Epidemiology and Outcomes of Hospitalizations With Invasive Aspergillosis in the United States, 2009-2013

Background

Though invasive aspergillosis (IA) complicates care of up to 13% of patients with immunocompromise, little is known about its morbidity and mortality burden in the United States.

Methods

We analyzed the Health Care Utilization Project's data from the Agency for Healthcare Research and Quality for 2009-2013. Among subjects with high-risk conditions for IA, IA was identified via International Classification of Diseases, Ninth Revision, Clinical Modification codes 117.3, 117.9, and 484.6. We compared characteristics and outcomes between those with (IA) and without IA (non-IA). Using propensity score matching, we calculated the IA-associated excess mortality and 30-day readmission rates, length of stay, and costs.

Results

Of the 66634683 discharged patients meeting study inclusion criteria, 154888 (0.2%) had a diagnosis of IA. The most common high-risk conditions were major surgery (50.1%) in the non-IA and critical illness (41.0%) in the IA group. After propensity score matching, both mortality (odds ratio, 1.43; 95% confidence interval, 1.36-1.51) and 30-day readmission (1.39; 1.34-1.45) rates were higher in the IA group. IA was associated with 6.0 (95% confidence interval, 5.7-6.4) excess days in the hospital and $15542 ($13869-$17215) in excess costs per hospitalization.

Conclusions

Although rare even among high-risk groups, IA is associated with increased hospital mortality and 30-day readmission rates, excess duration of hospitalization, and costs. Given nearly 40000 annual admissions for IA in the United States, the aggregate IA-attributable excess costs may reach $600 million annually.

Hospital resource use of patients receiving isavuconazole vs voriconazole for invasive mold infections in the phase III SECURE trial

OBJECTIVE

In the phase III SECURE trial, isavuconazole was non-inferior to voriconazole for all-cause mortality for the primary treatment of invasive mold disease (IMD) caused by Aspergillus spp. and other filamentous fungi. This analysis assessed whether hospital resource utilization was different between patients treated with isavuconazole vs voriconazole in SECURE.

METHODS

The analysis population comprised adults with proven/probable/possible IMD enrolled in SECURE. The primary endpoint was hospital length of stay (LOS) in the overall trial population. Patients were also stratified by estimated glomerular filtration rate-modification of diet in renal disease category (< 60 mL/min/1.73 m(2) [moderate-to-severe impairment] and ≥60 mL/min/1.73 m(2) [mild or no impairment]), body mass index (BMI; <25, ≥25-<30, and ≥30 kg/m(2)), and age (≤45, >45-≤65, and >65 years).

RESULTS

Data from 516 patients (258 per arm) were evaluated. Overall, median LOS was not statistically significantly different between the isavuconazole (15.0 days) and voriconazole (16.0 days; p = 0.607) arms. Median LOS was statistically significantly shorter in patients with moderate-to-severe renal impairment treated with isavuconazole (9.0 days) vs voriconazole (19.0 days; hazard ratio [HR]: 3.44; 95% confidence interval [CI] = 1.51-7.83). Median LOS was shorter, but not significantly, in patients with a BMI ≥30 kg/m(2) (isavuconazole 13.5 days vs voriconazole 22 days; HR = 1.57; 95% CI = 0.70-3.52) or aged >65 years (isavuconazole 15.0 days vs voriconazole 20.0 days; HR = 1.37; 95% CI = 0.87-2.16).

LIMITATIONS

As the patient subgroups analyzed were small, sub-group findings should be interpreted with caution in light of the lack of statistical significance for each sub-group-by-treatment interaction.

CONCLUSIONS

Isavuconazole may reduce hospital LOS in certain subgroups of patients with IMD, especially those with moderate-to-severe renal impairment.

