Burden of hospitalization of patients with Candida and Aspergillus infections in Australia

Invasive aspergillosis in adult patients in Australia and New Zealand: 2017-2020

Background

New and emerging risks for invasive aspergillosis (IA) bring the need for contemporary analyses of the epidemiology and outcomes of IA, in order to improve clinical practice.

Methods

The study was a retrospective, multicenter, cohort design of proven and probable IA in adults from 10 Australasian tertiary centres (January 2017-December 2020). Descriptive analyses were used to report patients' demographics, predisposing factors, mycological characteristics, diagnosis and management. Accelerated failure-time model was employed to determine factor(s) associated with 90-day all-cause mortality (ACM).

Findings

Of 382 IA episodes, 221 (in 221 patients) fulfilled inclusion criteria - 53 proven and 168 probable IA. Median patient age was 61 years (IQR 51-69). Patients with haematologic malignancies (HM) comprised 49.8% of cases. Fifteen patients (6.8%) had no pre-specified immunosuppression and eleven patients (5.0%) had no documented comorbidity. Only 30% of patients had neutropenia. Of 170 isolates identified, 40 (23.5%) were identified as non-Aspergillus fumigatus species complex. Azole-resistance was present in 3/46 (6.5%) of A. fumigatus sensu stricto isolates. Ninety-day ACM was 30.3%. HM (HR 1.90; 95% CI 1.04-3.46, p = 0.036) and ICU admission (HR 4.89; 95% CI 2.93-8.17, p < 0.001) but not neutropenia (HR 1.45; 95% CI 0.88-2.39, p = 0.135) were associated with mortality. Chronic kidney disease was also a significant predictor of death in the HM subgroup (HR 3.94; 95% CI 1.15-13.44, p = 0.028).

Interpretation

IA is identified in high number of patients with mild/no immunosuppression in our study. The relatively high proportion of non-A. fumigatus species complex isolates and 6.5% azole-resistance rate amongst A. fumigatus sensu stricto necessitates accurate species identification and susceptibility testing for optimal patient outcomes.

Funding

This work is unfunded. All authors' financial disclosures are listed in detail at the end of the manuscript.

Cost-utility analysis of caspofungin and fluconazole for primary treatment of invasive candidiasis and candidemia in Ethiopia

Background

Invasive candidiasis and/or candidemia (IC/C) is a common fungal infection leading to significant health and economic losses worldwide. Caspofungin was shown to be more effective than fluconazole in treating inpatients with IC/C. However, cost-effectiveness of caspofungin for treating IC/C in Ethiopia remains unknown. We aimed to assess the cost-utility of caspofungin compared to fluconazole-initiated therapies as primary treatment of IC/C in Ethiopia.

Methods

A Markov cohort model was developed to compare the cost-utility of caspofungin versus fluconazole antifungal agents as first-line treatment for adult inpatients with IC/C from the Ethiopian health system perspective. Treatment outcome was categorized as either a clinical success or failure, with clinical failure being switched to a different antifungal medication. Liposomal amphotericin B (L-AmB) was used as a rescue agent for patients who had failed caspofungin treatment, while caspofungin or L-AmB were used for patients who had failed fluconazole treatment. Primary outcomes were expected quality-adjusted life years (QALYs), costs (US$2021), and the incremental cost-utility ratio (ICUR). These QALYs and costs were discounted at 3% annually. Cost data was obtained from Addis Ababa hospitals while locally unavailable data were derived from the literature. Cost-effectiveness was assessed against the recommended threshold of 50% of Ethiopia’s gross domestic product/capita (i.e.,US$476). Deterministic and probabilistic sensitivity analyses were conducted to assess the robustness of the findings.

Results

In the base-case analysis, treatment of IC/C with caspofungin as first-line treatment resulted in better health outcomes (12.86 QALYs) but higher costs (US$7,714) compared to fluconazole-initiated treatment followed by caspofungin (12.30 QALYs; US$3,217) or L-AmB (10.92 QALYs; US$2,781) as second-line treatment. Caspofungin as primary treatment for IC/C was not cost-effective when compared to fluconazole-initiated therapies. Fluconazole-initiated treatment followed by caspofungin was cost-effective for the treatment of IC/C compared to fluconazole with L-AmB as second-line treatment, at US$316/QALY gained. Our findings were sensitive to medication costs, drug effectiveness, infection recurrence, and infection-related mortality rates. At a cost-effectiveness threshold of US$476/QALY, treating IC/C patient with fluconazole-initiated treatment followed by caspofungin was more likely to be cost-effective in 67.2% of simulations.

Conclusion

Our study showed that the use of caspofungin as primary treatment for IC/C in Ethiopia was not cost-effective when compared with fluconazole-initiated treatment alternatives. The findings supported the use of fluconazole-initiated therapy with caspofungin as a second-line treatment for patients with IC/C in Ethiopia.

