[Trends in systemic antifungal use in critically ill patients. Multicenter observational study, 2006-2010]

Antifungal stewardship: the Latin American experience

Antifungal stewardship is a critical component of healthcare management that focuses on optimizing the use of antifungal medications to improve patient outcomes, minimize resistance, and reduce healthcare costs.  In resource-limited settings, the prevalence of fungal infections remains a significant health concern, often exacerbated by factors such as compromised immune systems, inadequate diagnostic capabilities, and limited access to antifungal agents. This paper reviews the current state of antifungal stewardship practices in developing countries, addressing the unique socioeconomic and healthcare landscape.

Mecanismos de resistencia a fluconazol expresados por Candida glabrata: una situación para considerar en la terapéutica

Introducción: Los esfuerzos terapéuticos orientados a atender las micosis por Candida spp. se han enfocado en el empleo de azoles; sin embargo, en la literatura científica se discute su beneficio, por los amplios y descritos mecanismos de resistencia. Objetivo: Describir los mecanismos de resistencia al fluconazol expresados por la especie Candida glabrata, con la intención de que sean considerados dentro de las variables de elegibilidad para la intervención. Método: Se realizó una revisión integrativa utilizando la pregunta orientadora: ¿cuáles son los mecanismos de resistencia al fluconazol expresados por la especie Candida glabrata? Veintinueve estudios obtenidos de la base de datos PubMed cumplieron los criterios del análisis crítico propuesto por el instrumento PRISMA, utilizado para la selección de los artículos incluidos para su revisión en este manuscrito. Las categorías bajo las cuales se organizaron los elementos de análisis fueron: sobrexpresión de bombas de eflujo y modificaciones en la enzima lanosterol 14-alfa-desmetilasa. Resultados: Los mecanismos de resistencia al fluconazol expresados por Candida glabrata están determinados principalmente por la regulación a la alza de bombas de adenosina-trifosfato Binding Cassette (ABC) y por la modificación del punto de unión con su blanco farmacológico: la enzima lanosterol 14-alfa-desmetilasa. Conclusión: Los mecanismos de resistencia expresados por Candida glabrata se asocian con la modificación estructural de la diana farmacológica y la sobreexpresión de bombas de eflujo de manera diferencial a otras especies. Se sugiere que Candida glabrata es intrínsecamente menos susceptible al fluconazol.

Polymerase Chain Reaction Versus Blood Culture to Detect Candida Species in High-Risk Patients with Suspected Invasive Candidiasis: The MICAFEM Study

INTRODUCTION

We evaluated the diagnostic reliability of serum polymerase chain reaction (PCR) versus blood culture, abdominal fluid or both (composite measure) in patients receiving empirical antifungal treatment for suspected invasive candidiasis.

METHODS

This observational, prospective, non-interventional, multicentre study in Spain enrolled 176 critically ill patients admitted to the intensive care unit. Separate blood samples for culture and serum PCR were taken before the start of antifungal therapy. Patient assessment was performed according to each site's usual clinical practice. The primary end point was concordance between serum PCR and blood culture. Secondary end points were concordance between serum PCR and a positive abdominal fluid sample or the composite measure. Quality indices included sensitivity, specificity, positive/negative predictive values (PPV/NPV) and kappa indices.

RESULTS

Among 175 evaluable patients, rates of Candida detection were similar for serum PCR (n = 16/175, 9.1%) versus blood culture (n = 14/175, 8.0%). Quality indices for serum PCR relative to blood culture were: sensitivity 21.4%; specificity 91.9%; PPV 18.8%; NPV 93.1%; kappa index 0.125. Thirty-two abdominal fluid samples were positive. Quality indices for serum PCR versus abdominal fluid were: sensitivity 31.3%; specificity 83.0%; PPV 15.6%; NPV 92.3%; kappa index 0.100. Quality indices for serum PCR versus the composite measure were: sensitivity 15.8%; specificity 92.7%; PPV 37.5%; NPV 79.9%; kappa index 0.107.

CONCLUSION

The sensitivity of serum PCR for Candida detection was low and the rate of concordance was low between serum PCR and the other diagnostic techniques used to identify Candida infections. Hospital-based diagnostic tests need optimising to improve outcomes in patients with suspected invasive candidiasis.

FUNDING

Astellas Pharma Inc.

