Early diagnosis of candidemia in intensive care unit patients with sepsis: a prospective comparison of (1→3)-β-D-glucan assay, Candida score, and colonization index

A novel quantitative double antigen sandwich ELISA for detecting total antibodies against Candida albicans enolase 1

PURPOSE

This study aimed to develop a double antigen sandwich ELISA (DAgS-ELISA) method for more efficient, accurate, and quantitative detection of total antibodies against Candida albicans enolase1 (CaEno1) for diagnosing invasive candidiasis (IC).

METHODS

DAgS-ELISA was developed using recombinant CaEno1 and a monoclonal antibody as the standard. Performance evaluation included limit of detection, accuracy, and repeatability. Dynamic changes in antibody levels against CaEno1 in serum from systemic candidiasis mice were analyzed using DAgS-ELISA. Patient serum samples from IC, Candida colonization, bacterial infections, and healthy controls were analyzed with DAgS-ELISA and indirect ELISA.

RESULTS

DAgS-ELISA outperformed indirect ELISA in terms of linear range and test background. In systemic candidiasis mice, a distinctive 'double-peak' pattern in dynamic antibody levels was observed. Additionally, there was a high level of consistency in the positive rates of CaEno1 antibodies detected by both DAgS-ELISA and indirect ELISA. While the positivity rates differed among patient groups, no significant variations in antibody levels were detected among the various positive patient groups.

CONCLUSIONS

DAgS-ELISA offers a reliable novel approach for IC diagnosis, enabling rapid, accurate, and quantitative detection of CaEno1 antibodies. Further validation and optimization are needed for its clinical application and effectiveness.

Evaluation of colonization index and (1,3)- ß- D glucan as diagnostic tools of invasive candidiasis in a pediatric Intensive Care Unit

PURPOSE

The study aimed to evaluate the corrected colonization index (CCI) and (1, 3)-ß-D Glucan (BDG) in diagnosis of Invasive Candidiasis (IC) in critically ill pediatric patients.

METHODS

A prospective observational study in a tertiary care (PICU) were surveyed for Candida colonization and CCI was calculated. For cases with suspicious clinical presentation, samples were cultured, and double(1,3) ß-D- glucan (BDG) performed.

RESULTS

According to the European Organization for Research and Treatment of Cancer EORTC case definition for critically ill non-neutropenic patients, only 7.14 % (9/188) were diagnosed as IC (4 proven and 5 probable cases). The combined use of CCI with BDG proved to have excellent discriminative power AUC= 0.946, improved sensitivity 87.5 % and specificity 85.71 %.

CONCLUSION

The key in diagnosis of IC relies in compiling proofs from the clinical context, high CCI (≥ 0.4) and BDG.

Diagnosis and management of invasive fungal diseases in non-neutropenic ICU patients, with focus on candidiasis and aspergillosis: a comprehensive review

Invasive fungal diseases pose a significant threat to non-neutropenic ICU patients, with Candida and Aspergillus infections being the most common. However, diagnosing these infections in the ICU population remains challenging due to overlapping clinical features, poor sensitivity of blood cultures, and invasive sampling requirements. The classical host criteria for defining invasive fungal disease do not fully apply to ICU patients, leading to missed or delayed diagnoses. Recent advancements have improved our understanding of invasive fungal diseases, leading to revised definitions and diagnostic criteria. However, the diagnostic difficulties in ICU patients remain unresolved, highlighting the need for further research and evidence generation. Invasive candidiasis is the most prevalent form of invasive fungal disease in non-neutropenic ICU patients, presenting as candidemia and deep-seated candidiasis. Diagnosis relies on positive blood cultures or histopathology, while non-culture-based techniques such as beta-D-glucan assay and PCR-based tests show promise. Invasive aspergillosis predominantly manifests as invasive pulmonary aspergillosis in ICU patients, often associated with comorbidities and respiratory deterioration in viral pneumonia. Diagnosis remains challenging due to poor sensitivity of blood cultures and difficulties in performing lung biopsies. Various diagnostic criteria have been proposed, including mycological evidence, clinical/radiological factors and expanded list of host factors. Non-culture-based techniques such as galactomannan assay and PCR-based tests can aid in diagnosis. Antifungal management involves tailored therapy based on guidelines and individual patient factors. The complexity of diagnosing and managing invasive fungal diseases in ICU patients underscore the importance of ongoing research and the need for updated diagnostic criteria and treatment approaches. Invasive fungal disease, Invasive fungal infection, Invasive candidiasis, Invasive aspergillosis, Antifungal drugs.

Early diagnosis of candidemia with explainable machine learning on automatically extracted laboratory and microbiological data: results of the AUTO-CAND project

BACKGROUND

Candidemia is associated with a heavy burden of morbidity and mortality in hospitalized patients. The availability of blood culture results could require up to 48-72 h after blood draw; thus, early treatment decisions are made in the absence of a definite diagnosis.

METHODS

In this retrospective study, we assessed the performance of different supervised machine learning algorithms for the early differential diagnosis of candidemia and bacteremia in adult patients on a large dataset automatically extracted within the AUTO-CAND project.

RESULTS

Overall, 12,483 episodes of candidemia (1275; 10%) or bacteremia (11,208; 90%) were included in the analysis. A random forest classifier achieved the best diagnostic performance for candidemia, with sensitivity 0.98 and specificity 0.65 on the training set (true skill statistic [TSS] = 0.63) and sensitivity 0.74 and specificity 0.57 on the test set (TSS = 0.31). Then, the random classifier was trained in the subgroup of patients with available serum β-D-glucan (BDG) and procalcitonin (PCT) values by exploiting the feature ranking learned in the entire dataset. Although no statistically significant differences were observed from the performance measures obtained by employing BDG and PCT alone, the performance measures of the classifier that included the features selected in the entire dataset, plus BDG and PCT, were the highest in most cases.

CONCLUSIONS

Random forest classifiers trained on large datasets of automatically extracted data have the potential to improve current diagnostic algorithms for candidemia. However, further development through implementation of automatically extracted clinical features may be necessary to achieve crucial improvements.

Detailed β-(1→3)-D-glucan and mannan antigen kinetics in patients with candidemia

Fungal antigens such as β-(1→3)-D-glucan (BDG) or mannan (Mn) are useful for detection of candidemia. However, detailed data on serum levels before diagnosis and during treatment are scarce. We conducted a prospective study at two German tertiary care centers for 36 months. Sera from adult patients with candidemia were tested for BDG (Fungitell assay) and Mn (Platelia Candida Ag-Plus assay). For each patient, the clinical course and biomarker kinetics were closely followed and compared. 1,243 sera from 131 candidemia episodes and 15 relapses were tested. In 35% of episodes, empirical therapy included an antifungal drug. Before blood culture sampling, BDG and Mn levels were elevated in 62.4% and 30.8% of patients, respectively. Sensitivity at blood culture sampling was 78.6% (BDG) and 35.1% (Mn). BDG levels of non-survivors were significantly higher than those of survivors. During follow-up, a therapeutic response was associated with decreasing BDG and Mn levels in 84.3% or 70.5% of episodes, respectively. A median increase of 513 pg BDG/mL and 390 pg Mn/mL indicated a relapse of candidemia with a sensitivity of 80% or 46.7%, respectively. In 72.9% and 46.8% of patients, increasing BDG or Mn levels were associated with a fatal outcome. Prior to discharge, BDG and Mn levels had dropped or normalized in 65.7% or 82.1% of patients, respectively. Summarising, in patients with candidemia, biomarker positivity usually precedes culture positivity. Relapses are mostly accompanied by secondary biomarker increases. Rising concentrations of BDG and Mn predict lethality, whereas decreasing levels suggest a favorable outcome in the majority of patients.

Invasive Candida infection: epidemiology, clinical and therapeutic aspects of an evolving disease and the role of rezafungin

INTRODUCTION

Invasive Candida Infections (ICIs) have undergone a series of significant epidemiological, pathophysiological, and clinical changes during the last decades, with a shift toward non-albicans species, an increase in the rate of exogenous infections and clinical manifestations ranging from candidemia to an array of highly invasive and life-threatening clinical syndromes. The long-acting echinocandin rezafungin exhibits potent in-vitro activity against most wild-type and azole-resistant Candida spp. including C.auris.

AREAS COVERED

The following topics regarding candidemia only and ICIs were reviewed and addressed: i) pathogenesis; ii) epidemiology and temporal evolution of Candida species; iii) clinical approach; iv) potential role of the novel long-acting rezafungin in the treatment of ICIs.

