Prospective surveillance for invasive fungal infections in hematopoietic stem cell transplant recipients, 2001-2006: overview of the Transplant-Associated Infection Surveillance Network (TRANSNET) Database

Update on epidemiology of and preventive strategies for invasive fungal infections in cancer patients

Changes in antineoplastic treatments and transplant practices are driving shifts in the epidemiology of invasive fungal diseases (IFDs). Patients with acute myelogenous leukemia (AML) and those undergoing bone marrow transplant (BMT) are at greatest risk for contracting IFDs. Unfortunately, there are few large population studies that can be used to track trends and help us to better understand why certain individuals within recognized high-risk groups are at greater risks than others for contracting IFDs. The growing use of antifungals in prophylaxis and treatment influences which species will cause an IFD as well as the resistance patterns of these fungi. On the one hand, antifungal prophylaxis has mitigated, but not eliminated, the threat of candidiasis. Furthermore, prophylaxis trials have shown trends of reduced aspergillosis in BMT patients; however, no survival benefits were seen, and 1 trial indicated a lower rate of aspergillosis and survival benefits in patients with AML. Future prophylaxis trials should reduce the heterogeneity of risk in study participants in order to better assess benefit; these trials should also incorporate fungal biomarkers into their design. The threat of emerging fungal resistance in prophylaxis strategies is real and must be monitored.

The Screening Performance of Serum 1,3-Beta-D-Glucan in Patients with Invasive Fungal Diseases: A Meta-Analysis of Prospective Cohort Studies

The serum 1,3-beta-D-glucan (BG) assay aids in the early diagnosis of invasive fungal diseases (IFDs) and has been approved for their diagnosis. However, reports on the screening performance of BG are scarce. We performed a meta-analysis of data extracted from only prospective cohort studies to evaluate the screening performance of the BG assay in the diagnosis of IFDs. We specifically searched 4 databases (the PubMed, Web of Science, Elsevier, and Cochrane Collaboration databases) according to EORTC-MSG criteria. A total of 1068 patients in 11 studies were analyzed. Deeks’ funnel plot asymmetry test suggested a low likelihood of publication bias for the included studies (p = 0.055). The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the summary receiver operating characteristic curve, with 95% confidence intervals, were 0.75(0.63,0.84), 0.87(0.81,0.92), 5.85(3.96,8.63), 0.30(0.20,0.45), 19.53(11.16,34.18), and 0.89(0.86,0.91), respectively. The findings of this meta-analysis suggest that the BG assay is a useful screening tool with high sensitivity and specificity for discriminating between patients with and without IFDs. In clinical practice, BG assay results should be evaluated together with clinical and microbiological findings.

Healthcare-associated outbreaks due to Mucorales and other uncommon fungi

BACKGROUND

Healthcare-associated outbreaks of fungal infections, especially with uncommon and emerging fungi, have become more frequent in the past decade.

MATERIALS AND METHOD

Here, we reviewed the history and definition of healthcare-associated outbreaks of uncommon fungal infections and discussed the principles of investigating, containing and treatment of these outbreaks.

RESULTS

In case of these uncommon diseases, occurrence of two or more cases in a short period is considered as an outbreak. Contaminated medical devices and hospital environment are the major sources of these outbreaks. Care must be taken to differentiate a real infection from colonization or contamination. Defining and identifying cases, describing epidemiologic feature of cases, finding and controlling the source of the outbreak, treating patients, and managing asymptomatic exposed patients are main steps for outbreak elimination. These fungal outbreaks are not only difficult to detect but also hard to treat. Early initiation of appropriate antifungal therapy is strongly associated with improved outcomes in infected patients. Choice of antifungal drugs should be made based on spectrum, pharmacodynamic and pharmacokinetic characteristics and adverse effects of available drugs. Combination antifungal therapy and surgical intervention may be also helpful in selected cases.

CONCLUSIONS

A multidisciplinary approach and close collaboration between all key partners are necessary for successful control of fungal outbreaks.

Histoplasmosis and Blastomycosis in Solid Organ Transplant Recipients

Histoplasmosis and blastomycosis are geographically restricted dimorphic fungi that cause infection after the conidia produced in the mold phase are inhaled into the lungs. In the lungs, at 37 °C, these organisms undergo transformation into the yeast phase. In transplant recipients, infection can occur by exposure to the mold in the environment, by reactivation of infection that had occurred previously and had been controlled by the host until immunosuppressive medications were given post-transplantation, and finally by transmission from the donor organ in the case of histoplasmosis. In transplant recipients, disseminated infection is common, and pulmonary infection is more likely to be severe than in a non-immunosuppressed person. Diagnosis has been improved, allowing earlier treatment, with the use of rapid antigen tests performed on serum and urine. Initial treatment, for all but the mildest cases of acute pulmonary histoplasmosis, should be with a lipid formulation of amphotericin B. After clinical improvement has occurred, step-down therapy with itraconazole is recommended for a total of 12 months for most transplant recipients, but some patients will require long-term suppressive therapy to prevent relapse of disease.