Clinical and economic burden of invasive fungal diseases in Europe: focus on pre-emptive and empirical treatment of Aspergillus and Candida species

Invasive fungal diseases (IFDs) have been widely studied in recent years, largely because of the increasing population at risk. Aspergillus and Candida species remain the most common causes of IFDs, but other fungi are emerging. The early and accurate diagnosis of IFD is critical to outcome and the optimisation of treatment. Rapid diagnostic methods and new antifungal therapies have advanced disease management in recent years. Strategies for the prevention and treatment of IFDs include prophylaxis, and empirical and pre-emptive therapy. Here, we review the available primary literature on the clinical and economic burden of IFDs in Europe from 2000 to early 2011, with a focus on the value and outcomes of different approaches.

Comparative survival and cost of antifungal therapy: posaconazole versus standard antifungals in the treatment of refractory invasive aspergillosis

BACKGROUND

Refractory invasive aspergillosis (IA) is a life-threatening condition. Cost of treatment, although secondary, is important if newer drugs are to be widely accepted. Posaconazole has been shown to have activity against aspergillosis.

METHODS

Analyses were conducted to compare the effectiveness and cost of posaconazole 800 mg/day with those of standard antifungal therapy, using Walsh et al. 2007 data. All-cause mortality and total drug costs were analyzed for three patient groups: All Refractory, Refractory Non-neutropenic, and Refractory Neutropenic IA Patients. Comparative survival analysis using Kaplan-Meier estimates after censoring data at 28, 42, 84, 182, and 365 days and Cox proportional hazard method was used to estimate hazard rates after controlling for difference in baseline neutropenia. For cost analysis, only antifungal drug acquisition cost was used.

RESULTS

Significantly more of the 94 patients treated with posaconazole remained alive at every time point compared with the 68 external control patients within the All Refractory group (p = 0.0001). Similar results were obtained for the other two groups. For the posaconazole-treated patients mean total drug costs were $11846 (±$12406), $12642 (±$11811), and $8903 (±$14345), and for the external controls total drug costs were $35537 (±$73059), $48097 (±$88702), and $13556 (±$16324) for the All Refractory, Refractory Non-neutropenic, and Neutropenic IA groups, respectively. Key limitations of the study included noninclusion of hospitalization or other drug costs, low patient numbers beyond 84 days, and the fact that the Walsh et al. 2007 study was completed before other newer antifungal agents (such as voriconazole and caspofungin) were available.

CONCLUSIONS

Posaconazole appears to confer a survival benefit and reduced total drug cost compared with standard antifungal therapy, such as amphotericin B (lipid and nonlipid formulations), itraconazole, or both, to treat patients with probable or proven refractory IA.

[Invasive aspergillosis in hematooncological patients: advantages and disadvantages of various diagnostic methods, treatment options and financial costs of therapy]

BACKGROUND

Invasive aspergillosis (IA) is a leading invasive fungal infection in hematooncological patients. The aim of this study was to analyse the incidence, diagnostic procedures and treatment of IA in hematooncological department in large hospital in the Czech Republic.

PATIENTS AND METHODS

A retrospective analysis of medical and laboratory records from patients hospitalised in our department with proven/probable IA between January 2000 and December 2006 was performed.

RESULTS

52 cases of IA in 51 patients were identified (17.3% proven IA/82.7% probable IA). Number of IA cases notably increased during study period (1 case of IA in 2000 vs 21 cases of IA in 2006) and majority of them was of nosocomial origin (61.5%). Pulmonary aspergillosis was diagnosed in 46 cases (88.5%). Patients treated for acute leukemia or undergoing allogeneic stem cell transplantation represent the group at the highest risk of IA (in total 52% of cases). Fever and signs of pulmonary involvement were the most common clinical signs of infection (presented in 92.3% and 69.2 cases respectively). Conventional diagnostic methods including autopsy were able to diagnose only 15 cases of IA (28.8%). In all other cases (71.2%) the diagnosis was done by detection of galactomannan (GM) in serum. Introduction of GM monitoring enabled erlier initiation of antifungal treatment by 4 days. Initial therapy of IA led to the treatment response (partial and complete) in 18 (34.6%) of infections--the highest percentage of response has been seen in voriconazole monotherapy group (42%) and when combination of voriconazole and caspofungin has been used (83%). Salvage therapy was initiated due to the failure of initial treatment in 21 (40.3%) of cases. Patients were treated mostly with combination ofvoriconazole and caspofungin and/or monotherapy with voriconazole has been used with treatment response 55% and 50% respectively. Introduction of new antifungal drugs together with increased number of patients with IA led to the marked increase of total costs spent on treatment of IA per year--from 11,5 thousands CZK in 2000 to 6,2 millions CZK in 2006.