EXPERT OPINION

Authors' expert opinion focused on considering the potential role of rezafungin in the evolving context of ICIs. Rezafungin, which combines a potent in-vitro activity against Candida species, including azole-resistant strains and C.auris, with a low likelihood of drug-drug interactions and a good safety profile, may revolutionize the treatment of candidemia/ICI. Indeed, it may shorten the length of hospital stays when clinical conditions allow and extend outpatient access to treatment of invasive candidiasis, especially when prolonged treatment duration is expected.

Clinical Sensitivity of the (1-3)-β-D-glucan Test for Predicting Candidemia

The sensitivity of the (1-3)-β-D-glucan (BDG) diagnostic test for candidemia varies in different clinical settings, and its usefulness in early diagnosis of candidemia is suboptimal. We evaluated the sensitivity of the test for early candidemia prediction. All adult patients with culture-proven candidemia who underwent a serum Goldstream Fungus (1-3)-β-D-Glucan Test within seven days prior to candidemia onset at a tertiary referral hospital between January 2017 and May 2021 were included. Any-positive BDG results within seven days prior to candidemia onset were obtained in 38 out of 93 (40.9%) patients. The positive rate increased when the test was performed near the day of candidemia onset (P=0.04) but reached only 52% on the day of candidemia onset. We observed no significant differences between BDG-positive and -negative groups in terms of underlying disease, risk factors for candidemia, clinical presentation, origin of candidemia, and 30-day mortality. Candida albicans was significantly associated with positive BDG results than with all-negative BDG results (P=0.04). The Goldstream BDG test is unreliable for candidemia prediction because of its low sensitivity. Negative BDG results in patients with a high risk of invasive candidiasis should be interpreted with caution.

Invasive candidiasis: current clinical challenges and unmet needs in adult populations

Invasive candidiasis (IC) is a serious infection caused by several Candida species, and the most common fungal disease in hospitals in high-income countries. Despite overall improvements in health systems and ICU care in the last few decades, as well as the development of different antifungals and microbiological techniques, mortality rates in IC have not substantially improved. The aim of this review is to summarize the main issues underlying the management of adults affected by IC, focusing on specific forms of the infection: IC developed by ICU patients, IC observed in haematological patients, breakthrough candidaemia, sanctuary site candidiasis, intra-abdominal infections and other challenging infections. Several key challenges need to be tackled to improve the clinical management and outcomes of IC patients. These include the lack of global epidemiological data for IC, the limitations of the diagnostic tests and risk scoring tools currently available, the absence of standardized effectiveness outcomes and long-term data for IC, the timing for the initiation of antifungal therapy and the limited recommendations on the optimal step-down therapy from echinocandins to azoles or the total duration of therapy. The availability of new compounds may overcome some of the challenges identified and increase the existing options for management of chronic Candida infections and ambulant patient treatments. However, early identification of patients that require antifungal therapy and treatment of sanctuary site infections remain a challenge and will require further innovations.

Validation of an Automated System for the Extraction of a Wide Dataset for Clinical Studies Aimed at Improving the Early Diagnosis of Candidemia

There is increasing interest in assessing whether machine learning (ML) techniques could further improve the early diagnosis of candidemia among patients with a consistent clinical picture. The objective of the present study is to validate the accuracy of a system for the automated extraction from a hospital laboratory software of a large number of features from candidemia and/or bacteremia episodes as the first phase of the AUTO-CAND project. The manual validation was performed on a representative and randomly extracted subset of episodes of candidemia and/or bacteremia. The manual validation of the random extraction of 381 episodes of candidemia and/or bacteremia, with automated organization in structured features of laboratory and microbiological data resulted in ≥99% correct extractions (with confidence interval < ±1%) for all variables. The final automatically extracted dataset consisted of 1338 episodes of candidemia (8%), 14,112 episodes of bacteremia (90%), and 302 episodes of mixed candidemia/bacteremia (2%). The final dataset will serve to assess the performance of different ML models for the early diagnosis of candidemia in the second phase of the AUTO-CAND project.

Quantitatively detecting Candida albicans enolase1 with a one-step double monoclonal antibody sandwich ELISA assay

Invasive candidiasis (IC) is often a cause of severe concern for the hospitalized patients, particularly those who are critically sick. However management of this disease is challenging due to a lack of effective laboratory diagnostic techniques. Hence, we have developed a one-step double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) using a pair of specific monoclonal antibodies (mAbs) for the quantitative detection of Candida albicans enolase1 (CaEno1), which is considered as an important diagnostic biomarker for IC. The diagnostic efficiency of the DAS-ELISA was evaluated by using a rabbit model of systemic candidiasis and compared with other assays. The method validation results demonstrated that the developed method was sensitive, reliable, and feasible. The findings of the rabbit model plasma analysis indicated that the diagnostic efficiency of the CaEno1 detection assay was better in comparison to the (1,3)-β-D-glucan detection and blood culture. CaEno1 is present in the blood of infected rabbits for a brief period and at relatively low levels and thus the combination of CaEno1 antigen and IgG antibodies detection could aid to increase diagnostic efficiency. However, to improve the clinical application of CaEno1 detection in the future, efforts should be made to increase the detection limit of the test by promoting technical developments and by optimizing the protocol for the clinical serial determinations.

The Changing Landscape of Invasive Fungal Infections in ICUs: A Need for Risk Stratification to Better Target Antifungal Drugs and the Threat of Resistance

The landscape of invasive candidiasis and invasive aspergillosis has changed dramatically in intensive care units over the past two decades. Today, we are faced with new risk factors such as the emergence of resistance, but are also equipped with new therapeutic strategies and diagnostic tools which are changing epidemiological data and diagnostic algorithms. Some common points need to be addressed: (i) the best way to use microbiological tools and to integrate their results in decisional algorithms; (ii) the need to find the optimum balance between under-diagnosis and overtreatment; (iii) and the need to decipher pathophysiology. In this short review, we will try to illustrate these points.

Performance of existing clinical scores and laboratory tests for the diagnosis of invasive candidiasis in critically ill, nonneutropenic, adult patients: a systematic review with qualitative evidence synthesis

BACKGROUND

The Fungal Infections Definitions in Intensive Care Unit (ICU) patients (FUNDICU) project aims to provide standard sets of definitions for invasive fungal diseases in critically ill, adult patients.

OBJECTIVES

To summarize the available evidence on the diagnostic performance of clinical scores and laboratory tests for invasive candidiasis (IC) in nonneutropenic, adult critically ill patients.

METHODS

A systematic review was performed to evaluate studies assessing the diagnostic performance for IC of clinical scores and/or laboratory tests vs. a reference standard or a reference definition in critically ill, nonneutropenic, adult patients in ICU.

RESULTS

Clinical scores, despite the heterogeneity of study populations and IC prevalences, constantly showed a high negative predictive value (NPV) and a low positive predictive value (PPV) for the diagnosis of IC in the target population. Fungal antigen-based biomarkers (with most studies assessing serum beta-D-glucan) retained a high NPV similar to that of clinical scores, with a higher PPV, although the latter showed important heterogeneity across studies, possibly reflecting the targeted or untargeted use of these tests in patients with a consistent clinical picture and risk factors for IC.

CONCLUSIONS

Both clinical scores and laboratory tests showed high NPV for the diagnosis of IC in nonneutropenic critically ill patients. The PPV of laboratory tests varies significantly according to the baseline patients' risk of IC. This qualitative synthesis will provide the FUNDICU panel with baseline evidence to be considered during the development of definitions of IC in critically ill, nonneutropenic adult patients in ICU.

Risk factors for invasive candida infection in critically ill patients - a systematic review and meta-analysis

Background

Current guidelines recommend empirical antifungal therapy in patients with sepsis with high risk of invasive Candida infection. However, many different risk factors have been derived from multiple studies. These risk factors lack specificity, and broad application would render most ICU patients eligible for empirical antifungal therapy.

Research Question

What risk factors for invasive Candida infection can be identified by a systematic review and meta-analysis?

Study Design and Methods

We searched PubMed, Web of Science, ScienceDirect, Biomed Central, and Cochrane and extracted the raw and adjusted OR for each risk factor associated with invasive Candida infection. We calculated pooled ORs for risk factors present in more than one study.