Mononuclear phagocyte-mediated antifungal immunity: the role of chemotactic receptors and ligands

Over the past two decades, fungal infections have emerged as significant causes of morbidity and mortality in patients with hematological malignancies, hematopoietic stem cell or solid organ transplantation and acquired immunodeficiency syndrome. Besides neutrophils and CD4(+) T lymphocytes, which have long been known to play an indispensable role in promoting protective antifungal immunity, mononuclear phagocytes are now being increasingly recognized as critical mediators of host defense against fungi. Thus, a recent surge of research studies has focused on understanding the mechanisms by which resident and recruited monocytes, macrophages and dendritic cells accumulate and become activated at the sites of fungal infection. Herein, we critically review how a variety of G-protein coupled chemoattractant receptors and their ligands mediate mononuclear phagocyte recruitment and effector function during infection by the most common human fungal pathogens.

Cryptococcus gattii infection in solid organ transplant recipients: description of Oregon outbreak cases

Cryptococcus gattii was recognized as an emerging infection in the Pacific Northwest in 2004. Out of 62 total infections in Oregon since the outbreak, 11 were in solid organ transplant (SOT) recipients. SOT recipients were more likely to have disseminated disease and higher mortality than normal hosts, who mostly had isolated mass lesions. The median time from transplantation to C. gattii diagnosis was 17.8 months. The primary sites of infection were lung (n = 4), central nervous system (n = 3), or both (n = 4). The Oregon-endemic strain, VGII (subtypes IIa and IIc) was present in 10 of 11 patients; the median fluconazole minimum inhibitory concentration (MIC) was 12 μg/mL (range 2-32 μg/mL) for this strain. We found C. gattii infection among organ transplant recipients was disseminated at diagnosis, had low cerebrospinal fluid cryptococcal antigen titers, and was associated with an elevated fluconazole MIC and high attributable mortality.

Paving the way for predictive diagnostics and personalized treatment of invasive aspergillosis

Invasive aspergillosis (IA) is a life-threatening fungal disease commonly diagnosed among individuals with immunological deficits, namely hematological patients undergoing chemotherapy or allogeneic hematopoietic stem cell transplantation. Vaccines are not available, and despite the improved diagnosis and antifungal therapy, the treatment of IA is associated with a poor outcome. Importantly, the risk of infection and its clinical outcome vary significantly even among patients with similar predisposing clinical factors and microbiological exposure. Recent insights into antifungal immunity have further highlighted the complexity of host-fungus interactions and the multiple pathogen-sensing systems activated to control infection. How to decode this information into clinical practice remains however, a challenging issue in medical mycology. Here, we address recent advances in our understanding of the host-fungus interaction and discuss the application of this knowledge in potential strategies with the aim of moving toward personalized diagnostics and treatment (theranostics) in immunocompromised patients. Ultimately, the integration of individual traits into a clinically applicable process to predict the risk and progression of disease, and the efficacy of antifungal prophylaxis and therapy, holds the promise of a pioneering innovation benefiting patients at risk of IA.

Isavuconazole: a new extended spectrum triazole for invasive mold diseases

ABSTRACT 

Isavuconazole is the first broad spectrum prodrug triazole with efficacy against invasive fungal diseases including aspergillosis and mucormycosis. Characteristics include linear dose-proportional pharmacokinetics, intravenous and oral formulations allowing therapeutic streamlining, once daily dosing, absence of nephrotoxic solubilizing agents and excellent oral bioavailability independent of prandial status and gastric acidity. An open label noncomparator study demonstrated encouraging results for isavuconazole as primary or salvage therapy for a range of fungi including mucormycosis. Isavuconazole had fewer premature drug discontinuations and adverse events in the eye, hepatobiliary and psychiatry systems than the comparator agent, voriconazole in a randomized double-blind clinical trial. Cross-resistance of isavuconazole best correlates with voriconazole. In vitro resistance is not invariably predictive of clinical failure. Isavuconazole signals progress in pharmacokinetics, bioavailability and toxicity/tolerability supported by clinical efficacy from Phase III trials.

Impaired T cell responsiveness to interleukin-6 in hematological patients with invasive aspergillosis

Invasive mold infections (IMI) are among the most devastating complications following chemotherapy and hematopoietic stem cell transplantation (HSCT), with high mortality rates. Yet, the molecular basis for human susceptibility to invasive aspergillosis (IA) and mucormycosis remain poorly understood. Herein, we aimed to characterize the immune profile of individuals with hematological malignancies (n = 18) who developed IMI during the course of chemotherapy or HSCT, and compared it to that of hematological patients who had no evidence of invasive fungal infection (n = 16). First, we measured the expression of the pattern recognition receptors pentraxin 3, dectin-1, and Toll-like receptors (TLR) 2 and 4 in peripheral blood of chemotherapy and HSCT recipients with IMI. Compared to hematological controls, individuals with IA and mucormycosis had defective expression of dectin-1; in addition, patients with mucormycosis had decreased TLR2 and increased TLR4 expression. Since fungal recognition via dectin-1 favors T helper 17 responses and the latter are highly dependent on activation of the signal transducer and activator of transcription (STAT) 3, we next used phospho-flow cytometry to measure the phosphorylation of the transcription factors STAT1 and STAT3 in response to interferon-gamma (IFN-γ) and interleukin (IL)-6, respectively. While IFN-γ/STAT1 signaling was similar between groups, naïve T cells from patients with IA, but not those with mucormycosis, exhibited reduced responsiveness to IL-6 as measured by STAT3 phosphorylation. Furthermore, IL-6 increased Aspergillus-induced IL-17 production in culture supernatants from healthy and hematological controls but not in patients with IA. Altogether, these observations suggest an important role for dectin-1 and the IL-6/STAT3 pathway in protective immunity against Aspergillus.

