500
Views
41
CrossRef citations to date
0
Altmetric
Review

Epidemiology and treatment approaches in management of invasive fungal infections

, &
Pages 175-191 | Published online: 19 May 2011

Abstract

Over the past 20 years, the number of invasive fungal infections has continued to persist, due primarily to the increased numbers of patients subjected to severe immunosuppression. Despite the development of more active, less toxic antifungal agents and the standard use of antifungal prophylaxis, invasive fungal infections (especially invasive mold infections) continue to be a significant factor in hematopoietic cell and solid organ transplantation outcomes, resulting in high mortality rates. Since the use of fluconazole as standard prophylaxis in the hematopoietic cell transplantation setting, invasive candidiasis has come under control, but no mold-active antifungal agent (except for posaconazole in the setting of acute myelogenous leukemia and myelodysplastic syndrome) has been shown to improve the survival rate over fluconazole. With the advent of new azole and echinocandin agents, we have seen the emergence of more azole-resistant and echinocandin-resistant fungi. The recent increase in zygomycosis seen in the hematopoietic cell transplantation setting may be due to the increased use of voriconazole. This has implications for the empiric approach to pulmonary invasive mold infections when zygomycosis cannot be ruled out. It is imperative that an amphotericin B product, an antifungal that has never developed resistance in over 50 years, be initiated. The clinical presentations of invasive mold infections and invasive candidiasis can be nonspecific and the diagnostic tests insensitive, so a high index of suspicion and immediate initiation of empiric therapy is required. Unfortunately, our currently available serologic tests do not predict infection ahead of disease, and, therefore cannot be used to initiate “preemptive” therapy. Also, the Aspergillus galactomannan test gives a false negative result in patients receiving antimold prophylaxis, ie, virtually all of our patients with hematologic malignancy and hematopoietic cell transplant recipients. We may eventually be able to select patients at highest risk for invasive fungal infections for prophylaxis by genetic testing. However, with our current armamentarium of antifungal agents and widespread use of prophylaxis in high-risk groups (hematologic malignancy, hematopoietic cell transplantation), we continue to see high incidence and mortality rates, and our future hope lies in reversing the immunosuppression or augmenting the immune system of these severely immunocompromised hosts by developing and utilizing immunotherapy, immunoprophylaxis, and vaccines.

Introduction

Invasive fungal infections are a growing problem in our severely immunocompromised patients. Hematopoietic cell and solid organ transplantations continue to increase, and despite recent development of more active and less toxic antifungal agents, mortality rates from invasive fungal infections remain unacceptably high. In this article we review invasive fungal infections in immunocompromised hosts. The focus will be on invasive mold infections, (particularly invasive aspergillosis) and invasive candidiasis, and on immunocompromised hosts, including neutropenic patients with hematologic malignancy, hematopoietic cell transplant recipients, solid organ transplant recipients, and high-risk intensive care unit patients. Specifically, the following topics will be reviewed: epidemiology, including incidence and mortality rates for invasive fungal infections; emerging resistance patterns; high-risk groups and risk factors; clinical presentation of each type of invasive fungal infection; diagnosis; antifungal treatment options; management; and future developments in the treatment and prevention of invasive fungal infections.

