Increased resource use associated with catheter-related bloodstream infection in the surgical intensive care unit

Systematic scoping review of automated systems for the surveillance of healthcare-associated bloodstream infections related to intravascular catheters

INTRODUCTION

Intravascular catheters are crucial devices in medical practice that increase the risk of healthcare-associated infections (HAIs), and related health-economic adverse outcomes. This scoping review aims to provide a comprehensive overview of published automated algorithms for surveillance of catheter-related bloodstream infections (CRBSI) and central line-associated bloodstream infections (CLABSI).

METHODS

We performed a scoping review based on a systematic search of the literature in PubMed and EMBASE from 1 January 2000 to 31 December 2021. Studies were included if they evaluated predictive performance of automated surveillance algorithms for CLABSI/CRBSI detection and used manually collected surveillance data as reference. We assessed the design of the automated systems, including the definitions used to develop algorithms (CLABSI versus CRBSI), the datasets and denominators used, and the algorithms evaluated in each of the studies.

RESULTS

We screened 586 studies based on title and abstract, and 99 were assessed based on full text. Nine studies were included in the scoping review. Most studies were monocentric (n = 5), and they identified CLABSI (n = 7) as an outcome. The majority of the studies used administrative and microbiological data (n = 9) and five studies included the presence of a vascular central line in their automated system. Six studies explained the denominator they selected, five of which chose central line-days. The most common rules and steps used in the algorithms were categorized as hospital-acquired rules, infection rules (infection versus contamination), deduplication, episode grouping, secondary BSI rules (secondary versus primary BSI), and catheter-associated rules.

CONCLUSION

The automated surveillance systems that we identified were heterogeneous in terms of definitions, datasets and denominators used, with a combination of rules in each algorithm. Further guidelines and studies are needed to develop and implement algorithms to detect CLABSI/CRBSI, with standardized definitions, appropriate data sources and suitable denominators.

Predictive performance of automated surveillance algorithms for intravascular catheter bloodstream infections: a systematic review and meta-analysis

BACKGROUND

Intravascular catheter infections are associated with adverse clinical outcomes. However, a significant proportion of these infections are preventable. Evaluations of the performance of automated surveillance systems for adequate monitoring of central-line associated bloodstream infection (CLABSI) or catheter-related bloodstream infection (CRBSI) are limited.

OBJECTIVES

We evaluated the predictive performance of automated algorithms for CLABSI/CRBSI detection, and investigated which parameters included in automated algorithms provide the greatest accuracy for CLABSI/CRBSI detection.

METHODS

We performed a meta-analysis based on a systematic search of published studies in PubMed and EMBASE from 1 January 2000 to 31 December 2021. We included studies that evaluated predictive performance of automated surveillance algorithms for CLABSI/CRBSI detection and used manually collected surveillance data as reference. We estimated the pooled sensitivity and specificity of algorithms for accuracy and performed a univariable meta-regression of the different parameters used across algorithms.

RESULTS

The search identified five full text studies and 32 different algorithms or study populations were included in the meta-analysis. All studies analysed central venous catheters and identified CLABSI or CRBSI as an outcome. Pooled sensitivity and specificity of automated surveillance algorithm were 0.88 [95%CI 0.84-0.91] and 0.86 [95%CI 0.79-0.92] with significant heterogeneity (I2 = 91.9, p < 0.001 and I2 = 99.2, p < 0.001, respectively). In meta-regression, algorithms that include results of microbiological cultures from specific specimens (respiratory, urine and wound) to exclude non-CRBSI had higher specificity estimates (0.92, 95%CI 0.88-0.96) than algorithms that include results of microbiological cultures from any other body sites (0.88, 95% CI 0.81-0.95). The addition of clinical signs as a predictor did not improve performance of these algorithms with similar specificity estimates (0.92, 95%CI 0.88-0.96).

CONCLUSIONS

Performance of automated algorithms for detection of intravascular catheter infections in comparison to manual surveillance seems encouraging. The development of automated algorithms should consider the inclusion of results of microbiological cultures from specific specimens to exclude non-CRBSI, while the inclusion of clinical data may not have an added-value. Trail Registration Prospectively registered with International prospective register of systematic reviews (PROSPERO ID CRD42022299641; January 21, 2022). https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022299641.

Incidence Rate, Pathogens and Economic Burden of Catheter-Related Bloodstream Infection: A Single-Center, Retrospective Case-Control Study

Purpose

Indwelling central venous catheters (CVCs) can cause catheter related bloodstream infection (CRBSI). CRBSI occurring in intensive care unit (ICU) patients may lead to the worse outcomes and extra medical costs. The present study aimed to assess the incidence and incidence density, pathogens and economic burden of CRBSI in ICU patients.

Patients and Methods

A case-control study was retrospectively carried out in six ICUs of one hospital between July 2013 and June 2018. The Department of Infection Control performed routinely surveillance for CRBSI on these different ICUs. Data of the clinical and microbiological characteristics of patients with CRBSI, the incidence and incidence density of CRBSI in ICUs, the attributable length of stay (LOS), and the costs among patients with CRBSI in ICU were collected and assessed.

Results

A total of 82 ICU patients with CRBSI were included into the study. The CRBSI incidence density was 1.27 per 1000 CVC-days in all ICUs, in which the highest was 3.52 per 1000 CVC-days in hematology ICU and the lowest was 0.14 per 1000 CVC-days in Special Procurement ICU. The most common pathogen causing CRBSI was Klebsiella pneumoniae (15/82, 16.67%), in which 12 (80%) were carbapenem resistant. Fifty-one patients were successfully matched with control patients. The average costs in the CRBSI group were $ 67,923, which were significantly higher (P < 0.001) than the average costs in the control group. The total average costs attributable to CRBSI were $33, 696.

Conclusion

The medical costs of ICU patients were closely related to the incidence of CRBSI. Imperative measures are needed to reduce CRBSI in ICU patients.

A Budget Impact Model of Maintenance Treatment of Chronic Inflammatory Demyelinating Polyneuropathy with IgPro20 (Hizentra) Relative to Intravenous Immunoglobulin in the United States

BACKGROUND

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare, progressive autoimmune disease causing peripheral nervous system dysfunction. Guidelines recommend immunoglobulin (IG) therapy as an immunomodulatory agent in CIDP. Drawbacks and unmet needs with intravenous immunoglobulin (IVIG) include adverse effects and wear-off effects, along with the burden of administration based on site of care. Subcutaneous administration of Hizentra, a subcutaneous immunoglobulin (SCIG) reduces patient burden by allowing self-administration outside the hospital setting and has fewer adverse events (AEs).

OBJECTIVE

We aimed to compare the expected cost of treatment and the budget impact of Hizentra compared with IVIG for maintenance treatment of CIDP in the United States.

METHODS

A decision tree model was developed to estimate the expected budget impact of maintenance treatment with Hizentra for US stakeholders. The model adopts primarily a US integrated delivery network perspective and, secondarily, a commercial perspective over a 1-year time horizon. Pharmacy costs were based on a payment mix of average sales price (73%), wholesale acquisition cost (2%), and average wholesale price (25%). Costs in the model reflect 2022 US dollars. In accordance with the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) guidelines and recommendations for budget impact modeling, no discounting was performed. The PATH clinical study of Hizentra maintenance in CIDP was used to determine clinical inputs for relapse rates at initial assessment (24 weeks) and at 52 weeks for Hizentra. The ICE clinical study of Gamunex maintenance in CIDP was the basis of relapse rates for Gamunex (and other IVIGs). Literature-based estimates were obtained for infusion costs by site of care, costs of IVIG infusion-related complications, and significant IVIG AE rates. Hizentra AE rates from the US Hizentra prescribing information were assessed but were not included in the model as the AEs in CIDP were mild, easily treated, and self-limited. Sensitivity analyses and scenario analyses were conducted to evaluate variations from the base case.

RESULTS

The model showed that a Hizentra starting dose of 0.2 g/kg is expected to result in annual cost savings of US$32,447 per patient compared with IVIG. For a hypothetical 25-million-member plan, the budget impact of a 10% market share shift from IVIG to Hizentra is expected to result in savings of US$2,296,235.

CONCLUSION

This analysis projects that Hizentra is likely associated with favorable economic benefit compared with IVIG in managing CIDP.

