Distribution of pathogens in central line-associated bloodstream infections among patients with and without neutropenia following chemotherapy: evidence for a proposed modification to the current surveillance definition

Association between parenteral nutrition-containing intravenous lipid emulsion and bloodstream infections in patients with single-lumen central venous access: A secondary analysis of a randomized trial

BACKGROUND

Distinguishing primary bloodstream infections (BSIs) related to central venous access devices (CVADs) from those that occur through other mechanisms, such as a damaged mucosal barrier, is difficult.

METHODS

Secondary analysis was conducted on data from patients with CVADs that were collected for a large, randomized trial. Patients were divided into two groups: those who received parenteral nutrition (PN)-containing intravenous lipid emulsion (ILE) and those who did not have PN-containing ILE. This study investigated the influence of PN-containing ILE (ILE PN) on primary BSIs in patients with a CVAD.

RESULTS

Of the 807 patients, 180 (22%) received ILE PN. Most (627/807; 73%) were recruited from the hematology and hematopoietic stem cell transplant unit, followed by surgical (90/807; 11%), trauma and burns (61/807; 8%), medical (44/807; 5%), and oncology (23/807; 3%). When primary BSI was differentiated as a central line-associated BSI (CLABSI) or mucosal barrier injury laboratory-confirmed BSI (MBI-LCBI), the incidence of CLABSI was similar in the ILE PN and non-ILE PN groups (15/180 [8%] vs 57/627 [9%]; P = 0.88) and the incidence of MBI-LCBI was significantly different between groups (31/180 [17%] ILE PN vs 41/627 [7%] non-ILE PN; P < 0.01).

CONCLUSION

Our data indicate that twice as many primary BSIs in ILE PN patients are due to MBIs than CVADs. It is important to consider the MBI-LCBI classification, as some CLABSI prevention efforts aimed at CVADs for the ILE PN population may be better directed to gastrointestinal tract protection interventions.

Peripherally inserted central catheter-related bloodstream infections in patients with hematological malignancies: A retrospective 7-years single-center study

OBJECTIVES

We sought to investigate the nature and incidence of bloodstream infection complications and to identify the risk factors of central catheter-related bloodstream infections (CRBSI).

METHODS

During the study period, 291 consecutive patients with hematological malignancies who underwent PICC placement were retrospectively enrolled. We analyzed the covariates that were specified a priori for their association with CRBSI through multivariate Cox proportional hazards regression models. The association between each predictor and the related outcome was expressed using hazard ratios (HRs) with corresponding 95% confidence intervals (CIs).

RESULTS

Of 391 peripherally inserted central catheter (PICCs) were inserted in 291 patients for a total of 63,714 catheter days during 7 years, with an infection rate of 0.71/1,000 catheter days. Among the patients with hematological malignancies, those with acute leukemia were prone to CRBSI. Having previous bloodstream infection (BSI) (HR 18.139; 95% CI, 8.19-40.174; P < .0001), the number of PICCs insertions (HR 4.695; 95% CI, 1.842-11.967; P = .001) (twice), (HR 6.794; 95% CI, 1.909-24.181; P = .003) (≥3 times) were significantly associated with CRBSI. Not accompanied by chronic comorbidities (HR 0.34; 95% CI, 0.131-0.887; P = .028) and longer duration of PICC use (days) (HR 0.997; 95% CI, 0.994-0.999; P = .008) might be protective factors preventing CRBSI.

CONCLUSIONS

Our finding suggests that previous BSI and a higher number of PICC insertions are associated with an increased risk of CRBSI. A lack of chronic comorbidities may help prevent CRBSI.

The role of bacterial translocation in sepsis: a new target for therapy

Sepsis is a leading cause of death in critically ill patients, primarily due to multiple organ failures. It is associated with a systemic inflammatory response that plays a role in the pathogenesis of the disease. Intestinal barrier dysfunction and bacterial translocation (BT) play pivotal roles in the pathogenesis of sepsis and associated organ failure. In this review, we describe recent advances in understanding the mechanisms by which the gut microbiome and BT contribute to the pathogenesis of sepsis. We also discuss several potential treatment modalities that target the microbiome as therapeutic tools for patients with sepsis.

Predictive Factors for Gram-negative Versus Gram-positive Bloodstream Infections in Children With Cancer

BACKGROUND

Identifying potential predictive factors for the type of bacteremia (Gram-negative vs. Gram-positive) in children with cancer would be crucial for the timely selection of the appropriate empiric antibiotic treatment.

MATERIALS AND METHODS

Demographic, clinical, and laboratory characteristics of children with cancer and a bacterial bloodstream infection (BSI) (February 1, 2011 to February 28, 2018) in a tertiary pediatric oncology department were retrospectively examined and were correlated with the type of isolated bacteria.

RESULTS

Among 224 monomicrobial bacterial BSI episodes, Gram-negative and Gram-positive bacteria were isolated in 110 and 114 episodes, respectively. Gram-negative bacteria were isolated significantly more frequently in girls (Gram-negative/Gram-positive ratio 1.7:1) versus boys (Gram-negative/Gram-positive ratio 0.72:1), P=0.002, in patients with previous BSI episodes (1.4:1) versus those without (0.8:1), P=0.042, and in children with hematologic malignancy (1.3:1) versus those who suffered from solid tumors (0.52:1), P=0.003. Gram-negative BSI episodes were more frequently correlated with a lower count of leukocytes, P=0.009, neutrophils, P=0.009 and platelets, P=0.002, but with significantly higher C-reactive protein (CRP) levels, P=0.049. Female sex, hematologic malignancy, and higher CRP levels remained independent risk factors for Gram-negative BSI in the multivariate analysis. Among neutropenic patients, boys with solid tumors and a recent central venous catheter placement appear to be at increased risk for Gram-positive BSI in the multivariate analysis.

CONCLUSIONS

Although Gram-negative and Gram-positive BSIs are close to balance in children with cancer, Gram-negative bacteria are more likely to be isolated in girls, children with hematologic malignancies and those with higher CRP level at admission. In contrast, neutropenic boys with solid tumors and a recently placed central venous catheter may be at increased risk for Gram-positive BSI indicating probably the need for initially adding antibiotics targeting Gram-positive bacteria.

Healthcare-associated blood stream infections in hematological patients in Finland during the years 2006-2016

OBJECTIVES

The aim was to identify the clinical characteristics, outcome, and antimicrobial susceptibility of healthcare-associated bloodstream infections (BSIs) in hematological patients.