CONCLUSIONS

IA is the most frequent cause of infection-related mortality in patients with haematological malignancies. Routine use of non-culture base methods in diagnosis of IA together with treatment using new, effective antifungals can improve prognosis of patients with this life threatening infection.

Resource use and cost of treatment with voriconazole or conventional amphotericin B for invasive aspergillosis

BACKGROUND

Voriconazole, a broad-spectrum triazole, has demonstrated significantly improved survival compared with conventional amphotericin B (CAB) as initial therapy for invasive aspergillosis (IA).

OBJECTIVE

To compare health care resource use and cost at 12 weeks following first-line treatment with voriconazole compared with CAB for IA using resource use data collected during a clinical trial.

METHODS

Days of hospitalization, intensive care, antifungal drug use, and outpatient care were collected during a large randomized, controlled trial of patients with IA receiving initial treatment with voriconazole or CAB. Unit costs based on published data sources were applied to healthcare use to estimate 12-week costs following initiation of therapy. Resource use and costs were compared for each treatment arm overall and by survival. The sensitivity of total costs to changes in healthcare use and unit costs was examined.

RESULTS

Total hospital days and intensive care unit (ICU) days were similar for voriconazole and CAB (total: 27.8 vs. 27.7, P=0.97 and ICU: 5.6 vs. 8.1, P=0.11). Among survivors, voriconazole was associated with similar numbers of total hospital days (29.8 vs. 32.0 days, P=0.54) to CAB, but fewer ICU days (3.9 vs. 8.2, P=0.03). For non-survivors, those treated with voriconazole had a similar number of total hospital days (23.0 vs. 21.8, P=0.73) and ICU days (9.8 vs. 7.9, P=0.44). Patients treated with voriconazole had significantly more days alive and out of the hospital than with CAB at 12 weeks (40.3 vs. 28.4 days, P<0.001). Total costs were similar with voriconazole compared with CAB ($78,860 vs. $83,857, P=0.51). Differences in cost were not sensitive to changes in the input parameter values.

CONCLUSIONS

Using voriconazole first-line for treatment of IA resulted in significantly fewer deaths and similar treatment costs. Hospital-free survival was significantly greater for patients initially treated with voriconazole.

Economic evaluation of targeted treatments of invasive aspergillosis in adult haematopoietic stem cell transplant recipients in the Netherlands: a modelling approach

OBJECTIVES

The aim of this study was to assess the cost-effectiveness of a targeted treatment model of antifungal treatment strategies for adult haematopoietic stem cell transplant (HSCT) recipients in the Netherlands from a hospital perspective, using a decision analytic modelling approach.

METHODS

The economic evaluation of desoxycholate amphotericin B, liposomal amphotericin B, voriconazole and caspofungin was undertaken. These drugs could be used alone, in various combinations or sequentially. In our model, first-line therapy consisted of either voriconazole or liposomal amphotericin B. If necessary, treatment was switched to a second-line treatment, including combination antifungal therapy. The theoretical population in this model consisted of adult HSCT recipients with proven or probable invasive aspergillosis (IA). Long-term survival was extrapolated from survival after 12 weeks of treatment and life expectancy.