Candida Bloodstream Infections: Changes in Epidemiology and Increase in Drug Resistance

The literature on bloodstream infections (BSIs) have predominantly been biased towards bacteria, given their superior clinical significance in comparison with the other types of microorganisms. Fungal pathogens have epidemiologically received relatively less attention, although they constitute an important proportion of BSI aetiologies. In this review, the authors discuss the clinical relevance of fungal BSIs in the context of Candida species, as well as treatment options for the infections, emphasizing the compelling need to develop newer antifungals and strengthen antimicrobial stewardship programmes in the wake of the rapid spread of antifungal resistance.

Broad-Spectrum Solvent-free Layered Black Phosphorus as a Rapid Action Antimicrobial

Antimicrobial resistance has rendered many conventional therapeutic measures, such as antibiotics, ineffective. This makes the treatment of infections from pathogenic micro-organisms a major growing health, social, and economic challenge. Recently, nanomaterials, including two-dimensional (2D) materials, have attracted scientific interest as potential antimicrobial agents. Many of these studies, however, rely on the input of activation energy and lack real-world utility. In this work, we present the broad-spectrum antimicrobial activity of few-layered black phosphorus (BP) at nanogram concentrations. This property arises from the unique ability of layered BP to produce reactive oxygen species, which we harness to create this unique functionality. BP is shown to be highly antimicrobial toward susceptible and resistant bacteria and fungal species. To establish cytotoxicity with mammalian cells, we showed that both L929 mouse and BJ-5TA human fibroblasts were metabolically unaffected by the presence of BP. Finally, we demonstrate the practical utility of this approach, whereby medically relevant surfaces are imparted with antimicrobial properties via functionalization with few-layer BP. Given the self-degrading properties of BP, this study demonstrates a viable and practical pathway for the deployment of novel low-dimensional materials as antimicrobial agents without compromising the composition or nature of the coated substrate.

A New Gold Rush: A Review of Current and Developing Diagnostic Tools for Urinary Tract Infections

Urinary tract infections (UTIs) are one of the most common infections in the United States and consequently are responsible for significant healthcare expenditure. The standard urine culture is the current gold standard for diagnosing urinary tract infections, however there are limitations of the test that directly contribute to increased healthcare costs. As a result, new and innovative techniques have been developed to address the inefficiencies of the current standard-it remains to be seen whether these tests should be performed adjunctly to, or perhaps even replace the urine culture. This review aims to analyze the advantages and disadvantages of the newer and emerging diagnostic techniques such as PCR, expanded quantitative urine culture (EQUC), and next generation sequencing (NGS).

Glycobiology of Human Fungal Pathogens: New Avenues for Drug Development

Invasive fungal infections (IFI) are an increasing threat to the developing world, with fungal spores being ubiquitous and inhaled every day. Some fungal species are commensal organisms that are part of the normal human microbiota, and, as such, do not pose a threat to the immune system. However, when the natural balance of this association is disturbed or the host's immune system is compromised, these fungal pathogens overtake the organism, and cause IFI. To understand the invasiveness of these pathogens and to address the growing problem of IFI, it is essential to identify the cellular processes of the invading organism and their virulence. In this review, we will discuss the prevalence and current options available to treat IFI, including recent reports of drug resistance. Nevertheless, the main focus of this review is to describe the glycobiology of human fungal pathogens and how various components of the fungal cell wall, particularly cell wall polysaccharides and glycoconjugates, are involved in fungal pathogenicity, their biosynthesis and how they can be potentially exploited to develop novel antifungal treatment options. We will specifically describe the nucleotide sugar transporters (NSTs) that are important in fungal survival and suggest that the inhibition of fungal NSTs may potentially be useful to prevent the establishment of fungal infections.

A population-based analysis of invasive fungal disease in haematology-oncology patients using data linkage of state-wide registries and administrative databases: 2005 - 2016

BACKGROUND

Little is known about the morbidity and mortality of invasive fungal disease (IFD) at a population level. The aim of this study was to determine the incidence, trends and outcomes of IFD in all haematology-oncology patients by linking Victorian hospital data to state-based registries.

METHODS

Episodes of IFD complicating adult haematological malignancy (HM) and haematopoietic stem cell transplantation (HSCT) patients admitted to Victorian hospitals from 1^st July 2005 to 30^th June 2016 were extracted from the Victorian Admitted Episodes Dataset and linked to the date of HM diagnosis from the Victorian Cancer Registry and mortality from the Victorian Death Index. Descriptive analyses and regression modelling were used.

RESULTS

There were 619,702 inpatient-episodes among 32,815 HM and 1,765 HSCT-patients. IFD occurring twelve-months from HM-diagnosis was detected in 669 (2.04%) HM-patients and 111 (6.29%) HSCT-recipients, respectively. Median time to IFD-diagnosis was 3, 5, 15 and 22 months in acute myeloid leukaemia, acute lymphoblastic leukaemia, Hodgkin lymphoma and multiple myeloma, respectively. Median survival from IFD-diagnosis was 7, 7 and 3 months for invasive aspergillosis, invasive candidiasis and mucormycosis, respectively. From 2005-2016, IFD incidence decreased 0.28% per 1,000 bed-days. Fungal incidence coincided with spring peaks on time-series analysis.