Evaluation of Candida bloodstream infection and antifungal utilization in a tertiary care hospital

BACKGROUND

Candida bloodstream infections carry a significant mortality risk, justifying the importance of adequate antifungal therapy. This study describes trends in antifungal consumption using the Defined Daily Dose (DDD) and Days of Therapy (DOT) metrics, identifies the microbiological profile, the time to initiation of empirical therapy, the adjustment after positive blood culture results for Candida, and the impact on in-hospital mortality rate in patients with candidemia.

METHODS

An analysis of antifungal consumption from 2008 to 2016, and of candidemia cases from 2012 to 2016 was carried out in a private tertiary hospital.

RESULTS

A total of 11,273 admissions were identified with a prescription for at least one type of antifungal therapy. Fluconazole was the most prescribed antifungal drug in terms of general consumption. Through the DDD and DOT metrics, we observed that over time, there was an increase in the consumption of liposomal amphotericin B, micafungin and voriconazole. Candida albicans was the most isolated species in blood cultures. Regarding candidemia, we analyzed samples from 115 patients. Empirical therapy was started within 24 h of blood culture in 44.3% of the cases, and in 81.7% of the cases, the antifungal was deemed to be adequate based in antifungal susceptibility testing, both of which were not associated with the in-hospital mortality rate.

CONCLUSIONS

Our study reinforces the importance of monitoring the consumption of antifungal agents, which helps in proposing actions that lead to their rational use and, consequently, reduces the appearance of resistant strains.

Antifungal stewardship considerations for adults and pediatrics

Antifungal stewardship refers to coordinated interventions to monitor and direct the appropriate use of antifungal agents in order to achieve the best clinical outcomes and minimize selective pressure and adverse events. Antifungal utilization has steadily risen over time in concert with the increase in number of immunocompromised adults and children at risk for invasive fungal infections (IFI). Challenges in diagnosing IFI often lead to delays in treatment and poorer outcomes. There are also emerging data linking prior antifungal exposure and suboptimal dosing to the emergence of antifungal resistance, particularly for Candida. Antimicrobial stewardship programs can take a multi-pronged bundle approach to ensure suitable prescribing of antifungals via post-prescription review and feedback and/or prior authorization. Institutional guidelines can also be developed to guide diagnostic testing in at-risk populations; appropriate choice, dose, and duration of antifungal agent; therapeutic drug monitoring; and opportunities for de-escalation and intravenous-to-oral conversion.

Contribution of Candida biomarkers and DNA detection for the diagnosis of invasive candidiasis in ICU patients with severe abdominal conditions

BACKGROUND

To assess the performance of Candida albicans germ tube antibody (CAGTA), (1 → 3)-ß-D-glucan (BDG), mannan antigen (mannan-Ag), anti-mannan antibodies (mannan-Ab), and Candida DNA for diagnosing invasive candidiasis (IC) in ICU patients with severe abdominal conditions (SAC).

METHODS

A prospective study of 233 non-neutropenic patients with SAC on ICU admission and expected stay ≥ 7 days. CAGTA (cutoff positivity ≥ 1/160), BDG (≥80, 100 and 200 pg/mL), mannan-Ag (≥60 pg/mL), mannan-Ab (≥10 UA/mL) were measured twice a week, and Candida DNA only in patients treated with systemic antifungals. IC diagnosis required positivities of two biomarkers in a single sample or positivities of any biomarker in two consecutive samples. Patients were classified as neither colonized nor infected (n = 48), Candida spp. colonization (n = 154) (low-grade, n = 130; high-grade, n = 24), and IC (n = 31) (intra-abdominal candidiasis, n = 20; candidemia, n = 11).

RESULTS

The combination of CAGTA and BDG positivities in a single sample or at least one of the two biomarkers positive in two consecutive samples showed 90.3 % (95 % CI 74.2-98.0) sensitivity, 42.1 % (95 % CI 35.2-98.8) specificity, and 96.6 % (95 % CI 90.5-98.8) negative predictive value. BDG positivities in two consecutive samples had 76.7 % (95 % CI 57.7-90.1) sensitivity and 57.2 % (95 % CI 49.9-64.3) specificity. Mannan-Ag, mannan-Ab, and Candida DNA individually or combined showed a low discriminating capacity.