Epidemiology, management, and outcome of invasive fungal disease in patients undergoing hematopoietic stem cell transplantation in China: a multicenter prospective observational study

The China Assessment of Antifungal Therapy in Hematological Disease study, the first large-scale observational study of invasive fungal disease (IFD) in China, enrolled 1401 patients undergoing hematopoietic stem cell transplantation (HSCT) (75.2% allogeneic and 24.8% autologous) at 31 hospitals across China. The overall incidence of proven or probable IFD was 7.7% (108 of 1401); another 266 cases (19.0%) were possible IFD. After allogeneic or autologous HSCT, the incidence of proven/probable IFD was 8.9% (94 of 1053) and 4.0% (14 of 348), respectively. Some cases (14 of 108) developed during conditioning before transplantation. The cumulative incidence of proven/probable IFD increased steeply in the first month after transplantation and after 6 months, the incidence was significantly higher in allogeneic than it was in autologous transplant recipients (9.2% versus 3.5%; P = .001) and when stem cells were derived from cord blood or bone marrow and peripheral blood (P = .02 versus other sources). Independent risk factors for proven/probable IFD in allogeneic HSCT were diabetes, HLA-matched unrelated donor, prolonged severe neutropenia (absolute neutrophil count > 500/mm(3) for >14 days), and immunosuppressants (odds ratio, 2.0 to 3.4 for all). Antifungal prophylaxis was independently protective (P = .01). Previous IFD and prolonged severe neutropenia were significant independent risk factors among autologous transplantation patients (P < .01, P = .04, respectively). In total, 1175 (83.9%) patients received antifungal prophylaxis (91.6% triazoles) and 514 (36.7%) were treated in the hospital with therapeutic antifungals (89.1% triazoles; median 27 days). Empirical, pre-emptive, and targeted antifungals were used in 82.3%, 13.6%, and 4.1% of cases, respectively. Overall mortality (13.4%; 188 deaths) was markedly higher in patients with proven (5 of 16; 31.3%), probable (20 of 92; 21.7%), or possible (61 of 266; 22.9%) IFD; allogeneic (171 of 1053; 16.2%) rather than autologous (17 of 348; 4.9%) HSCT and was significantly higher in patients receiving pre-emptive (18.6%) rather than empirical (6.1%) or targeted (9.5%) antifungal therapy (P = .002). Improvements in the selection and timing of prophylactic antifungals would be welcome. Health care providers should remain alert to the increased risk of IFD and associated mortality in allogeneic HSCT recipients and the ongoing risk of IFD even after discharge from the hospital.

Causes of death in a contemporary cohort of patients with invasive aspergillosis

Information regarding the processes leading to death in patients with invasive aspergillosis (IA) is lacking. We sought to determine the causes of death in these patients, the role that IA played in the cause, and the timing of death. The factors associated with IA-related mortality are also analyzed. We conducted a multicenter study (2008-2011) of cases of proven and probable IA. The causes of death and whether mortality was judged to be IA-related or IA-unrelated were determined by consensus using a six-member review panel. A multivariate analysis was performed to determine risk factors for IA-related death. Of 152 patients with IA, 92 (60.5%) died. Mortality was judged to be IA-related in 62 cases and IA-unrelated in 30. The most common cause of IA-related death was respiratory failure (50/62 patients), caused primarily by Aspergillus infection, although also by concomitant infections or severe comorbidities. Progression of underlying disease and bacteremic shock were the most frequent causes of IA-unrelated death. IA-related mortality accounted for 98% and 87% of deaths within the first 14 and 21 days, respectively. Liver disease (HR 4.54; 95% CI, 1.69-12.23) was independently associated with IA-related mortality, whereas voriconazole treatment was associated with reduced risk of death (HR 0.43; 95% CI, 0.20-0.93). In conclusion, better management of lung injury after IA diagnosis is the main challenge for physicians to improve IA outcomes. There are significant differences in causes and timing between IA-related and IA-unrelated mortality and these should be considered in future research to assess the quality of IA care.

Systematic review and mixed treatment comparison meta-analysis of randomized clinical trials of primary oral antifungal prophylaxis in allogeneic hematopoietic cell transplant recipients

BACKGROUND

Antifungal prophylaxis is a promising strategy for reducing invasive fungal infections (IFIs) in allogeneic hematopoietic cell transplant (alloHCT) recipients, but the optimum prophylactic agent is unknown. We used mixed treatment comparison (MTC) meta-analysis to compare clinical trials examining the use of oral antifungals for prophylaxis in alloHCT recipients, with the goal of informing medical decision-making.