Identification and design of a multi-epitope subunit vaccine against the opportunistic pathogen Staphylococcus epidermidis: An immunoinformatics approach

Staphylococcus epidermidis is one of the major causes of nosocomial infections around the globe that leads to a high rate of mortality and morbidity in both immunocompromised patients and preterm infants. Despite the alarming increase in multi-drug resistance, no promising vaccines are readily available against this pathogen. Thus, the present study is focused on designing a multi-epitope subunit vaccine using five antigenic proteins of S. epidermidis through an immunoinformatics approach. The final vaccine comprised B-cell, HTL, and CTL binding epitopes followed by Lipoprotein LprA adjuvant added at N-terminal to augment the immunogenicity. Physicochemical assessment of the vaccine reveals the antigenic and non-allergic nature. The vaccine structure was designed, refined, validated, and disulfide engineered to obtain the best model. Molecular docking and dynamics simulation of the proposed vaccine with toll-like receptors (TLR-2 and TLR-4) showed strong and stable interactions. MM-PBSA analysis was implemented as an efficient tool to determine the intermolecular binding free energies of the system. The vaccine was subjected to immune simulation to predict its immunogenic profile. In silico cloning suggested that the proposed vaccine can be expressed efficiently in E.coli. Furthermore, in vivo animal experiment is needed to determine the effectiveness of the in silico designed vaccine.Communicated by Ramaswamy H. Sarma.

Smartphone compatible nitric oxide releasing insert to prevent catheter-associated infections

A large fraction of nosocomial infections is associated with medical devices that are deemed life-threatening in immunocompromised patients. Medical device-related infections are a result of bacterial colonization and biofilm formation on the device surface that affects >1 million people annually in the US alone. Over the past few years, light-based antimicrobial therapy has made substantial advances in tackling microbial colonization. Taking the advantage of light and antibacterial properties of nitric oxide (NO), for the first time, a robust, biocompatible, anti-infective approach to design a universal disposable catheter disinfection insert (DCDI) that can both prevent bacterial adhesion and disinfect indwelling catheters in situ is reported. The DCDI is engineered using a photo-initiated NO donor molecule, incorporated in polymer tubing that is mounted on a side glow fiber optic connected to an LED light source. Using a smartphone application, the NO release from DCDI is photoactivated via white light resulting in tunable physiological levels of NO for up to 24 h. When challenged with microorganisms S. aureus and E. coli, the NO-releasing DCDI statistically reduced microbial attachment by >99% versus the controls with just 4 h of exposure. The DCDI also eradicated ∼97% of pre-colonized bacteria on the CVC catheter model demonstrating the ability to exterminate an established catheter infection. The smart, mobile-operated novel universal antibacterial device can be used to both prevent catheter infections or can be inserted within an infected catheter to eradicate the bacteria without complex surgical interventions. The therapeutic levels of NO generated via illuminating fiber optics can be the next-generation biocompatible solution for catheter-related bloodstream infections.

Antimicrobial persistence of two alcoholic preoperative skin preparation solutions

BACKGROUND

Normal skin flora and suboptimal skin antisepsis are the primary drivers of healthcare-associated infections (HAIs). Antimicrobial persistence of preoperative skin preparation is necessary to limit microorganisms on the skin and help minimize their entry into an incision or device-insertion site after application.

AIM

To assess the antimicrobial persistence of two preoperative skin preparation solutions.

METHODS

A randomized, single-centre, partially blinded, clinical study was conducted in 103 healthy volunteers to evaluate the persistent antimicrobial properties of BD ChloraPrep™ (2% w/v chlorhexidine gluconate [CHG] + 70% v/v isopropyl alcohol [IPA]) and BD PurPrep™ (8.3% w/w povidone-iodine [PVP-I] + 72.5% w/w IPA) skin preparations out to 7 days and 96 hours, respectively, on abdomen and groin testing sites. An additional 32 healthy volunteers participated in a neutralization procedure to ensure the study recovery solution was non-toxic to microorganisms, and a spore-recovery procedure to demonstrate that microorganisms could be successfully recovered from the PVP-I+IPA film-forming product.

RESULTS

Both CHG+IPA and PVP-I+IPA produced a mean bacterial log₁₀ reduction >2 and >3 on the abdomen and groin, respectively, 10 minutes after application. CHG+IPA maintained antimicrobial persistence out to 7 days post-application, while PVP-I+IPA maintained antimicrobial persistence out to 96 hours post-application, the longest timepoint selected for this product.

CONCLUSION

CHG+IPA and PVP-I+IPA were both found to be effective persistent antiseptic skin preparations. Overall, skin irritation was uncommon, and only 1 adverse event occurred following product application, which was not considered product related but was considered procedure related.

Comparative effect of seven prophylactic locks to prevent biofilm biomass and viability in intravenous catheters

BACKGROUND

Patients requiring long-term intravenous access are at risk of intraluminal catheter bloodstream infection. 'Prophylactic' locks aim to limit this risk but there is uncertainty regarding the most effective lock.

OBJECTIVES

To develop a novel technique intended to replicate clinical procedures to compare the effectiveness of various 'prophylactic' locks against biofilm biomass ('biomass') formation and biofilm viability ('viability') of Escherichia coli and Staphylococcus epidermidis in intravenous catheters.

METHODS

For 10 consecutive days 106 cfu/mL E. coli NCTC 10418 and S. epidermidis ATCC 12228 were separately cultured in single lumen 9.6 French silicone tunnelled and cuffed catheters. These were flushed with 0.9% w/v sodium chloride using a push-pause technique before and after instillation of seven 'prophylactic' locks (water, ethanol, sodium chloride, heparinized sodium chloride, citrate, taurolidine plus citrate, and taurolidine; each in triplicate) for 6 h daily. Intraluminal 'biomass' and 'viability' were quantified using crystal violet staining and flush culture, respectively.

RESULTS

The reduction of 'biomass' and 'viability' depended on both agent and species. Citrate was least effective against E. coli 'viability' and 'biomass' but most effective against S. epidermidis 'viability', and taurolidine was most effective against E. coli 'biomass' and 'viability' but least effective against S. epidermidis 'viability'. 'Biomass' and 'viability' were significantly correlated in E. coli between (r = 0.997, P < 0.001) and within (r = 0.754, P = 0.001) interventions, but not in S. epidermidis.

CONCLUSIONS

A novel technique found the effect of 'prophylactic' agents in reducing 'biomass' and 'viability' varied by species. The choice of agent depends on the most likely infecting organism.

Multi-epitope based vaccine design against Staphylococcus epidermidis: A subtractive proteomics and immunoinformatics approach

Staphylococcus epidermidis has emerged as a major contributor of nosocomial infections across the world. With the increased rate of emerging resistant and previously undefined infectious diseases, there is a growing need to develop a novel vaccine possessing required immunogenic properties. The adopted reverse vaccinology approach identified "IMPNQILTI" of LysM domain protein, "YSYTYTIDA" of staphylococcal secretory antigen SsaA, and "YNYDANTGQ" neutral metalloproteinaseas potential peptides for vaccine design. The 9-mer epitope of target proteins is antigenic, virulent, surface-exposed, non-allergenic, and conserved across various strains of S. epidermidis. Protein-protein interactions study indicated the involvement of target proteins in major biological pathways for S. epidermidis pathogenesis. Protein-peptide docking was performed, and population coverage analysis showed significant interactions of T-cell epitopes with the HLA-binding molecules while covering 90.58% of the world's population. Further, a multi-epitope vaccine of 177 amino acids long was constructed. Docking with Toll-like receptor (TLR-2) molecule confirmed the effective interaction of the vaccine with the receptor. The vaccine efficiency in generating an effective immune response in the host was evaluated by immune simulation. Finally, in silico cloning confirmed that the constructed vaccine can be efficiently expressed in E. coli. However, the designed vaccine needs experimental validation to determine the effectiveness and immunogenicity profile, which will ensure an active immunity against S. epidermidis.

Short-Course Versus Long-Course Systemic Antibiotic Treatment for Uncomplicated Intravascular Catheter-Related Bloodstream Infections due to Gram-Negative Bacteria, Enterococci or Coagulase-Negative Staphylococci: A Systematic Review

INTRODUCTION

The optimal duration of systemic antimicrobial treatment for catheter-related bloodstream infections (CRBSI) is unknown. In this systematic review, we aimed to assess the efficacy of short-course treatment for CRBSI due to Gram-negative bacteria, coagulase-negative staphylococci and enterococci.