CONCLUSIONS

Data linkage is an efficient means of evaluating the epidemiology of a rare disease, however the burden of IFD is likely underestimated, arguing for better quality hospital level surveillance data to improve management strategies.

Insights into the global emergence of antifungal drug resistance

The global prevalence of fungal diseases has escalated in the last several decades. Currently, it is estimated that fungi infect 1.7 billion people annually and result in 1.5 million deaths every year1. Deaths due to fungal infections are increasing, with mortality often exceeding 50%, further increasing to 100% if treatment is delayed1. Despite these staggering figures, the contribution of fungal infections to the global burden of disease remains under-recognised. In Australia, over a 5-year period fungal infections cost Australia an estimated $583 million2. The median cost for one invasive fungal disease (IFD) is AU$30957, increasing to AU$80291 if the patient is admitted to an intensive care unit3. Treatment of fungal infections poses significant challenges due to the small number of safe and effective antifungal drugs available and emerging antifungal drug resistance. Resistance to every class of antifungal drugs has been described and for some drug classes is extremely common4,5.

Economic evaluation of micafungin versus liposomal amphotericin B (LAmB) for treating patients with candidaemia and invasive candidiasis (IC) in Turkey

Micafungin was reported to be non-inferior to liposomal amphotericin B (LAmB) in treating patients with candidaemia and invasive candidiasis (IC). The current study aimed to evaluate the economic impact of using micafungin versus LAmB for treatment of candidaemia and IC in Turkey. A decision analytic model, which depicted economic consequences upon administration of micafungin or LAmB for treating patients with candidaemia and IC in the Turkish hospitals, was constructed. Patients were switched to an alternative antifungal agent if initial treatment failed due to mycological persistence. All patients were followed up until treatment success or death. Outcome probabilities were obtained from published literature and cost inputs were derived from the latest Turkish resources. Expert panels were used to estimate data that were not available in the literature. Cost per patient treated for each intervention was then calculated. Sensitivity analyses including Monte Carlo simulation were performed. For treatment of candidaemia and IC, micafungin (€4809) was associated with higher total cost than LAmB (€4467), with an additional cost of €341 per treated patient. Cost of initial antifungal treatment was the major cost driver for both comparators. The model outcome was robust over a wide variation in input variables except for drug acquisition cost and duration of initial antifungal treatment with micafungin or LAmB. LAmB is cost-saving relative to micafungin for the treatment of candidaemia and IC from the Turkish hospital perspective, with variation in drug acquisition cost of the critical factor affecting the model outcome.

Cyclodextrin complexes for treatment improvement in infectious diseases

Infectious diseases are a heterogeneous group of maladies that represent a serious burden to healthcare systems worldwide. Most of the available antimicrobial drugs display poor biopharmaceutical properties that compromise their effectiveness. Cyclodextrins (CDs) are cyclic oligosaccharides of glucopyranose formed by a variable number of repeating units that combine a hydrophilic surface with a hydrophobic cavity. The production of drug/CD complexes has become one of the most extensively investigated technology approaches to improve the stability, solubility, dissolution rate and bioavailability of drugs. The present work overviews the applications of CDs for the formulation of anti-infective agents along with the most relevant administration routes. Finally, an update on the complexes with CDs available on the market to treat infectious diseases is presented.

Efficacy and cost-effectiveness of voriconazole prophylaxis for prevention of invasive aspergillosis in high-risk liver transplant recipients

Aspergillus infection remains a significant and deadly complication after liver transplantation (LT). We sought to determine whether the antifungal prophylactic use of voriconazole reduces the incidence of invasive aspergillosis (IA) in high-risk LT recipients without prohibitively increasing cost. During the study era (April 2008 to April 2014), 339 deceased donor LTs were performed. Of those patients, 174 high-risk recipients were administered antifungal prophylaxis with voriconazole. The median biological Model for End-Stage Liver Disease score at the time of LT was 33 (range, 18-49) with 56% requiring continuous renal replacement therapy and 50% requiring ventilatory support immediately before transplantation. Diagnosis of IA was stratified as proven, probable, or possible according to previously published definitions. No IA was documented in patients receiving voriconazole prophylaxis. At 90 days after LT, the institutional cost of prophylaxis was $5324 or 5.6% of the predicted cost associated with post-LT aspergillosis. There was no documentation of resistant strains isolated from any recipient who received voriconazole. In conclusion, these data suggest that voriconazole prophylaxis is safe, clinically effective, and cost-effective in high-risk LT recipients.