METHODS

Randomized controlled trials (RCTs) of fluconazole, itraconazole, posaconazole, and voriconazole for primary antifungal prophylaxis were identified through a systematic literature review. Outcomes of interest (incidence of IFI/invasive aspergillosis/invasive candidiasis, all-cause mortality, and use of other antifungals) were extracted from eligible RCTs and incorporated into a Bayesian hierarchical random-effects MTC.

RESULTS

Five eligible RCTs, randomizing 2147 patients in total, were included. Relative to fluconazole, prophylaxis with itraconazole (odds ratio [OR]: 0.52; interquartile range [IQR]: 0.35-0.76), posaconazole (OR: 0.56; IQR: 0.32-0.99), and voriconazole (OR: 0.46; IQR: 0.28-0.73) reduced incidence of overall proven/probable IFI. Posaconazole (OR: 0.31; IQR: 0.17-0.58) and voriconazole (OR: 0.33; IQR: 0.17-0.58) prophylaxis reduced proven/probable invasive aspergillosis more than itraconazole (OR: 0.68; IQR: 0.42-1.12). All-cause mortality was similar across all mould-active agents.

CONCLUSION

As expected, mould-active azoles prevented IFIs, particularly invasive aspergillosis, more effectively than fluconazole in alloHCT recipients. The paucity of comparative efficacy data suggests that other factors such as long-term tolerability, availability of intravenous formulations, local IFI epidemiology, and drug costs may need to form the basis for selection among the mould-active azoles.

Population-based analysis of invasive fungal infections, France, 2001-2010

These infections are underrecognized as a cause of death in the general population and high-risk groups.

To determine the epidemiology and trends of invasive fungal infections (IFIs) in France, we analyzed incidence, risk factors, and in-hospital death rates related to the most frequent IFIs registered in the national hospital discharge database during 2001–2010. The identified 35,876 IFI cases included candidemia (43.4%), Pneumocystis jirovecii pneumonia (26.1%), invasive aspergillosis (IA, 23.9%), cryptococcosis (5.2%), and mucormycosis (1.5%). The overall incidence was 5.9/100,000 cases/year and the mortality rate was 27.6%; both increased over the period (+1.5%, +2.9%/year, respectively). Incidences substantially increased for candidemia, IA, and mucormycosis. Pneumocystis jirovecii pneumonia incidence decreased among AIDS patients (−14.3%/year) but increased in non-HIV–infected patients (+13.3%/year). Candidemia and IA incidence was increased among patients with hematologic malignancies (>+4%/year) and those with chronic renal failure (>+10%/year). In-hospital deaths substantially increased in some groups, e.g., in those with hematologic malignancies. IFIs occur among a broad spectrum of non–HIV-infected patients and should be a major public health priority.

Multilaboratory testing of antifungal drug combinations against Candida species and Aspergillus fumigatus: utility of 100 percent inhibition as the endpoint

Four laboratories tested three isolates of Candida species and two isolates of Aspergillus fumigatus using 96-well plates containing combinations of amphotericin B, anidulafungin, caspofungin, micafungin, fluconazole, itraconazole, posaconazole, and voriconazole. The majority of summation fractional inhibitory concentration indices (ΣFICI) based on the Lowe additivity formula suggested indifferent drug interactions (ΣFICI > 0.5 and ≤4.0) and no instance of drug antagonism (ΣFICI > 4.0). The intra- and interlaboratory agreement rates were superior when MIC100 readings were used as endpoints (at a 99% confidence interval [CI]).

Identification and deletion of Tft1, a predicted glycosyltransferase necessary for cell wall β-1,3;1,4-glucan synthesis in Aspergillus fumigatus

Aspergillus fumigatus is an environmental mold that causes severe, often fatal invasive infections in immunocompromised patients. The search for new antifungal drug targets is critical, and the synthesis of the cell wall represents a potential area to find such a target. Embedded within the main β-1,3-glucan core of the A. fumigatus cell wall is a mixed linkage, β-D-(1,3;1,4)-glucan. The role of this molecule or how it is synthesized is unknown, though it comprises 10% of the glucans within the wall. While this is not a well-studied molecule in fungi, it has been studied in plants. Using the sequences of two plant mixed linkage glucan synthases, a single ortholog was identified in A. fumigatus (Tft1). A strain lacking this enzyme (tft1Δ) was generated along with revertant strains containing the native gene under the control of either the native or a strongly expressing promoter. Immunofluorescence staining with an antibody against β-(1,3;1,4)-glucan and biochemical quantification of this polysaccharide in the tft1Δ strain demonstrated complete loss of this molecule. Reintroduction of the gene into the knockout strain yielded reappearance in amounts that correlated with expected expression of the gene. The loss of Tft1 and mixed linkage glucan yielded no in vitro growth phenotype. However, there was a modest increase in virulence for the tft1Δ strain in a wax worm model. While the precise roles for β-(1,3;1,4)-glucan within A. fumigatus cell wall are still uncertain, it is clear that Tft1 plays a pivotal role in the biosynthesis of this cell wall polysaccharide.