CONCLUSIONS

Positive Candida albicans germ tube antibody and (1 → 3)-ß-D-glucan in a single blood sample or (1 → 3)-ß-D-glucan positivity in two consecutive blood samples allowed discriminating invasive candidiasis from Candida spp. colonization in critically ill patients with severe abdominal conditions. These findings may be helpful to tailor empirical antifungal therapy in this patient population.

Consumption of systemic antifungal agents among acute care hospitals in Catalonia (Spain), 2008-2013

Objective To know the patterns and consumption trends (2008-2013) of antifungal agents for systemic use in 52 acute care hospitals affiliated to VINCat Program in Catalonia (Spain). Methods Consumption was calculated in defined daily doses (DDD)/100 patient-days and analyzed according to hospital size and complexity and clinical departments. Results Antifungal consumption was higher in intensive care units (ICU) (14.79) than in medical (3.08) and surgical departments (1.19). Fluconazole was the most consumed agent in all type of hospitals and departments. Overall antifungal consumption increased by 20.5%during the study period (p = 0.066); a significant upward trend was observed in the consumption of both azoles and echinocandins. In ICUs, antifungal consumption increased by 12.4% (p = 0.019). Conclusions The study showed a sustained increase in the overall consumption of systemic antifungals in a large number of acute care hospitals of different characteristics in Catalonia. In ICUs there was a trend towards the substitution of older agents by the new ones.

Combination of Candida biomarkers in patients receiving empirical antifungal therapy in a Spanish tertiary hospital: a potential role in reducing the duration of treatment

OBJECTIVES

Initiation of empirical antifungal therapy for invasive candidiasis (IC) is usually based on clinical suspicion. Serological biomarkers have not yet been studied as a means of ruling out IC. We evaluated the potential role of two combined biomarkers in stopping unnecessary antifungals in patients at risk of IC in the ICU and in other wards.

METHODS

This was a prospective observational study including adults starting empirical antifungal treatment for suspected IC, at Gregorio Marañón Hospital, Madrid (Spain). Patients were stratified according to admission department (ICU or other wards) and final diagnosis (no IC or proven or probable IC). Type of candidiasis (candidaemia or deep-seated candidiasis) was also considered. The Candida albicans germ tube antibody (CAGTA) test and the β-d-glucan (BDG) test were performed on serum samples collected by venepuncture on days 0, 3 and 5 after starting empirical antifungal therapy.

RESULTS

Sixty-three ICU patients and 37 non-ICU patients were included. High-risk gastrointestinal surgery and sepsis in non-surgical patients were the main indications for empirical treatment (30% each). Patients had no IC (58%), proven IC (30%) or probable IC (12%). Overall, sensitivity and negative predictive value of the combination of both the CAGTA test and the BDG test were 97% for the entire population. The best performance was observed in ICU patients (sensitivity and negative predictive value of 100%). Among patients without IC, all biomarkers were negative in 31 patients.

CONCLUSIONS

Serial determination of CAGTA/BDG during empirical antifungal therapy has a high sensitivity and negative predictive value. If properly confirmed, this strategy could be used to discontinue antifungal treatment in at least 31% of patients as a complementary tool in antifungal stewardship programmes.

Hospital use of systemic antifungal drugs: a multi-center surveillance update from Germany

BACKGROUND

The consumption of antifungal agents increased over the last decade, resulting in the development of resistant organisms and causing a significant pharmaco economic burden. Antifungal drugs are widely used for the treatment of systemic fungal infections and high-risk patients, especially with severe hematological or oncological conditions. Up to date, there are no reliable and systematically reported data on the consumption of antifungal substances on a nationwide level available. The presented study gives an update to the previously published multicenter study investigating antifungal consumption in different settings from five university hospital centers in Germany from 2001 to 2003.

METHODS

Consumption data for systemic antifungal drugs were obtained through the hospital pharmacies for 2001-2003 and 2008-2011 regarding the medical and surgical services of five university hospital centers in Germany (A-E). Drug use densities were calculated as yearly RDDs/100 patient days. These calculations were performed for the surgical and medical services, and independently for surgical and medical ICUs, as well as for the hematology-oncology services.

