Consensus guidelines for antifungal stewardship, surveillance and infection prevention, 2021.

Invasive fungal diseases (IFD) are serious infections associated with high mortality, particularly in immunocompromised patients. The prescribing of antifungal agents to prevent and treat IFD is associated with substantial economic burden on the health system, high rates of adverse drug reactions, significant drug-drug interactions and the emergence of antifungal resistance. As the population at risk of IFD continues to grow due to the increased burden of cancer and related factors, the need for hospitals to employ antifungal stewardship (AFS) programmes and measures to monitor and prevent infection has become increasingly important. These guidelines outline the essential components, key interventions and metrics, which can help guide implementation of an AFS programme in order to optimise antifungal prescribing and IFD management. Specific recommendations are provided for quality processes for the prevention of IFD in the setting of outbreaks, during hospital building works, and in the context of Candida auris infection. Recommendations are detailed for the implementation of IFD surveillance to enhance detection of outbreaks, evaluate infection prevention and prophylaxis interventions and to allow benchmarking between hospitals. Areas in which information is still lacking and further research is required are also highlighted.

COVID-19 vaccination in haematology patients: an Australian and New Zealand consensus position statement.

Australia and New Zealand have achieved excellent community control of COVID-19 infection. In light of the imminent COVID-19 vaccination roll out in both countries, representatives from the Haematology Society of Australia and New Zealand and infectious diseases specialists have collaborated on this consensus position statement regarding COVID-19 vaccination in patients with haematological disorders. It is our recommendation that patients with haematological malignancies, and some benign haematological disorders, should have expedited access to high-efficacy COVID-19 vaccines, given that these patients are at high risk of morbidity and mortality from COVID-19 infection. Vaccination should not replace other public health measures in these patients, given that the effectiveness of COVID-19 vaccination, specifically in patients with haematological malignancies, is not known. Given the limited available data, prospective collection of safety and efficacy data of COVID-19 vaccination in this patient group is a priority.

Australia and New Zealand Transplant and Cellular Therapies COVID-19 vaccination consensus position statement.

Australia and New Zealand have achieved excellent community control of COVID-19 infection. In light of the imminent COVID-19 vaccination roll out in both countries, representatives of all adult and paediatric allogeneic bone marrow transplant and cellular therapy (TCT) centres as well as representatives from autologous transplant only centres in Australia and New Zealand collaborated with infectious diseases specialists with expertise in TCT on this consensus position statement regarding COVID-19 vaccination in TCT patients in Australia and New Zealand. It is our recommendation that TCT patients, should have expedited access to high-efficacy COVID-19 vaccines given that these patients are at high risk of morbidity and mortality from COVID-19 infection. We also recommend prioritising vaccination of TCT healthcare workers and household members of TCT patients. Vaccination should not replace other public health measures in TCT patients given the effectiveness of COVID-19 vaccination in TCT patients is unknown. Furthermore, given the limited available data, prospective collection of safety and efficacy data of COVID-19 vaccination in this patient group is a priority.

Fluoroquinolone antibiotics and adverse events.

Fluoroquinolones are broad-spectrum antibiotics with good oral bioavailability. They are used for the treatment of a wide variety of infections, but there are restrictions on prescribing these drugs. Epidemiological studies have reported an increased risk of rare adverse effects. These include tendinopathy and tendon rupture, peripheral neuropathy and aortic aneurysm. Safe prescribing of fluroquinolones requires recognition of patients with risk factors for toxicity. Prompt drug discontinuation is recommended in the event of an adverse reaction. Practising antimicrobial stewardship by prescribing fluoroquinolones only when alternative drugs are unavailable is also key to limiting adverse events and antibiotic resistance.

'Cold and lonely': emergency presentations of patients with hypothermia to a large Australian health network.