Molecular and nonmolecular diagnostic methods for invasive fungal infections

Invasive fungal infections constitute a serious threat to an ever-growing population of immunocompromised individuals and other individuals at risk. Traditional diagnostic methods, such as histopathology and culture, which are still considered the gold standards, have low sensitivity, which underscores the need for the development of new means of detecting fungal infectious agents. Indeed, novel serologic and molecular techniques have been developed and are currently under clinical evaluation. Tests like the galactomannan antigen test for aspergillosis and the β-glucan test for invasive Candida spp. and molds, as well as other antigen and antibody tests, for Cryptococcus spp., Pneumocystis spp., and dimorphic fungi, have already been established as important diagnostic approaches and are implemented in routine clinical practice. On the other hand, PCR and other molecular approaches, such as matrix-assisted laser desorption ionization (MALDI) and fluorescence in situ hybridization (FISH), have proved promising in clinical trials but still need to undergo standardization before their clinical use can become widespread. The purpose of this review is to highlight the different diagnostic approaches that are currently utilized or under development for invasive fungal infections and to identify their performance characteristics and the challenges associated with their use.

Safety of voriconazole and sirolimus coadministration after allogeneic hematopoietic SCT

Antifungal prophylaxis with azoles is considered standard in allogeneic hematopoietic SCT (allo-HSCT). Although sirolimus is being used increasingly for the prevention of GVHD, it is a substrate of CYP3A4, which is inhibited by voriconazole, and concurrent administration can lead to significantly increased exposure to sirolimus. We identified 67 patients with hematologic malignancies who underwent allo-HSCT with sirolimus, tacrolimus and low-dose MTX and received concomitant voriconazole prophylaxis from April 2008 to June 2011. All patients underwent a non-myeloablative or reduced-intensity conditioned allo-HSCT. Patients received sirolimus and voriconazole concurrently for a median of 113 days. The median daily dose reduction of sirolimus at the start of coadministration was 90%. The median serum sirolimus trough levels before and at steady state of coadministration were 5.8 ng/mL (range: 0-47.6) and 6.1 ng/mL (range: 1-14.2) (P=0.45), respectively. One patient with an average sirolimus level of 6 ng/mL developed sirolimus-related thrombotic microangiopathy that resolved after sirolimus discontinuation. No sinusoidal obstructive syndrome was reported. Seventeen patients (25%) prematurely discontinued voriconazole because of the adverse events. Only two patients (3%) presented with possible invasive fungal infections at day 100. We demonstrate that sirolimus and voriconazole coadministration with an empiric 90% sirolimus dose reduction and close monitoring of sirolimus trough levels is safe and well tolerated.

Epidemiology and outcome of candidaemia in patients with oncological and haematological malignancies: results from a population-based surveillance in Spain

A prospective, population-based surveillance on candidaemia was implemented in five metropolitan areas of Spain from May 2010 to April 2011. We aimed to describe the distribution and susceptibility pattern of Candida species, and to evaluate risk factors for mortality in patients with oncological (solid tumours) and haematological malignancies. Adults (≥ 16 years) with cancer were included in the present report. Impact of therapeutic strategies on 7- and 30-day mortality were analysed by logistic regression, adjusting for propensity score by inverse weighting probability of receiving early antifungal treatment and catheter removal. We included 238 (32.6%) patients (195 oncological, 43 haematological). Compared with oncological patients, haematological patients were more likely to have received chemotherapy (53.5% versus 17.4%, p < 0.001) or corticosteroids (41.9% versus 21%, p < 0.001), and have neutropenia (44.2% versus 1.5%, p < 0.001). Overall, 14.8% of patients developed breakthrough candidaemia. Non-albicans Candida species (71.1% versus 55.6%, p 0.056) and Candida tropicalis (22.2% versus 7.6%, p 0.011) were more frequent in haematological patients. Based on EUCAST breakpoints, 27.6% of Candida isolates were non-susceptible to fluconazole. Resistance to echinocandins was negligible. Mortality at 7 and 30 days was 12.2% and 31.5%, respectively, and did not differ significantly between the patient groups. Prompt antifungal therapy together with catheter removal (≤ 48 hours) was associated with lower mortality at 7 days (adjusted OR 0.05; 95% CI 0.01-0.42) and 30 days (adjusted OR 0.27; 95% CI 0.16-0.46). In conclusion, non-albicans species are emerging as the predominant isolates, particularly in haematological patients. Prompt, adequate antifungal treatment plus catheter removal may lead to a reduction in mortality.