Results

We included 34 studies in our meta-analysis resulting in the assessment of 29 possible risk factors. Risk factors for invasive Candida infection included demographic factors, comorbid conditions, and medical interventions. Although demographic factors do not play a role for the development of invasive Candida infection, comorbid conditions (eg, HIV, Candida colonization) and medical interventions have a significant impact. The risk factors associated with the highest risk for invasive Candida infection were broad-spectrum antibiotics (OR, 5.6; 95% CI, 3.6-8.8), blood transfusion (OR, 4.9; 95% CI, 1.5-16.3), Candida colonization (OR, 4.7; 95% CI, 1.6-14.3), central venous catheter (OR, 4.7; 95% CI, 2.7-8.1), and total parenteral nutrition (OR, 4.6; 95% CI, 3.3-6.3). However, dependence between the various risk factors is probably high.

Interpretation

Our systematic review and meta-analysis identified patient- and treatment-related factors that were associated with the risk for the development of invasive Candida infection in the ICU. Most of the factors identified were either related to medical interventions during intensive care or to comorbid conditions.

Monocyte human leukocyte antigen-DR but not β-D-glucan may help early diagnosing invasive Candida infection in critically ill patients

Background

Precision medicine risk stratification is desperately needed to both avoid systemic antifungals treatment delay and over prescription in the critically ill with risk factors. The aim of the present study was to explore the combination of host immunoparalysis biomarker (monocyte human leukocyte antigen-DR expression (mHLA-DR)) and Candida sp wall biomarker β-d-glucan in risk stratifying patients for secondary invasive Candida infection (IC).

Methods

Prospective observational study. Two intensive care units (ICU). All consecutive non-immunocompromised septic shock patients. Serial blood samples (n = 286) were collected at day 0, 2 and 7 and mHLA-DR and β-d-glucan were then retrospectively assayed after discharge. Secondary invasive Candida sp infection occurrence was then followed at clinicians’ discretion.

Results

Fifty patients were included, 42 (84%) had a Candida score equal or greater than 3 and 10 patients developed a secondary invasive Candida sp infection. ICU admission mHLA-DR expression and β-d-glucan (BDG) failed to predict secondary invasive Candida sp infection. Time-dependent cause-specific hazard ratio of IC was 6.56 [1.24–34.61] for mHLA-DR < 5000 Ab/c and 5.25 [0.47–58.9] for BDG > 350 pg/mL. Predictive negative value of mHLA-DR > 5000 Ab/c and BDG > 350 pg/mL combination at day 7 was 81% [95% CI 70–92].

Conclusions

This study suggests that mHLA-DR may help predicting IC in high-risk patients with septic shock. The added value of BDG and other fungal tests should be regarded according to the host immune function markers.

Post-Prescription Audit Plus Beta-D-Glucan Assessment Decrease Echinocandin Use in People with Suspected Invasive Candidiasis

Background and Objectives: Overtreatment with antifungal drugs is often observed. Antifungal stewardship (AFS) focuses on optimizing the treatment for invasive fungal diseases. The objective of the present study was to evaluate the utility of a post-prescription audit plus beta-D-glucan (BDG) assessment on reducing echinocandin use in persons with suspected invasive candidiasis. Materials and Methods: This is a prospective, pre-post quasi-experimental study of people starting echinocandins for suspected invasive candidiasis. The intervention of the study included review of each echinocandin prescription and discontinuation of treatment if a very low probability of fungal disease or a negative BDG value were found. Pre-intervention data were compared with the intervention phase. The primary outcome of the study was the duration of echinocandin therapy. Secondary outcomes were length of hospital stay and mortality. Results: Ninety-two echinocandin prescriptions were reviewed, 49 (53.3%) in the pre-intervention phase and 43 (46.7%) in the intervention phase. Discontinuation of antifungal therapy was possible in 21 of the 43 patients in the intervention phase (48.8%). The duration of echinocandin therapy was 7.4 (SD 4.7) in the pre-intervention phase, 4.1 days (SD 2.9) in persons undergoing the intervention, and 8.6 (SD 7.3) in persons in whom the intervention was not feasible (p at ANOVA = 0.016). Length of stay and mortality did not differ between pre-intervention and intervention phases. Conclusions: An intervention based on pre-prescription restriction and post-prescription audit when combined with BDG measurement is effective in optimizing antifungal therapy by significantly reducing excessive treatment duration.

EORTC/MSGERC Definitions of Invasive Fungal Diseases: Summary of Activities of the Intensive Care Unit Working Group

The EORTC/MSGERC recently revised and updated the consensus definitions of invasive fungal disease (IFD). These definitions primarily focus on patients with cancer and stem cell or solid-organ transplant patients. They may therefore not be suitable for intensive care unit (ICU) patients. More in detail, while the definition of proven IFD applies to a broad range of hosts, the categories of probable and possible IFD were primarily designed for classical immunocompromised hosts and may therefore not be ideal for other populations. Moreover, the scope of the possible category of IFD has been diminished in the recently revised definitions for classically immunocompromised hosts. Diagnosis of IFD in the ICU presents many challenges, which are different for invasive candidiasis and for invasive aspergillosis. The aim of this article is to review progresses made in recent years and difficulties remaining in the development of definitions applicable in the ICU setting.

Assessment of the Role of 1,3-β-d-Glucan Testing for the Diagnosis of Invasive Fungal Infections in Adults

Detection of 1,3-β-d-glucan (BDG) in serum has been evaluated for its inclusion as a mycological criterion of invasive fungal infections (IFI) according to EORTC and Mycoses Study Group (MSG) definitions. BDG testing may be useful for the diagnosis of both invasive aspergillosis and invasive candidiasis, when interpreted in conjunction with other clinical/radiological signs and microbiological markers of IFI. However, its performance and utility vary according to patient population (hematologic cancer patients, solid-organ transplant recipients, intensive care unit patients) and pretest likelihood of IFI. The objectives of this article are to provide a systematic review of the performance of BDG testing and to assess recommendations for its use and interpretation in different clinical settings.

Performance of Repeated Measures of (1-3)-β-D-Glucan, Mannan Antigen, and Antimannan Antibodies for the Diagnosis of Invasive Candidiasis in ICU Patients: A Preplanned Ancillary Analysis of the EMPIRICUS Randomized Clinical Trial

Background

We aimed to assess the prognostic value of repeated measurements of serum (1–3)-β-D-glucan (BDG), mannan-antigen (mannan-Ag), and antimannan antibodies (antimannan-Ab) for the occurrence of invasive candidiasis (IC) in a high-risk nonimmunocompromised population.

Methods

This was a preplanned ancillary analysis of the EMPIRICUS Randomized Clinical Trial, including nonimmunocompromised critically ill patients with intensive care unit–acquired sepsis, multiple Candida colonization, and multiple organ failure who were exposed to broad-spectrum antibacterial agents. BDG (>80 and >250 pg/mL), mannan-Ag (>125 pg/mL), and antimannan-Ab (>10 AU) were collected repeatedly. We used cause-specific hazard models. Biomarkers were assessed at baseline in the whole cohort (cohort 1). Baseline covariates and/or repeated measurements and/or increased biomarkers were then studied in the subgroup of patients who were still alive at day 3 and free of IC (cohort 2).

Results

Two hundred thirty-four patients were included, and 215 were still alive and free of IC at day 3. IC developed in 27 patients (11.5%), and day 28 mortality was 29.1%. Finally, BDG >80 pg/mL at inclusion was associated with an increased risk of IC (CSHR[IC], 4.67; 95% CI, 1.61–13.5) but not death (CSHR[death], 1.20; 95% CI, 0.71–2.02).

Conclusions

Among high-risk patients, a first measurement of BDG >80 pg/mL was strongly associated with the occurrence of IC. Neither a cutoff of 250 pg/mL nor repeated measurements of fungal biomarkers seemed to be useful to predict the occurrence of IC. The cumulative risk of IC in the placebo group if BDG >80 pg/mL was 25.39%, which calls into question the efficacy of empirical therapy in this subgroup.

(1,3)-β-D-glucan is able to predict therapeutic failure of patients with candidemia and not only mortality

BACKGROUND

Candidemia is a major cause of bloodstream infection in tertiary hospitals worldwide and fungal biomarkers may provide early diagnosis.

OBJECTIVES

To evaluate the performance of (1-3)-β-D-glucan (BDG) in the diagnosis of candidemia and its ability to predict therapeutic failure.

PATIENTS AND METHODS

This was a prospective, multi-centre study conducted in 3 Brazilian hospitals. Clinical outcome was evaluated along 2 weeks of treatment, and therapeutic failure was defined as the occurrence of persistent candidemia, Candida deep-seated infection or death. Baseline BDG detection was performed with the Fungitell^® assay (Associates of Cape Cod, Falmouth-USA).