BACKGROUND: Extreme heat is a public health priority in Australia with the health effects of cold poorly studied. A record-breaking cold winter prompted an institutional investigation into the epidemiology and outcomes of hypothermic presentations. AIMS: To describe the clinical and epidemiological characteristics of hypothermic emergency presentations including patient outcomes as well as gaps in practice. METHODS: This was a retrospective cohort observational study of hypothermic emergency presentations between 7 July 2009 and 1 September 2016 with a temperature of ≤35°C. Independent predictors for inpatient mortality and characteristics of exposure versus non-exposure presentations were evaluated. RESULTS: There were 217 patients with 226 presentations comprising male gender in 54%, median age 76.5 years (interquartile range (IQR) 53-88) and median initial temperature 33.3°C (IQR 31.2-34.3°C). Non-exposure presentations being found indoors, accounted for 78% overall, with elderly persons ≥65 years (P = 0.002) and multimorbidity (Charlson comorbidity index ≥4, P = 0.013) overrepresented in this subgroup. Among the non-exposure cohort, 55% were pensioners and 42% lived alone. Inpatient mortality was 11% overall and significantly higher in non-exposure versus exposure cohorts (16 vs 2%, P = 0.01). Independent predictors of inpatient mortality included heart failure (P = 0.04), metastatic malignancy (P < 0.01), chronic kidney disease (P < 0.05) and sepsis (P < 0.01). In contrast, exposure-related presentations were characterised by younger patients with intoxication due to alcohol and/or illicit drugs and psychiatric comorbidity. CONCLUSIONS: Hypothermia is a marker of clinical and socioeconomic vulnerability. The dominant presentation of the elderly patient with multimorbidity, and few social supports being found indoors, raises broader questions around the social determinants of health.

A population-based analysis of attributable hospitalisation costs of invasive fungal diseases in haematological malignancy patients using data linkage of state-wide registry and costing databases: 2009-2015.

BACKGROUND: Invasive fungal diseases (IFD) are associated with significant treatment-related costs in patients with haematological malignancies (HM). OBJECTIVES: The objectives of this study were to characterise the gross and attributable hospitalisation costs of a variety of IFD in patients with HM by linking state-wide hospital administrative and costing datasets. PATIENTS/METHODS: We linked the Victorian Admitted Episodes Dataset, Victorian Cancer Registry and the Victorian Cost Data Collection from 1 July 2009 to 30 June 2015. IFD cases and uninfected controls were matched 1:1 based on age within ten years, same underlying HM and length of stay prior to IFD diagnosis. The cost difference between surviving cases and controls, indexed to 2019 Australian dollars (AUD) calculated twelve months from IFD diagnosis, was determined using Poisson and negative binomial regression (NBR). RESULTS: From 334 matched pairs, the gross hospitalisation cost of cases was AUD$67 277 compared to AUD$51 158 among uninfected controls, associated with an excess median hospitalisation cost of AUD$16 119 (P < .001) attributable to IFD, approximating to USD$11 362 and €10 154 at purchasing power parity. Median attributable costs were highest for patients with invasive aspergillosis (AUD$55 642; P < .001) and mucormycosis (AUD$51 272; P = .043) followed by invasive candidiasis AUD$24 572 (P < .001). No change in median excess attributable costs was observed over the study period (P = .90) Analyses by NBR revealed a 1.36-fold increase (P < .001) in total hospitalisation costs among cases as compared to controls twelve months from IFD diagnosis. CONCLUSION: Invasive aspergillosis and mucormycosis have high attributable hospitalisation costs but the overall excess IFD cost of AUD$16 119 is modest, potentially reflecting missed or miscoded fungal episodes arguing for better quality surveillance data at hospital level.

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 1st July 2005 to 30th 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.

Cytomegalovirus Reactivation Is Associated with Increased Risk of Late-Onset Invasive Fungal Disease after Allogeneic Hematopoietic Stem Cell Transplantation: A Multicenter Study in the Current Era of Viral Load Monitoring.

Opportunistic infections such as cytomegalovirus (CMV) reactivation and invasive fungal disease (IFD) cause significant morbidity and mortality to recipients of hematopoietic stem cell transplant (HSCT). We aimed to characterize the risk and relationship of CMV reactivation post-HSCT to IFD in the current era of CMV viral load monitoring using highly sensitive plasma DNA. A multicenter, retrospective, cohort study was conducted of consecutive patients undergoing allogeneic HSCT from January 2006 to December 2010 in Melbourne, Australia. CMV reactivation was defined as detection of plasma CMV DNA ≥ 546 IU/mL or development of CMV disease. IFD was classified in accordance with current international consensus guidelines. Of the 419 study participants, the median age was 44 years (IQR, 34 to 54), and CMV reactivation occurred in 106 participants (25%) at a median time of 56 days (IQR, 45 to 79). Thirty-eight participants (9.1%) were identified with 41 cases of IFD (n = 22 proven, n = 8 probable, n = 11 possible) at a median time of 76 days (IQR, 24 to 344). The incidence of IFD was higher in participants with CMV reactivation compared with no CMV reactivation (15% versus 7%, P = .012). In a multivariate analysis CMV reactivation remained an independent risk factor for IFD (hazard ratio, 3.7; 95% CI, 1.6 to 8.5; P = .002). The cumulative incidence of all IFD in patients with and without CMV reactivation using a competing risk regression was a hazard ratio of 2.2 (95% CI, 1.2 to 4.1; P = .017) and for late-onset IFD was a hazard ratio of 3.95 (95% CI, 1.7 to 9; P = .001). The median time to IFD onset was longer in participants with than without CMV reactivation (184 versus 37 days, P = .03). The peak viral load, detection of any level of viremia, and experiencing more than 1 episode of CMV reactivation were not associated with development of IFD. CMV reactivation in HSCT recipients in the post-transplant period is associated with an increased risk of developing late-onset IFD. Further research is warranted to understand the interaction between these 2 important infectious complications.