METHODS

We systematically searched the electronic bibliographic databases MEDLINE, EMBASE and Cochrane Library for studies published before February 2021. All studies that investigated the duration of adequate systemic antibiotic treatment in adult patients with uncomplicated intravascular catheter infections due to Gram-negative bacteria, coagulase-negative staphylococci or enterococci were eligible for inclusion. Studies including concomitant treatment with antibiotic lock therapy were excluded. The primary outcomes were clinical failure/cure, mortality and microbiologic-confirmed relapse.

RESULTS

Seven retrospective cohort studies and one case-cohort study met the inclusion criteria. No randomized controlled studies met inclusion criteria. The quality of the included studies was low (n = 7) to moderate (n = 1). No significant differences were observed regarding mortality and microbiological relapse between short-course and long-course systemic antibiotic treatment in patients with CRBSI due to coagulase-negative staphylococci or Gram-negative bacteria. No association was found between mortality and treatment duration in the two studies assessing enterococcal CRBSI.

CONCLUSION

The limited data available suggests that shorter systemic antibiotic treatment duration may be sufficient for uncomplicated CRBSI. Further well-designed prospective studies are needed to confirm these findings.

TRIAL REGISTRATION NUMBER

CRD42021224946 (PROSPERO).

The Financial Impact of an Inpatient Diabetes Management Service

CONTEXT

Diabetes is a leading metabolic disorder with a substantial cost burden, especially in inpatient settings. The complexity of inpatient glycemic management has led to the emergence of inpatient diabetes management service (IDMS), a multidisciplinary team approach to glycemic management.

OBJECTIVE

To review recent literature on the financial and clinical impact of IDMS in hospital settings.

METHODS

We searched PubMed using a combination of controlled vocabulary and keyword terms to describe the concept of IDMS and combined the search terms with a comparative effectiveness filter for costs and cost analysis developed by the National Library of Medicine.

FINDINGS

In addition to several improved clinical endpoints such as glycemic management outcomes, IDMS implementation is associated with hospital cost savings through decreased length of stay, preventing hospital readmissions, hypoglycemia reduction, and optimizing resource allocation. There are other downstream potential cost savings in long-term patient health outcomes and avoidance of litigation related to suboptimal glycemic management.

CONCLUSION

IDMS may play an important role in helping both academic and community hospitals to improve the quality of diabetes care and reduce costs. Clinicians and policymakers can utilize existing literature to build a compelling business case for IDMS to hospital administrations and state legislatures in the era of value-based healthcare.

Eco friendly silver nanoparticles synthesis by Brassica oleracea and its antibacterial, anticancer and antioxidant properties

Production of environmentally amenable silver nanoparticles (AgNPs) has garnered the interest of the scientific community owing to their broad application primarily in the field of optronics, sensing and extensively in pharmaceuticals as promising antioxidant, antimicrobial and anticancer agents. The current study emphases on production of ecofriendly silver nanoparticles from Brassica oleracea (BO) and investigated their antibacterial, anticancer and antioxidant activity. The characteristics of synthesized BO-AgNPs were studied by ultraviolet-visible spectroscopy, particle size analysis, electro kinetic/zeta potential analysis, and Transmission electron microscope (TEM). A distinctive absorption maximum at 400 nm confirmed the formation of BO-AgNPs and data on TEM analysis have shown that the synthesized nanoparticles were predominantly spherical in shape. The BO-AgNPs obtained were assessed for antibacterial, antioxidant, and cytotoxic ability in MCF-7 cells. The antibacterial activity expressed was maximum against Staphylococcus epidermidis (Gram positive) and Pseudomonas aeruginosa (Gram negative) with DIZ of 14.33 ± 0.57 and 12.0 ± 0.20 mm respectively. Furthermore, the ability of the synthesized green nanoparticles to scavenge free radicals revealed a strong antioxidant activity. The cytotoxicity increased proportionately with increasing concentration of the green synthesized BO-AgNPs with maximum effect at 100 μg/ml and IC50 of 55 μg/ml. In conclusion, the data obtained in the study is reflective of the role of BO-AgNPs as potential and promising antimicrobial agent against bacterial infections and potential anticancer agent in cancer therapy.

Clinical impact of early reinsertion of a central venous catheter after catheter removal in patients with catheter-related bloodstream infections

OBJECTIVE

Early replacement of a new central venous catheter (CVC) may pose a risk of persistent or recurrent infection in patients with a catheter-related bloodstream infection (CRBSI). We evaluated the clinical impact of early CVC reinsertion after catheter removal in patients with CRBSIs.

METHODS

We conducted a retrospective chart review of adult patients with confirmed CRBSIs in 2 tertiary-care hospitals over a 7-year period.

RESULTS

To treat their infections, 316 patients with CRBSIs underwent CVC removal. Among them, 130 (41.1%) underwent early CVC reinsertion (≤3 days after CVC removal), 39 (12.4%) underwent delayed reinsertion (>3 days), and 147 (46.5%) did not undergo CVC reinsertion. There were no differences in baseline characteristics among the 3 groups, except for nontunneled CVC, presence of septic shock, and reason for CVC reinsertion. The rate of persistent CRBSI in the early CVC reinsertion group (22.3%) was higher than that in the no CVC reinsertion group (7.5%; P = .002) but was similar to that in the delayed CVC reinsertion group (17.9%; P > .99). The other clinical outcomes did not differ among the 3 groups, including rates of 30-day mortality, complicated infection, and recurrence. After controlling for several confounding factors, early CVC reinsertion was not significantly associated with persistent CRBSI (OR, 1.59; P = .35) or 30-day mortality compared with delayed CVC reinsertion (OR, 0.81; P = .68).

CONCLUSIONS

Early CVC reinsertion in the setting of CRBSI may be safe. Replacement of a new CVC should not be delayed in patients who still require a CVC for ongoing management.

Minimising Blood Stream Infection: Developing New Materials for Intravascular Catheters

Catheter related blood stream infection is an ever present hazard for those patients requiring venous access and particularly for those requiring long term medication. The implementation of more rigorous care bundles and greater adherence to aseptic techniques have yielded substantial reductions in infection rates but the latter is still far from acceptable and continues to place a heavy burden on patients and healthcare providers. While advances in engineering design and the arrival of functional materials hold considerable promise for the development of a new generation of catheters, many challenges remain. The aim of this review is to identify the issues that presently impact catheter performance and provide a critical evaluation of the design considerations that are emerging in the pursuit of these new catheter systems.

<p>Central Venous Catheter Insertion in Colorectal Cancer Patients, PICC or PC?</p>

Purpose

Methods

Results

Conclusion

Supercritical Fluid Applications in the Design of Novel Antimicrobial Materials

Bacterial resistance to antibiotics is one of the biggest problems in the modern world. The prevention of bacterial spreading from hospitals to the community and vice versa is an issue we have to deal with. This review presents a vast potential of contemporary high-pressure techniques in the design of materials with antimicrobial activity. Scientists from all over the world came up with ideas on how to exploit extraordinary properties of supercritical fluids in the production of advantageous materials in an environmentally friendly way. The review summarizes reported methods and results.

Nanoengineered Antibacterial Coatings and Materials: A Perspective

This feature article begins by outlining the problem of infection and its implication on healthcare. The initial introductory section is followed by a description of the four distinct classes of antibacterial coatings and materials, i.e., bacteria repealing, contact killing, releasing and responsive, that were developed over the years by our team and others. Specific examples of each individual class of antibacterial materials and a discussion on the pros and cons of each strategy are provided. The article contains a dedicated section focused on silver nanoparticle based coatings and materials, which have attracted tremendous interest from the scientific and medical communities. The article concludes with the author’s view regarding the future of the field.