Epidemiology

The epidemiology of invasive fungal infections has been difficult to glean from the literature because of the different definitions used, the different risk groups studied, and variation from institution to institution. To date, the most comprehensive multicenter epidemiologic surveillance study of invasive fungal infections in transplantation has been from the Transplant-Associated Infection Surveillance Network (TRANSNET) database.Citation1Citation4 TRANSNET is a network of 23 US transplant centers performing hematopoietic cell and/or solid organ transplantations. Incidence, clinical and diagnostic information, and outcomes such as 12-month (and 3-month for hematopoietic cell transplant) mortality rates were evaluated.Citation2,Citation4 The database consists of invasive fungal infections occurring between 2001 and 2006. Prior to this period, the overall incidence of invasive fungal infection was 18%, based on data from a single US center in a placebo-controlled group not on antifungal prophylaxis.Citation5 According to TRANSNET data, there were 983 proven and probable cases of invasive fungal infection in hematopoietic cell transplant recipients, comprising of 21% autologous, 38% matched-related, 34% matched-unrelated, and 6% mismatched-related transplants. The overall incidence during a 12-month period for invasive fungal infections among hematopoietic cell transplant recipients was 3.4% (range 0.9%–13.2%).Citation2 This lower incidence is likely due to the now standard use of antifungal prophylaxis in hematopoietic cell transplantation. The incidence of invasive fungal infections was lowest for autologous hematopoietic cell transplants (1.2%), and increased for matched-related donor (5.8%), matched-unrelated donor (7.7%), and mismatched-related donor (8.1%). There are 3 phases of hematopoietic cell transplantation, ie, phase I (pre-engraftment), phase II (postengraftment, <100 days posttransplant), and phase III (late phase, >100 days posttransplant).Citation6 The majority of invasive fungal infections occurred during phase II and phase III. TRANSNET data revealed an overall 3-month invasive fungal infection mortality rate of 51%.Citation2 The 12-month mortality rate for overall invasive fungal infection was not reported. Other studies have reported the overall median 12-month mortality rate to be approximately 80% for all invasive fungal infections in hematopoietic cell transplantation patients.Citation7

In the TRANSNET database, there were 1063 proven and probable cases of invasive fungal infection in solid organ transplant recipients.Citation4 The overall incidence of invasive fungal infection was 3.1% in a 12-month period, similar to that for hematopoietic cell transplantation.Citation4 Historically, the incidence has ranged from 5.6% to 10.9%,Citation8 and varies according to transplant type.Citation9 The highest incidence for fungal infections was with liver transplant (7%–42%), followed by pancreas (18%–38%), heart and heart-lung (15%–35%), and the lowest with kidney transplant (0%–14%).Citation9 The addition of antifungal prophylaxis has lowered the incidence of invasive fungal infection in solid organ transplantation. In comparison with the older studies, the more recent TRANSNET data demonstrated small bowel transplants as having the highest risk of invasive fungal infection at 11.6%, followed by lung and heart-lung transplants 8.6%, liver 4.7%, and pancreas and pancreas-kidney 4%.Citation4 Heart transplant recipients had a lower risk at 3.4%, and kidney had the least risk at 1.3%. The majority of invasive fungal infections occurred more than 90 days posttransplant. Overall 12-month mortality for invasive fungal infection was not presented in the TRANSNET data.

Currently there are no large multicenter, prospective, surveillance studies in nontransplant patients with hematologic malignancy, such as acute myelogenous leukemia and myelodysplastic syndrome. However, data are available from prophylactic trials.Citation10,Citation11 The incidence of invasive fungal infections was 2%–8% depending on the antifungal prophylaxis regimen used.Citation10,Citation11 Comparison with older studies is difficult. The data from clinical trials varies due to the different definitions of invasive fungal infection. One prophylactic study reported invasive fungal infection rates of 20% (proven and probable cases) in the placebo armCitation12 and 4.4% (proven deep-seated invasive fungal infections) in another study.Citation13 In the latter study, the 2-month mortality rate for invasive fungal infection was 56%.Citation13 In a recent clinical trial,Citation10 mortality for invasive fungal infection was not evaluated. However, overall 100-day mortality was evaluated, and was 22% in a fluconazole / itraconazole prophylaxis group and 14% in a posaconazole prophylaxis group.Citation10