RESULTS

First-line antifungal treatment strategies with voriconazole were both more effective and less costly over first-line strategies employing liposomal amphotericin B at a dosage of 4 mg/kg/day. The strategy of voriconazole followed by caspofungin (voriconazole/caspofungin) was dominant over the strategies of voriconazole followed by liposomal amphotericin B (voriconazole/liposomal amphotericin B) or desoxycholate amphotericin B (voriconazole/desoxycholate amphotericin B). However, the voriconazole followed by the combination of liposomal amphotericin B and caspofungin strategy (voriconazole/liposomal amphotericin B+caspofungin) was more effective though more expensive than the voriconazole/caspofungin strategy resulting in an incremental cost-effectiveness ratio (ICER) of about euro107,000 for a life-year saved. At a dosage of 1 mg/kg/day of liposomal amphotericin B, the voriconazole/caspofungin strategy was more effective but more costly than the voriconazole/desoxycholate amphotericin B strategy with an ICER of euro10,000 for each extra life-year saved. Between the voriconazole/liposomal amphotericin B+caspofungin and the voriconazole/caspofungin strategies, the ICER was euro40,000.

CONCLUSIONS

Probabilistic analyses on net monetary benefit showed that the voriconazole/caspofungin strategy had the highest probability of being the most cost-effective strategy.

Invasive aspergillosis: is treatment with "inexpensive" amphotericin B cost saving if "expensive" voriconazole is only used on demand?

BACKGROUND

Voriconazole for the treatment of invasive aspergillosis (IA) shows superior clinical outcome and tolerability compared to conventional amphotericin B. However, the latter is often used as initial treatment due to lower drug acquisition costs. Therefore we performed a cost-effectiveness analysis.

METHODS

A decision analytic model was designed to compare the cost-effectiveness of a regimen of voriconazole followed by conventional amphotericin B to a regimen of conventional amphotericin B followed by voriconazole. Patients initiated on treatment either completed initial therapy or switched to second line therapy due to toxicity or non-response. Probability of a switch was based on clinical trial data and local rates of renal toxicity. Resource use in the hospital was taken from the Global Comparative Aspergillosis (GCA) study. Costs were based on local drug acquisition costs, local cost estimates for hospitalisation and adjusted additional costs of amphotericin B-induced acute renal failure from the literature. Effectiveness was defined as survival at 12 weeks from the GCA study. An incremental cost-effectiveness ratio was estimated as the incremental cost per life saved comparing voriconazole to conventional amphotericin B.

RESULTS

Based on this model, initial therapy of IA with voriconazole reduced total costs when compared to initial therapy with conventional amphotericin B (CHF 37 878/patient vs CHF 49 861/patient) and resulted in better survival at 12 weeks, making it the dominant treatment in terms of incremental cost-effectiveness. Results were most sensitive to alternative assumptions of the incidence of acute renal failure, but cost savings were sustained for voriconazole over a wide range of values.

CONCLUSION

Considering that initial therapy with voriconazole is both cost-saving and results in better clinical outcomes, voriconazole is the dominant cost-effective option for initial therapy of IA, despite very low drug acquisition costs of conventional amphotericin B.

Epidemiology, outcomes, and costs of invasive aspergillosis in immunocompromised children in the United States, 2000

OBJECTIVE

Invasive aspergillosis (IA) is the most common filamentous fungal infection observed in immunocompromised patients. The incidence of invasive aspergillosis has increased significantly in recent decades in parallel with the increasing number and improved survival of immunocompromised patients. IA in adults has been well characterized; however, only a few small studies of IA in children have been reported. Therefore, the objective of this study was to describe the incidence and outcomes of children with IA.

METHODS

We performed a retrospective cohort study using the 2000 Kids Inpatient Database, a national database of hospital inpatient stays during 2000. IA was defined as aspergillosis that occurred in a child with malignancy (solid tumor, leukemia, or lymphoma), hematologic/immunologic deficiency, or transplant (bone marrow or solid organ). Discharge weighting was applied to the data to obtain nationally representative estimates of disease.