Effect of daptomycin and vancomycin on Staphylococcus epidermidis biofilms: An in vitro assessment using fluorescence in situ hybridization

Colonization of in-dwelling catheters by microbial biofilms is a major concern in patient health eventually leading to catheter-related blood stream infections. Biofilms are less susceptible to standard antibiotic therapies that are effective against planktonic bacteria. Standard procedure for the detection of microorganisms on the catheter tip is culture. However, viable but non-culturable cells (VBNCs) may be missed. The aim of this study was to evaluate the use of fluorescence in situ hybridization (FISH) as an indicator to visualize and quantify the effect of the antibiotics daptomycin and vancomycin on biofilms in situ. We established an in vitro catheter biofilm model of Staphylococcus epidermidis biofilms on polyurethane catheters. Biofilm activity was measured by FISH and correlated to colony forming units (CFU) data. Digital image analysis was used for quantification of total biofilm mass and the area of the FISH positive biofilm cells. FISH showed a pronounced effect of both antibiotics on the biofilms, with daptomycin having a significantly stronger effect in terms of both reduction of biofilm mass and number of FISH-positive cells. This supports the anti-biofilm capacity of daptomycin. Interestingly, neither antibiotic was able to eradicate all of the FISH-positive cells. In summary, FISH succeeded in visualization, quantification, and localization of antibiotic activity on biofilms. This technique adds a new tool to the arsenal of test systems for anti-biofilm compounds. FISH is a valuable complementary technique to CFU since it can be highly standardized and provides information on biofilm architecture and quantity and localization of survivor cells.

Non-biofilm-forming commensal Staphylococcus epidermidis isolates produce biofilm in the presence of trypsin

Epidemiological studies comparing clinical and commensal Staphylococcus epidermidis isolates suggest that biofilm formation is a discriminant biomarker. A study showed that four non-biofilm-forming clinical S. epidermidis isolates could form an induced biofilm by trypsin treatment, suggesting that S. epidermidis can form biofilms in a protease-independent way and in a trypsin-induced way. In this study, the trypsin capacity to induce biofilm formation was evaluated in non-biofilm-forming S. epidermidis isolates (n = 133) in order to support this mechanism and to establish the importance of total biofilms (meaning the sum of protease-independent biofilm and trypsin-induced biofilm). Staphylococcus epidermidis isolates from ocular infections (OI; n = 24), prosthetic joint infections (PJI; n = 64), and healthy skin (HS-1; n = 100) were screened for protease-independent biofilm formation according to Christensen's method. The result was that there are significant differences (p < .0001) between clinical (43.2%) and commensal (17%) protease-independent biofilm producers. Meanwhile, non-biofilm-forming isolates were treated with trypsin, and biofilm formation was evaluated by the same method. The number of commensal trypsin-induced biofilm producers significantly increased from 17% to 79%. In contrast, clinical isolates increased from 43.2% to 72.7%. The comparison between clinical and commensal total biofilm yielded no significant differences (p = .392). A similar result was found when different isolation sources were compared (OI vs. HS-1 and PJI vs. HS-1). The genotype icaA^- /aap⁺ was associated with the trypsin-induced biofilm phenotype; however, no correlation was observed between aap mRNA expression and the level of trypsin-induced biofilm phenotype. Studying another group of commensal S. epidermidis non-biofilm-forming isolates (HS-2; n = 139) from different body sites, it was found that 70 isolates (60.3%) formed trypsin-induced biofilms. In conclusion, trypsin is capable of inducing biofilm production in non-biofilm-forming commensal S. epidermidis isolates with the icaA^- /aap⁺ genotype, and there is no significant difference in total biofilms when comparing clinical and commensal isolates, suggesting that total biofilms are not a discriminant biomarker.

Evolution of Daptomycin Resistance in Coagulase-Negative Staphylococci Involves Mutations of the Essential Two-Component Regulator WalKR

Coagulase-negative staphylococci (CoNS) represent one of the major causes of health care- and medical device-associated infections. Emerging antimicrobial resistance has complicated the treatment of systemic infections caused by CoNS. Here, we describe the prevalence of antimicrobial resistance in clinical CoNS strains from a tertiary care hospital over a 4-year period, and we observed a significant increase in resistance to daptomycin. Notably, Staphylococcus capitis accounted for the majority of these daptomycin-resistant (DAP-R) CoNS. To further investigate the mechanisms of daptomycin resistance in CoNS, daptomycin-susceptible clinical strains of S. capitis and Staphylococcus epidermidis underwent in vitro daptomycin exposure to generate DAP-R CoNS mutants. Unlike that seen with Staphylococcus aureus, alteration of cell surface charge was not observed in the DAP-R CoNS strains, but biofilm formation was compromised. Whole-genome sequencing analysis of the DAP-R CoNS strains identified single nucleotide polymorphisms (SNPs) in walKR, the essential two-component regulatory system controlling cell wall biogenesis. PCR and sequencing of walK and walR from 17 DAP-R CoNS clinical isolates identified seven nonsynonymous mutations. The results were confirmed by the recreation of the walK SNP in S. epidermidis, which resulted in reduced susceptibility to daptomycin and vancomycin. This study highlights the significance of CoNS in evolving daptomycin resistance and showed that walKR is shared among the staphylococcal species and is involved in antibiotic resistance development. Notably, we did not observe mutations in genes responsible for phospholipid biosynthesis or an altered cell surface charge, suggesting that reduced daptomycin susceptibility in CoNS may emerge in a fashion distinct from that in S. aureus.

The clinical impacts and risk factors for non-central line-associated bloodstream infection in 5046 intensive care unit patients: an observational study based on electronic medical records

Background

Most of the previous studies focused on central line-associated bloodstream infection (CLABSI), while non-central line-associated bloodstream infection (N-CLABSI) was poorly studied. This study was performed to investigate the clinical impacts and risk factors for N-CLABSI in intensive care unit (ICU) patients.

Methods

An observational study was conducted in an adult general ICU. The electronic medical records from 2013 to 2017 of all patients aged ≥ 18 years admitted to the ICU > 2 days were analyzed retrospectively. Patients with N-CLABSI and without N-CLABSI or with CLABSI were compared for clinical features and outcomes. Predicted death in ICU included death in ICU and discharging from ICU against medical advice because of critical conditions and the desire to pass away at home. Propensity score (PS) matching was used to ensure that both two groups had similar baseline characteristics. Multivariate regression models were used to confirm whether N-CLABSI was an independent risk factor for each of the outcomes and to analyze the risk factors for N-CLABSI in ICU patients.

Results

Of 5046 patients included, 155 developed 168 ICU-acquired N-CLABSI episodes (2.1 episodes per 1000 patient-days) in the ICU, accounted for the majority of nosocomial bloodstream infections (NBSIs; 71.8%). After PS matching, patients with N-CLABSI had prolonged length of stay (LOS) in ICU (median 15 days, p <  0.001) and LOS in hospital (median 13 days, p <  0.001), excess hospitalization costs (median, $27,668 [in US dollar 2017, 1:6.75], p <  0.001), and increased mortality in ICU (8.8%, p = 0.013) and predicted mortality in ICU (22.7%, p <  0.001), compared with those without N-CLABSI. There were no significant differences in all the outcomes between N-CLABSI and CLABSI. N-CLABSI was an independent risk factor for each of the outcomes. Gastrointestinal bleeding (adjusted odds ratio [aOR] 2.30), trauma (aOR 2.52), pancreatitis (aOR 3.45), surgical operation (aOR 1.82), intravascular catheters (aOR 2.93), sepsis (aOR 1.69), pneumonia (aOR 1.53), intraabdominal infection (IAI, aOR 8.37), or healthcare-associated infections other than NBSI, pneumonia, and IAI (aOR 3.89) were risk factors for N-CLABSI in ICU patients.

Conclusions

N-CLABSI was associated with similar poor outcomes with CLABSI, including prolonged LOS in ICU and in hospital and increased hospitalization costs and predicted mortality in ICU. The risk factors for N-CLABSI identified in this study provide further insight in preventing N-CLABSI.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2353-5) contains supplementary material, which is available to authorized users.

Staphylococcus aureus coagulases are exploitable yet stable public goods in clinically relevant conditions

Coagulation is an innate defense mechanism intended to limit blood loss and trap invading pathogens during infection. However, Staphylococcus aureus has the ability to hijack the coagulation cascade and generate clots via secretion of coagulases. Although many S. aureus have this characteristic, some do not. The population dynamics regarding this defining trait have yet to be explored. We report here that coagulases are public goods that confer protection against antimicrobials and immune factors within a local population or community, thus promoting growth and virulence. By utilizing variants of a methicillin-resistant S. aureus we infer that the secretion of coagulases is a cooperative trait, which is subject to exploitation by invading mutants that do not produce the public goods themselves. However, overexploitation, "tragedy of the commons," does not occur at clinically relevant conditions. Our micrographs indicate this is due to spatial segregation and population viscosity. These findings emphasize the critical role of coagulases in a social evolution context and provide a possible explanation as to why the secretion of these public goods is maintained in mixed S. aureus communities.