RESULTS

We enrolled a total of 71 patients with candidemia and a control group with 110 healthy volunteers. The sensitivity and specificity of BDG for diagnosing candidemia were as follows: 71.8% (95% confidence interval [95% CI] 59.7% - 81.5%) and 98.2% (95% CI 92.9% - 99.7%), respectively. The only predictor of therapeutic failure was a higher BDG value at diagnosis of candidemia; a value > 226 pg/mL predicted failure with sensitivity and specificity of 75% and 78%, respectively.

CONCLUSIONS

A high baseline serum BDG value was associated with therapeutic failure.

Quantification of 1,3-β-d-glucan by Wako β-glucan assay for rapid exclusion of invasive fungal infections in critical patients: A diagnostic test accuracy study

OBJECTIVES

Rapid and reliable exclusion of invasive fungal infections (IFI) by markers able to avoid unnecessary empirical antifungal treatment is still a critical unmet clinical need. We investigated the diagnostic performance of a newly available β-d-Glucan (BDG) quantification assay, focusing on the optimisation of the BDG cut-off values for IFI exclusion.

METHODS

BDG results by Wako β-glucan assay (lower limit of detection [LLOD] = 2.16 pg/mL, positivity ≥ 11 pg/mL) on two consecutive serum samples were retrospectively analysed in 170 patients, admitted to haematological wards (N = 42), intensive care units (ICUs; N = 80), or other wards (N = 48), exhibiting clinical signs and/or symptoms suspected for IFI. Only patients with proven IFI (EORTC/MSG criteria) were considered as true positives in the assessment of BDG sensitivity, specificity and predictive values.

RESULTS

Patients were diagnosed with no IFI (69.4%), proven IFI (25.3%) or probable IFI (5.3%). Two consecutive BDG values < LLOD performed within a median of 1 (interquartile range: 1-3) day were able to exclude a proven IFI with 100% sensitivity and negative predictive value (primary study goal). Test's specificity improved by using two distinct positivity and negativity cut-offs (7.7 pg/mL and LLOD, respectively), but remained suboptimal in ICU patients (50%), as compared to haematological or other patients (93% and 90%, respectively).

CONCLUSIONS

The classification of Wako's results as negative when < LLOD, and positive when > 7.7 pg/mL, could be a promising diagnostic approach to confidently rule out an IFI in both ICU and non-ICU patients. The poor specificity in the ICU setting remains a concern, due to the difficulty to interpret positive results in this fragile population.

(1,3)-β-D-Glucan-based empirical antifungal interruption in suspected invasive candidiasis: a randomized trial

Background

(1,3)-β-d-Glucan has been widely used in clinical practice for the diagnosis of invasive Candida infections. However, such serum biomarker showed potential to guide antimicrobial therapy in order to reduce the duration of empirical antifungal treatment in critically ill septic patients with suspected invasive candidiasis.

Methods

This was a single-centre, randomized, open-label clinical trial in which critically ill patients were enrolled during the admission to the intensive care unit (ICU). All septic patients who presented invasive Candida infection risk factors and for whom an empirical antifungal therapy was commenced were randomly assigned (1:1) in those stopping antifungal therapy if (1,3)-β-d-glucan was negative ((1,3)-β-d-glucan group) or those continuing the antifungal therapy based on clinical rules (control group). Serum 1,3-β-d-glucan was measured at the enrolment and every 48/72 h over 14 days afterwards. The primary endpoint was the duration of antifungal treatment in the first 30 days after enrolment.

Results

We randomized 108 patients into the (1,3)-β-d-glucan (n = 53) and control (n = 55) groups. Median [IQR] duration of antifungal treatment was 2 days [1–3] in the (1,3)-β-d-glucan group vs. 10 days [6–13] in the control group (between-group absolute difference in means, 6.29 days [95% CI 3.94–8.65], p < 0.001). Thirty-day mortality was similar (28.3% [(1,3)-β-d-glucan group] vs. 27.3% [control group], p = 0.92) as well as the overall rate of documented candidiasis (11.3% [(1,3)-β-d-glucan group] vs. 12.7% [control group], p = 0.94), the length of mechanical ventilation (p = 0.97) and ICU stay (p = 0.23).

Conclusions

In critically ill septic patients admitted to the ICU at risk of invasive candidiasis, a (1,3)-β-d-glucan-guided strategy could reduce the duration of empirical antifungal therapy. However, the safety of this algorithm needs to be confirmed in future, multicentre clinical trial with a larger population.

Trial registration

ClinicalTrials.gov, NCT03117439, retrospectively registered on 18 April 2017

(1→3)-β-D-glucan testing for the detection of invasive fungal infections in immunocompromised or critically ill people

BACKGROUND

Invasive fungal infections (IFIs) are life-threatening opportunistic infections that occur in immunocompromised or critically ill people. Early detection and treatment of IFIs is essential to reduce morbidity and mortality in these populations. (1→3)-β-D-glucan (BDG) is a component of the fungal cell wall that can be detected in the serum of infected individuals. The serum BDG test is a way to quickly detect these infections and initiate treatment before they become life-threatening. Five different versions of the BDG test are commercially available: Fungitell, Glucatell, Wako, Fungitec-G, and Dynamiker Fungus.

OBJECTIVES

To compare the diagnostic accuracy of commercially available tests for serum BDG to detect selected invasive fungal infections (IFIs) among immunocompromised or critically ill people.

SEARCH METHODS

We searched MEDLINE (via Ovid) and Embase (via Ovid) up to 26 June 2019. We used SCOPUS to perform a forward and backward citation search of relevant articles. We placed no restriction on language or study design.

SELECTION CRITERIA

We included all references published on or after 1995, which is when the first commercial BDG assays became available. We considered published, peer-reviewed studies on the diagnostic test accuracy of BDG for diagnosis of fungal infections in immunocompromised people or people in intensive care that used the European Organization for Research and Treatment of Cancer (EORTC) criteria or equivalent as a reference standard. We considered all study designs (case-control, prospective consecutive cohort, and retrospective cohort studies). We excluded case studies and studies with fewer than ten participants. We also excluded animal and laboratory studies. We excluded meeting abstracts because they provided insufficient information.

DATA COLLECTION AND ANALYSIS

We followed the standard procedures outlined in the Cochrane Handbook for Diagnostic Test Accuracy Reviews. Two review authors independently screened studies, extracted data, and performed a quality assessment for each study. For each study, we created a 2 × 2 matrix and calculated sensitivity and specificity, as well as a 95% confidence interval (CI). We evaluated the quality of included studies using the Quality Assessment of Studies of Diagnostic Accuracy-Revised (QUADAS-2). We were unable to perform a meta-analysis due to considerable variation between studies, with the exception of Candida, so we have provided descriptive statistics such as receiver operating characteristics (ROCs) and forest plots by test brand to show variation in study results.

MAIN RESULTS

We included in the review 49 studies with a total of 6244 participants. About half of these studies (24/49; 49%) were conducted with people who had cancer or hematologic malignancies. Most studies (36/49; 73%) focused on the Fungitell BDG test. This was followed by Glucatell (5 studies; 10%), Wako (3 studies; 6%), Fungitec-G (3 studies; 6%), and Dynamiker (2 studies; 4%). About three-quarters of studies (79%) utilized either a prospective or a retrospective consecutive study design; the remainder used a case-control design. Based on the manufacturer's recommended cut-off levels for the Fungitell test, sensitivity ranged from 27% to 100%, and specificity from 0% to 100%. For the Glucatell assay, sensitivity ranged from 50% to 92%, and specificity ranged from 41% to 94%. Limited studies have used the Dynamiker, Wako, and Fungitec-G assays, but individual sensitivities and specificities ranged from 50% to 88%, and from 60% to 100%, respectively. Results show considerable differences between studies, even by manufacturer, which prevented a formal meta-analysis. Most studies (32/49; 65%) had no reported high risk of bias in any of the QUADAS-2 domains. The QUADAS-2 domains that had higher risk of bias included participant selection and flow and timing.

AUTHORS' CONCLUSIONS

We noted considerable heterogeneity between studies, and these differences precluded a formal meta-analysis. Because of wide variation in the results, it is not possible to estimate the diagnostic accuracy of the BDG test in specific settings. Future studies estimating the accuracy of BDG tests should be linked to the way the test is used in clinical practice and should clearly describe the sampling protocol and the relationship of time of testing to time of diagnosis.