METHODS

This retrospectively collected laboratory-based surveillance data include 3404 healthcare-associated BSIs in 2296 patients with a hematological malignancy in hospitals participating in the Finnish Hospital Infection Program from January 1, 2006, to December 31, 2016.

RESULTS

The most common underlying diseases were acute myelogenous leukemia (35%) and non-Hodgkin lymphoma (22%). Gram-positive organisms accounted for 60%-46% and gram-negative organisms for 24%-36% of BSIs in 2006-2016. The most common causative organism was coagulase-negative staphylococci (CoNS) (n = 731). The 7- and 28-day case fatality rates were 5.2% and 11.4%, respectively, and was highest in BSIs caused by Candida species (10.8% and 30.8%). The median age of patients increased from 59 years in 2006-2008 to 62 years in 2015-2016 (P < .01). Five percent of S aureus isolates were resistant to methicillin and five percent of Pseudomonas aeruginosa isolates were multidrug-resistant. Four percent of Klebsiella and seven percent of E coli isolates were resistant to ceftazidime.

CONCLUSIONS

The proportion of gram-positive bacteria decreased and gram-negative bacteria increased over time. The case fatality rate was low and the median age of patients increased during the study.

Microbiologically Documented Bloodstream Infection in Children With Malignancies: A Single-center Experience

BACKGROUND

Bloodstream infection (BSI) remains a considerable cause of morbidity and mortality for cancer patients. With a better understanding of it, better methods can be used. The primary objective of this study was to describe the characteristics of BSIs in our institution, and the second was to determine the possible risk factors associated with them.

MATERIALS AND METHODS

Data of cancer patients from 2009 to 2015 at our institution were included. Medical information and blood cultures were analyzed to determine the BSI rate. The χ and Fisher exact tests were used for categorical data and to determine risk factors associated with BSIs and pathogens.

RESULTS

A total of 565 (8.6%) events were diagnosed with BSIs. Although Gram-negative bacteria (52.6%) were the most commonly isolated pathogens, Gram-positive microorganisms (45.0%) were also prevalent. Oral and gastrointestinal organisms were common. Pathogens were more likely to be identified in patients with central venous catheters and in patients with prolonged neutropenia (P<0.05).

CONCLUSIONS

This study provides updated epidemiology in BSIs and helps with the prevention and management of suspected BSIs in vulnerable patients. Better anti-infection therapy could be provided to these patients based on the isolated pathogens.

Mucosal barrier injury-associated bloodstream infections in pediatric oncology patients

BACKGROUND

Single-center reports of central line-associated bloodstream infection (CLABSI) and the subcategory of mucosal barrier injury laboratory-confirmed bloodstream infection (MBI-LCBI) in pediatric hematology oncology transplant (PHO) patients have focused on the inpatient setting. Characterization of MBI-LCBI across PHO centers and management settings (inpatient and ambulatory) is urgently needed to inform surveillance and prevention strategies.

METHODS

Prospectively collected data from August 1, 2013, to December 31, 2015, on CLABSI (including MBI-LCBI) from a US PHO multicenter quality improvement network database was analyzed. CDC National Healthcare Safety Network definitions were applied for inpatient events and adapted for ambulatory events.

RESULTS

Thirty-five PHO centers reported 401 ambulatory and 416 inpatient MBI-LCBI events. Ambulatory and inpatient MBI-LCBI rates were 0.085 and 1.01 per 1000 line days, respectively. Fifty-three percent of inpatient CLABSIs were MBI-LCBIs versus 32% in the ambulatory setting (P  <  0.01). Neutropenia was the most common criterion defining MBI-LCBI in both settings, being present in ≥90% of events. The most common organisms isolated in MBI-LCBI events were Escherichia coli (in 28% of events), Klebsiella spp. (23%), and viridans streptococci (12%) in the ambulatory setting and viridans streptococci (in 29% of events), E. coli (14%), and Klebsiella spp. (14%) in the inpatient setting.

CONCLUSION

In this largest study of PHO MBI-LCBI inpatient events and the first such study in the ambulatory setting, the burden of MBI-LCBI across the continuum of care of PHO patients was substantial. These data should raise awareness of MBI-LCBI among healthcare providers for PHO patients, help benchmarking across centers, and help inform prevention and treatment strategies.

Prospective Initiative to Reduce Mucosal Barrier Injuries and Bloodstream Infections in Patients With Hematologic Malignancy Receiving Inpatient Chemotherapy

PURPOSE:

Mucosal barrier injury (MBI) occurs during periods of prolonged neutropenia in patients receiving cytotoxic chemotherapy for hematologic malignancies. This can lead to laboratory-confirmed bloodstream infections (LCBIs) and subsequent complications, including sepsis, organ failure, and possible death. There are no published prevention strategies for MBI. The purpose of our proposal was to decrease our MBI-LCBI events per month by 25%.

METHODS:

A multidisciplinary team was assembled to achieve this proposal. Cause-and-effect diagrams in addition to Pareto charts were used to investigate potential interventions. Using Plan-Do-Study-Act (PDSA) cycles, multiple tests of change were designed over the course of 3 years.

RESULTS:

The number of baseline events per month for MBI-LCBIs was 1.1. With the completion of the first PDSA cycle, the MBI-LCBI events dropped to 1.0 event per month. A second PDSA cycle involving implementation of an oral care kit improved to 0.35 events per month. This unfortunately was not sustained, and a root cause analysis demonstrated that physician noncompliance with ordering the oral kit was the main reason. After the change of a physician-driven protocol to a nurse-driven protocol, the third PDSA cycle resulted in a decrease in MBI-LCBI events to 0.89 events per month.

CONCLUSION:

To our knowledge, this is the first published report of an intervention to prevent MBI-LCBI events. Through a multidisciplinary approach and with quality improvement tools, we were able to demonstrate a significant reduction in MBI-LCBI events.

Salmonella Typhimurium biofilm disruption by a human antibody that binds a pan-amyloid epitope on curli

Bacterial biofilms, especially those associated with implanted medical devices, are difficult to eradicate. Curli amyloid fibers are important components of the biofilms formed by the Enterobacteriaceae family. Here, we show that a human monoclonal antibody with pan-amyloid-binding activity (mAb 3H3) can disrupt biofilms formed by Salmonella enterica serovar Typhimurium in vitro and in vivo. The antibody disrupts the biofilm structure, enhancing biofilm eradication by antibiotics and immune cells. In mice, 3H3 injections allow antibiotic-mediated clearance of catheter-associated S. Typhimurium biofilms. Thus, monoclonal antibodies that bind a pan-amyloid epitope have potential to prevent or eradicate bacterial biofilms.