Consensus guidelines for implementation of quality processes to prevent invasive fungal disease and enhanced surveillance measures during hospital building works, 2014

Healthcare-associated fungal outbreaks impose a substantial economic burden on the health system and typically result in high patient morbidity and mortality, particularly in the immunocompromised host. As the population at risk of invasive fungal infection continues to grow due to the increased burden of cancer and related factors, the need for hospitals to employ preventative measures has become increasingly important. These guidelines outline the standard quality processes hospitals need to accommodate into everyday practice and at times of healthcare-associated outbreak, including the role of antifungal stewardship programmes and best practice environmental sampling. Specific recommendations are also provided to help guide the planning and implementation of quality processes and enhanced surveillance before, during and after high-risk activities, such as hospital building works. Areas in which information is still lacking and further research is required are also highlighted.

Cost effectiveness of caspofungin vs. voriconazole for empiric therapy in Turkey

Invasive fungal infections from febrile neutropenia are associated with significant cost and mortality. The mainstay of treatment has been liposomal amphotericin B, however, echinocandins and azoles have shown promise as alternative treatments. Data on clinical efficacy exist, however, data incorporating pharmacoeconomic considerations are required in Turkey. The aim of this study was to investigate the cost effectiveness of caspofungin vs. voriconazole in empiric treatment of febrile neutropenia in Turkey. A decision analytic model was utilised, built upon two randomised-controlled trials and supplemented with expert panel input from clinicians in Turkey. A five-point composite outcome measure was utilised and sensitivity analyses were performed to demonstrate the robustness of the model. The base case scenario resulted in caspofungin being preferred by TL2,533, TL29,256 and TL2,536 per patient treated, successfully treated patient and patient survival, respectively (approx. USD1414, 16 328 and 1415); sensitivity analyses did not change the outcome. Monte Carlo simulation highlighted a 78.8% chance of favouring caspofungin. The result was moderately sensitive to treatment duration and acquisition cost of the antifungal agents compared. This is the first pharmacoeconomic study comparing caspofungin to voriconazole within Turkey, resulting in an advantage towards caspofungin. The study will aid in formulary decision-making based on the clinical and economic consequences of each agent in the Turkish health care setting.

Galactomannan antigen assay from bronchoalveolar lavage fluid in diagnosis of invasive pulmonary aspergillosis in intensive care units patients

Background:

Invasive pulmonary aspergillosis (IPA) is an important infection in critically ill patients including patients of intensive care units (ICU). Different diagnostic tools are available and since its mortality is high, it is vital to start the antifungal therapy as soon as possible. Knowing the epidemiology of this disease in each ICU and area will help to better and more rapid management of such patients. The aim of this study is to determine the frequency of IPA based on the level of galactomannan in bronchoalveolar lavage fluid in ICU of Al-Zahra hospital, Isfahan, Iran.

Materials and Methods:

This was a cross sectional study, which was conducted in Al-Zahra hospital, Isfahan, Iran, between 2010 to 2011. The study population was all the patients admitted to ICU and were suspected to have invasive Aspergillus spp pneumonia. The level of galactomannan in bronchoalveolar lavage was measured and demographic data were gathered by the questionnaire.

Results:

The frequency of IPA in this study was calculated as 2.43% while galactomannan level in bronchoalveolar lavage fluid of this patient (2.50) was significantly higher than others (0.03 ± 0.02).

Conclusion:

Larger studies are required to determine the exact frequency of IPA and the best antifungal therapy for it.

Candida identification: a journey from conventional to molecular methods in medical mycology

The incidence of Candida infections have increased substantially in recent years due to aggressive use of immunosuppressants among patients. Use of broad-spectrum antibiotics and intravascular catheters in the intensive care unit have also attributed with high risks of candidiasis among immunocompromised patients. Among Candida species, C. albicans accounts for the majority of superficial and systemic infections, usually associated with high morbidity and mortality often caused due to increase in antimicrobial resistance and restricted number of antifungal drugs. Therefore, early detection of candidemia and correct identification of Candida species are indispensable pre-requisites for appropriate therapeutic intervention. Since blood culture based methods lack sensitivity, and species-specific identification by conventional method is time-consuming and often leads to misdiagnosis within closely related species, hence, molecular methods may provide alternative for accurate and rapid identification of Candida species. Although, several molecular approaches have been developed for accurate identification of Candida species but the internal transcribed spacer 1 and 2 (ITS1 and ITS2) regions of the rRNA gene are being used extensively in a variety of formats. Of note, ITS sequencing and PCR-RFLP analysis of ITS region seems to be promising as a rapid, easy, and cost-effective method for identification of Candida species. Here, we review a number of existing techniques ranging from conventional to molecular approaches currently in use for the identification of Candida species. Further, advantages and limitations of these methods are also discussed with respect to their discriminatory power, reproducibility, and ease of performance.