Delta neutrophil index as a predictive and prognostic factor for Candidemia patients: a matched case-control study

Background

Delayed antifungal therapy for candidemia leads to increased mortality. Differentiating bacterial infection from candidemia in systemic inflammatory response syndrome (SIRS) patients is complex and difficult. The Delta Neutrophil Index (DNI) has recently been considered a new factor to distinguish infections from non-infections and predict the severity of sepsis. We aimed to assess if the DNI can predict and provide a prognosis for candidemia in SIRS patients.

Methods

A matched case-control study was conducted from July 2016 to June 2017 at Kangdong Sacred Heart Hospital. Among patients with a comorbidity of SIRS, those with candidemia were classified as the case group, whereas those with negative blood culture results were classified as the control group. The matching conditions included age, blood culture date, and SIRS onset location. Multivariate logistic regression was performed to evaluate DNI as a predictive and prognostic factor for candidemia.

Results

The 140 included patients were assigned to each group in a 1:1 ratio. The DNI_D1 values measured on the blood culture date were higher in the case group than in the control group (p <  0.001). The results of multivariate analyses confirmed DNI_D1 (odds ratio [ORs] 2.138, 95% confidential interval [CI] 1.421–3.217, p <  0.001) and Candida colonization as predictive factors for candidemia. The cutoff value of DNI for predicting candidemia was 2.75%. The area under the curve for the DNI value was 0.804 (95% CI, 0.719–0.890, p < 0.001), with a sensitivity and specificity of 72.9 and 78.6%, respectively. Analysis of 14-day mortality in patients with candidemia showed significantly higher DNI_D1 and DNI_48 in the non-survivor group than in the survivor group.

Conclusions

DNI was identified as a predictive factor for candidemia in patients with SIRS and a prognostic factor in predicting 14-day mortality in candidemia patients. DNI, along with clinical patient characteristics, was useful in determining the occurrence of candidemia in patients with SIRS.

Impact of the Beta-Glucan Test on Management of Intensive Care Unit Patients at Risk for Invasive Candidiasis

The 1,3-beta-d-glucan (BDG) test is used for the diagnosis of invasive candidiasis (IC) in intensive care units (ICUs). However, its utility for patient management is unclear. This study assessed the impact of BDG test results on therapeutic decisions. This was a single-center observational study conducted in an ICU over two 6-month periods. All BDG test requests for the diagnosis of IC were analyzed. Before the second period, the ICU physicians received a pocket card instruction (algorithm) for targeted BDG testing in high-risk patients. The performance of the BDG test for IC diagnosis was assessed, as well as its impact on antifungal (AF) prescription. Overall, 72 patients had ≥1 BDG test, and 14 (19%) patients had an IC diagnosis. The BDG test results influenced therapeutic decisions in 41 (57%) cases. The impact of the BDG test was positive in 30 (73%) of them, as follows: AF abstention/interruption following a negative BDG result (n = 27), and AF initiation/continuation triggered by a positive BDG test result and subsequently confirmed IC (n = 3). In 10 (24%) cases, a positive BDG test result resulted in AF initiation/continuation with no further evidence of IC. A negative BDG result and AF abstention with subsequent IC diagnosis were observed in one case. The positive predictive value (PPV) of BDG was improved if testing was restricted to the algorithm's indications (80% versus 36%, respectively). However, adherence to the algorithm was low (26%), and no benefit of the intervention was observed. The BDG result had an impact on therapeutic decisions in more than half of the cases, which consisted mainly of safe AF interruption/abstention. Targeted BDG testing in high-risk patients improves PPV but is difficult to achieve in ICU.

Detecting Invasive Fungal Disease in Surgical Patients: Utility of the (13)- β-d-Glucan Assay

Background: The specificity and sensitivity of the (13)-β-d-glucan (BDG) assay in surgical patients needs further investigation. We hypothesized that the BDG assay would have lower sensitivity/specificity compared with that of medical patients. Methods: We reviewed patients who had undergone laparotomy, gastrectomy, hepatectomy, or colectomy and had a BDG assay post-operatively. Results: A total of 71 patients met study criteria. There were 29 (40.8%) who had proven/probable invasive fungal infection. Sensitivity for BDG level ≥80 diagnosed within one week of the assay draw was 77.3% (95% confidence interval [CI], 54.6-92.2%), and specificity was 44.9% (95% CI, 30.7-59.8). The positive predictive value was 38.6% (95% CI, 31.0-46.9%), and negative predictive value was 82.5% (95% CI, 65.7-91.0%). A BDG assay result of 149 pg/mL had a classification rate of 63.4%. Therefore, a BDG assay result ≥150 pg/mL has a sensitivity of 78.6% and a specificity of 41.4%. Conclusion: A BDG assay can be useful for ruling out invasive fungemia in post-operative patients.

What´s new in intraabdominal candidiasis in critically ill patients, a review

A high prevalence of invasive candidiasis has been reported in recent years. Patients admitted to an intensive care unit are at the highest risk for invasive candidiasis, mostly due to the severity of their disease, immune-suppressive states, prolonged length of stay, broad-spectrum antibiotics, septic shock, and Candida colonization. Intraabdominal candidiasis comprises a range of clinical manifestations, from just the suspicion based on clinical scenario to fever, leukocytosis, increase in biomarkers to the isolation of the responsible microorganism. In critically ill patients with IAC prompt treatment and adequate source control remains the ultimate goal.

Federation of Infectious Diseases Societies of Southern Africa guideline: Recommendations for the detection, management and prevention of healthcare-associated Candida auris colonisation and disease in South Africa

Candida auris has been detected at almost 100 South African hospitals, causing large outbreaks in some facilities, and this pathogen now accounts for approximately 1 in 10 cases of candidaemia. The objective of this guideline is to provide updated, evidence-informed recommendations outlining a best-practice approach to prevent, diagnose and manage C. auris disease in public- and private-sector healthcare settings in South Africa. The 18 practical recommendations cover five focus areas: laboratory identification and antifungal susceptibility testing, surveillance and outbreak response, infection prevention and control, clinical management and antifungal stewardship.

Microbiological Laboratory Testing in the Diagnosis of Fungal Infections in Pulmonary and Critical Care Practice. An Official American Thoracic Society Clinical Practice Guideline

Background: Fungal infections are of increasing incidence and importance in immunocompromised and immunocompetent patients. Timely diagnosis relies on appropriate use of laboratory testing in susceptible patients.Methods: The relevant literature related to diagnosis of invasive pulmonary aspergillosis, invasive candidiasis, and the common endemic mycoses was systematically reviewed. Meta-analysis was performed when appropriate. Recommendations were developed using the Grading of Recommendations Assessment, Development, and Evaluation approach.Results: This guideline includes specific recommendations on the use of galactomannan testing in serum and BAL and for the diagnosis of invasive pulmonary aspergillosis, the role of PCR in the diagnosis of invasive pulmonary aspergillosis, the role of β-d-glucan assays in the diagnosis of invasive candidiasis, and the application of serology and antigen testing in the diagnosis of the endemic mycoses.Conclusions: Rapid, accurate diagnosis of fungal infections relies on appropriate application of laboratory testing, including antigen testing, serological testing, and PCR-based assays.

The diagnostic value of (1,3)-β-D-glucan alone or combined with traditional inflammatory markers in neonatal invasive candidiasis

Background

Asymptom of invasive candidiasis (IC) and low positive rate of blood culture lead to delay diagnose of neonatal infection. Serum (1,3)-β-D-glucan (BDG) performs well in adult IC, but its use in neonatal IC is unclear. We evaluated the use of BDG, procalcitonin (PCT), high-sensitive C-reactive protein (hsCRP) or platelet count (PC) in neonatal IC.

Methods

We collected the data of neonates admitted to our institute. Eighty neonates were enrolled, and divided into IC group, bacterial infection (BI) group and control (CTRL) group. We analyzed the difference of these indicators between groups, and generated Receiver operator characteristic (ROC) curve. The value of BDG in antifungal therapy efficacy assessment was also investigated.

Results

The BDG level was higher in IC group compared with BI and CTRL group. C. albicans lead to significant increase of BDG compared with C. parapsilosis. IC group had highest hsCRP level and lowest PC. PCT level was similar between groups. ROC showed that BDG or hsCRP performs well in neonatal IC, the optimal cut-off for BDG was 13.69 mg/ml. Combined BDG with hsCRP, PCT and PC increased diagnostic value. Serum BDG level was decreased during antifungal treatment.