Curli amyloid fibers are important components of bacterial biofilms formed by E. coli and Salmonella. Here, Tursi et al. show that a human monoclonal antibody with pan-amyloid binding activity can disrupt biofilms formed by Salmonella Typhimurium in vitro and in vivo.

A systematic review of central-line-associated bloodstream infection (CLABSI) diagnostic reliability and error

OBJECTIVE

To establish the reliability of the application of National Health and Safety Network (NHSN) central-line-associated bloodstream infection (CLABSI) criteria within established reporting systems internationally.

DESIGN

Diagnostic-test accuracy systematic review.

METHODS

We conducted a search of Medline, SCOPUS, the Cochrane Library, CINAHL (EbscoHost), and PubMed (NCBI). Cohort studies were eligible for inclusion if they compared publicly reported CLABSI rates and were conducted by independent and expertly trained reviewers using NHSN/Centers for Disease Control (or equivalent) criteria. Two independent reviewers screened, extracted data, and assessed risk of bias using the QUADAS 2 tool. Sensitivity, specificity, negative and positive predictive values were analyzed.

RESULTS

A systematic search identified 1,259 publications; 9 studies were eligible for inclusion (n = 7,160 central lines). Publicly reported CLABSI rates were more likely to be underestimated (7 studies) than overestimated (2 studies). Specificity ranged from 0.70 (95% confidence interval [CI], 0.58-0.81) to 0.99 (95% CI, 0.99-1.00) and sensitivity ranged from 0.42 (95% CI, 0.15-0.72) to 0.88 (95% CI, 0.77-0.95). Four studies, which included a consecutive series of patients (whole cohort), reported CLABSI incidence between 9.8% and 20.9%, and absolute CLABSI rates were underestimated by 3.3%-4.4%. The risk of bias was low to moderate in most included studies.

CONCLUSIONS

Our findings suggest consistent underestimation of true CLABSI incidence within publicly reported rates, weakening the validity and reliability of surveillance measures. Auditing, education, and adequate resource allocation is necessary to ensure that surveillance data are accurate and suitable for benchmarking and quality improvement measures over time.

REGISTRATION

Prospectively registered with International prospective register of systematic reviews (PROSPERO ID CRD42015021989; June 7, 2015). https://www.crd.york.ac.uk/PROSPERO/display_record.php?ID%3dCRD42015021989.

Precision identification of diverse bloodstream pathogens in the gut microbiome

A comprehensive evaluation of every patient with a bloodstream infection includes an attempt to identify the infectious source. Pathogens can originate from various places, such as the gut microbiota, skin and the external environment. Identifying the definitive origin of an infection would enable precise interventions focused on management of the source1,2. Unfortunately, hospital infection control practices are often informed by assumptions about the source of various specific pathogens; if these assumptions are incorrect, they lead to interventions that do not decrease pathogen exposure3. Here, we develop and apply a streamlined bioinformatic tool, named StrainSifter, to match bloodstream pathogens precisely to a candidate source. We then leverage this approach to interrogate the gut microbiota as a potential reservoir of bloodstream pathogens in a cohort of hematopoietic cell transplantation recipients. We find that patients with Escherichia coli and Klebsiella pneumoniae bloodstream infections have concomitant gut colonization with these organisms, suggesting that the gut may be a source of these infections. We also find cases where typically nonenteric pathogens, such as Pseudomonas aeruginosa and Staphylococcus epidermidis, are found in the gut microbiota, thereby challenging the existing informal dogma of these infections originating from environmental or skin sources. Thus, we present an approach to distinguish the source of various bloodstream infections, which may facilitate more accurate tracking and prevention of hospital-acquired infections.

Two-Year Hospital-Wide Surveillance of Central Line-Associated Bloodstream Infections in a Korean Hospital

BACKGROUND

Surveillance and interventions of central line-associated bloodstream infections (CLABSIs) had mainly been targeted in intensive care units (ICUs). Central lines are increasingly used outside ICUs. Therefore, we performed a hospital-wide survey of CLABSIs to evaluate the current status and develop strategies to reduce CLBASI rates.

METHODS

All hospitalized patients with central venous catheters (CVCs) were screened for CLABSIs from January 2014 through December 2015 at a 1,328 bed tertiary care teaching hospital in Korea using an electronic data-collecting system. Clinical information including type of CVC was collected. CLABSI rates were calculated using the definitions of the National Health and Safety Network after excluding mucosal barrier injury laboratory-confirmed bloodstream infection (BSI).

RESULTS

A total of 154 CLABSIs were identified, of which 72 (46.8%) occurred in general wards and 82 (53.2%) in ICUs (0.81 and 2.71 per 1,000 catheter days), respectively. Non-tunneled CVCs were most common (68.6%) among 70 CLABSI events diagnosed within one week of their maintenance. On the other hand, tunneled CVCs and peripherally inserted central catheters (PICCs) were more common (60.5%) among 114 CLABSI events diagnosed more than a week after maintenance. Whereas the majority (72.2%) of CLABSIs in ICUs were associated with non-tunneled CVCs, tunneled CVCs (38.9%) and PICCs (36.8%) were more common in general wards.

CONCLUSION

CLABSIs are less common in general wards than in ICUs, but they are more often associated with long-term indwelling catheters. Therefore, interventions to prevent CLABSIs should be tailored according to the type of ward and type of catheter.

Update on infection control practices in cancer hospitals

Therapies in oncology have evolved rapidly over the last years. At the same pace, supportive care for patients receiving cancer therapy has also evolved, allowing patients to safely receive the newest advances in treatment in both an inpatient and outpatient basis. The recognition of the role of infection control and prevention (ICP) in the outcomes of patients living with cancer has been such that it is now a requirement for hospitals and involves multidisciplinary groups. Some unique aspects of ICP for patients with cancer that have gained momentum over the past few decades include catheter-related infections, multidrug-resistant organisms, community-acquired viral infections, and the impact of the health care environment on the horizontal transmission of organisms. Furthermore, as the potential for infections to cross international borders has increased, alertness for outbreaks or new infections that occur outside the area have become constant. As the future approaches, ICP in immunocompromised hosts will continue to integrate emerging disciplines, such as antibiotic stewardship and the microbiome, and new techniques for environmental cleaning and for controlling the spread of infections, such as whole-genome sequencing. CA Cancer J Clin 2018;000:000-000. © 2018 American Cancer Society.