Pharmacoeconomic evaluation of voriconazole vs. liposomal amphotericin B in empiric treatment of invasive fungal infections in Turkey

Background

Invasive fungal infections (IFI) are associated with considerable expense and mortality on healthcare systems. There is a need to provide evidence of both clinical efficacy and value for money with any health technology. The current pharmacoeconomic evaluation investigated the use of liposomal amphotericin B (LAmB) and voriconazole for the empiric treatment of IFI in the Turkish setting.

Methods

Decision analytic modelling was used to create a pathway for patient treatment with a 5-point composite outcome measure. The data was obtained from a major non-inferiority multicentre randomised controlled study, with an expert panel of clinicians in Turkey providing transition probabilities and cost not available in the literature. Sensitivity analyses were performed on the inputs from the clinical trial and the expert panel.

Results

As per the base case analysis, voriconazole was preferred by Turkish Lira (TL) 2,523 per patient treated and TL2,520 per surviving patient. LAmB was the preferred alternative by TL5,362 per successfully treated patient. Removing fever resolution as part of the composite outcome measure resulted in voriconazole being the preferred alternative per successfully treated patient. Univariate sensitivity analysis highlighted that increasing the duration of voriconazole by >1.2 days or decreasing LAmB by >1.0 days changes the result. Monte Carlo Simulation resulted in 69.4% of simulations favouring voriconazole per patient treated.

Conclusion

There is a strong likelihood that voriconazole is economically more favourable than LAmB in the empiric treatment of IFI in Turkey.

Diagnosis and inflammatory response of patients with candiduria

Candiduria is common in hospitalised patients, but the clinical relevance is still unclear. This study was done to further our knowledge on detection of and host responses to candiduria. Urines and clinical data from 136 patients in whom presence of yeast was diagnosed by microscopic urinalysis were collected. Diagnosis by standard urine culture methods on blood and MacConkey agar as well as on fungal culture medium (Sabouraud dextrose agar) was compared. Inflammatory parameters (IL-6 and IL-17, Ig) were quantified in the urine and compared with levels in control patients without candiduria. Standard urine culture methods detected only 37% of Candida spp. in urine. Sensitivity was especially low (23%) for C. glabrata and was independent of fungal burden. Candida specific IgG but not IgA was significantly elevated when compared with control patients (P < 0.0001 and 0.07 respectively). In addition, urine levels of IL-6 and IL-17 were significantly higher in candiduric patients when compared with control patients (P < 0.001). Multivariate analysis documented an independent association between an increased IgG (odds ratio (OR) 136.0, 95% confidence interval (CI) 25.7-719.2; P < 0.0001), an increased IL-17 (OR 17.4, 95% CI 5.3-57.0; P < 0.0001) and an increased IL-6 level (OR 4.9, 95% CI 1.9-12.4; P = 0.001) and candiduria. In summary, our data indicate that clinical studies on candiduria should include fungal urine culture and that inflammatory parameters may be helpful to identify patients with clinically relevant candiduria.

Cost-effectiveness of posaconazole versus fluconazole or itraconazole in the prevention of invasive fungal infections among high-risk neutropenic patients in Spain

BACKGROUND

We evaluated the cost-effectiveness of posaconazole compared with standard azole therapy (SAT; fluconazole or itraconazole) for the prevention of invasive fungal infections (IFI) and the reduction of overall mortality in high-risk neutropenic patients with acute myelogenous leukaemia (AML) or myelodysplastic syndromes (MDS). The perspective was that of the Spanish National Health Service (NHS).

METHODS

A decision-analytic model, based on a randomised phase III trial, was used to predict IFI avoided, life-years saved (LYS), total costs, and incremental cost-effectiveness ratio (ICER; incremental cost per LYS) over patients' lifetime horizon. Data for the analyses included life expectancy, procedures, and costs associated with IFI and the drugs (in euros at November 2009 values) which were obtained from the published literature and opinions of an expert committee. A probabilistic sensitivity analysis (PAS) was performed.

RESULTS

Posaconazole was associated with fewer IFI (0.05 versus 0.11), increased LYS (2.52 versus 2.43), and significantly lower costs excluding costs of the underlying condition (€6,121 versus €7,928) per patient relative to SAT. There is an 85% probability that posaconazole is a cost-saving strategy compared to SAT and a 97% probability that the ICER for posaconazole relative to SAT is below the cost per LYS threshold of €30,000 currently accepted in Spain.

CONCLUSIONS

Posaconazole is a cost-saving prophylactic strategy (lower costs and greater efficacy) compared with fluconazole or itraconazole in high-risk neutropenic patients.

[Cost analysis of 3 candins in the treatment of invasive candidiasis in adult non-neutropaenic patients in Spain]

OBJECTIVE

To estimate the cost of 3 candins (anidulafungin, caspofungin and micafungin) in the treatment of adult non-neutropaenic patients with invasive candidiasis (IC) in a Spanish hospital pharmacy setting.