Conclusion

Serum BDG performs well in identification of neonatal IC and in monitoring the antifungal therapy efficacy.

Considerations for Medications Commonly Utilized in the Oncology Population in the Intensive Care Unit

An increasing number of oncologic patients are presenting to the intensive care unit with complications from both their chronic disease states and cancer therapies due to improved survival rates. The management of these patients is complex due to immunosuppression (from the malignancy and/or treatment), metabolic complications, and diverse medication regimens with the potential for significant drug-drug interactions and overlapping adverse effects. This chapter will provide clinicians with an overview of non-chemotherapy medications frequently encountered in the critically ill oncologic patient, with a focus on practical considerations.

Performance evaluation of the (1,3)-β-D-glucan detection assay in non-intensive care unit adult patients

Objectives

To assess the performance of the (1,3)-β-D-glucan (BDG) detection assay in a large cohort of patients with suspected candidemia who were admitted to non-intensive care unit hospital wards.

Methods

This observational, retrospective cohort study was conducted in a 1,100-bed university hospital in Rome, where an infectious disease consultation team has been operational. Two groups of patients were included in the analysis: Group 1, patients with Candida bloodstream infection (BSI) who had at least one BDG test performed ±48 hours from the first positive blood culture (Candida BSI Group) and Group 2, patients with risk factors for candidemia who had at least one BDG test but had negative blood cultures (Control Group). Both Group 1 and Group 2 did not receive prior antifungal therapy. Different BDG cutoff values were considered: 80, 200, 300, 400, and ≥500 pg/mL. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the receiver operating characteristic curve were calculated.

Results

A total of 1,296 patients were studied. Of them, 100 patients (candidemic) were in Group 1 and the remaining 1,196 patients (controls) were in Group 2. There were no differences in demographic characteristics between patients of the two groups. According to the above cutoff values, sensitivity (%) and specificity (%) of the BDG assay ranged from 91 to 60.7 and 87.7 to 97.8, respectively, whereas the PPV (%) and NPV (%) ranged from 38.2 to 68.3 and 99.1 to 97.0, respectively.

Conclusion

Serum BDG has a very high NPV in a population witĥ10% prevalence of candidemia. This NPV may support decisions to discontinue antifungal therapy in those patients who were empirically treated because of the suspect of candidemia.

Serum 1,3-Beta-D-Glucan Values During and After Laparoscopic and Open Intestinal Surgery

Background

1,3-beta-D Glucan (BDG) assay has good accuracy for distinguishing patients with invasive fungal infections from patients without. Some procedures and medications affect BDG levels, resulting in false-positive BDG results. The extent of intestinal surgery on BDG kinetics is unknown. We evaluated the influence of laparoscopic and open intestinal surgery on peri- and postsurgical serum BDG values.

Methods

BDG was determined in 346 samples from 50 patients undergoing laparoscopic (24) or open (26) intestinal surgery at the following time points: after insertion of arterial but before skin incision, after skin incision but before dissection of the intestinal mucosa, after completion of anastomosis, after completion of skin sutures, in the evening after surgery, day 2 after surgery, 4–5 days after surgery.

Results

BDG was positive (ie, concentration ≥80 pg/mL) in 54% to 61% of patients during laparoscopic and open surgery (highest rates after completion of skin sutures). BDG was still positive in 12% (open) to 17% (laparoscopic) of patients without any suspected or proven fungal infection or anastomotic leakage 4–5 days after surgery. After completion of gut anastomosis, the BDG increase was higher in open compared with laparoscopic intestinal surgery.

Conclusions

The value of positive BDG tests in the perioperative setting up to 5 days postsurgery seems to be limited due to BDG elevations from intestinal surgical procedures.

Prospective evaluation of lymphocyte subtyping for the diagnosis of invasive candidiasis in non-neutropenic critically ill patients

OBJECTIVES

This study aimed to investigate the distinguishing ability of lymphocyte subtyping for Invasive candidiasis (IC) diagnosis and prognosis in non-neutropenic critically ill patients.

METHODS

We assessed the quantitative changes in key parameters of lymphocyte subtyping at the onset of clinical signs of infection in non-neutropenic critically ill patients and their potential influence on diagnosis and outcome of IC. The primary outcome was 28-day mortality.

RESULTS

Among the 182 consecutive critically ill patients, 22 (12.1%) were in the IC group. The CD28⁺CD8⁺ T-cell counts (AUC 0.863, 95%CI 0.804-0.909, P<0.001) had greater diagnostic value for IC than other parameters had. Adding CD28⁺CD8⁺ T to Candida score significantly improved the predictive value of Candida score (P=0.039). Multivariate logistic regression analysis identified CD28⁺CD8⁺ T-cell counts≤78 cells/mm³ (OR 24.544, 95%CI 6.461-93.236, P<0.001) as an independent predictor for IC diagnosis. CD28⁺CD8⁺ T-cell counts could also predict 28-day mortality. Kaplan-Meier survival analysis provided evidence that CD28⁺CD8⁺ T-cell count <144cells/mm³ (log-rank test; P=0.03) were associated with lower survival probabilities.

CONCLUSIONS

CD28⁺CD8⁺ T-cell counts play an important role in early diagnosis of IC. Low counts are associated with early mortality in non-neutropenic critically ill patients. These results suggest the potential usefulness of measuring CD28⁺CD8⁺ T-cell lymphocyte levels in the early recognition and diagnosis of IC.

TRIAL REGISTRATION

ChiCTR-ROC-17010750. Registered 28 February 2017.

Management of patients with septic shock due to Candida infection

Septic shock represents a serious complication occurring between 6% and 30% of all hospitalized patients; Candida septic shock represents a challenge for clinicians due to the absence of specific risk factors, diagnostic tests, and management. Identification of specific risk factors and use of biomarkers are useful tools considering that differentiation of Candida from bacterial septic shock is demanding. Early effective antifungal treatment, preferably with echinocandins with an adequate source control, represents the best approach for improving survival of patients with septic shock due to Candida. Given the importance of adequate therapy and source control in septic shock attributable to Candida clinical strategies and pathways are needed. This review will focus on epidemiology of septic shock in patients with invasive candidiasis with special attention to diagnostic pathways and treatment strategies.

Invasive Fungal Disease in Critically Ill Patients at High Risk: Usefulness of Lymphocyte Subtyping

OBJECTIVES

This study aimed to investigate the distinguishing ability of lymphocyte subtyping for diagnosis and prognosis of invasive fungal disease (IFD).

METHODS

We assessed lymphocyte subtyping and evaluated the quantitative changes in key immunological parameters at intensive care unit (ICU) admission in critically ill patients at high risk and their potential influence on diagnosis and outcome of IFD. The primary outcome was 28-day mortality.

RESULTS

Among the 124 critically ill patients with mean Candida score 3.89 (0.76), 19 (15.3%) were in the IFD group. CD28⁺CD8⁺ T-cell counts (area under the curve [AUC] 0.899, 95% confidence interval [CI], 0.834-0.964, P < .001) had better distinguishing ability than other immune parameters for IFD diagnosis. The cutoff value of CD28⁺CD8⁺ T-cell counts at ICU admission for IFD diagnosis was 59.5 cells/mm³, with 83.3% sensitivity and 86.4% specificity. Multivariate logistic regression analysis identified CD28⁺CD8⁺ T-cell count <59.5 cells/mm³ (odds ratio 59.7, 95% CI, 7.33-486.9, P < .001) as an independent predictor for IFD diagnosis. CD28⁺CD8⁺ T-cell counts could also predict 28-day mortality (AUC 0.656, 95% CI, 0.525-0.788, P = .045). Kaplan-Meier survival analysis provided evidence that natural killer cell count <76.0 cells/mm³ (log-rank test; P = .001), CD8⁺ T-cell count <321.5 cells/mm³ (log-rank test; P = .04), and CD28⁺CD8⁺ T-cell count <129.0 cells/mm³ (log-rank test; P = .02) at ICU admission were associated with lower survival probabilities.

CONCLUSION

CD28⁺CD8⁺ T-cell counts play an important role in early diagnosis of IFD. Low counts are associated with early mortality in critically ill patients at high risk of IFD. Our findings add evidence to the utility of lymphocyte subtyping in a diagnostic algorithm to better define IFD in critically ill patients at high risk.