Study on the cost attributable to central venous catheter-related bloodstream infection and its influencing factors in a tertiary hospital in China

Background

Central venous catheters (CVC) have been widely used for patients with severe conditions. However, they increase the risk of catheter-related bloodstream infection (CRBSI), which is associated with high economic burden. Until now, no study has focused on the cost attributable to CRBSI in China, and data on its economic burden are unavailable. The aim of this study was to assess the cost attributable to CRBSI and its influencing factors.

Methods

A retrospective matched case-control study and multivariate analysis were conducted in a tertiary hospital, with 94 patients (age ≥ 18 years old) from January 2011 to November 2015. Patients with CRBSI were matched to those without CRBSI by age, principal diagnosis, and history of surgery. The difference in cost between the case group and control group during the hospitalization was calculated as the cost attributable to CRBSI, which included the total cost and five specific cost categories: drug, diagnostic imaging, laboratory testing, health care technical services, and medical material. The relation between the total cost attributable to CRBSI and its influencing factors such as demographic characteristics, diagnosis and treatment, and pathogenic microorganism, was analysed with a general linear model (GLM).

Results

The total cost attributable to CRBSI was $3528.6, and the costs of specific categories including drugs, diagnostic imaging, laboratory testing, health care technical services, and medical material, were $2556.4, $112.1, $321.7, $268.7, $276.5, respectively. GLM analysis indicated that the total cost was associated with the intensive care unit (ICU), pathogenic microorganism, age, and catheter number, according to the sequence of standardized estimate (β). ICU contributed the most to the model R-square.

Conclusion

Central venous catheter–related bloodstream infection represents a great economic burden for patients. More attentions should be paid to further prevent and control this infection in China.

Retrospective Cohort Analysis of Central Line Associated Blood Stream Infection following Introduction of a Central Line Bundle in a Neonatal Intensive Care Unit

Background

Central Line Associated Bloodstream Infections (CLABSI) constitute a leading cause of morbidity and mortality in neonatal populations. There has been an overwhelming increase in the use of evidence-based care practices, also known as bundles, in the reduction of these infections. In this report, rates of CLABSI and central line utilisation were examined following the introduction of a central line bundle in our Neonatal Intensive Care Unit (NICU) at the Canberra Hospital.

Methods

The research undertaken was a retrospective cohort study in which newborn infants admitted to the Canberra Hospital NICU between January 2011 and December 2016 and had a central line inserted were included in the study. Data regarding central line days, bed days, infection rates, and patient demographics were collected before and after the introduction of an intervention bundle. CLABSI rates were calculated per 1,000 central line days for before (2011-2013) and after (2014-2016) the introduction of the bundle. The postintervention period was retrospectively analysed for compliance, with data regarding the completion of maintenance forms and insertion forms collected.

Results

Overall, the results showed a significant decrease in CLABSI rates from 8.8 per 1,000 central line days to 4.9 per 1,000 central line days in the intervention period (p<0.001). Central line utilisation ratio (CLUR: ratio of central line days to bed days) was also reduced between pre- and postintervention periods, from 0.177 (4414/25013) to 0.13 (3633/27384; p<0.001). Compliance to insertion forms and maintenance forms was observed to increase within the intervention period.

Conclusion

The implementation of a central line bundle was effective in reducing both CLABSI rates and dwell time (CLUR) for central venous catheters.

Modern Strategies in the Prevention of Implant-Associated Infections

The application of medical devices either for temporary or permanent use has become an indispensible part of almost all fields of medicine. However, foreign bodies are associated with a substantial risk of bacterial and fungal infections. Implant-associated infections significantly contribute to the still increasing problem of nosocomial infections.

To reduce the incidence of such infections, specific guidelines providing evidence-based recommendations and comprising both technological and nontechnological strategies for prevention have been established. Strict adherence to hygienic rules during insertion or implantation of the device are aspects of particular importance. Besides such basic and indispensable aspects, the development of new materials which could withstand microbial adherence and colonization has become a major topic in recent years. Modification of surface by primarily physico-chemical methods may lead to a change in specific and unspecific interactions with microorganisms and, thus, to a reduction in microbial adherence. Medical devices made out of a material that would be ideally antiadhesive or at least colonization-resistant would be the most suitable candidates to avoid colonization and subsequent infection. However, it appears impossible to create a surface with an absolute “zero”-adherence due to thermodynamical reasons and due to the fact that a modified material surface is in vivo rapidly covered by plasma and connective tissue proteins. Therefore, another concept for the prevention of implant-associated infections involves the impregnation of devices with various antimicrobial substances such as antibiotics, antiseptics, and/or metals.

In fact, already commercially available materials for clinical use such as antimicrobial catheters have been introduced, in part with considerable impact on subsequent infections. However, future studies are warranted to translate the knowledge on the pathogenesis of device-associated infections into applicable prevention strategies.

Antibiotic-Impregnated Central Venous Catheters Do Not Change Antibiotic Resistance Patterns

BACKGROUND

Antibiotic-impregnated central venous catheters (CVCs) decrease the incidence of infection in high-risk patients. However, use of these catheters carries the hypothetical risk of inducing antibiotic resistance. We hypothesized that routine use of minocycline and rifampin-impregnated catheters (MR-CVC) in a single intensive care unit (ICU) would change the resistance profile for Staphylococcus aureus.

METHODS

We reviewed antibiotic susceptibilities of S. aureus isolates obtained from blood cultures in a large urban teaching hospital from 2002-2015. Resistance patterns were compared before and after implementation of MR-CVC use in the surgical ICU (SICU) in August 2006. We also compared resistance patterns of S. aureus obtained in other ICUs and in non-ICU patients, in whom MR-CVCs were not used.

RESULTS

Data for rifampin, oxacillin, and clindamycin were available for 9,703 cultures; tetracycline resistance data were available for 4,627 cultures. After implementation of MR-CVC use in the SICU, rifampin resistance remained unchanged, with rates the same as in other ICU and non-ICU populations (3%). After six years of use of MR-CVCs in the SICU, the rate of tetracycline resistance was unchanged in all facilities (1%-3%). The use of MR-CVCs was not associated with any change in S. aureus oxacillin-resistance rates in the SICU (66% vs. 60%). However, there was a significant decrease in S. aureus clindamycin resistance (59% vs. 34%; p < 0.05) in SICU patients.

CONCLUSIONS

Routine use of rifampin-minocycline-impregnated CVCs in the SICU was not associated with increased resistance of S. aureus isolates to rifampin or tetracyclines.

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.

An educational program for decreasing catheter-related bloodstream infections in intensive care units: a pre- and post-intervention observational study

Background

Central venous catheters (CVCs) are commonly used in the management of critically ill patients. This study aimed to determine whether an educational program could reduce the rate of catheter-related bloodstream infections (CRBSIs) in intensive care units (ICUs).

Findings

All patients admitted to a medical ICU at a college affiliated with the Japan Society of Intensive Care Medicine between January 2008 and December 2014 were surveyed prospectively for the development of CRBSIs. A mandatory educational program (the intervention) targeting an infection control committee consisting of physicians was developed by a multidisciplinary task force to highlight correct practices for preventing CRBSIs. The program included a 30-min video-based introduction, 120-min lectures with a number of hands-on training sessions, a post-test, posters, safety check sheets, and feedback from the infection control committee. Lectures based on the education program were held every 3 months, and participants were free to choose when they attended the lectures. Each participant was required to view the 30-min introduction before attending the 120-min lectures and complete the post-test after each lecture. Safety check sheets were made to ascertain adherence to contents of the educational program. Posters describing the educational program were posted throughout the ICU. A pre- and post-intervention observational study design was employed, with the main outcome measure being yearly CRBSIs. We also calculated cost savings that resulted from improved CRBSI rates.

During the 12-month pre-intervention period, four episodes of CRBSIs occurred in 1171 patient ICU-days (i.e., 3.4 per 1000 patient ICU-days). In the first year after the intervention, the rate of CRBSIs decreased to 0 in 1157 patient ICU-days (P ≤ 0.05). The estimated cost savings secondary to this decreased rate for the 1 year following introduction of the program was between 1850,000 and 27,000,000 yen ($14,800–$216,000).