RESULTS

During 2000, there were an estimated 666 pediatric cases of IA among 152,231 immunocompromised children, yielding an annual incidence of 437/100,000 (0.4%) among hospitalized immunocompromised children. Children with malignancy accounted for the majority (74%) of cases of IA. The highest incidence of IA was seen in children who had undergone allogeneic bone marrow transplantation (4.5%) and those with acute myelogenous leukemia (4%). The overall in-hospital mortality of immunocompromised children with IA was 18%. Children with malignancy and IA were at higher risk for death than children with malignancy and without IA. Pediatric patients with IA had a significantly longer median length of hospital stay (16 days) than immunocompromised children without IA (3 days). The median total hospital charges for patients with IA were $49309 compared with immunocompromised children without IA ($9035).

CONCLUSIONS

The impact of IA on increases in mortality, length of hospital stay, and the burden of cost in the hospital setting underscores the need for improved means of diagnosis, prevention, and treatment of IA in immunocompromised children.

Economic evaluation of voriconazole versus conventional amphotericin B in the treatment of invasive aspergillosis in Germany

OBJECTIVE

To assess the costs and cost-effectiveness of voriconazole in comparison to conventional amphotericin B (CAB) for the treatment of invasive aspergillosis in Germany.

METHODS

The cost-effectiveness of voriconazole in comparison to CAB was evaluated with a lifetime Markov model, focusing on the long-term survival of patients treated for invasive aspergillosis. Long-term survival was extrapolated from survival after 12 weeks of treatment, obtained from a randomized aspergillosis study. Information on medical resource consumption and treatment pathways were obtained from this study and an expert committee. With probabilistic analysis the cost-effectiveness of voriconazole compared with amphotericin B was analyzed and expressed in incremental costs per life-weeks gained. The evaluation was performed from a limited societal perspective (both inpatient and outpatient costs) and hospital perspective (only inpatient costs).

RESULTS

Average survival of patients treated with voriconazole was 174.4 life-weeks (95% confidence interval [CI] 159.4-191.3), compared with 119.4 life-weeks (95% CI 106.4-132.3) for amphotericin B. With voriconazole, the mean total costs per patient were 30,026 euros (95% CI 23 euros ,118-37,947) compared with 26,669 euros for amphotericin B (95% CI 21,259-34,263 euros ) from the limited societal perspective. The corresponding incremental cost-effectiveness ratio was 62 euros per life-week gained (i.e., 3224 euros per life-year gained). Hospital costs were approximately 90% of the mean total costs.

CONCLUSIONS

In the treatment of invasive aspergillosis, voriconazole is cost-effective in comparison to amphotericin B. Hospital costs are comparable for both treatments and are expected to be reimbursed based on the German diagnosis-related groups (DRG) system 2005.

Economic evaluation of voriconazole in the treatment of invasive aspergillosis in the Netherlands

OBJECTIVE

To asses the cost-effectiveness of voriconazole in comparison to conventional amphotericin B and itraconazole for the treatment of invasive aspergillosis in the Netherlands.

METHODS

The cost-effectiveness of voriconazole in comparison to conventional amphotericin B or itraconazole was evaluated with a decision tree model followed by a life-time Markov model, focusing on long-term survival of patients treated for invasive aspergillosis. Efficacy after 12 weeks of treatment from clinical trials was used to estimate long-term effectiveness by extrapolating these short-term results over time. Information on medical resource consumption, treatment pathways and switch proportions were obtained from both the literature and Experts. Probabilistic analysis was used to compare the cost-effectiveness among the regimens.

RESULTS

With voriconazole, the mean cost for treating invasive aspergillosis per patient was E32 651 (2.5th percentile and 97.5th of uncertainty distribution: E30 037; E36 859), compared to E33 616 (E30 920; E39 633) for conventional amphotericin B and E29 115 (E23 537; E61 414) for itraconazole. The mean survival of patients treated with voriconazole was 174.0 life weeks (160.1; 188.8), compared to 116.1 life weeks (104.8; 128.0) for conventional amphotericin B and 150.4 life weeks (109.1; 194.4) for itraconazole. The beneficial effects of voriconazole on both cost and effectiveness compared with conventional amphotericin B resulted in a probability of 69.8% that voriconazole was a dominant treatment (i.e. less costs and longer survival). The incremental cost-effectiveness ratio of voriconazole versus itraconazole was E150 per life week (i.e. 7800 euros per life-year gained). Depending on the willingness to pay (WTP) the probability of being cost-effective vs. itraconazole increased to a maximum probability of 70%.