The overall incidence of invasive fungal infections in prospective surveillance data that directly compare high-risk groups is limited, and may differ by institution. Autopsy data are available from a single-center review (2707 of 10,151 patients) for 1993–2005.Citation14 Patients with the following underlying diseases were included: hematologic malignancy, solid tumors, transplant (either solid organ or hematopoietic cell transplantation), acquired immunodeficiency syndrome, and other diagnoses. Overall, the prevalence of invasive fungal infections was 8.2%. Invasive fungal infection rates were tabulated by time periods in order to evaluate trends, and were as follows: 1993–1996 (6.6%), 1997–2000 (8.6%), and 2001–2005 (10.4%). The highest prevalence was found in patients with hematologic malignancy (33%), followed by transplant (22.9%), acquired immunodeficiency syndrome (19.7%), solid tumors (4.8%), followed by other diagnoses (3.5%). The most common infecting fungal organisms were Aspergillus species, then Candida species. Other fungal organisms (eg, Cryptococcus species and Zygomycetes) were all found in approximately 1% or less of the cases reviewed. The study did note that the prevalence of invasive fungal infection decreased over time in the transplant group when comparing the 1997–2000 and 2001–2005 periods. As noted earlier, this is most likely attributable to the use of antifungal prophylaxis in the transplant population.

Aspergillosis

During the 1990s, in patients who did not receive antifungal prophylaxis, invasive fungal infections caused by Candida species were most frequent (18%), followed by invasive fungal infections caused by Aspergillus species (1.4%).Citation5 This pattern has changed over the past two decades. The introduction of fluconazole prophylaxis, which prevented many infections caused by Candida species, altered the epidemiology of invasive fungal infection. According to TRANSNET data, the overall incidence of invasive aspergillosis is 1.6%.Citation2 However, invasive aspergillosis is now the most common invasive fungal infection in hematopoietic cell transplantation (43%, ). Aspergillus fumigatus was the most common Aspergillus species (44%).Citation2 The median time to infection occurred at the end of the late posthematopoietic cell transplantation phase II (day 99). In the solid organ transplantation group, the incidence of invasive aspergillosis was 0.7%, and accounted for 18.8% of invasive fungal infections in the solid organ transplant group.Citation4 It was most frequent in lung transplant (44%), whereas it was the second or third most frequent invasive fungal infection in other transplant types (5%–23%). The median time to onset of invasive aspergillosis was 184 days. For nontransplant patients with hematologic malignancies, data from antifungal prophylaxis clinical trials reported an incidence for invasive aspergillosis of 1%–7% with azole prophylaxisCitation10 and 4%–5% with prophylaxis using amphotericin B lipid formulations.Citation10,Citation11 The majority of invasive fungal infections were also due to invasive aspergillosis (33%–69%). In critically ill patients, the infection rate for invasive aspergillosis has been reported to be 2.6%, and the proportion of invasive fungal infections caused by invasive aspergillosis was 11%.Citation15

Table 1 Proportion of invasive fungal infections reported in the literature

Similar to the changing epidemiology of invasive fungal infections over recent years, mortality rates have also changed. The 3-month overall invasive aspergillosis mortality rate had been 42% with conventional amphotericin B,Citation16 and 68% in hematopoietic cell transplantation.Citation7 The 1-year mortality rates in hematopoietic cell transplantation associated with invasive aspergillosis during the 1990s was 80%.Citation7 The 12-month mortality rates for transplant patients in the most recent TRANSNET data were 75% for hematopoietic cell transplantation and 41% for solid organ transplantation.Citation2,Citation4 Another TRANSNET data report indicated 3-month mortality rates for hematopoietic cell transplantation of 57.5% (239/415) and for solid organ transplantation of 34.4% (78/227).Citation1 The same report by TRANSNET did evaluate mortality rate over time.Citation1 Mortality rates in hematopoietic cell and solid organ transplant recipients were shown to decrease over time from approximately 72% and 43% in 2001 to 55% and 27% in 2005–2006, respectively. Allogeneic hematopoietic cell transplantation, neutropenia, cytomegalovirus disease, renal or hepatic insufficiency, and corticosteroid use were associated with higher mortality rates.Citation1 The species of Aspergillus also plays a role in mortality. A. fumigatus was associated with a 63% 3-month mortality rate compared with Aspergillus terreus, a much more antifungal-resistant species, with a reported mortality rate of 100%.Citation17