Conclusions

A program aimed at educating healthcare providers on the prevention of CRBSIs led to a dramatic decrease in the rate of primary bloodstream infections. This suggests that educational programs may substantially decrease medical care costs and patient morbidity attributed to central venous catheterization when implemented as part of mandatory training.

Central line-associated blood stream infections: characteristics and risk factors for mortality over a 5.5-year period

BACKGROUND/AIM

Central line-associated bloodstream infections (CLABSIs) are associated with substantial morbidity and mortality and the infection rates vary in a wide range1397645907(high: 62.5%; low: 20%) in developing countries. We aimed to investigate the characteristics and the risk factors for mortality in patients with CLABSIs in intensive care units (ICUs) and provide the relevant data.

MATERIALS AND METHODS

The electronic medical records database and file records obtained through active surveillance by an infection control committee of a hospital were screened to identify patients with CLABSIs hospitalized from January 2008 through July 2013.

RESULTS

A total of 166 CLABSI episodes in 158 patients out of 17,553 on 38,562 catheter and 94,512 hospitalization days were evaluated. The infection developed in catheterized patients at a median of 14 days (range 2-88), and the highest infection rate with 13.4% (n = 20) was the femoral region among the places where the catheter was inserted. Of the patients catheterized, 54.4% survived whereas 45.6% died. In patients having Candida infection, the mortality was significantly higher. High APACHE II scores and Candida infections were found to be significant risk factors associated with mortality.

CONCLUSION

APACHE II scores and bloodstream infection with Candida species were the most powerful predictors of mortality. In ICU practice, health-care givers must consider the emerging role of Candida for both invasiveness and mortality.

Drug eluting antimicrobial vascular catheters: Progress and promise

Vascular catheters are critical tools in modern healthcare yet present substantial risks of serious bloodstream infections that exact significant health and economic burdens. Drug-eluting antimicrobial vascular catheters have become important tools in preventing catheter-related bloodstream infections and their importance is expected to increase as significant initiatives are expanded to eliminate and make the occurrence of these infections unacceptable. Here we review clinically significant and emerging drug-eluting antimicrobial catheters within the categories of antibiotic, antiseptic, novel bioactive agents and energy-enhanced drug eluting antimicrobial catheters. Important representatives of each category are reviewed from the standpoints of mechanisms of action, physical-chemical properties, safety, in vitro and clinical effectiveness.

Chlorhexidine-silver sulfadiazine-impregnated venous catheters are efficient even at subclavian sites without tracheostomy

BACKGROUND

Chlorhexidine-silver sulfadiazine (CHSS)-impregnated catheters have been found to decrease the risk of catheter-related bloodstream infection (CRBSI) and central venous catheter (CVC)-related costs. However, there are no published data about cost-effectiveness of the use of CHSS-impregnated catheters in subclavian venous access without the presence of tracheostomy (thus, with a very low risk of CRBSI). That was the objective of this study.

METHODS

This was a retrospective study of patients admitted to a mixed intensive care unit who underwent placement of subclavian venous catheters without the presence of tracheostomy.

RESULTS

Patients with standard catheters (n = 747) showed a higher CRBSI incidence density (0.95 vs 0/1,000 catheter-days; P = .02) and higher CVC-related cost per day ($3.78 ± $7.43 vs $3.31 ± $2.72; P < .001) than patients with a CHSS-impregnated catheter (n = 879). Exact logistic regression analysis showed that catheter duration (P = .02) and the type of catheter used (P = .01) were associated with the risk of CRBSI. Kaplan-Meier method showed that CHSS-impregnated catheters were associated with more prolonged CRBSI-free time than standard catheters (log-rank = 9.76; P = .002). Poisson regression analysis showed that CHSS-impregnated catheters were associated with a lower central venous catheter-related cost per day than standard catheters (odds ratio, 0.87; 95% confidence interval, 0.001-0.903; P < .001).

CONCLUSIONS

The use of CHSS-impregnated catheters is an effective and efficient measure for the prevention of CRBSI even at subclavian venous access sites without the presence of tracheostomy.

Prevalence, risk factors, and outcomes of idle intravenous catheters: An integrative review

OBJECTIVE

Complications of intravenous catheters remain a major contributor to health care costs and are a patient safety problem. An intravenous catheter not actively in use-an idle catheter-may increase the risk of infectious and noninfectious complications. We conducted an integrative review of the available literature to evaluate the prevalence, risk factors, and outcomes associated with idle intravenous catheters.

METHODS

Searches of multiple computerized databases were conducted to identify studies on idle intravenous catheters. Data on definitions of idle catheter, type of catheter, prevalence, risk factors, and patient outcomes were extracted.

RESULTS

Thirteen studies met inclusion criteria and were included in the review. The location and setting of the studies were diverse, including cross-sectional, retrospective, and prospective, and were conducted in varied geographic locations. The definition of an idle catheter was variable across studies. Although studies varied in terms of line-days or number of catheters placed, the primary definition of idle device was based on number of days or percent of devices left in situ without use. Four studies evaluated patient outcomes associated with idle catheters and found increased risk of infection, intensive care unit admission, and phlebitis.

CONCLUSIONS

Idle intravenous catheters are common and are associated with adverse outcomes. Prospective studies incorporating uniform definitions of idle catheters to test interventions to reduce idle catheter use are urgently needed.

Co-release of dicloxacillin and thioridazine from catheter material containing an interpenetrating polymer network for inhibiting device-associated Staphylococcus aureus infection

Approximately half of all nosocomial bloodstream infections are caused by bacterial colonization of vascular catheters. Attempts have been made to improve devices using anti-adhesive or antimicrobial coatings; however, it is often difficult to bind coatings stably to catheter materials, and the low amounts of drug in thin-film coatings limit effective long-term release. Interpenetrating polymer networks (IPNs) are polymer hybrid materials with unique drug release properties. While IPNs have been extensively investigated for use in tablet- or capsule-based drug delivery systems, the potential for use of IPNs in drug release medical devices remains largely unexplored. Here, we investigated the use of silicone-hydrogel IPNs as a catheter material to provide slow anti-bacterial drug-release functionality. IPN catheters were produced by the sequential method, using supercritical CO₂ as a solvent to polymerize and crosslink poly(2-hydroxyethyl methacrylate) (PHEMA) in silicone elastomer. The design was tested against Staphylococcus aureus colonization after loading with dicloxacillin (DCX) alone or in combination with thioridazine (TDZ), the latter of which is known to synergistically potentiate the antibacterial effect of DCX against both methicillin-sensitive and methicillin-resistant S. aureus. The hydrophilic PHEMA component allowed for drug loading in the catheters by passive diffusion and provided controlled release properties. The drug-loaded IPN material inhibited bacterial growth on agar plates for up to two weeks and in blood cultures for up to five days, and it withstood 24h of seeding with resilient biofilm aggregates. The combined loading of DCX+TDZ enhanced the antibacterial efficiency in static in vitro experiments, although release analyses revealed that this effect was due to an enhanced loading capacity of DCX when co-loaded with TDZ. Lastly, the IPN catheters were tested in a novel porcine model of central venous catheter-related infection, in which drug-loaded IPN catheters were found to significantly decrease the frequency of infection.

Why Is It That Internists Do Not Follow Guidelines for Preventing Intravascular Catheter Infections?

Background and Objective:

High morbidity of CVC-related infections has led to national guidelines for their prevention. Despite recommendations for the use of maximal barrier precautions (mask, sterile gloves, gown, and large drape) and skin antisepsis with 2% Chlorhexidine gluconate during CVC insertion, internists in the United States are not implementing these practices frequently. This study sought to identify and characterize the obstacles to and potential opportunities for improving adherence.

Design:

Cross-sectional survey.

Participants:

One thousand randomly selected physician-members of the American College of Physicians-American Society of Internal Medicine.

Methods:

Several potential determinants of adherence to maximal barrier precautions were assessed, including awareness of, agreement with, and ability to implement the recommendation, as well as the practice and training characteristics of the respondents. Factors influencing antiseptic selection were also recorded.