Economic evaluation of a preemptive treatment strategy for invasive fungal infection in neutropenic patients with hematological diseases

We compared the expected medical costs of empirical and preemptive treatment strategies for invasive fungal infection in neutropenic patients with hematological diseases. Based on the results of two clinical trials with different backgrounds reported by Oshima et al. [J Antimicrob Chemother 60(2):350-355; Oshima study] and Cordonnier et al. [Clin Infect Dis 48(8):1042-1051; PREVERT study], we developed a decision tree model that represented the outcomes of empirical and preemptive treatment strategies, and estimated the expected medical costs of medications and examinations in the two strategies. We assumed that micafungin was started in the empirical group at 5 days after fever had developed, while voriconazole was started in the preemptive group only when certain criteria, such as positive test results of imaging studies and/or serum markers, were fulfilled. When we used an incidence of positive test results of 6.7 % based on the Oshima study, the expected medical costs of the empirical and preemptive groups were 288,198 and 150,280 yen, respectively. Even in the case of the PREVERT study, in which the incidence of positive test results was 32.9 %, the expected medical costs in the empirical and preemptive groups were 291,871 and 284,944 yen, respectively. A sensitivity analysis indicated that the expected medical costs in the preemptive group would exceed those in the empirical group when the incidence of positive test results in the former was over 34.4 %. These results suggest that a preemptive treatment strategy can be expected to reduce medical costs compared with empirical therapy in most clinical settings.

Pneumonia in the immunocompromised host

PURPOSE OF REVIEW

Novel treatment modalities for previously fatal diseases, including newer chemotherapeutic and biologic agents and the expansion of the indications for solid organ and stem cell transplantation, have resulted in prolonged patient survival and a significant increase in the population of immunocompromised hosts (ICHs).

RECENT FINDINGS

This review discusses the increasing spectrum of opportunistic infections in the ICH, the general approach for early diagnosis and treatment of pulmonary infections in this population, and the current and novel diagnostic modalities available to establish a rapid and specific microbiologic diagnosis, focusing on recent controversies and advances.

SUMMARY

Early diagnosis and prompt initiation of effective therapy for infection help reduce morbidity in ICHs. Advances in diagnostic assays using nonculture-based methods, such as nucleic acid amplification, may allow for earlier targeted therapy. Invasive procedures including bronchoscopy and biopsy remain essential and should be vigorously pursued in ICHs given the broad differential diagnosis of possible pulmonary pathogens in this population, and the need to establish a specific diagnosis to allow accurate targeted therapy.

Antifungal activity of compounds targeting the Hsp90-calcineurin pathway against various mould species

OBJECTIVES

Invasive mould infections are associated with a high mortality rate and the emergence of MDR moulds is of particular concern. Calcineurin and its chaperone, the heat shock protein 90 (Hsp90), represent an important pathway for fungal virulence that can be targeted at different levels. We investigated the antifungal activity of compounds directly or indirectly targeting the Hsp90-calcineurin axis against different mould species.

METHODS

The in vitro antifungal activity of the anticalcineurin drug FK506 (tacrolimus), the Hsp90 inhibitor geldanamycin, the lysine deacetylase inhibitor trichostatin A and the Hsp70 inhibitor pifithrin-μ was assessed by the standard broth dilution method against 62 clinical isolates of Aspergillus spp. and non-Aspergillus moulds (Mucoromycotina, Fusarium spp., Scedosporium spp., Purpureocillium/Paecilomyces spp. and Scopulariopsis spp.)

RESULTS

FK506 had variable antifungal activity against different Aspergillus spp. and was particularly active against Mucor spp. Geldanamycin had moderate antifungal activity against Fusarium spp. and Paecilomyces variotii. Importantly, trichostatin A had good activity against the triazole-resistant Aspergillus ustus and the amphotericin B-resistant Aspergillus terreus as well as the MDR Scedosporium prolificans. Moreover, trichostatin A exhibited synergistic interactions with caspofungin against A. ustus and with geldanamycin against Rhizopus spp. for which none of the other agents showed activity. Pifithrin-μ exhibited little antifungal activity.

CONCLUSIONS

Targeting the Hsp90-calcineurin axis at different levels resulted in distinct patterns of susceptibility among different fungal species. Lysine deacetylase inhibition may represent a promising novel antifungal strategy against emerging resistant moulds.

Infectious Complications

Infections remain a cause of significant morbidity and mortality following hematopoietic stem cell transplantation (HSCT). The conditioning regimen (chemotherapy, radiation therapy), mucosal damage, type of transplant, immune suppressive therapy, and graft-versus-host disease (GVHD) all predispose the HSCT recipient to infection. Abnormal B- and T-lymphocyte function results in impaired humoral and cellular immunity, respectively. Neutrophil function is impaired by the use of corticosteroids and other medications. Hypogammaglobulinemia and functional asplenia are common. The occurrence of infections in an individual patient varies according to the phase of the transplant process and reflects the type(s) of immune defect(s), underlying disease, endogenous host flora, exposure history, and pre-treatment infections.

Secondary antifungal prophylaxis in hematological malignancy patients with previous invasive fungal disease: a retrospective analysis

BACKGROUND

Invasive fungal disease (IFD) causes morbidity and mortality in patients with hematological malignancy. Recurrence of IFD after chemotherapy or hematopoietic stem cell transplantation (HSCT) is associated with poor prognosis. The present study aimed to investigate the efficacy of different strategies of secondary antifungal prophylaxis (SAP) for IFD and choose an appropriate SAP regimen.