Invasive candidiasis

The epidemiology of invasive candidiasis has also changed. In the 1990s, the incidence of invasive candidiasis was reported at one institution to be 15%, and accounted for 88% of all invasive fungal infections in hematopoietic cell transplantation.Citation5 In the most recent data from TRANSNET, this proportion has changed. The incidence of invasive candidiasis is now 1.1% for hematopoietic cell transplantation and just under 2% for solid organ transplantation.Citation2,Citation4 In hematopoietic cell transplantation and lung transplantation, invasive candidiasis is the next largest proportion of invasive fungal infections after invasive aspergillosis, at 28% and 23%, respectively.Citation2,Citation4 In solid organ transplantation, approximately half (52.9%) of invasive fungal infection cases were invasive candidiasis.Citation4 Invasive candidiasis made up the highest proportion of invasive fungal infections across the remaining transplant types. Invasive candidiasis generally occurred in the posthematopoietic cell transplantation engraftment phase II (day 61), earlier than the onset of other invasive fungal infections. Similar to hematopoietic cell transplantation, the onset of invasive candidiasis in solid organ transplantation followed a similar pattern, with an earlier median onset (103 days) posttransplant compared with other invasive fungal infections. The data from clinical trials for patients with hematologic malignancy demonstrated invasive candidiasis incidences of 1%–3%, and invasive candidiasis comprised the next largest proportion of invasive fungal infections (13.5%–44%) after invasive aspergillosis.Citation10,Citation11 Breakthrough Candida infections on anti-fungal prophylaxis reported in the literature are of importance to the changing epidemiology of invasive candidiasis. Micafungin prophylaxis has been associated with invasive candidiasis caused by Candida parapsilosis.Citation18

Critically ill patients in intensive care are at an increased risk of invasive candidiasis.Citation19Citation21 In the intensive care unit, invasive candidiasis is the third most common cause of infections globally (17%), and the second most common cause in the US (18.2%) after infections caused by Staphylococcus aureus (26.9%).Citation15 The proportion of invasive fungal infections caused by Candida species was 79%. In the US, Candida species are also the third most common cause of catheter-related blood stream infections.Citation22 C. albicans is the most common Candida species (50%–60%), followed by C. glabrata (15%–20%), C. parapsilosis (10%–20%), and C. tropicalis (6%–12%), and the remainder are made up by C. krusei, C. guillermondii, and C. lusitaniae (1.3%).Citation19

Historically, 3-month mortality due to invasive candidiasis was at least 50% in critically ill patients.Citation23 In more recent data, the reported 2-month mortality was 42.6%.Citation24 The 12-month mortality in hematopoietic cell transplantation was 66.4%Citation2 and 34% in solid organ transplantation.Citation4 Outcomes also differed with Candida species. The overall 3-month mortality among all patients with invasive candidiasis ranged from highest with C. krusei (52.9%) to lowest with C. parapsilosis (23.7%).Citation21

Zygomycosis

According to TRANSNET data, the proportion of invasive fungal infections caused by zygomycosis is 8% in hematopoietic cell transplantationCitation2 and 2.3% in solid organ transplantation.Citation4 The incidence in hematopoietic cell and solid organ transplantation was approximately 0.3% and 0.1%, respectively.Citation2,Citation4 Most infections occurred after day 100 after posthematopoietic cell transplantation and at median day of 312 postsolid organ transplantation. The overall 3-month and 12-month mortality rates in hematopoietic cell transplantation were approximately 64%–72%.Citation2,Citation25 There is also an increasing rate of zygomycosis infection in hematopoietic cell transplantation recipients.Citation3 In 2001, the 1-year incidence of zygomycosis was 1.7/1000 patients. In 2004, it increased to 6.2/1000 patients. Another study found similar results with the advent of newer antifungals, such as voriconazole and caspofungin, correlating with significant increases in zygomycosis.Citation26 The rates increased from 0.57/100,000 admissions prior to 2003 to 6.3/100,000 admissions after 2003. These increasing trends likely correlate with recent reports of breakthrough infections in those receiving prophylaxis with newer antifungals, such as voriconazole and echinocandins, in hematopoietic cell transplantation.Citation26Citation29