CONCLUSION

In the treatment of invasive aspergillosis, voriconazole is dominant over amphotericin B and cost-effective in comparison to itraconazole.

Cost Advantage of Voriconazole over Amphotericin B Deoxycholate for Primary Treatment of Invasive Aspergillosis

STUDY OBJECTIVES

Using data from a published clinical trial, our objectives were to compare the cost advantage of voriconazole over amphotericin B deoxycholate (AmBd) for primary treatment of invasive aspergillosis and to determine the financial impact the findings would have in a real-world clinical setting.

DESIGN

Pharmacoeconomic analysis.

SETTING

University hospital.

PATIENTS

Two hundred seventy-seven patients in the modified intent-to-treat population.

MEASUREMENTS AND MAIN RESULTS

An analysis was performed of drug acquisition costs for all patients in the modified intent-to-treat population, which consisted of 144 patients in the voriconazole group and 133 in the AmBd group. The analysis included costs of initial drug therapy; conversion from intravenous to oral treatment for patients receiving voriconazole; and the types, dosages, and duration of other licensed [Food and Drug Administration-approved] antifungal therapy (OLAT) for up to three OLAT regimens/patient. Current drug costs for our university hospital were used for all calculations. Total voriconazole costs were $784,405 ($581,008 for initial therapy with voriconazole, $203,397 for OLAT) compared with $852,238 for AmBd ($31,677 for initial AmBd therapy, $820,561 for OLAT). Over the 12-week study period, the cost/patient was $961 less for patients whose initial treatment was voriconazole than for those whose initial treatment was AmBd. Other licensed antifungal therapy accounted for 26% and 96% of total drug costs for voriconazole and AmBd, respectively. Other licensed antifungal therapy was given to 36% of voriconazole-treated patients and 80% of AmBd-treated patients.

CONCLUSION

These data demonstrate the importance of evaluating total drug costs when comparing treatment regimens and not just initial therapy. Initial therapy with voriconazole had a cost advantage over AmBd in total antifungal drug cost/patient.

Economic effects of aspergillosis management in high-risk patients

Aspergillosis mortality has risen exponentially over the last 2 decades, related primarily to the availability of medical treatments and procedures that prolong the survival of patients with other disorders who are at high risk because of immunologic compromise. In addition to excess mortality, aspergillosis results in increased costs for hospitalization and treatment, including management of adverse events associated with conventional amphotericin B treatment. Compared with amphotericin B, the triazole antifungal voriconazole has excellent efficacy and a favorable side-effect profile. Reliable oral bioavailability of voriconazole may permit switching to an oral formulation in the inpatient setting and offers the possibility of earlier hospital discharge and potentially substantial cost savings.

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

OBJECTIVES

This study examined the burden of hospitalization of patients with Aspergillus and Candida infections in Australia from 1995 to 1999.

METHODS

Data were extracted from the National Hospital Morbidity Database. A hospitalization with an aspergillosis diagnosis was defined as any discharge with a diagnosis of aspergillosis. A hospitalization with a candidiasis diagnosis was defined as any discharge with a diagnosis of disseminated, invasive, or non-invasive candidiasis. Outcome measures included number of hospitalizations, length of stay (LOS), cost (AUS$), and mortality.

RESULTS

4583 hospitalizations with an aspergillosis diagnosis and 57,758 hospitalizations with a candidiasis diagnosis were identified. These hospitalizations were associated with a total of 813,398 hospital days, AUS$563 million in cost, and 4967 in-hospital deaths during the study period. The mean LOS for a hospitalization with an aspergillosis diagnosis was 12 days, cost AUS$9,334, and was associated with 8% mortality. For disseminated, invasive, and non-invasive candidiasis, the respective mean LOS were 31, 17, and 12 days; costs were AUS$33,274, AUS$12,954, and AUS$7,694; and mortality was 26%, 9%, and 8%.