Administration of taurolidine-citrate lock solution for prevention of central venous catheter infection in adult neutropenic haematological patients: a randomised, double-blinded, placebo-controlled trial (TAURCAT)

Background

Catheter-related bloodstream infection (CRBSI) is one of the most frequent complications in patients with cancer who have central venous catheters (CVCs) implanted and is associated with substantial morbidity and mortality. Taurolidine is a non-antibiotic agent with broad-spectrum antimicrobial activity, which has been used as a lock solution to prevent CRBSI in some settings. However, little is known about its usefulness in high-risk adult neutropenic patients with cancer. This prospective randomised clinical trial aims to test the hypothesis that taurolidine-citrate lock solution is more effective than placebo for preventing catheter infection in neutropenic haematological patients.

Methods

This study is a prospective, multicentre, randomised, double-blinded, parallel, superiority, placebo-controlled trial. Patients with haematological cancer who are expected to develop prolonged neutropenia (> 7 days) and who have a non-tunnelled CVC implanted will be randomised to receive prophylactic taurolidine-citrate-heparin solution using a lock technique (study group) or heparin alone (placebo group). The primary endpoint will be bacterial colonisation of the CVC hubs. The secondary endpoints will be the incidence of CRBSI, CVC removal, adverse events, and 30-day case-fatality rate.

Discussion

The lock technique is a preventive strategy that inhibits bacterial colonisation in the catheter hubs, which is the initial step of endoluminal catheter colonisation and the development of infection. Taurolidine is a nontoxic agent that does not develop antibiotic resistance because it acts as an antiseptic rather than an antibiotic. Taurolidine has shown controversial results in the few trials conducted in cancer patients. These studies have important limitations due to the lack of data on adult and/or high-risk neutropenic patients, the type of catheters studied (tunnelled or ports), and the lack of information regarding the intervention (e.g. dwelling of the solution, time, and periodicity of the lock technique). If our hypothesis is proven, the study could provide important solid evidence on the potential usefulness of this preventive procedure in a population at high risk of CRBSI, in whom this complication may significantly impair patient outcome.

Trial registration

ISRCTN, ISRCTN47102251. Registered on 9 September 2015.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2647-y) contains supplementary material, which is available to authorized users.

Changes in Central Line-Associated Bloodstream Infection Rates Among Children With Immune Compromised Conditions: An 11-Year Review

This article describes changes in central line-associated bloodstream infection (CLABSI) rates among common causative organisms over an 11-year period on a pediatric inpatient unit prior to and following CLABSI reduction strategies. The setting for this descriptive cohort design study was a 32-bed inpatient unit in a tertiary pediatric hospital serving children with immune compromised conditions, including cancer and recipients of hematopoietic stem cell and solid organ transplants. Between January 2006 and December 2016, 265 CLABSIs involving 189 patients were reported. Data were organized into three time periods: 5-year preintervention baseline (2006-2010), implementation of maintenance care bundles (2011-2012), and addition of formalized supportive care practices to the maintenance care bundles (2013-2016). Organisms were categorized into four groups based on the National Health Safety Network organism list. Time-by-class Poisson regression models evaluated changes in CLABSI rates. Characteristics of patients who developed CLABSIs were unchanged. Infections occurred most frequently among patients with hematologic malignancies and neutropenia. Significant log rate decreases in CLABSI rates were observed with the implementation of maintenance care bundles plus enhanced supportive cares compared to preintervention baseline for the following organisms: (1) common commensal organisms (-1.05, p = .005), (2) mucosal barrier injury (MBI) organisms common to the mouth (-.708, p = .007), and (3) other noncommensal/non-MBI pathogens (-.77, p = .005). Rates were unchanged for MBI organisms common to the lower gastrointestinal tract. Central line maintenance care bundles and formalized supportive care practices resulted in sustained decreased CLABSI rates. Additional interventions are needed to reduce CLABSIs involving MBI-associated organisms common to the lower gastrointestinal tract.

Impact of mucosal barrier injury laboratory-confirmed bloodstream infection (MBI-LCBI) on central line-associated bloodstream infections (CLABSIs) in department of hematology at single university hospital in Japan

BACKGROUND

Central line-associated bloodstream infections (CLABSIs) are among the most serious complications especially in blood cancer patients. In January 2013, Centers for Disease and Prevention (CDC) introduced a new surveillance definition of mucosal barrier injury-associated laboratory-confirmed bloodstream infection (MBI-LCBI). This study was to determine the impact of MBI-LCBI on CLABSIs and compare the clinical characteristics of MBI versus non-MBI-LCBI cases.

PATIENTS AND METHODS

We retrospectively reviewed the records of 250 consecutive patients. They were admitted in department of hematology at Aichi Medical University Hospital. We applied the revised 2013 CLABSI surveillance protocol to all CLABSI cases identified during the 47-months period from May 2012 through June 2016.

RESULTS

A total of 44 CLABSIs were identified. The median patient age was 65 years (range, 12 to 89). Among 44 patients, 31 patients were diagnosed as leukemia (70.5%) and 12 patients as lymphoma (27.3%). Six patients underwent bone transplantation for leukemia or myelodysplastic syndrome (13.6%). A total of 20 patients (45.5%) were classified as MBI-LCBI and 24 (54.5%) were classified as non-MBI-LCBI. The primary disease type (P = 0.018), neutropenic within 3 days before CLABSI (MBI-LCBI vs. non-MBI-LCBI: 95.0% vs. 26.3%, P = <0.0001), line(s) removed owing to CLABSI (15.0% vs. 54.2%, P = 0.011) and Gram-negative organisms cultured (70.0% vs. 37.5%, P = 0.004) showed significantly difference between the groups.

CONCLUSION

Our data showed that MBI-LCBI cases account for 45.5% of the CLABSI cases identified in blood cancer patients, and constituted a significant burden to this high-risk patient population.