Listeria monocytogenes peritonitis in an HIV-infected patient.

We report the first case of Listeria monocytogenes peritoneal dialysis (PD) peritonitis in a human immunodeficiency virus-infected individual successfully treated with intraperitoneal ampicillin, without the need for catheter removal. Suspicion of listerial infection in at-risk individuals is critical as empiric antimicrobial treatment for PD-associated infections may be ineffective against this organism.

Primary antifungal prophylaxis in adult patients with acute lymphoblastic leukaemia: a multicentre audit.

OBJECTIVES: The primary objectives were to investigate the prescribing practices of primary antifungal prophylaxis (PAP) and incidence of invasive fungal disease (IFD) in adult patients with ALL receiving induction-consolidation chemotherapy. Secondary objectives were to determine risk factors for IFD and resource utilization associated with IFD. METHODS: A retrospective chart review of adult patients with ALL from commencement of induction until completion of consolidation chemotherapy was undertaken from January 2008 to June 2013 in four hospitals in Melbourne, Australia. IFD was classified according to the revised European Organisation for Research and Treatment of Cancer criteria. Cost analysis was performed from an Australian public hospital perspective. RESULTS: Ninety-eight patients were included in the audit; 83 (85%) received PAP. Most patients (49/83, 59%) switched between two different antifungal agents, predominantly between liposomal amphotericin B and an azole. Five proven/probable and six possible IFD cases were identified. Proven/probable IFD was most common in patients receiving the BFM95 chemotherapy protocol. The incidence of proven/probable IFD was significantly lower in patients receiving PAP compared with those who did not (2/78, 2.6% versus 3/14, 21.4%; P = 0.024). For every five patients receiving PAP, one proven/probable IFD case would be prevented. Proven/probable IFD was associated with an additional median cost of 121,520 Australian dollars (95% CI: 90,781-180,141 Australian dollars; P < 0.001) compared with patients without IFD. CONCLUSIONS: This is the first multicentre study evaluating PAP use in patients with ALL. With the caveats of interpretation of retrospective, non-randomized data, PAP was associated with a reduced IFD risk.

Safety, clinical effectiveness and trough plasma concentrations of intravenous posaconazole in patients with haematological malignancies and/or undergoing allogeneic haematopoietic stem cell transplantation: off-trial experience.

OBJECTIVES: This study describes the safety, clinical effectiveness and trough plasma concentration (Cmin) of intravenous (iv) posaconazole, provided as part of Merck Sharp and Dohme Australia's Named Patient Programme (NPP) in non-clinical trial settings. METHODS: A multicentre, retrospective study on the NPP use of iv posaconazole between July 2014 and March 2015 across seven Australian hospitals. RESULTS: Seventy courses of iv posaconazole were prescribed and evaluated in 61 patients receiving treatment for haematological malignancy. Sixty-one courses were prescribed for prophylaxis against invasive fungal disease (IFD), the majority of which (59) were initiated in patients with gastrointestinal disturbances and/or intolerance to previous antifungals. The median (IQR) duration for prophylaxis was 10 (6-15) days. No breakthrough IFD was observed during or at cessation of iv posaconazole. Nine courses of iv posaconazole were prescribed for treatment of IFD with a median (IQR) duration of 19 (7-30) days. Improvement in signs and symptoms of IFD was observed in five cases at cessation of, and six cases at 30 days post-iv posaconazole. Cmin was measured in 39 courses of iv posaconazole, with the initial level taken [median (IQR)] 4 (3-7) days after commencing iv posaconazole. The median (IQR) of initial Cmin was 1.16 (0.69-2.06) mg/L. No severe adverse events specifically attributed to iv posaconazole were documented, although six courses were curtailed due to potential toxicity. CONCLUSIONS: This non-clinical trial experience suggests that iv posaconazole appeared to be safe and clinically effective for prophylaxis or treatment of IFD in patients receiving treatment for haematological malignancies.