Other invasive fungal infections

Other invasive fungal infections in the transplant population occur less frequently than invasive aspergillosis, invasive candidiasis, and zygomycosis. In the hematopoietic cell transplantation population, the incidences for non-Aspergillus and unspecified mold were approximately 0.3% and 0.2%, respectively.Citation2 The proportion of invasive fungal infections caused by Fusarium species was 3%. Acremonium, Alternaria, and Scedosporium species accounted for 7%. Unspecified molds accounted for 6% of invasive fungal infections. The majority of these infections occurred after day 100 posthematopoietic cell transplantation.Citation2 In the solid organ transplantation population, the incidences were 0.1%–0.2% for other molds and endemic invasive fungal infections. Cryptococcus infections comprised 8% of all invasive fungal infections, and other molds comprised 6.5%. Endemic fungal infections comprised 5.3% of all invasive fungal infections.Citation4 In intensive care patients, infections caused by other fungi occurred at a rate of 2.2%, representing 10% of all invasive fungal infections.Citation15

Mortality rates for molds other than Aspergillus species and Zygomycetes vary according to pathogen. The highest mortality rate is seen with fusariosis in hematopoietic cell transplantation (93.7%).Citation2 The 12-month mortality among solid organ transplant recipients was 39% for other molds, and 27% for Cryptococcus.Citation4 Other studies have reported 3-month mortality rates of 80% in hematopoietic cell transplantation from infections due to Fusarium and Scedosporium species.Citation25

Resistance and trends

The potential for increasing antifungal resistance has long been a concern in the treatment of invasive fungal infections. Fungal pathogens can exhibit various mechanisms of resistance. The most common for antifungals are target mutations or change in expression of genes, such as overexpression of the efflux pumps that remove antifungals.Citation30,Citation31

Candida and resistance

Azole resistance was first noted in Candida species in patients with acquired immunodeficiency syndrome.Citation32 There was a total of 348 isolates tested against fluconazole, and 33% were found to be resistant compared with 11% in isolates from patients without acquired immunodeficiency syndrome. This was related to prolonged exposure and use for such conditions as Candida esophagitis. A similar concern exists for transplant and other immunocompromised patients because they may be exposed to prolonged use of azole antifungal agents as well.Citation33

Overexpression of efflux genes is the most common mechanism of resistance to azoles in Candida species, and has also been associated with cross-resistance within the class.Citation30,Citation31 Progressive loss of echinocandin activity has been observed in Candida species when exposed to prolonged echinocandin use.Citation34 The most common mechanism of echinocandin resistance is associated with mutation in the FKS1 gene, a gene that produces the FKS1 protein for β-1,3-D-glucan synthase.

Aspergillus and resistance

Similar to Candida species, the mechanism of resistance in molds, such as Aspergillus species, is due to point mutations and efflux pump overexpression; however, the targets are different.Citation34 The CYP51 gene (important for encoding 14-α-sterol demethylase) target mutation results in decreased azole susceptibility,Citation34,Citation35 and may lead to cross-resistance between itraconazole and posaconazole, but not for echinocandins.Citation34 Overexpression of multidrug-resistant efflux pumps confers decreased susceptibility in A. fumigatus,Citation36 and has been shown to be inducible with voriconazole treatment in a mouse biofilm model.

Resistance patterns

Overall susceptibility patterns have also been changing over time due to use of prophylactic antifungal agents. In a large collection of 519 A. fumigatus isolates, resistance to azoles increased between 1997 and 2007.Citation37 There was no resistance found in isolates from 1997, and only 3%–7% resistance in the years prior to 2004. Between 2004 and 2007, resistance increased each year to 17% in 2007. Each year after 2004, multiazole resistance increased. In another study, the epidemiology of 269 oral Candida isolates was evaluated in patients with hematologic malignancies, and in those with head and neck and solid tumors.Citation38 C. albicans comprised the majority (74%) of isolates. Resistance patterns for azoles were as follows: fluconazole 4.5% (C. albicans, C. glabrata, C. krusei), itraconazole 11.7% (C. albicans, C. glabrata, C. tropicalis), and voriconazole 0.75% (C. glabrata). Resistance to caspofungin was 4.1% (C. albicans, C. parapsilosis) and 10.2% had intermediate susceptibility. None were resistant to amphotericin B.