METHODS

Clinical data of patients with previous IFD who underwent chemotherapy or HSCT between Jan 2008 and Jun 2013 were retrospectively reviewed and followed up to 180 days post-chemotherapy or HSCT. The clinical characteristics and diagnosis were analyzed according to the diagnostic criteria for IFD. The efficacy of different strategies for SAP and risk factors influencing the failure of SAP were evaluated.

RESULTS

Of the 164 patients enrolled, 121 patients received SAP regimen (73.78%), and IFD recurred in 40 patients: 16.5% (20/121) in SAP group and 46.5% (20/43) in non-SAP group. In SAP group, 58 received SAP agents which were proven effective for their previous IFD, while other 63 patients received other broad-spectrum antifungal agents. There was no significant difference in the recurrence rates between these two subgroups (13.8% (8/58) vs 19.0% (12/63), P = 0.437). The IFD recurrence rates were statistically significant between patients with allogeneic HSCT and chemotherapy or autologous HSCT (25% vs 8.2%, P = 0.013). Multivariate analysis indicated that allogeneic HSCT was the independent risk factor of IFD recurrence after SAP.

CONCLUSIONS

Secondary antifungal prophylaxis is necessary to prevent IFD recurrence in patients with hematological malignancy, especially for patients in the setting of allogeneic HSCT.

Early invasive pulmonary aspergillosis in a kidney transplant recipient caused by Aspergillus lentulus: first Brazilian report

We report the first Brazilian case of pulmonary invasive aspergillosis caused by Aspergillus lentulus, a new opportunistic Aspergillus species included in the section fumigati that is usually resistant to amphotericin B and azoles.

Treatment of infections by cryptic Aspergillus species

The best treatment for patients with invasive aspergillosis caused by cryptic Aspergillus species remains uncertain, mainly due to the limited clinical data that have been published so far. In face of this limitation, patients should be treated with standard first-line therapy for invasive aspergillosis, with therapy being modified according to in vitro susceptibility testing. In this review, we summarize the importance of cryptic Aspergillus species in modern medicine, including their prevalence, methods for detection and response to antifungal drugs.

Infections After High-Dose Chemotherapy and Autologous Hematopoietic Stem Cell Transplantation

Infection represents an important cause of morbidity after autologous hematopoietic stem cell transplantation (HSCT). Immunodeficiency is the key risk factor and results from interplay between the underlying disease and its therapy. Various defects in the immune system coexist in HSCT recipients. In the early post-transplant period, neutropenia, oral and gastrointestinal mucositis, and the presence of central venous catheters are the main risk factors. Bacterial infections predominate, and the agents and antibiotic susceptibility profiles vary widely in different regions. Invasive candidiasis is infrequent with fluconazole use, but the incidence of invasive aspergillosis is on the rise, mainly in patients receiving purine analogues or intensive chemotherapy before transplant. In the post-engraftment period, infections are less frequent, but may contribute to significant non-relapse mortality. The dynamics of immune reconstitution drives the risk for infection in this period. The most frequent infections are varicella-zoster virus disease and respiratory tract infections. Assessment of the risk of infection in each period and the identification of patients at higher risk of specific infections are critical to the appropriate management of infectious complications after autologous hematopoietic stem cell transplantation.

Risk factors for invasive fusariosis in patients with acute myeloid leukemia and in hematopoietic cell transplant recipients

BACKGROUND

Risk factors for invasive fusariosis (IF) have not been characterized. We attempted to identify risk factors for IF in a prospective cohort of hematologic patients treated in 8 centers in Brazil.

METHODS

Patients with (cases) and without (controls) proven or probable IF diagnosed in a cohort of patients with acute myeloid leukemia (AML) or myelodysplasia (MDS), and in allogeneic hematopoietic cell transplant (HCT) recipients (early, until day 40; late, after day 40 posttransplant) were compared by univariate Cox regression analysis.

RESULTS

Among 237 induction remission courses of AML/MDS and 663 HCTs (345 allogeneic and 318 autologous), 25 cases of IF were diagnosed. In the AML/MDS cohort, active smoking (hazard ratio [HR], 9.11 [95% confidence interval {CI}, 2.04-40.71]) was associated with IF. Variables associated with IF in the early phase of allogeneic HCT were receipt of antithymocyte globulin (HR, 22.77 [95% CI, 4.85-101.34]), hyperglycemia (HR, 5.17 [95% CI, 1.40-19.11]), center 7 (HR, 5.15 [95% CI, 1.66-15.97]), and AML (HR, 4.38 [95% CI, 1.39-13.81]), and in the late phase were nonmyeloablative conditioning regimen (HR, 35.08 [95% CI, 3.90-315.27]), grade III/IV graft-vs-host disease (HR, 16.50 [95% CI, 2.67-102.28]), and previous invasive mold disease (HR, 10.65 [95% CI, 1.19-95.39]).