Bloodstream Infections

Bacteremia and sepsis are conditions associated with high mortality and are of great impact to health care operations. Among the top causes of mortality in the United States, these conditions cause over 600 fatalities each day. Empiric, broad-spectrum treatment is a common but often a costly approach that may fail to effectively target the correct microbe, may inadvertently harm patients via antimicrobial toxicity or downstream antimicrobial resistance. To meet the diagnostic challenges of bacteremia and sepsis, laboratories must understand the complexity of diagnosing and treating septic patients, in order to focus on creating algorithms that can help direct a more targeted approach to antimicrobial therapy and synergize with existing clinical practices defined in new Surviving Sepsis Guidelines. Significant advances have been made in improving blood culture media; as yet no molecular or antigen-based method has proven superior for the detection of bacteremia in terms of limit of detection. Several methods for rapid molecular identification of pathogens from blood cultures bottles are available and many more are on the diagnostic horizon. Ultimately, early intervention by molecular detection of bacteria and fungi directly from whole blood could provide the most patient benefit and contribute to tailored antibiotic coverage of the patient early on in the course of the disease. Although blood cultures remain as the best means of diagnosing bacteremia and candidemia, complementary testing with antigen tests, microbiologic investigations from other body sites, and histopathology can often aid in the diagnosis of disseminated disease, and application of emerging nucleic acid test methods and other new technology may greatly impact our ability to bacteremic and septic patients, particularly those who are immunocompromised.

Catheter-related infections in patients with haematological malignancies: novel preventive and therapeutic strategies

Central venous catheters are essential for the treatment of patients with haematological malignancies and the recipients of stem-cell transplant. This patient population is, however, at high risk for catheter-related bloodstream infections that can result in substantial morbidity, mortality, and health-care-associated costs. Efficient prevention, early diagnosis, and effective treatment are essential to providing the best care to these patients. Although confirming the catheter as a source of infection remains challenging, the Infectious Diseases Society of America definition of catheter-related bloodstream infection remains the most precise definition to use in these patients. Gram-positive bacteria, particularly coagulase-negative Staphylococcus spp, remain the leading cause of catheter-related bloodstream infection, although an increase in Gram-negative bacteria as the causative agent has been noted. Although removal of the line and appropriate intravenous antibiotics remain the mainstay of treatment in most cases, novel technologies, including exchange with antibiotic-coated catheters and treatment with lock solutions, are particularly relevant in this patient population. In this Review we present the types of central venous catheters used in this patient population and analyse the different definitions of catheter-related infections, with an overview of their prevention and management.

Using Practice-Based Evidence to Improve Supportive Care Practices to Reduce Central Line–Associated Bloodstream Infections in a Pediatric Oncology Unit

Children with cancer are a subset of patients with central lines with distinct risk factors for infection including periods of prolonged neutropenia and compromised mucous membrane integrity. This article relates the implementation of principles of practice-based evidence to identify interventions in addition to best practice maintenance care bundles to reduce central line–associated bloodstream infections involving viridans group streptococci and coagulase-negative staphylococci on an inpatient pediatric oncology unit. Review of individual events combined with review of current clinical practice guided the development of structured protocols emphasizing routine oral care and general supportive cares. Key principles of the protocols emphasized a 1-2-3 mnemonic and included daily bathing, twice daily oral care, and out-of-bed activity 3 times daily. Poisson regression identified a significant main effect for time period for central line–associated bloodstream infection rates involving both viridans group streptococci and coagulase-negative staphylococci. Significant differences were present between the preintervention baseline and implementation of the supportive care protocols. Project outcomes demonstrate the added value of using principles of practice-based evidence to guide the development of interventions to improve clinical care when evidence-based sources are limited.

A clinical practical approach to the surveillance definition of central line-associated bloodstream infection in cancer patients with mucosal barrier injury

BACKGROUND

The Centers for Disease Control and Prevention recently introduced the concept of mucosal barrier injury (MBI) in an attempt to recognize the possibility of a gastrointestinal source for certain bloodstream infections. This could underestimate the central venous catheter (CVC) as the source of central line-associated bloodstream infection (CLABSI) in cancer. The definition of catheter-related bloodstream infection (CRBSI) by the Infectious Diseases Society of America is a more specific and stringent definition that identifies the CVC as the source of infection. In our study, we compared the 2 definitions in cancer patients.

METHODS

We retrospectively reviewed 149 CLABSI cases that occurred at our center between January 2013 and March 2014 who had 2 simultaneously positive blood cultures drawn from the CVC and peripheral site or concurrent paired tip and blood cultures.

RESULTS

Of the 149 patients with CLABSI, only 70 (47%) had definite CRBSI. CRBSI was identified more commonly in non-MBI CLABSI cases than MBI CLABSI (69% vs 18%, P < .0001).

CONCLUSIONS

The CRBSI definition may be more accurate in identifying the catheter as the source of bloodstream infection in patients with MBI. Because CRBSI continues to occur in patients with MBI, we caution against excluding all MBI patients from CLABSI surveillance.

Surveillance of bloodstream infections in pediatric cancer centers - what have we learned and how do we move on?

Pediatric patients receiving conventional chemotherapy for malignant disease face an increased risk of bloodstream infection (BSI). Since BSI may represent an acute life-threatening event in patients with profound immunosuppression, and show further negative impact on quality of life and anticancer treatment, the prevention of BSI is of paramount importance to improve and guarantee patients' safety during intensive treatment. The great majority of all pediatric cancer patients (about 85%) have a long-term central venous access catheter in use (type Broviac or Port; CVAD). Referring to the current surveillance definitions a significant proportion of all BSI in pediatric patients with febrile neutropenia is categorized as CVAD-associated BSI. This state of the art review summarizes the epidemiology and the distinct pathogen profile of BSI in pediatric cancer patients from the perspective of infection surveillance. Problems in executing the current surveillance definition in this patient population are discussed and a new concept for the surveillance of BSI in pediatric cancer patients is outlined.

Central line-associated bloodstream infections in non-ICU inpatient wards: a 2-year analysis

OBJECTIVE

Little is known about patient-specific factors contributing to central line-associated bloodstream infection (CLABSI) outside of the intensive care unit (ICU). We sought to describe these factors and hypothesized that dialysis patients would comprise a significant proportion of this cohort.

DESIGN

Retrospective observational study from January 2010 to December 2011.

SETTING

An 880-bed tertiary teaching hospital.

PATIENTS

Patients with CLABSI in non-ICU wards.