Results:

Of 526 respondents, 178 (34%) had recently inserted CVCs. Clinician experience and subspecialty, awareness of CDC guidelines, and external influences (eg, time to collect equipment) did not affect maximal barrier precautions adherence. The only independent predictor of adherence was high outcome expectancy for the use of large sterile drapes (OR, 5.3; CI95, 2.2-12.6). Availability had the greatest influence on internists' selection of specific antiseptic agents, whereas cost was the least important determinant.

Conclusions:

Despite established efficacy, use of maximal barrier precautions and Chlorhexidine gluconate is low among internists. Because improved adherence to these practices will require increased outcome expectancy for maximal barrier precautions and availability of Chlorhexidine gluconate, targeting these areas through focused education and systems modifications is essential (Infect Control Hosp Epidemiol2005;26:525-533).

Characterizing the in vitro biofilm phenotype of Staphylococcus epidermidis isolates from central venous catheters

Central venous catheter (CVC)-related infections are commonly caused by Staphylococcus epidermidis that is able to form a biofilm on the catheter surface. Many studies involving biofilm formation by Staphylococcus have been published each adopting an own in vitro model. Since the capacity to form a biofilm depends on multiple environmental factors, direct comparison of results obtained in different studies remains challenging. This study characterized the phenotype (strong versus weak biofilm-producers) of S. epidermidis from CVCs in four different in vitro biofilm models, covering differences in material type (glass versus polymer) and nutrient presentation (static versus continuous flow). A good correlation in phenotype was obtained between glass and polymeric surfaces independent of nutrient flow, with 85% correspondence under static growth conditions and 80% under dynamic conditions. A 80% correspondence between static and dynamic conditions on polymeric surfaces could be demonstrated as well. Incubation time had a significant influence on the biofilm phenotype with only 55% correspondence between the dynamic models at different incubation times (48h versus 17h). Screening for the presence of biofilm-related genes only revealed that ica A was correlated with biofilm formation under static but not under dynamic conditions. In conclusion, this study highlights that a high level of standardization is necessary to interpret and compare results of different in vitro biofilm models.

Clinical and economic burden of bloodstream infections in critical care patients with central venous catheters

PURPOSE

Bloodstream infections (BSIs) complicate the management of intensive care unit (ICU) patients. We assessed the clinical and economic impact of BSI among patients of a managed care provider group who had a central venous catheter (CVC) placed in the ICU.

METHODS

We considered hospitalizations occurring between January 1, 2011, and September 30, 2014, that involved an ICU stay during which a CVC was placed. Comparisons were made between episodes where the patient did vs did not develop BSI after CVC insertion. Length of stay, costs of index hospitalization, and total costs over the 180 days after discharge were compared using linear mixed models. Inhospital mortality and 30-day readmission rates were compared using negative binomial regression models.

RESULTS

Development of BSI was associated with longer hospital stay (+7 days), more than 3-fold increase in risk of inhospital death, and an additional $129 000 in costs for the index hospitalization. No statistically significant differences in 30-day readmission rates or costs of care over the 180-day period after discharge from the index admission were observed.

CONCLUSION

Bloodstream infections after CVC placement in ICU patients are associated with significant increases in costs of care and risk of death during the index hospitalization but no differences in readmissions or costs after discharge.

Strategies to Prevent Central Line-Associated Bloodstream Infections in Acute Care Hospitals: 2014 Update

Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections (HAIs). The intent of this document is to highlight practical recommendations in a concise format designed to assist acute care hospitals in implementing and prioritizing their central line-associated bloodstream infection (CLABSI) prevention efforts. This document updates “Strategies to Prevent Central Line-Associated Bloodstream Infections in Acute Care Hospitals,” published in 2008. This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA) and is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA), the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise. The list of endorsing and supporting organizations is presented in the introduction to the 2014 updates.

Antimicrobial-impregnated catheters for the prevention of catheter-related bloodstream infections

Central venous catheters are commonly used in critically ill patients. Such catheterization may entail mechanical and infectious complications. The interest in catheter-related infection lies in the morbidity, mortality and costs that it involved. Numerous contributions have been made in the prevention of catheter-related infection and the current review focuses on the possible current role of antimicrobial impregnated catheters to reduce catheter-related bloodstream infections (CRBSI). There is evidence that the use of chlorhexidine-silver sulfadiazine (CHSS), rifampicin-minocycline, or rifampicin-miconazol impregnated catheters reduce the incidence of CRBSI and costs. In addition, there are some clinical circumstances associated with higher risk of CRBSI, such as the venous catheter access and the presence of tracheostomy. Current guidelines for the prevention of CRBSI recommended the use of a CHSS or rifampicin-minocycline impregnated catheter in patients whose catheter is expected to remain in place > 5 d and if the CRBSI rate has not decreased after implementation of a comprehensive strategy to reduce it.

Impact of definition and procedures used for absent blood culture data on the rate of intravascular catheter infection during parenteral nutrition

BACKGROUND

Diagnosis of intravascular catheter infection may be affected by the definition and procedures applied in the absence of blood culture data.

AIM

To examine the extent to which different definitions of catheter infection and procedures for handling absent blood culture data can affect reported catheter infection rates.

METHODS

Catheter infection rates were established in a cohort of hospitalized patients administered parenteral nutrition according to three clinical and four published definitions. Paired and unpaired comparisons were made using available case analyses, sensitivity analyses and intention-to-categorize analyses.

FINDINGS

Complete data were available for each clinical definition (N = 193), and there were missing data (4.1-26.9%) for the published definitions. In an available case analysis, the catheter infection rate was 13.0-36.8% for the clinical definitions and 2.1-12.4% for the published definitions. For the published definitions, the rate was 1.6-32.1% in a sensitivity analysis and 11.4-16.9% in an intention-to-categorize analysis, with suggestion of bias towards a higher catheter infection rate in those with missing data, in keeping with the analyses of the clinical definitions. For paired comparisons, the strength of agreement between definitions varied from 'poor' (Cohen's kappa <0.21) to 'very good' (Cohen's kappa ≥0.81).

CONCLUSION

The use of different definitions of catheter infection and procedures applied in the absence of blood culture data produced widely different catheter infection rates, which could compromise measurements or comparisons of service quality or study outcome. As such, there is a need to establish and use a valid, consistent and practical definition.

Limitations of Murine Models for Assessment of Antibody-Mediated Therapies or Vaccine Candidates against Staphylococcus epidermidis Bloodstream Infection

Staphylococcus epidermidis is normally a commensal colonizer of human skin and mucus membranes, but, due to its ability to form biofilms on indwelling medical devices, it has emerged as a leading cause of nosocomial infections. Bacteremia or bloodstream infection is a frequent and costly complication resulting from biofilm fouling of medical devices. Our goal was to develop a murine model of S. epidermidis infection to identify potential vaccine targets for the prevention of S. epidermidis bacteremia. However, assessing the contribution of adaptive immunity to protection against S. epidermidis challenge was complicated by a highly efficacious innate immune response in mice. Naive mice rapidly cleared S. epidermidis infections from blood and solid organs, even when the animals were immunocompromised. Cyclophosphamide-mediated leukopenia reduced the size of the bacterial challenge dose required to cause lethality but did not impair clearance after a nonlethal challenge. Nonspecific innate immune stimulation, such as treatment with a Toll-like receptor 4 (TLR4) agonist, enhanced bacterial clearance. TLR2 signaling was confirmed to accelerate the clearance of S. epidermidis bacteremia, but TLR2(-/-)mice could still resolve a bloodstream infection. Furthermore, TLR2 signaling played no role in the clearance of bacteria from the spleen. In conclusion, these data suggest that S. epidermidis bloodstream infection is cleared in a highly efficient manner that is mediated by both TLR2-dependent and -independent innate immune mechanisms. The inability to establish a persistent infection in mice, even in immunocompromised animals, rendered these murine models unsuitable for meaningful assessment of antibody-mediated therapies or vaccine candidates.

Antimicrobial lock solutions for the prevention of catheter-related infection in patients undergoing haemodialysis: study protocol for network meta-analysis of randomised controlled trials

INTRODUCTION

Catheter-related infection (CRI) is a difficult clinical problem in renal medicine, with blood stream infections occurring in up to 40% of patients with haemodialysis (HD) catheters, conferring significant rates of morbidity and mortality. Several approaches have been assessed as a means to prevent CRI. Currently, an intervention that is the source of much discussion is the use of antimicrobial lock solutions (ALS). A number of past conventional meta-analyses have compared different ALS with heparin. However, there is no consensus recommendation regarding which type of ALS is best. The purpose of our study is to carry out a network meta-analysis comparing the efficacy of different ALS for prevention of CRI in patients with HD and ranking these ALS for practical consideration.

