropenic mice; and only a little effect on histopathology. G-CSF treatment is very expensive, likewise glycopeptides. The more interest in infection control measures, and prevent the spread of MRSA infections is more rational.

Use of molecular epidemiology to monitor the nosocomial dissemination of methicillin-resistant Staphylococcus aureus in a University Hospital from 1991 to 2001

Methicillin-resistant Staphylococcus aureus (MRSA) has been the cause of major outbreaks and epidemics among hospitalized patients, with high mortality and morbidity rates. We studied the genomic diversity of MRSA strains isolated from patients with nosocomial infection in a University Hospital from 1991 to 2001. The study consisted of two periods: period I, from 1991 to 1993 and period II from 1995 to 2001. DNA was typed by pulsed-field gel electrophoresis and the similarity among the MRSA strains was determined by cluster analysis. During period I, 73 strains presented five distinctive DNA profiles: A, B, C, D, and E. Profile A was the most frequent DNA pattern and was identified in 55 (75.3%) strains; three closely related and four possibly related profiles were also identified. During period II, 80 (68.8%) of 117 strains showed the same endemic profile A identified during period I, 18 (13.7%) closely related profiles and 18 (13.7%) possibly related profiles and, only one strain presented an unrelated profile. Cluster analysis showed a 96% coefficient of similarity between profile A from period I and profile A from period II, which were considered to be from the same clone. The molecular monitoring of MRSA strains permitted the determination of the clonal dissemination and the maintenance of a dominant endemic strain during a 10-year period and the presence of closely and possibly related patterns for endemic profile A. However, further studies are necessary to improve the understanding of the dissemination of the endemic profile in this hospital.

Bloodstream infections caused by Staphylococcus aureus in a university hospital in Turkey: clinical and molecular epidemiology of methicillin-resistant Staphylococcus aureus

In total, 177 patients with bloodstream infections caused by Staphylococcus aureus (BSISA) were investigated prospectively between June 1999 and June 2001. Of these, 19.8% had community-acquired BSISA, while 80.2% had nosocomial BSISA. Surgical intervention, foreign body, mechanical ventilation, total parenteral nutrition, and previous antibiotic treatment were found to be important risk factors for the nosocomial BSISA group. Secondary BSISA formed a greater proportion (62.9%) of community-acquired infections than of nosocomial infections (26.8%; p 0.0001). Catheter-related nosocomial BSISA was observed in 72.1% of patients. The suppurative complication rate was significantly higher among community-acquired infections (22.9%) than among nosocomial infections (6.3%; p 0.008). Of the nosocomial BSISA, 65.5% were methicillin-resistant. Analysis of 80 methicillin-resistant S. aureus isolates by pulsed-field gel electrophoresis identified ten main clones (A-J), but 61 (76.3%) of the 80 isolates belonged to clone A.

The Impact of Methicillin Resistance on the Outcome of Poststernotomy Mediastinitis Due toStaphylococcus aureus

The impact of methicillin resistance on morbidity and mortality among patients with severe Staphylococcus aureus infection remains highly controversial. We retrospectively analyzed patients with mediastinitis due to methicillin-susceptible S. aureus (MSSA; 145 patients) or methicillin-resistant S. aureus (MRSA; 73 patients) who were treated with closed drainage using Redon catheters. Initial empirical antibiotic therapy was appropriate for every patient. Patients with MRSA mediastinitis were older, had higher disease severity scores at admission to the intensive care unit (ICU), and had longer periods of MRSA incubation. Multivariate analysis revealed that ICU mortality was associated with age of > or =65 years, incubation time of < or =15 days, bacteremia, higher Acute Physiology and Chronic Health Evaluation II score, and receipt of mechanical ventilation > or =2 days after surgical debridement, but not with methicillin resistance. After adjustment, durations of mechanical ventilation and Redon catheter drainage were similar for both groups (for patients infected with MRSA, only the time to mediastinal effluent sterilization remained longer). Methicillin resistance did not significantly affect ICU mortality among patients with poststernotomy mediastinitis who benefited from optimal treatments.

Hospital mortality for patients with bacteremia due to Staphylococcus aureus or Pseudomonas aeruginosa

STUDY OBJECTIVES

To evaluate the relationship between hospital mortality and bloodstream infections due to Staphylococcus aureus or Pseudomonas aeruginosa.

DESIGN

Prospective cohort study.

SETTING

A 1,400-bed, university-affiliated urban teaching hospital.

PATIENTS

Between December 2001 and September 2002, 314 patients with bacteremia due to S aureus or P aeruginosa were prospectively evaluated.

INTERVENTION

Prospective patient surveillance and data collection.

RESULTS

Thirteen patients (4.1%) received inadequate initial antibiotic treatment. Fifty-four patients (17.2%) died during hospitalization. Hospital mortality was statistically greater for patients with bloodstream infections due to P aeruginosa (n = 49) compared to methicillin-sensitive S aureus (MSSA) [n = 117; 30.6% vs 16.2%, p = 0.036] and methicillin-resistant S aureus (MRSA) [n = 148; 30.6% vs 13.5%, p = 0.007]. Multiple logistic regression analysis identified the lack of response to initial medical treatment (adjusted odds ratio [AOR], 2.69; 95% confidence interval [CI], 1.83 to 3.94; p = 0.010) and endocarditis (AOR, 4.62; 95% CI, 2.45 to 8.73; p = 0.016) as independent determinants of hospital mortality. Patients with bloodstream infections due to P aeruginosa were statistically more likely to be nonresponders to early medical treatment compared to patients with MSSA (73.5% vs 11.1%, p < 0.001) and MRSA (73.5% vs 16.9%, p < 0.001) bloodstream infections.

CONCLUSIONS

These data suggest that bloodstream infections due to P aeruginosa have a greater risk of hospital mortality compared to bloodstream infections due to S aureus despite adequate antibiotic treatment.