METHODS

CLABSI patients were identified from existing infection-control databases and primary chart review was conducted. National Health and Safety Network (NHSN) definitions were utilized for CLABSI and pathogen classification. CLABSI rates were calculated per patient day. Total mortality rates were inclusive of hospice patients.

RESULTS

Over a 2-year period, 104 patients incurred 113 CLABSIs for an infection rate of 0.35 per 1,000 patient days. The mean length of hospital stay prior to CLABSI was 16±13.3 days, which was nearly 3 times that of hospital-wide non-ICU length of stay. Only 11 patients (10.6%) received dialysis within 48 hours of CLABSI. However, 67% of patients had a hematologic malignancy, and 91.8% of those admitted with a malignant hematologic diagnosis were neutropenic at the time of CLABSI. Enterococcus spp. was the most common organism recovered, and half of all central venous catheters (CVCs) present were peripherally inserted central catheters (PICC lines). Mortality rates were 18.3% overall and 27.3% among dialysis patients.

CONCLUSIONS

In patients with CLABSIs outside of the ICU, only 10.6% received dialysis prior to infection. However, underlying hematologic malignancy, neutropenia, and PICC lines were highly prevalent in this population.

Probabilistic Measurement of Central Line–Associated Bloodstream Infections

OBJECTIVE

To develop a probabilistic method for measuring central line–associated bloodstream infection (CLABSI) rates that reduces the variability associated with traditional, manual methods of applying CLABSI surveillance definitions.

DESIGN

Multicenter retrospective cohort study of bacteremia episodes among patients hospitalized in adult patient-care units; the study evaluated presence of CLABSI.

SETTING

Hospitals that used SafetySurveillor software system (Premier) and who also reported to the Centers for Disease Control and Prevention’s National Healthcare Safety Network (NHSN).

PATIENTS

Patients were identified from a stratified sample from all eligible blood culture isolates from all eligible hospital units to generate a final set with an equal distribution (ie, 20%) from each unit type. Units were divided a priori into 5 major groups: medical intensive care unit, surgical intensive care unit, medical-surgical intensive care unit, hematology unit, or general medical wards.

INTERVENTIONS

Episodes were reviewed by 2 experts, and a selection of discordant reviews were re-reviewed. Data were joined with NHSN data for hospitals for in-plan months. A predictive model was created; model performance was assessed using the c statistic in a validation set and comparison with NHSN reported rates for in-plan months.

RESULTS

A final model was created with predictors of CLABSI. The c statistic for the final model was 0.75 (0.68–0.80). Rates from regression modeling correlated better with expert review than NHSN-reported rates.

CONCLUSIONS

The use of a regression model based on the clinical characteristics of the bacteremia outperformed traditional infection preventionist surveillance compared with an expert-derived reference standard.

Infect. Control Hosp. Epidemiol. 2016;37(2):149–155

Comparison of a silver-coated needleless connector and a standard needleless connector for the prevention of central line-associated bloodstream infections

OBJECTIVE

To assess the impact of a novel, silver-coated needleless connectors (NCs) on central-line-associated bloodstream infection (CLABSI) rates compared with a mechanically identical NCs without a silver coating.

DESIGN

Prospective longitudinal observation study SETTING Two 500-bed university hospitals

PATIENTS

All hospitalized adults from November 2009 to June 2011 with non-hemodialysis central lines

INTERVENTIONS

Hospital A started with silver-coated NCs and switched to standard NCs in September 2010; hospital B started with standard NCs and switched to silver-coated NCs. The primary outcome was the difference revealed by Poisson multivariate regression in CLABSI rate using standard Centers for Disease Control and Prevention surveillance definitions. The secondary outcome was a comparison of organism-specific CLABSI rates by NC type.

RESULTS

Among 15,845 hospital admissions, 140,186 central-line days and 221 CLABSIs were recorded during the study period. In a multivariate model, the CLABSI rate per 1,000 central-line days was lower with silver-coated NCs than with standard NCs (1.21 vs 1.79; incidence rate ratio=0.68 [95% CI: 0.52-0.89], P=.005). A lower CLABSI rate per 1,000 central-line days for the silver-coated NCs versus the standard NCs was observed with S. aureus (0.11 vs 0.30, P=.02), enterococci (0.10 vs 0.27, P=.03), and Gram-negative organisms (0.28 vs 0.63, P=.003) but not with coagulase-negative staphylococci (0.31 vs 0.36) or Candida spp. (0.42 vs 0.40).

CONCLUSIONS

The use of silver-coated NCs decreased the CLABSI rate by 32%. CLABSI reduction efforts should include efforts to minimize contamination of NCs.

Multidisciplinary team review of best practices for collection and handling of blood cultures to determine effective interventions for increasing the yield of true-positive bacteremias, reducing contamination, and eliminating false-positive central line-associated bloodstream infections

BACKGROUND

A literature search was conducted using keywords for articles published in English from January 1990 to March 2015. Using criteria related to blood culture collection and handling, the search yielded 101 articles. References used also included Microbiology Laboratory standards, guidelines, and textbook information.

RESULTS

The literature identified diverse and complex issues surrounding blood culture practices, including the impact of false-positive results, laboratory definition of contamination, effect on central line-associated bloodstream infection (CLABSI) reporting, indications for collecting blood cultures, drawing from venipuncture sites versus intravascular catheters, selection of antiseptics, use of needleless connectors, inoculation of blood culture bottles, and optimizing program management in emergency departments, education, and implementation of bundled practice initiatives.

CONCLUSION

Hospitals should optimize best practice in the collection, handling, and management of blood culture specimens, an often overlooked but essential component in providing optimal care of patients in all settings and populations, reducing financial burdens, and increasing the accuracy of reportable CLABSI. Although universal concepts exist in blood culture practices, some issues require further research to determine benefit. Institutions undertaking a review of their blood culture programs are encouraged to use a checklist that addresses elements that encompass the research contained in this review.

The burden of mucosal barrier injury laboratory-confirmed bloodstream infection among hematology, oncology, and stem cell transplant patients

OBJECTIVE

To evaluate the impact and burden of the new National Healthcare Safety Network surveillance definition, mucosal barrier injury laboratory-confirmed bloodstream infection (MBI-LCBI), in hematology, oncology, and stem cell transplant populations.

DESIGN

Retrospective cohort study.

SETTING

Two hematology, oncology, and stem cell transplant units at a large academic medical center.