METHODS

The overall cost impact was evaluated by varying the percentage dosage required of each candin in different possible scenarios. The prices (in euros) for each presentation were obtained from the Drug Catalogue (in August 2010). Only drug purchase costs were considered. The results are expressed as total cost for each of the 3 candins.

RESULTS

The cost per episode (14 days) of anidulafungin was constant at €5400 per patient. The cost of caspofungin varied from €4281 to €7991, depending on patient weight and liver dysfunction. The cost of micafungin varied from €6000 (100mg/day) to €9000 (when increasing the dose due to inadequate response). Based on a hypothetic cohort of 100 patients with IC, the total cost of anidulafungin treatment would be €540,000, for caspofungin it would be €631,459, and for micafungin it would be €632,998, depending on any dose adjustment required.

CONCLUSION

Patients treated with anidulafungin did not require dose adjustment, unlike those treated with caspofungin or micafungin. The use of anidulafungin is a cost-saving treatment for adult non-neutropaenic patients with IC, which would result in better control of the Spanish pharmacy budget.

Cost-effectiveness analysis of anidulafungin versus fluconazole for the treatment of invasive candidiasis

BACKGROUND

Anidulafungin was found to be non-inferior to and possibly more efficacious than fluconazole for treatment of invasive candidiasis (IC) in a major randomized clinical trial (RCT). There are no data comparing the cost-effectiveness between azoles and echinocandins in treating IC. This economic analysis investigated the cost-effectiveness of anidulafungin compared with fluconazole for treatment of IC in an Australian setting.

METHODS

A decision analytic model was constructed to capture downstream consequences of using either agent for treatment of IC. The main outcomes analysed in the model were treatment success and treatment failure (observed and indeterminate). Outcome probabilities and treatment pathways were derived from a published RCT. Resources used were estimated by an expert panel and cost inputs were derived from the latest Australian resources. The analysis was based on an Australian hospital perspective. Sensitivity analyses were conducted using Monte Carlo simulation.

RESULTS

Anidulafungin (AU$74,587) had a higher total cost than fluconazole (AU$60,945) per successfully treated patient, primarily due to its higher acquisition cost. Hospitalization was the main cost driver for both comparators. However, when the rates of mortality in both treatment arms were considered, treatment with anidulafungin was expected to save an additional 0.53 life-years, with an incremental cost-effectiveness ratio (ICER) of AU$25 740 per life-years saved, which was below the implicit ICER threshold value for Australia. The results were robust over a wide range of variables.

CONCLUSIONS

This is the first economic evaluation of anidulafungin versus fluconazole in the treatment of IC in Australia. Anidulafungin appears to be a cost-effective option.

Attributable hospital cost and antifungal treatment of invasive fungal diseases in high-risk hematology patients: an economic modeling approach

Studies using patient-level data to determine the attributable cost of invasive fungal diseases (IFDs) are few. Using a case-control study with activity-based costing of patients admitted to a quaternary hospital from 2002 to 2007, we determined attributable hospitalization cost (and 12 weeks thereafter), length of stay (LOS), and costly antifungal treatment (C-AT; liposomal amphotericin B, voriconazole, posaconazole, caspofungin), expressed as defined daily doses (DDDs) per IFD episode, in patients with hematological malignancies and hematopoietic stem cell recipients. Matching criteria and median regression modeling controlled for confounding variables, including LOS prior to IFD onset. Multiple mycoses were identified in 43 matched case-control pairs (n=86). A separate sensitivity analysis included 22 unmatched patients. IFD status was associated with a median excess cost of AU$30,957 (95% confidence interval [CI]=AU$2,368 to AU$59,546; P=0.034), approximating at purchasing power parity US$21,203 (95% CI=US$1,622 to US$40,784) and €15,788 (95% CI=€1,208 to €30,368), increasing to AU$80,291 (95% CI=AU$33,636 to AU$126,946; P=0.001), i.e., US$54,993 (95% CI=US$23,038 to US$86,948) and €40,948 (95% CI=€17,154 to €64,742), with intensive care unit (ICU) requirement. Cost determinants were pharmacy costs (64%; P<0.001) inclusive of antifungal treatment (27%; P<0.001) and ward costs (27%; P=0.091), with proportions persisting through 12 weeks for 25 surviving matched pairs (pharmacy, 60% [P=0.12]; ward, 31% [P=0.21]). Median LOS was not significantly increased unless unmatched patients were included (8 days, 95% CI=1.8 to 14 days; P=0.012). Excess C-ATs were 17 DDDs (95% CI=15 to 19 DDDs; P<0.001) per case patient and 19 DDDs (95% CI=16 to 22 DDDs; P<0.001) per ICU patient. The sensitivity analysis was confirmatory (for median cost, AU$29,441, 95% CI=AU$5,571 to AU$53,310, P=0.016; for C-AT, 17 DDDs, 95% CI=16 to 18 DDDs, P<0.001). IFD results in increased hospital and ICU costs, with pharmacy costs, including antifungal treatment, being major determinants. Consumption of costly antifungal drugs may be a novel resource metric with wider generalizability than cost alone.