METHODS AND ANALYSIS

We will search six electronic databases, earlier relevant meta-analyses and reference lists of included studies for randomised controlled trials (RCTs) that compared ALS for preventing episodes of CRI in patients with HD either head-to-head or against control interventions using non-ALS. Study selection and data collection will be performed by two reviewers independently. The Cochrane Risk of Bias Tool will be used to assess the quality of included studies. The primary outcome of efficacy will be catheter-related bloodstream infection (CRBSI). We will perform a Bayesian network meta-analysis to compare the relative efficacy of different ALS by WinBUGS (V.1.4.3) and STATA (V.13.0). The quality of evidence will be assessed by GRADE.

ETHICS AND DISSEMINATION

Ethical approval is not required given that this study includes no confidential personal data and no data on interventions on patients. The results of this study will be submitted to a peer-review journal for publication.

TRIAL REGISTRATION NUMBER

CRD42015027010.

Chlorhexidine-silver sulfadiazine- or rifampicin-miconazole-impregnated venous catheters decrease the risk of catheter-related bloodstream infection similarly

BACKGROUND

The objective of this study was to compare the incidence of catheter-related bloodstream infection (CRBSI) with the use of second-generation chlorhexidine-silver sulfadiazine (CHSS)-impregnated catheters, rifampicin-miconazole (RM)-impregnated catheters, and standard catheters.

METHODS

Retrospective study of patients admitted to an intensive care unit who received CHSS, RM, or standard catheters in femoral venous access.

RESULTS

We diagnosed 18 CRBSIs in 245 patients with standard catheters in 2,061 days, zero CRBSI in 169 patients with CHSS-impregnated catheters in 1,489 days, and zero CRBSI in 227 patients with RM-impregnated catheters in 2,009 days. Patients with standard catheters compared with CHSS- and RM-impregnated catheters showed a higher rate of CRBSI (7.3%, 0%, and 0%, respectively; P < .001) and higher incidence density of CRBSI (8.7, 0, and 0 per 1,000 catheter days, respectively; P < .001). We found in the exact Poisson regression that standard catheters were associated with a higher CRBSI incidence than CHSS-impregnated catheters (P < .001) and RM-impregnated catheters (P < .001), controlling for catheter duration. We found in survival analysis that standard catheters were associated with a lower CRBSI-free time than CHSS-impregnated catheters (P < .001) and RM-impregnated catheters (P < .001).

CONCLUSION

We found that CHSS- and RM-impregnated catheters decreased similarly the risk of CRBSI.

Detection of central venous catheter-related bloodstream infections in haematooncological patients

BACKGROUND

Catheter-related bloodstream infections (CRBSIs) are currently detected in patients with clinically suspicion. The aim of our study was to evaluate whether CRBSIs could be anticipated and detected in a subclinical stage by peptide nucleic acid fluorescence in situ hybridization (PNA FISH) using universal hybridization probes or acridine orange leucocyte cytospin (AOLC) tests in haematooncological patients with central venous catheters (CVCs) in situ.

MATERIALS AND METHODS

Peptide nucleic acid fluorescence in situ hybridization and AOLC tests using blood samples from one CVC lumen/port chamber in haematooncological patients were continuously performed. These results were compared to those obtained from routinely performed CRBSI diagnostic tests.

RESULTS

One hundred and eighty-two patients with 342 catheter periods were investigated. Seventeen CRBSI cases were detected in 6466 CVC days by routine measures resulting in a CRBSI rate of 2.6/1000 catheter days. Two of 17 showed positive PNA FISH tests, and five positive AOLC test results before the diagnosis were established with routine measures. The screening revealed further seven patients with positive universal PNA FISH tests and 10 positive AOLC tests without symptoms indicative for infection and were therefore considered not to have CRBSI.

CONCLUSIONS

Sampling of only one CVC lumen/port chamber screening for CRBSI in haematooncological patients seems not to be a useful tool for anticipative diagnosis of CRBSI. Reasons for false-negative results might include origin of CRBSIs from the other CVC lumina not sampled for screening, and false-positive results might origin from catheter colonization without subsequent spread of micro-organisms into the peripheral bloodstream.

Advances in prevention and management of central line-associated bloodstream infections in patients with cancer

Central lines, which are essential for treating cancer, are associated with at least 400,000 episodes of bloodstream infection in patients with cancer every year in the United States. Effective novel interventions for preventing and managing these infections include antimicrobial-coated catheters and antimicrobial lock solutions.

Efficiency of chlorhexidine-silver sulfadiazine-impregnated venous catheters at subclavian sites

BACKGROUND

Cost-effectiveness analyses show that chlorhexidine-silver sulfadiazine (CHSS)-impregnated catheters reduce catheter-related bloodstream infection (CRBSI) and central venous catheter (CVC)-related costs. However, no studies have reported the efficiency of CHSS-impregnated catheters for venous access when the risk of CRBSI is low; for example, at the subclavian site. This study determined the cost of a CVC, diagnosis of CRBSI, and antimicrobial agents to treat CRBSI; we did not consider the cost of increased hospital stay.

METHODS

This retrospective study included patients admitted to the intensive care unit at Hospital Universitario de Canarias (Tenerife, Spain) who had a subclavian venous catheter.

RESULTS

Patients with CHSS catheters (n = 353) had a lower incidence density of CRBSI (2.12 vs 0 out of 1,000 catheter-days; P = .02) and lower CVC-related cost per catheter-day (3.35 ± 3.75 vs 3.94 ± 9.95; P = .002) than those with standard catheters (n = 518). CHSS-impregnated catheters were associated with a lower risk of CRBSI (exact logistic regression) (odds ratio, 0.10; 95% confidence interval, -∞ to 0.667; P = .008) than standard catheters when controlling for catheter duration. CHSS-impregnated catheters were also associated with a lower CVC-related cost per catheter day than standard catheters (Poisson regression) (odds ratio, 0.85; 95% confidence interval, 0.001-0.873; P < .001).

CONCLUSIONS

CHSS-impregnated catheters may be efficient in preventing CRBSI in patients with subclavian venous access.

Cost-Effectiveness Analysis of a Transparent Antimicrobial Dressing for Managing Central Venous and Arterial Catheters in Intensive Care Units

OBJECTIVE

To model the cost-effectiveness impact of routine use of an antimicrobial chlorhexidine gluconate-containing securement dressing compared to non-antimicrobial transparent dressings for the protection of central vascular lines in intensive care unit patients.

DESIGN

This study uses a novel health economic model to estimate the cost-effectiveness of using the chlorhexidine gluconate dressing versus transparent dressings in a French intensive care unit scenario. The 30-day time non-homogeneous markovian model comprises eight health states. The probabilities of events derive from a multicentre (12 French intensive care units) randomized controlled trial. 1,000 Monte Carlo simulations of 1,000 patients per dressing strategy are used for probabilistic sensitivity analysis and 95% confidence intervals calculations. The outcome is the number of catheter-related bloodstream infections avoided. Costs of intensive care unit stay are based on a recent French multicentre study and the cost-effectiveness criterion is the cost per catheter-related bloodstream infections avoided. The incremental net monetary benefit per patient is also estimated.

PATIENTS

1000 patients per group simulated based on the source randomized controlled trial involving 1,879 adults expected to require intravascular catheterization for 48 hours.

INTERVENTION

Chlorhexidine Gluconate-containing securement dressing compared to non-antimicrobial transparent dressings.

RESULTS

The chlorhexidine gluconate dressing prevents 11.8 infections /1,000 patients (95% confidence interval: [3.85; 19.64]) with a number needed to treat of 85 patients. The mean cost difference per patient of €141 is not statistically significant (95% confidence interval: [€-975; €1,258]). The incremental cost-effectiveness ratio is of €12,046 per catheter-related bloodstream infection prevented, and the incremental net monetary benefit per patient is of €344.88.

CONCLUSIONS

According to the base case scenario, the chlorhexidine gluconate dressing is more cost-effective than the reference dressing.

TRIAL REGISTRATION

This model is based on the data from the RCT registered with www.clinicaltrials.gov (NCT01189682).