Diagnostic Efficacy of Serum 1,3-β-D-glucan for Invasive Fungal Infection: An Update Meta-Analysis Based on 37 Case Or Cohort Studies

Objective

The aim of this study was to investigate the diagnostic performance of serum 1,3-β-D-gluan as biomarker for invasive fungal infection through meta-analysis.

Methods

The electronic databases of Medline, Cochrane, Embase, Web of Science, OVID and CNKI were systematic searched to identified the case-control or Cohort studies relevant to diagnostic efficacy of serum 1,3-β-D-glucan for invasive fungal infection. The data of true positive (tp), false positive (fp), false negative (fn) and true negative (tn) patients number were extracted from each of the original included studies. The diagnostic sensitivity, specificity and systematic receiver operating characteristic (SROC) curve were calculated and pooled through random or fixed effect method. The publication bias was evaluated by the Deek's funnel plot.

Results

Thirty-seven relevant studies were fulfilled the inclusion criteria and included in our present meta-analysis. The combined sensitivity, specificity, positive likely hood ratio (+lr), negative likely hood ratio (-lr) and diagnostic odds ratio(dor) for 1,3-β-D-glucan in diagnosis of invasive fungal infectionwere 0.83 (95%CI:0.38-0.61), 0.81 (95%CI:0.80-0.82), 5.13 (95%CI:3.98-6.62), 0.23 (95%CI:0.18-0.30), and 29.68 (95%CI:18.94-46.52) respectively. The pooled area under the ROC curve (AUC) was 0.91.The Deek's funnel plot asymmetry test showed there was no publication bias for 1,3-β-D-glucan in diagnosis of invasive fungal infection of the included 37 studies.

Conclusion

Serum 1,3-β-D-glucan assay was a promising biomarker for invasive fungal infection diagnosis.

(1,3)-β-D-glucan-based diagnosis of invasive Candida infection versus culture-based diagnosis in patients with sepsis and with an increased risk of invasive Candida infection (CandiSep): study protocol for a randomized controlled trial

BACKGROUND

The time to diagnosis of invasive Candida infection (ICI) is often too long to initiate timely antifungal therapy in patients with sepsis. Elevated serum (1,3)-β-D-glucan (BDG) concentrations have a high diagnostic sensitivity for detecting ICI. However, the clinical significance of elevated BDG concentrations is unclear in critically ill patients. The goal of this study is to investigate whether measurement of BDG in patients with sepsis and a high risk for ICI can be used to decrease the time to empiric antifungal therapy and thus, increase survival.

METHODS/DESIGN

This prospective multicenter open randomized controlled trial is being conducted in 19 German intensive care units. All adult patients with severe sepsis or septic shock and an increased risk for ICI are eligible for enrolment. Risk factors are total parenteral nutrition, previous abdominal surgery, previous antimicrobial therapy, and renal replacement therapy. Patients with proven ICI or those already treated with systemic antifungal substances are excluded. Patients are allocated to a BDG or standard care group. The standard care group receives targeted antifungal therapy as necessary. In the BDG group, BDG serum samples are taken after randomization and 24 h later. Antifungal therapy is initiated if BDG is ≥80 pg/ml in at least one sample. We plan to enroll 312 patients. The primary outcome is 28-day mortality. Other outcomes include antifungal-free survival within 28 days after enrolment, time to antifungal therapy, and the diagnostic performance of BDG compared to other laboratory tests for early ICI diagnosis. The statistical analysis will be performed according to the intent-to-treat principle.

DISCUSSION

Because of the high risk of death, American guidelines recommend empiric antifungal therapy in sepsis patients with a high risk of ICI despite the limited evidence for such a recommendation. In contrast, empiric antifungal therapy is not recommended by European guidelines. BDG may offer a way out of this dilemma since BDG potentially identifies patients in need of early antifungals. However, the evidence for such an approach is inconclusive. This clinical study will generate solid evidence for health-care providers and authors of guidelines for the use of BDG in critically ill patients.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT02734550 . Registered 12 April 2016.

Treatment of Invasive Candidiasis: A Narrative Review

Invasive candidiasis occurs frequently in hospitalized patients, and is associated with high mortality rates due to delays in recognition and initiation of appropriate antifungals. Management of invasive candidiasis must take into account multiple host, pathogen, and drug-related factors, including the site of infection, host immune status, severity of sepsis, resistance and tolerance to antifungal agents, biofilm formation, and pharmacokinetic/pharmacodynamic considerations. Recent treatment directives have been shaped by the widespread introduction of echinocandins, highly potent and safe antifungals, into clinical use, as well as important changes in drug susceptibility patterns and the emergence of known and novel drug-resistant Candida species. Advances in molecular diagnostics have the potential to guide early targeted treatment of high-risk patients.

Choosing wisely: what is the actual role of antimicrobial stewardship in Intensive Care Units?

More than two-thirds of critically ill patients receive an antimicrobial therapy with a percentage between 30% and 50% of all prescribed antibiotics reported to be unnecessary, inappropriate or misused. Since inappropriate prescription of antibiotic drugs concurs to dissemination of the multidrug resistant organisms, a reasoned antibiotics use is crucial especially in Intensive Care Unit (ICU), where up to 60% of the admitted patients develops an infection during their ICU stay. Even if the concept of antimicrobial stewardship (AS) has been clearly described as a series of coordinated interventions designed to improve antimicrobial agents use, few studies are reporting about its effectiveness to improve outcomes, reduce adverse events and costs and decrease resistance rate spread. Moreover, although it is recognized that AS programs are particularly indicated in the critical setting due to the huge number of antimicrobial drugs used, the optimal characteristics of these interventions and the best system to evaluate their effectiveness are still unclear. Specific interventions, designed tacking into account the peculiarities of the ICU setting, are hence necessary to set-up an "in-ICU-stewardship," including prompt identification of infected patients, selection of appropriate empiric treatments, optimization of dosing and route of administration, improvement of diagnostic techniques, early de-escalation to achieve shorter duration and avoid unnecessary therapies. The present narrative review summarizes the "state of art" about AS programmes and discusses the effects of the interventions possibly applied in ICU setting to optimize the patient's treatment, reduce the micro-organisms resistance and contain the hospital resources utilization.

Use of T2MR in invasive candidiasis with and without candidemia

The mortality associated with invasive candidiasis remains unacceptably high. The T2 magnetic resonance (T2MR) assay is a novel US FDA-approved molecular diagnostic assay for the diagnosis of candidemia that can rapidly detect the five most commonly isolated Candida spp. In clinical trials, T2MR has exhibited good clinical sensitivity and specificity. Potential benefits from the adoption of T2MR technology in the diagnostic and therapeutic algorithms for invasive candidiasis can arise from timely diagnosis of disease, increased case detection, tailored therapy and decrease in empiric antifungal treatment. As everyday clinical experience with the assay is evolving, we discuss the utility of T2MR in invasive candidiasis with and without candidemia based on the currently available evidence regarding its performance.

T2 Magnetic Resonance Assay: Overview of Available Data and Clinical Implications

Invasive candidiasis is a common healthcare-associated infection with a high mortality rate that can exceed 60% in cases of septic shock. Blood culture performance is far from ideal, due to the long time to positivity and suppression by antifungal agents. The T2 Magnetic Resonance (T2MR) assay is an FDA-approved qualitative molecular diagnostic method that can detect and speciate the 5 most common Candida spp.; namely, Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis, and Candida krusei, in approximately 5 h. In a multicenter clinical trial that included both a prospective and a contrived arm to represent the full range of clinically relevant concentrations of Candida spp., T2MR demonstrated a sensitivity and specificity of 91.1% and 98.1%, respectively. The utility of T2MR in candidemia depends on the prevalence of disease in each clinical setting. In intensive care units and other high-prevalence settings, the incorporation of T2MR in diagnostic algorithms is very appealing. T2MR is expected to allow timely initiation of antifungal therapy and help with anti-fungal stewardship. In low-prevalence settings, the positive predictive value of T2MR might not be enough to justify initiation of antifungal treatment in itself. The performance of T2MR has not been studied in cases of deep-seated candidiasis. Despite some promising evidence in published clinical trials, further studies are needed to determine the performance of T2MR in invasive candidiasis without candidemia. Overall, experience with T2MR in everyday clinical practice is evolving but, in the right setting, this technology is expected to provide “actionable information” for the management of patients evaluated for candidemia.