Pharmacoeconomics of voriconazole

IMPORTANCE OF THE FIELD

The recent increase in the use of antineoplastic and immune suppressive agents and the use of broad-spectrum antibiotics, prosthetic interventions, organ transplants and more aggressive surgery have been related to a greater prevalence of invasive fungal infections (IFI). Over the past few years, several new antifungal therapies have become available for these patients. Pharmacoeconomic data can play a useful role in comparing the relative benefits of treatment.

AREAS COVERED IN THIS REVIEW

This review summarizes all the available evidence regarding the pharmacoeconomics of voriconazole. A systematic review of pharmacoeconomic analyses through a non-restricted literature search was conducted (until May 2009).

WHAT THE READER WILL GAIN

The reader will gain a greater understanding of the pharmacoeconomics role of voriconazole.

TAKE HOME MESSAGE

The majority of economic analyses have shown that voriconazole is a more cost-effective alternative in the treatment of invasive fungal infections than the antifungal drugs with which it was compared.

Candidemia and invasive candidiasis: a review of the literature for the burns surgeon

Advances in critical care, operative techniques, early fluid resuscitation, antimicrobials to control bacterial infections, nutritional support to manage the hypermetabolic response and early wound excision and coverage has improved survival rates in major burns patients. These advances in management have been associated with increased recognition of invasive infections caused by Candida species in critically ill burns patients. Candida albicans is the most common species to cause invasive Candida infections, however, non-albicans Candida species appear to becoming more frequent. These later species may be less fluconazole susceptible than Candida albicans. High crude and attributable mortality rates from invasive Candida sepsis are multi-factorial. Diagnosis of invasive candidiasis and candidemia remains difficult. Prophylactic and pre-emptive therapies appear promising strategies, but there is no specific approach which is well-studied and clearly efficacious in high-risk burns patients. Treatment options for invasive candidiasis include several amphotericin B formulations and newer less toxic antifungal agents, such as azoles and echinocandins. We review the currently available data on diagnostic and management strategies for invasive candidiasis and candidemia; whenever possible providing reference to the high-risk burn patients. We also present an algorithm for the management of candidemia and invasive candidiasis in burn patients.

A C. elegans-based, whole animal, in vivo screen for the identification of antifungal compounds

Traditional antimicrobial screens focus on compounds that block the growth of microbial organisms. A new Caenorhabditis elegans-based bioassay can be used for the identification of antifungal compounds that are effective against Candida albicans. According to the protocol, adult nematodes are infected with C. albicans and moved to 96-well plates containing the tested compounds. In the presence of compounds with no antifungal activity, the fungus kills the worms and develops filaments that penetrate through the cuticle. In contrast to traditional screening methods and mammalian models, this facile, time-efficient and less costly assay allows the study of Candida cells in nonplanktonic form and may allow the concurrent evaluation of toxicity and antifungal activity and identify compounds that target virulence factors or modify host immune response. The screening assay takes about 5-6 d depending on the experimental design.

Genomics and the development of new diagnostics and anti-Candida drugs

Pathogenic Candida species remain a significant medical problem despite the availability of antifungal therapies. Two key issues must be addressed to improve the treatment of life-threatening systemic Candida infections. First, advanced diagnostic tools are required to facilitate the early identification of these infections, when therapeutic intervention is more likely to be effective. Second, improved antifungal therapies are needed. These therapies, which might include combinations of antifungals, need to be less toxic to the patient and more potent in killing a broader range of Candida species. Recent advances in unravelling the genomics of these species should facilitate efforts to achieve these goals. We discuss the contribution of genomics to the development of novel antifungals and new diagnostic tools.

Antifungal chemical compounds identified using a C. elegans pathogenicity assay

There is an urgent need for the development of new antifungal agents. A facile in vivo model that evaluates libraries of chemical compounds could solve some of the main obstacles in current antifungal discovery. We show that Candida albicans, as well as other Candida species, are ingested by Caenorhabditis elegans and establish a persistent lethal infection in the C. elegans intestinal track. Importantly, key components of Candida pathogenesis in mammals, such as filament formation, are also involved in nematode killing. We devised a Candida-mediated C. elegans assay that allows high-throughput in vivo screening of chemical libraries for antifungal activities, while synchronously screening against toxic compounds. The assay is performed in liquid media using standard 96-well plate technology and allows the study of C. albicans in non-planktonic form. A screen of 1,266 compounds with known pharmaceutical activities identified 15 (approximately 1.2%) that prolonged survival of C. albicans-infected nematodes and inhibited in vivo filamentation of C. albicans. Two compounds identified in the screen, caffeic acid phenethyl ester, a major active component of honeybee propolis, and the fluoroquinolone agent enoxacin exhibited antifungal activity in a murine model of candidiasis. The whole-animal C. elegans assay may help to study the molecular basis of C. albicans pathogenesis and identify antifungal compounds that most likely would not be identified by in vitro screens that target fungal growth. Compounds identified in the screen that affect the virulence of Candida in vivo can potentially be used as "probe compounds" and may have antifungal activity against other fungi.