CONCLUSIONS

Hospitalizations with diagnoses for fungal infections were associated with lengthy hospital stays, high costs, and high mortality.

Management of invasive aspergillosis in high-risk patients

Invasive aspergillosis can be difficult to diagnose and control, and conventional drug treatment is often highly toxic, producing medical complications that further compromise patients' health status and escalate health care costs. This article describes the clinical manifestations of Aspergillus infection and discusses approaches to its therapy, including newer pharmaceutical agents with fewer adverse effects, which offer the potential to improve outcomes and substantially lower the cost of treating aspergillosis.

Systemic Antifungal Therapy: New Options, New Challenges

The frequency of invasive fungal infections has increased dramatically in recent decades because of an expanding population at risk. Until now, treatment options for invasive mycoses have been primarily amphotericin B and the azoles, fluconazole and itraconazole. Traditional agents are limited by an inadequate spectrum of activity, drug resistance, toxicities, and drug-drug interactions. The recent approval of caspofungin and voriconazole clearly has expanded the number of existing antifungal drugs available. However, the enthusiasm that accompanies their availability is counterbalanced by limited clinical experience, high drug acquisition costs, and distinctive toxicities. The pharmacologic characteristics, extent of clinical experience (efficacy and toxicity), and drug acquisition costs among available systemic antifungal agents are compared, with emphasis on the new agents. Also, recommendations on the role of each agent are provided according to the most common indications for systemic antifungal therapy: invasive candidiasis, invasive aspergillosis, and febrile neutropenia.

Sequencing the Aspergillus fumigatus genome

Aspergillus fumigatus is the most common mould pathogen of human beings and unusually causes both invasive disease in immunocompromised patients and allergic disease in patients with atopic immune systems. 4% of patients dying in modern European teaching hospitals have invasive aspergillosis and it is the leading infectious cause of death in leukaemia and bone marrow transplant patients. Until 2001, only two licensed antifungal drugs were available to treat aspergillosis-amphotericin B and itraconazole. Its 28-30Mb genome is being sequenced in an international collaboration, with the Wellcome Trust Sanger Institute (UK) and The Institute for Genomic Research (TIGR, USA) as the two main centres. A whole-genome shotgun approach was adopted and initiated in 2001 with an expected completion date in 2003. The complete sequence will permit identification of pathways specific to pathogenic Aspergillus species, help identify new targets for antifungal drugs, and enable investigations into the basic biology of fungi. Numerous secondary metabolic pathways with biotechnological applications and pharmacological properties are found in the Aspergilli and the genome sequence will facilitate research in this area.

The direct cost and incidence of systemic fungal infections

OBJECTIVES

In this study we determined the incidence and direct inpatient and outpatient costs of systemic fungal infections (candidiasis, aspergillosis, cryptococcosis, histoplasmosis) in 1998.

METHODS

Using primarily the National Hospital Discharge Survey (NHDS) for incidence and the Maryland Hospital Discharge Data Set (MDHDDS) for costs, we surveyed four systemic fungal infections in patients who also had HIV/AIDS, neoplasia, transplant, and all other concomitant diagnoses. Using a case-control method, we compared the cases with controls (those without fungal infections with the same underlying comorbidity) to obtain the incremental hospitalization costs. We used the Student's t-test to determine significance of incremental hospital costs. We modeled outpatient costs on the basis of discharge status to calculate the total annual cost for systemic fungal infections in 1998.

RESULTS

For 1998, the projected average incidence was 306 per million US population, with candidiasis accounting for 75% of cases. The estimated total direct cost was $2.6 billion and the average per-patient attributable cost was $31,200. The most commonly reported comorbid diagnoses with fungal infections (HIV/AIDS, neoplasms, transplants) accounted for only 45% of all infections.

CONCLUSIONS

The cost burden is high for systemic fungal infections. Additional attention should be given to the 55% with fungal disease and other comorbid diagnoses.