The Utility of the Candida Score in Patients With Sepsis

BACKGROUND

Candida is a leading cause of infection in the intensive care unit. Colonization versus infection remains a challenge. A Candida Score (CS) of 3 or greater has been used to target antifungal therapy in surgical patients at risk of candidemia but has not been well evaluated in medical patients with sepsis.

OBJECTIVES

The aim of this study was to assess utility of the CS in detecting candidemia early in patients with sepsis.

METHODS

This was a secondary analysis of patients with sepsis (n = 77) who were followed up for development of new infections. Patients with known fungal infection at admission were excluded. Candida colonization was defined as Candida cultured from any baseline culture, except blood, as a part of routine clinical care.

RESULTS

Candidemia was detected in 8 of 77 participants (10.4%; 4 [15.4%] with a CS ≥3 and 4 [7.8%] with a CS <3). Demographic variables (age, race, sex) were similar among those who did and did not develop candidemia. Using the recommended CS of 3 or greater, sensitivity was (4/8) 50%, specificity was (47/69) 68.1%, positive predictive value was (4/26) 15.4%, and negative predictive value was (47/51) 92.2%. Baseline colonization was significantly higher among those who developed candidemia (50% vs 11.6%; P = .02), but no significant differences were observed among CS components or total scores.

CONCLUSIONS

Despite a relatively poor sensitivity, a reasonable specificity with a strong negative predictive value makes this tool a viable option for screening medically ill patients who may require antifungal agents. The CS should be evaluated in a larger, more inclusive, medical population.

Evaluation of the Use of Novel Biomarkers to Augment Antimicrobial Stewardship Program Activities

As antimicrobial stewardship increasingly receives worldwide attention for improving patient care by optimizing antimicrobial therapy, programs are evaluating new tools that may augment antimicrobial stewardship activities. Biomarkers are objective, accurate, and reproducible measures that provide information about medical conditions. A systematic literature search using PubMed/MEDLINE databases was performed to evaluate the use of novel biomarkers as additions to the antimicrobial stewardship armamentarium. Procalcitonin may help clinicians discriminate between bacterial and viral infections, help with antimicrobial discontinuation decisions, and predict mortality. β-d-glucan, Candida albicans germ tube antibody, and galactomannan are useful in suspected fungal infections and may reduce inappropriate antifungal use. Adrenomedullin and soluble triggering receptor on myeloid cells-1 may be useful for mortality prediction and the determination of a need for empiric antibacterials. Although studies evaluating these biomarkers are promising, these biomarkers are not without limitations and should be used in combination with clinical signs, symptoms, or other biomarkers. For successful implementation of biomarker use, stewardship programs should consider the populations most likely to benefit, without using them indiscriminately in all patients. Antimicrobial stewardship programs should facilitate education of clinicians through institutional guidelines to ensure the appropriate use and interpretation of these biomarkers.

What has changed in the treatment of invasive candidiasis? A look at the past 10 years and ahead

The treatment of invasive candidiasis has changed greatly in the past decade and must continue to evolve if we are to improve outcomes in this serious infection. A review of recent history may provide insights for the future. The morbidity and mortality of invasive candidiasis remain difficult to measure despite an obvious clinical burden. Current treatment guidelines now recommend echinocandins as first-line empirical treatment, with fluconazole as an acceptable alternative for selected patients, reflecting the efficacy demonstrated by echinocandins and increasing resistance observed with fluconazole. The selection of antifungal therapy now must consider not only resistance but also the shift in predominance from Candida albicans to non-albicans species, notably Candida glabrata. The recent emergence of Candida auris has been met with great interest, although the longer-term implications of this phenomenon remain unclear. The broad goal of treatment continues to be administration of safe, efficacious antifungal therapy as soon as possible. Diagnostic methods beyond traditional blood culture present an opportunity to shorten the time to an accurate diagnosis, and earlier treatment initiation based on prophylactic and empirical or pre-emptive strategies seeks to ensure timely therapeutic intervention. In addition, there are novel agents in the antifungal pipeline. These developments, as well as ongoing studies of dosing, toxicity and resistance development, are important items on the current research agenda and may play a role in future changes to the treatment of invasive candidiasis.

Management of candidemia in patients with Clostridium difficile infection

INTRODUCTION

Patients with C. difficile infection (CDI) experience intestinal microflora changes that can promote the overgrowth and subsequent translocation of gut resident pathogens into the blood. Consistently, CDI due to PCR-ribotype 027 strain, severe or relapsing CDI, and treatment with high-dosage vancomycin are independent risk factors for candidemia.

AREAS COVERED

We review the role played by the gut microbiota during CDI and its treatment, as well as the clinical profile of CDI patients who are at risk of developing candidemia. Also, we discuss the management of these patients by focusing on pre-emptive strategies aimed at reducing the risk of candidemia, and on innovative anti-C. difficile therapies that may mitigate CDI-related effects such as the altered gut microbiota composition and prolonged intestinal mucosa damage. Expert commentary: A closer clinical and diagnostic monitoring of patients with CDI should help to limit the CDI-associated long-term consequences, including Candida infections, which worsen the outcome of hospitalized patients.

Biomarker-based strategy for early discontinuation of empirical antifungal treatment in critically ill patients: a randomized controlled trial

PURPOSE

The aim of this study was to determine the impact of a biomarker-based strategy on early discontinuation of empirical antifungal treatment.

METHODS

Prospective randomized controlled single-center unblinded study, performed in a mixed ICU. A total of 110 patients were randomly assigned to a strategy in which empirical antifungal treatment duration was determined by (1,3)-β-D-glucan, mannan, and anti-mannan serum assays, performed on day 0 and day 4; or to a routine care strategy, based on international guidelines, which recommend 14 days of treatment. In the biomarker group, early stop recommendation was determined using an algorithm based on the results of biomarkers. The primary outcome was the percentage of survivors discontinuing empirical antifungal treatment early, defined as a discontinuation strictly before day 7.

RESULTS

A total of 109 patients were analyzed (one patient withdraw consent). Empirical antifungal treatment was discontinued early in 29 out of 54 patients in the biomarker strategy group, compared with one patient out of 55 in the routine strategy group [54% vs 2%, p < 0.001, OR (95% CI) 62.6 (8.1-486)]. Total duration of antifungal treatment was significantly shorter in the biomarker strategy compared with routine strategy [median (IQR) 6 (4-13) vs 13 (12-14) days, p < 0.0001). No significant difference was found in the percentage of patients with subsequent proven invasive Candida infection, mechanical ventilation-free days, length of ICU stay, cost, and ICU mortality between the two study groups.

CONCLUSIONS

The use of a biomarker-based strategy increased the percentage of early discontinuation of empirical antifungal treatment among critically ill patients with suspected invasive Candida infection. These results confirm previous findings suggesting that early discontinuation of empirical antifungal treatment had no negative impact on outcome. However, further studies are needed to confirm the safety of this strategy. This trial was registered at ClinicalTrials.gov, NCT02154178.

Combined use of serum (1,3)-β-D-glucan and procalcitonin for the early differential diagnosis between candidaemia and bacteraemia in intensive care units

Background

This study aimed to assess the combined performance of serum (1,3)-β-d-glucan (BDG) and procalcitonin (PCT) for the differential diagnosis between candidaemia and bacteraemia in three intensive care units (ICUs) in two large teaching hospitals in Italy.

Methods

From June 2014 to December 2015, all adult patients admitted to the ICU who had a culture-proven candidaemia or bacteraemia, as well as BDG and PCT measured closely to the time of the index culture, were included in the study. The diagnostic performance of BDG and PCT, used either separately or in combination, was assessed by calculating the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive and negative likelihood ratios (LR+ and LR–). Changes from pre-test probabilities to post-test probabilities of candidaemia and bacteraemia were inferred from Fagan’s nomograms.

Results

One hundred and sixty-six patients were included, 73 with candidaemia (44%) and 93 with bacteraemia (56%). When both markers indicated candidaemia (BDG ≥80 pg/ml and PCT <2 ng/ml) they showed higher PPV (96%) compared to 79% and 66% for BDG or PCT alone, respectively. When both markers indicated bacteraemia (BDG <80 pg/ml and PCT ≥2 ng/ml), their NPV for candidaemia was similar to that of BDG used alone (95% vs. 93%). Discordant BDG and PCT results (i.e. one indicating candidaemia and the other bacteraemia) only slightly altered the pre-test probabilities of the two diseases.

Conclusions

The combined use of PCT and BDG could be helpful in the diagnostic workflow for critically ill patients with suspected candidaemia.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1763-5) contains supplementary material, which is available to authorized users.