Excess costs of hospital care associated with neonatal candidemia

BACKGROUND

Nosocomial bloodstream infections are associated with increased hospital costs in adult and pediatric patients. Candida is an increasingly important nosocomial pathogen within intensive care nurseries. The purpose of this study was to determine the attributable cost of candidemia in neonates.

METHODS

This case-control study included all neonates with candidemia receiving care in hospitals in Connecticut and in Baltimore County and the city of Baltimore, MD. We identified 47 cases and 130 control patients. Multivariable linear regression was used to control for state, birth weight and mortality to determine the effect of candidemia on length of stay, cost per day and total hospital costs.

RESULTS

Candidemia was associated with a $28,000 increase in total hospital costs in multivariable analysis. This increase in total cost was the result of both an increase in costs per day and length of hospital stay. Other cost-increasing variables included in the analysis were: state of origin (Connecticut), survival and decreasing birth weight.

CONCLUSIONS

This represents the first study of the adjusted costs of candidemia in neonates. In addition to high mortality, candidemia was associated with increased hospital costs. This cost analysis could be helpful in determining the financial benefits of preventing candidemia in high risk neonates.

Fluconazole for empiric antifungal therapy in cancer patients with fever and neutropenia

Background

Several clinical trials have demonstrated the efficacy of fluconazole as empiric antifungal therapy in cancer patients with fever and neutropenia. Our objective was to assess the frequency and resource utilization associated with treatment failure in cancer patients given empiric fluconazole antifungal therapy in routine inpatient care.

Methods

We performed a retrospective cohort study of cancer patients treated with oral or intravenous fluconazole between 7/97 and 6/01 in a tertiary care hospital. The final study cohort included cancer patients with neutropenia (an absolute neutrophil count below 500 cells/mm³) and fever (a temperature above 38°C or 100.4°F), who were receiving at least 96 hours of parenteral antibacterial therapy prior to initiating fluconazole. Patients' responses to empiric therapy were assessed by reviewing patient charts.

Results

Among 103 cancer admissions with fever and neutropenia, treatment failure after initiating empiric fluconazole antifungal therapy occurred in 41% (95% confidence interval (CI) 31% – 50%) of admissions. Patients with a diagnosis of hematological malignancy had increased risk of treatment failure (OR = 4.6, 95% CI 1.5 – 14.8). When treatment failure occurred the mean adjusted increases in length of stay and total costs were 7.4 days (95% CI 3.3 – 11.5) and $18,925 (95% CI 3,289 – 34,563), respectively.

Conclusion

Treatment failure occurred in more than one-third of neutropenic cancer patients on fluconazole as empiric antifungal treatment for fever in routine clinical treatment. The increase in costs when treatment failure occurs is substantial.

Pulmonary fungal infections

PURPOSE OF REVIEW

Invasive fungal infections of the lung have historically been associated with an extremely high mortality. This review aims to disseminate the most recent advances in the diagnosis and management of fungal infections of the lung.

RECENT FINDINGS

The number and diversity of immunosuppressed populations are growing rapidly. Transplant immunosuppression is becoming more aggressive early in the posttransplant period, potentially increasing the risk of invasive fungal infections. The galactomannan antigen test and the beta-D-glucan test have emerged as methods of serially monitoring at-risk patients for invasive aspergillosis. Their utility has been established in some neutropenic populations but not in solid organ transplant recipients. In-vitro studies, animal studies, and retrospective human studies support the use of combination antifungal therapy for invasive aspergillosis. Unfortunately no randomized clinical trials exist.

SUMMARY

Invasive pulmonary aspergillosis will continue to be a major problem in immunocompromised patients in the future. Immense advances in the last 2-3 years are sure to improve outcome. Well-designed multicenter evaluations are still necessary, however, to optimize management as management options widen.

Novel approaches to antifungal prophylaxis

Antifungal prophylaxis represents a significant advance in the management of patients at risk from fungal infections in a variety of settings. Identification of patients at the highest risk and the utilisation of safe and effective drugs maximises the benefits of prophylaxis. Situations in which antifungal prophylaxis has been shown to be useful are bone marrow transplantation, liver and lung transplantation, surgical and neonatal intensive care units, secondary prophylaxis of fungal infections associated with HIV and neutropenia associated haematological malignancies and their treatment. New antifungal agents, such as the echinocandins and the new azoles, are available and have a potential role in antifungal prophylaxis. Future studies should evaluate which strategy is more useful; prophylaxis or pre-emptive therapy.