CONCLUSIONS

Attempts to reduce the risk of IF may include smoking cessation, aggressive control of hyperglycemia, and the use of a mold-active agent as prophylaxis in patients receiving nonmyeloablative HCT or ATG in the conditioning regimen. Future research should further explore smoking and other prehospital variables as risks for IF.

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.

Invasive mold infections in solid organ transplant recipients

Invasive mold infections represent an increasing source of morbidity and mortality in solid organ transplant recipients. Whereas there is a large literature regarding invasive molds infections in hematopoietic stem cell transplants, data in solid organ transplants are scarcer. In this comprehensive review, we focused on invasive mold infection in the specific population of solid organ transplant. We highlighted epidemiology and specific risk factors for these infections and we assessed the main clinical and imaging findings by fungi and by type of solid organ transplant. Finally, we attempted to summarize the diagnostic strategy for detection of these fungi and tried to give an overview of the current prophylaxis treatments and outcomes of these infections in solid organ transplant recipients.

Systemic antifungal prescribing in neonates and children: outcomes from the Antibiotic Resistance and Prescribing in European Children (ARPEC) Study

The appropriate use of systemic antifungals is vital in the prevention and treatment of invasive fungal infection (IFI) in immunosuppressed children and neonates. This multicenter observational study describes the inpatient prescribing practice of antifungal drugs for children and neonates and identifies factors associated with prescribing variability. A single-day point prevalence study of antimicrobial use in hospitalized neonates and children was performed between October and December 2012. The data were entered through a study-specific Web-based portal using a standardized data entry protocol. Data were recorded from 17,693 patients from 226 centers. A total of 136 centers recorded data from 1,092 children and 380 neonates receiving at least one antifungal agent. The most frequently prescribed systemic antifungals were fluconazole (n=355) and amphotericin B deoxycholate (n=195). The most common indications for antifungal administration in children were medical prophylaxis (n=325), empirical treatment of febrile neutropenia (n=122), and treatment of confirmed or suspected IFI (n=100 [14%]). The treatment of suspected IFI in low-birthweight neonates accounted for the majority of prescriptions in the neonatal units (n=103). An analysis of variance (ANOVA) demonstrated no significant effect of clinical indication (prophylaxis or treatment of systemic or localized infection) on the total daily dose (TDD). Fewer than one-half of the patients (n=371) received a TDD within the dosing range recommended in the current guidelines. Subtherapeutic doses were prescribed in 416 cases (47%). The predominance of fluconazole and high incidence of subtherapeutic doses in participating hospitals may contribute to suboptimal clinical outcomes and an increased predominance of resistant pathogenic fungi. A global consensus on antifungal dosing and coordinated stewardship programs are needed to promote the consistent and appropriate use of antifungal drugs in neonates and children.

Sudden death in a patient with bone marrow transplant by a fungus among us

Mucormycosis is rare, presenting as breakthrough infection among haematological and transplant patients on prophylaxis with voriconazole. We report an unusual presentation of this infection, that which is pneumonia progressing to cardiac arrest. A 68-year-old woman with refractory acute myelogenous leukaemia on voriconazole prophylaxis was initially admitted for neutropenic fever and pneumonia. She was discharged improved on antibiotics and voriconazole for presumed aspergillosis. She returned after 1 month with the same presentation. She eventually improved on antibiotics and voriconazole, and eventually received bone marrow transplantation. Three days later, she developed pleuritic chest pain, dyspnoea, and hypoxia requiring intubation. An hour after intubation, the patient arrested and expired. Autopsy revealed Rhizopus pneumonitis with pulmonary infarction, and emboli to her cerebellum, heart, thyroid and kidney. Mucormycosis is an emerging, fatal infection that should be suspected in haematological and transplant patients who deteriorate on voriconazole.

Weekly use of fluconazole as prophylaxis in haematological patients at risk for invasive candidiasis

Background

The goal was to determine whether one medical centres’ unique antifungal prophylactic regimen for patients at high risk for invasive candidiasis because of their haematological malignancies, haematopoietic stem cell transplants, or high-dose chemotherapy might lead ultimately to a higher incidence of infection, to increasing fluconazole resistance, or to a shift in the predominant strain of Candida in invasive fungal episodes.

Methods

Data were collected retrospectively, for a ten-year period from ONKO-KISS surveillance records, and from hospital, medical, and pharmacy records and then evaluated with respect to incidence of fungal infection episodes, emergence of antifungal drug resistance, and predominance of specific Candida strains in isolate cultures. Fisher’s exact test and linear regression were used to compare minimum inhibitory concentrations and to compare the incidence of different Candida isolates, respectively.

Results

The incidence of infection remained quite stable over 10 years with a median of 0.67 episodes/1000 bed days. Overall, Candida glabrata was the predominant species with 29% followed by C. albicans and C. krusei (14% each). No significant increment of non-albicans Candida species with decreased fluconazole susceptibility was perceived over this decade.

Conclusions

Once weekly administration of 400 mg of fluconazole to prevent candidaemia appears to have no negative impact on the efficacy as a prophylaxis when compared to standard of care (400 mg of fluconazole daily).

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0573-5) contains supplementary material, which is available to authorized users.