RESULTS

We report an increased utilization of systemic antifungal drugs in both study periods. The mean drug use density (mean value of all 5 hospitals) in the medical services increased by 24% between 2001 and 2003. In 2011, this value was 37% above the level from 2001 (12.4 RDD/100 patient days in 2001, 15.4 RDD/100 patient days in 2003, 17.0 RDD/100 patient days in 2011). The 4-year average drug use density (2008-2011) of medical services ranged between 11.6 RDD/100 patient days (hospital E) and 23.8 RDD/100 patient days (hospital A). Drug use densities were in medical intensive care units 29.4 RDD/100 patient days and hematology-oncology services 49.9 RDD/100 patient days.

CONCLUSIONS

Despite the variability of the prescribing patterns between the tertiary hospitals, the presented pharmaco-epidemiological data are a cornerstone for the initiation and implementation of effective antifungal stewardship programmes and might serve as important benchmarking information for other hospitals with similar structures and baseline settings.

What's new in the clinical and diagnostic management of invasive candidiasis in critically ill patients

Invasive candidiasis (IC) is a severe complication in the ICU setting. A high proportion of ICU patients become colonized with Candida species, but only 5-30 % develop IC. Progressive colonization and major abdominal surgery are well-known risk factors for Candida infection. IC is difficult to predict and early diagnosis remains a major challenge. In addition, microbiological documentation often occurs late in the course of infection. Delays in initiating appropriate treatment have been associated with increased mortality. In an attempt to decrease Candida-related mortality, an increasing number of critically ill patients without documented IC receive empirical systemic antifungal therapy, leading to concern for antifungal overuse. Scores/predictive rules permit the stratification and selection of IC high-risk patients who may benefit from early antifungal therapy. However, they have a far better negative predictive value than positive predictive value. New IC biomarkers [mannan, anti-mannan, (1,3)-β-D-glucan, and polymerase chain reaction] are being increasingly used to enable earlier diagnosis and, ideally, to provide prognostic information and/or therapeutic monitoring. Although reasonably sensitive and specific, these techniques remain largely investigational, and their clinical usefulness has yet to be established.

Factors predicting prolonged empirical antifungal treatment in critically ill patients

Objective

To determine the incidence, risk factors, and impact on outcome of prolonged empirical antifungal treatment in ICU patients.

Methods

Retrospective observational study performed during a one-year period. Patients who stayed in the ICU >48 h, and received empirical antifungal treatment were included. Patients with confirmed invasive fungal disease were excluded. Prolonged antifungal treatment was defined as percentage of days in the ICU with antifungals > median percentage in the whole cohort of patients.

Results

Among the 560 patients hospitalized for >48 h, 153 (27%) patients received empirical antifungal treatment and were included in this study. Fluconazole was the most frequently used antifungal (46% of study patients). Median length of ICU stay was 19 days (IQR 8, 34), median duration of antifungal treatment was 8 days (IQR 3, 16), and median percentage of days in the ICU with antifungals was 48% (IQR 25, 80). Seventy-seven patients (50%) received prolonged empirical antifungal treatment. Chemotherapy (OR [95% CI] 2.6 [1.07-6.69], p = 0.034), and suspected infection at ICU admission (3.1 [1.05-9.48], p = 0.041) were independently associated with prolonged empirical antifungal treatment.

Duration of mechanical ventilation and ICU stay were significantly shorter in patients with prolonged empirical antifungal treatment compared with those with no prolonged empirical antifungal treatment. However, ICU mortality was similar in the two groups (46 versus 52%, p = 0.62).

Conclusion

Empirical antifungal treatment was prescribed in a large proportion of study patients. Chemotherapy, and suspicion of infection at ICU admission are independently associated with prolonged empirical antifungal treatment.

Does the current treatment of invasive fungal infection need to be reviewed?

Invasive fungal infections (IFIs) are becoming more frequent due to the increasing number of patients at risk. Over the last decade, their prognosis has improved with the diagnostic and therapeutic advances, including new antifungals. In the two years, from 2007 to 2009, antifungal consumption increased by 27%, 67 times more than antibacterial consumption, albeit with great differences between hospitals. The scientific evidence of the indications for antifungal prophylaxis and targeted antifungal therapy is strong; however, it is weak for empirical antifungal therapy, which is the most common indication. Antifungals are not harmless, since they are associated with a wide range of adverse effects and drug interactions, favor the development of resistance, contribute to other fungal superinfections and cause significant healthcare spending. Therefore, the question arises whether this extraordinary increase in consumption is justified, whether the use of antifungals is optimal, or whether it is necessary to reconsider the current treatment of IFIs instead.