International expert opinion on the management of infection caused by azole-resistant Aspergillus fumigatus.

An international expert panel was convened to deliberate the management of azole-resistant aspergillosis. In culture-positive cases, in vitro susceptibility testing should always be performed if antifungal therapy is intended. Different patterns of resistance are seen, with multi-azole and pan-azole resistance more common than resistance to a single triazole. In confirmed invasive pulmonary aspergillosis due to an azole-resistant Aspergillus, the experts recommended a switch from voriconazole to liposomal amphotericin B (L-AmB; Ambisome(®)). In regions with environmental resistance rates of ≥10%, a voriconazole-echinocandin combination or L-AmB were favoured as initial therapy. All experts recommended L-AmB as core therapy for central nervous system aspergillosis suspected to be due to an azole-resistant Aspergillus, and considered the addition of a second agent with the majority favouring flucytosine. Intravenous therapy with either micafungin or L-AmB given as either intermittent or continuous therapy was recommended for chronic pulmonary aspergillosis due to a pan-azole-resistant Aspergillus. Local and national surveillance with identification of clinical and environmental resistance patterns, rapid diagnostics, better quality clinical outcome data, and a greater understanding of the factors driving or minimising environmental resistance are areas where research is urgently needed, as well as the development of new oral agents outside the azole drug class.

Automatic detection of patients with invasive fungal disease from free-text computed tomography (CT) scans.

BACKGROUND: Invasive fungal diseases (IFDs) are associated with considerable health and economic costs. Surveillance of the more diagnostically challenging invasive fungal diseases, specifically of the sino-pulmonary system, is not feasible for many hospitals because case finding is a costly and labour intensive exercise. We developed text classifiers for detecting such IFDs from free-text radiology (CT) reports, using machine-learning techniques. METHOD: We obtained free-text reports of CT scans performed over a specific hospitalisation period (2003-2011), for 264 IFD and 289 control patients from three tertiary hospitals. We analysed IFD evidence at patient, report, and sentence levels. Three infectious disease experts annotated the reports of 73 IFD-positive patients for language suggestive of IFD at sentence level, and graded the sentences as to whether they suggested or excluded the presence of IFD. Reliable agreement between annotators was obtained and this was used as training data for our classifiers. We tested a variety of Machine Learning (ML), rule based, and hybrid systems, with feature types including bags of words, bags of phrases, and bags of concepts, as well as report-level structured features. Evaluation was carried out over a robust framework with separate Development and Held-Out datasets. RESULTS: The best systems (using Support Vector Machines) achieved very high recall at report- and patient-levels over unseen data: 95% and 100% respectively. Precision at report-level over held-out data was 71%; however, most of the associated false-positive reports (53%) belonged to patients who had a previous positive report appropriately flagged by the classifier, reducing negative impact in practice. CONCLUSIONS: Our machine learning application holds the potential for developing systematic IFD surveillance systems for hospital populations.

Making sense of posaconazole therapeutic drug monitoring: a practical approach.

PURPOSE OF REVIEW: Therapeutic drug monitoring (TDM) may be an important adjunct to optimizing the use of posaconazole. RECENT FINDINGS: Limited clinical studies suggest that an exposure-response relationship for posaconazole exists for the treatment of established invasive fungal diseases (IFDs), with emerging but less compelling data supporting its role in prophylaxis. The high prevalence of subtherapeutic levels has not translated to high prophylactic failure rates perhaps because of preferential uptake by effector cells important in the front-line defence against Aspergillus species. Nevertheless, TDM would appear prudent in patients deemed at highest risk for IFD with correction of patient modifiable factors and attention to drug administration important in optimizing drug exposure. TDM performed within a few days after commencing posaconazole may be predictive of steady-state levels, thus minimizing the delay in obtaining results in addition to identifying a subset of patients who may remain persistently subtherapeutic and also resistant to dose-escalation. Trough levels may be supplanted by untimed levels at steady state, thereby expanding the practicalities of TDM. We propose that TDM becomes one of the several measures in an integrated approach to IFD prevention combining screening of high-risk haematology patients for invasive aspergillosis at presentation, together with prospective surveillance for IFD, explicit criteria for switching to an alternative prophylactic agent and adherence to infection control practices. SUMMARY: Growing evidence supports the value of TDM for posaconazole to identify patients who may benefit from correction of modifiable factors impacting bioavailability, dosage adjustment or switch to an alternative agent.

The case for antifungal stewardship.