METHODS

Central line-associated bloodstream infections (CLABSIs) identified during a 14-month period were reviewed and classified as MBI-LCBI or non-MBI-LCBI (MBI-LCBI criteria not met). During this period, interventions to improve central line maintenance were implemented. Characteristics of patients with MBI-LCBI and non-MBI-LCBI were compared. Total CLABSI, MBI-LCBI, and non-MBI-LCBI rates were compared between baseline and postintervention phases of the study period.

RESULTS

Among 66 total CLABSI cases, 47 (71%) met MBI-LCBI criteria. Patients with MBI-LCBI and non-MBI-LCBI were similar in regard to most clinical and demographic characteristics. Between the baseline and postintervention study periods, the overall CLABSI rate decreased from 3.37 to 3.21 infections per 1,000 line-days (incidence rate ratio, 0.95; 4.7% reduction, P=.84), the MBI-LCBI rate increased from 2.08 to 2.61 infections per 1,000 line-days (incidence rate ratio, 1.25; 25.3% increase, P=.44), and the non-MBI-LCBI rate decreased from 1.29 to 0.60 infections per 1,000 line-days (incidence rate ratio, 0.47; 53.3% reduction, P=.12).

CONCLUSIONS

Most CLABSIs identified among hematology, oncology, and stem cell transplant patients met MBI-LCBI criteria, and CLABSI prevention efforts did not reduce these infections. Further review of the MBI-LCBI definition and impact is necessary to direct future definition changes and reporting mandates.

Mucosal Barrier Injury Laboratory-Confirmed Bloodstream Infections (MBI-LCBI): Descriptive Analysis of Data Reported to National Healthcare Safety Network (NHSN), 2013

OBJECTIVES To determine the impact of mucosal barrier injury laboratory-confirmed bloodstream infections (MBI-LCBIs) on central-line-associated bloodstream infection (CLABSI) rates during the first year of MBI-LCBI reporting to the National Healthcare Safety Network (NHSN) DESIGN Descriptive analysis of 2013 NHSN data SETTING Selected inpatient locations in acute care hospitals METHODS A descriptive analysis of MBI-LCBI cases was performed. CLABSI rates per 1,000 central-line days were calculated with and without the inclusion of MBI-LCBIs in the subset of locations reporting ≥1 MBI-LCBI, and in all locations (regardless of MBI-LCBI reporting) to determine rate differences overall and by location type. RESULTS From 418 locations in 252 acute care hospitals reporting ≥1 MBI-LCBIs, 3,162 CLABSIs were reported; 1,415 (44.7%) met the MBI-LCBI definition. Among these locations, removing MBI-LCBI from the CLABSI rate determination produced the greatest CLABSI rate decreases in oncology (49%) and ward locations (45%). Among all locations reporting CLABSI data, including those reporting no MBI-LCBIs, removing MBI-LCBI reduced rates by 8%. Here, the greatest decrease was in oncology locations (38% decrease); decreases in other locations ranged from 1.2% to 4.2%. CONCLUSIONS An understanding of the potential impact of removing MBI-LCBIs from CLABSI data is needed to accurately interpret CLABSI trends over time and to inform changes to state and federal reporting programs. Whereas the MBI-LCBI definition may have a large impact on CLABSI rates in locations where patients with certain clinical conditions are cared for, the impact of MBI-LCBIs on overall CLABSI rates across inpatient locations appears to be more modest. Infect. Control Hosp. Epidemiol. 2015;37(1):2-7.

Central line-associated bloodstream infections in Australian intensive care units: Time-trends in infection rates, etiology, and antimicrobial resistance using a comprehensive Victorian surveillance program, 2009-2013

BACKGROUND

The epidemiology of central line-associated bloodstream infections (CLABSI) in Australian intensive care units (ICUs) has not previously been reported. We sought to describe time-trends in CLABSI rates, infections by ICU peer-groups, etiology, and antimicrobial susceptibility of pathogens in a large cohort of Australian ICUs for the period January 1, 2009-December 31, 2013.

METHODS

Using National Healthcare Safety Network methods, CLABSI surveillance in adult patients was performed by hospitals participating in the Victorian Healthcare Associated Infection Surveillance System (n = 29). Hospitals were grouped by location, sector, and teaching status.

RESULTS

Overall, 384 CLABSI events were reported over 303,968 central venous catheter (CVC)-days, corresponding to a rate of 1.26/1,000 CVC-days (95% confidence interval, 1.14-1.40). Every 1-year increase was associated with a 26% reduction in CLABSI risk (risk ratio, 0.74, 95% confidence interval, 0.69-0.80; P < .001). The most frequently identified pathogens were Enterococcus spp (26.3%), followed by Candida spp (15.4%) and Staphylococcus aureus (13.3%). CLABSI due to Enterococcus spp, S aureus, and coagulase-negative Staphylococcus spp displayed significant reductions over time.

CONCLUSIONS

Internationally accepted surveillance methods have been employed in Australia, demonstrating CLABSI rates comparable to medical/surgical ICUs in the United States and a reduction in pathogen-specific infections over a 5-year period.

Central line-associated bloodstream infections among critically-ill patients in the era of bundle care

BACKGROUND/PURPOSE

Patients admitted to intensive care units (ICUs) are at high risk for central line-associated bloodstream infections (CLABSIs). Bundle care has been documented to reduce CLABSI rates in Western countries, however, few reports were from Asian countries and the differences in the epidemiology or outcomes of critically-ill patients with CLABSIs after implementation of bundle care remain unknown. We aimed to evaluate the incidence, microbiological characteristics, and factors associated with mortality in critically-ill patients after implementation of bundle care.

METHODS

Prospective surveillance was performed on patients admitted to ICUs at the National Taiwan University Hospital, Taipei, Taiwan from January 2012 to June 2013. The demographic, microbiological, and clinical data of patients who developed CLABSI according to the National Healthcare Safety Network definition were reviewed. A total of 181 episodes of CLABSI were assessed in 156 patients over 46,020 central-catheter days.

RESULTS

The incidence of CLABSI was 3.93 per 1000 central-catheter days. The predominant causative microorganisms isolated from CLABSI episodes were Gram-negative bacteria (39.2%), followed by Gram-positive bacteria (33.2%) and Candida spp. (27.6%). Median time from insertion of a central catheter to occurrence of CLABSI was 8 days. In multivariate analysis, the independent factors associated with mortality were higher Pitt bacteremia score [odds ratio (OR) 1.41; 95% confidence interval (CI) 1.18-1.68] and longer interval between onset of CLABSIs and catheter removal (OR 1.10; 95% CI 1.02-1.20), respectively.