PURPOSE OF REVIEW: Antimicrobial stewardship (AMS) has overwhelmingly focussed on antibiotics while antifungal agents have been largely neglected despite the few published audits of antifungal drug use demonstrating clear deficiencies in prescribing behaviour. In this review, we outline not only the elements of antifungal stewardship (AFS) in common with AMS but also features specific to antifungal drugs, combined with insights from our experience in AFS. RECENT FINDINGS: Invasive fungal diseases (IFDs) have a lower institutional incidence relative to infections caused by multiresistant bacteria, but their health and economic burden are substantial. Pharmacy costs inclusive of antifungal agents are a major determinant of IFD-attributable hospital cost. High drug costs and the toxicities of antifungal agents are the principal rationale for AFS while antifungal resistance is an emerging but less prevalent issue. The high mortality/morbidity associated with IFDs, including adverse impact on curative chemotherapy, combined with suboptimal diagnostic tools, has driven the overuse of antifungal drugs. De-escalation of empiric therapy is one of the most challenging aspects of AFS to implement. Nonculture-based tests may enhance AFS, but refinement of both target populations and clinical pathways incorporating their use is required. Performance indicators including structural, process and outcome measures are integral for demonstrating the value of AFS programmes. SUMMARY: Practice guidelines adapted to the local context are the cornerstone of AFS. Local epidemiology informs the choice of antifungal agents for the prevention and management of IFDs, underscoring the need for surveillance. Adherence to minimum standards of prescribing ensures that clinical outcomes are optimized and drug toxicities minimized, thus meeting healthcare quality and safety goals.

Comparative clinical effectiveness of prophylactic voriconazole/posaconazole to fluconazole/itraconazole in patients with acute myeloid leukemia/myelodysplastic syndrome undergoing cytotoxic chemotherapy over a 12-year period.

Post-induction aplasia for acute myeloid leukemia/myelodysplastic syndrome is a high-risk period for invasive fungal diseases. The effectiveness of fluconazole, itraconazole solution, voriconazole and posaconazole prophylaxis used consecutively from December 1998 to January 2010 in patients with acute myeloid leukemia/myelodysplastic syndrome undergoing remission-induction chemotherapy was retrospectively evaluated. A total of 216 consecutive patients received 573 prophylaxis courses. Breakthrough-invasive fungal disease incidence in fluconazole, itraconazole, voriconazole, posaconazole recipients was 25%, 16%, 14% and 3%, respectively. Voriconazole/posconazole versus fluconazole/itraconazole combined was associated with significant reductions in breakthrough-invasive fungal disease incidence (20% vs. 8%, P=0.011), premature discontinuations (46% vs. 22% P<0.001) and empiric antifungal treatment (31% vs. 8.5%, P<0.001). Microbiologically confirmed infections were molds. Posaconazole compared to other drugs was associated with fewer courses requiring computed-tomography (43% vs. 26%, P<0.001). Adoption of voriconazole/posaconazole has decreased invasive fungal disease incidence, empiric antifungal treatment and for posaconazole, computed-tomography demand, with effectiveness of posaconazole comparable to clinical trial experience.

Experiences of personal protective equipment by Australian healthcare workers during the COVID-19 pandemic, 2020: A cross-sectional study.

The aim of this study was to capture Australian frontline healthcare workers' (HCWs) experiences with personal protective equipment (PPE) during the COVID-19 pandemic in 2020. This was a cross-sectional study using an online survey consisting of five domains: demographics; self-assessment of COVID risk; PPE access; PPE training and confidence; and anxiety. Participants were recruited from community and hospital healthcare settings in Australia, including doctors, nurses, allied health professionals, paramedics, and aged care and support staff. Data analysis was descriptive with free-text responses analysed using qualitative content analysis and multivariable analysis performed for predictors of confidence, bullying, staff furlough and anxiety. The 2258 respondents, comprised 80% women, 49% doctors and 40% nurses, based in hospital (39%) or community (57%) settings. Key findings indicated a lack of PPE training (20%), calls for fit testing, insufficient PPE (25%), reuse or extended use of PPE (47%); confusion about changing guidelines (48%) and workplace bullying over PPE (77%). An absence of in-person workplace PPE training was associated with lower confidence in using PPE (OR 0.21, 95%CI 0.12, 0.37) and a higher likelihood of workplace bullying (OR 1.43; 95% CI 1.00, 2.03) perhaps reflecting deficiencies in workplace culture. Deficiencies in PPE availability, access and training linking to workplace bullying, can have negative physical and psychological impacts on a female dominant workforce critical to business as usual operations and pandemic response.

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.