CONCLUSION

In institutions with a high proportion of CLABSI caused by Gram-negative bacteria, severity of bacteremia and delay in catheter removal were significant factors associated with mortality.

Central line-associated bloodstream infections in neonates with gastrointestinal conditions: developing a candidate definition for mucosal barrier injury bloodstream infections

OBJECTIVE

To develop a candidate definition for central line-associated bloodstream infection (CLABSI) in neonates with presumed mucosal barrier injury due to gastrointestinal (MBI-GI) conditions and to evaluate epidemiology and microbiology of MBI-GI CLABSI in infants.

DESIGN

Multicenter retrospective cohort study.

SETTING

Neonatal intensive care units from 14 US children's hospitals and pediatric facilities.

METHODS

A multidisciplinary focus group developed a candidate MBI-GI CLABSI definition based on presence of an MBI-GI condition, parenteral nutrition (PN) exposure, and an eligible enteric organism. CLABSI surveillance data from participating hospitals were supplemented by chart review to identify MBI-GI conditions and PN exposure.

RESULTS

During 2009-2012, 410 CLABSIs occurred in 376 infants. MBI-GI conditions and PN exposure occurred in 149 (40%) and 324 (86%) of these 376 neonates, respectively. The distribution of pathogens was similar among neonates with versus without MBI-GI conditions and PN exposure. Fifty-nine (16%) of the 376 initial CLABSI episodes met the candidate MBI-GI CLABSI definition. Subsequent versus initial CLABSIs were more likely to be caused by an enteric organism (22 of 34 [65%] vs 151 of 376 [40%]; P = .009) and to meet the candidate MBI-GI CLABSI definition (19 of 34 [56%] vs 59 of 376 [16%]; P < .01).

CONCLUSIONS

While MBI-GI conditions and PN exposure were common, only 16% of initial CLABSIs met the candidate definition of MBI-GI CLABSI. The high proportion of MBI-GI CLABSIs among subsequent infections suggests that infants with MBI-GI CLABSI should be a population targeted for further surveillance and interventional research.

Investigation of the case numbers of catheter-related bloodstream infection overestimated by the central line-associated bloodstream infection surveillance definition

BACKGROUND/PURPOSE

Diagnosis of catheter-related bloodstream infection (CRBSI) requires specific laboratory evidence. A simpler definition, central line-associated bloodstream infection (CLABSI), is recommended for surveillance purposes. Because exclusion of all other infection sources is difficult, CRBSI cases may be overestimated by using the CLABSI definition.

METHODS

A retrospective observational study was performed at a regional hospital in southern Taiwan from September 2012 to December 2013. All 106 reported CLABSI cases were assessed. Cases with catheter tip cultures were reviewed. CRBSI was defined as the identification of same organisms from the paired blood and catheter tip cultures (≥15 colony-forming units) without evidence of secondary bacteremia from other infection sources.

RESULTS

Overall, 64 cases were included and 31 (48.4%) were defined as CRBSI cases. In 30 (46.9%) cases, catheter tips were cultured after the corresponding blood cultures were performed. Later tip cultures were significantly more frequent in cases with other catheter types (18/22, 81.8%) than those with central lines (12/42, 28.6%; p < 0.0001). The same significant difference was also found among the CRBSI cases (central lines, 3/17, 17.6%; others, 13/14, 92.9%; p < 0.00005). Twelve bacterial species were identified from the CRBSI cases, with Staphylococcus aureus being the most frequent (13, 41.9%), followed by Pseudomonas aeruginosa (5, 16.1%).

CONCLUSION

The positive predictive value of the CLABSI definition for CRBSI cases was 48.4%. One should be aware of this discrepancy and should interpret the CLABSI surveillance definition with care.

Management of sepsis in neutropenic patients: 2014 updated guidelines from the Infectious Diseases Working Party of the German Society of Hematology and Medical Oncology (AGIHO)

Sepsis is a major cause of mortality during the neutropenic phase after intensive cytotoxic therapies for malignancies. Improved management of sepsis during neutropenia may reduce the mortality of cancer therapies. Clinical guidelines on sepsis treatment have been published by others. However, optimal management may differ between neutropenic and non-neutropenic patients. Our aim is to give evidence-based recommendations for haematologist, oncologists and intensive care physicians on how to manage adult patients with neutropenia and sepsis.

Mucosal barrier injury laboratory-confirmed bloodstream infection: results from a field test of a new National Healthcare Safety Network definition

OBJECTIVE

To assess challenges to implementation of a new National Healthcare Safety Network (NHSN) surveillance definition, mucosal barrier injury laboratory-confirmed bloodstream infection (MBI-LCBI).

DESIGN

Multicenter field test.

SETTING

Selected locations of acute care hospitals participating in NHSN central line-associated bloodstream infection (CLABSI) surveillance.

METHODS

Hospital staff augmented their CLABSI surveillance for 2 months to incorporate MBI-LCBI: a primary bloodstream infection due to a selected group of organisms in patients with either neutropenia or an allogeneic hematopoietic stem cell transplant with gastrointestinal graft-versus-host disease or diarrhea. Centers for Disease Control and Prevention (CDC) staff reviewed submitted data to verify whether CLABSIs met MBI-LCBI criteria and summarized the descriptive epidemiology of cases reported.

RESULTS

Eight cancer, 2 pediatric, and 28 general acute care hospitals including 193 inpatient units (49% oncology/bone marrow transplant [BMT], 21% adult ward, 20% adult critical care, 6% pediatric, 4% step-down) conducted field testing. Among 906 positive blood cultures reviewed, 282 CLABSIs were identified. Of the 103 CLABSIs that also met MBI-LCBI criteria, 100 (97%) were reported from oncology/BMT locations. Agreement between hospital staff and CDC classification of reported CLABSIs as meeting the MBI-LCBI definition was high (90%; κ = 0.82). Most MBI-LCBIs (91%) occurred in patients meeting neutropenia criteria. Some hospitals indicated that their laboratories' methods of reporting cell counts prevented application of neutropenia criteria; revised neutropenia criteria were created using data from field testing.

CONCLUSIONS

Hospital staff applied the MBI-LCBI definition accurately. Field testing informed modifications for the January 2013 implementation of MBI-LCBI in the NHSN.