High-risk groups

Immunocompromised patients at highest risk for developing invasive fungal infection include hematopoietic cell transplant recipients, solid organ transplant recipients, patients with hematologic malignancy, and patients with other severe immunologic conditions. In hematopoietic cell transplant recipients, there are 3 phases of risk for invasive fungal infections.Citation6 Phase I is marked by neutropenia and barrier breakdown. In phase II, patients are at risk for invasive fungal infections due to impaired cellular immunity. Although CD8 T cells are increasing postengraftment, specific antifungal T cell immune reconstitution is not complete until months to a year after hematopoietic cell transplantation.Citation39 Acute graft versus host disease and its treatment with corticosteroids are the major contributors to the risk of invasive fungal infection during this phase. In phase III, chronic graft versus host disease and corticosteroid therapy remain significant risk factors for continuing impaired cellular immunity.

Solid organ transplant recipients are at increased risk of invasive fungal infection due to the long-term immunosuppressive therapies that may be required to prevent or treat rejection.Citation40 In solid organ transplantation, periods of infection risk posttransplant have also been noted. During the early posttransplant period (1 to 2 months), Aspergillus pneumonia can occur. Up to 6 months posttransplantation, chronic rejection is a risk factor for invasive fungal infections. Subsequently, beyond six months posttransplantation, the risk is mainly due to residual immunosuppression, exposure to T cell-depleting agents, and graft function.

For patients with hematologic malignancy, the main risk factor is prolonged neutropenia after immunosuppressive chemotherapy, such as induction, reinduction, and consolidation chemotherapy.Citation10,Citation41,Citation42 For critically ill patients, the main risk factors include severe disease and long-term stay in an intensive care unit.Citation20

Risk factors

There are risk factors specific for each invasive fungal infection (). Risk factors for invasive aspergillosis include graft versus host disease, corticosteroids, neutropenia, cytomegalo-virus infection, and prior lung disease. Risk factors for invasive candidiasis include neutropenia, central venous catheter, total parental nutrition, corticosteroids, gastrointestinal surgery, prolonged intensive care stay, and broad spectrum antibiotics. These risk factors relate to impairment of the host immune system, genetic predisposition, and environmental exposure.

Table 2 Risk factors for invasive fungal infections

Host/immune system

It has long been observed that the longer and more profound the neutropenia, the more at risk the patient will be for invasive fungal infections.Citation43 Circulating neutrophils have been demonstrated to have an inverse relationship with prevalence of infections.Citation44,Citation45 The duration of neutropenia was found to be the most important factor, especially when persisting for 3 weeks or more.Citation43,Citation44 In addition to risk for invasive fungal infections, recovery of neutrophil count is important in patient outcomes.

Invasive aspergillosis

One study found that risk factors varied slightly depending on when infection occurred, ie, within 40 days or after 40 days posthematopoietic cell transplantation.Citation46 Risk factors related to the host that were similar for both early and later onset of infection were underlying disease, donor type (autologous < matched-related < matched-unrelated < mismatch-related), and graft versus host disease. There were additional host immune factors found for infection risk 40 days posttransplant, ie, neutropenia and corticosteroid use. However, it is often difficult to determine if the risk of invasive aspergillosis is due to graft versus host disease itself or due to the corticosteroids used to treat the graft versus host disease. Compared with patients who did not have invasive aspergillosis, patients with hematologic malignancy in “non-first remission” were 8.9 times more at risk for onset of infection within 40 days posthematopoietic cell transplantation, and 3.06 times more at risk 40 days posttransplant. Mismatched-related donor hematopoietic cell transplantation has a significantly higher risk in the early posttransplant period, whereas after 40 days, the risk is higher with unrelated donor transplants. For invasive aspergillosis, the presence of graft versus host disease grades 2–4 had a relative risk of 2.6, neutropenia 5.9, and corticosteroid use 3.1.

Other studies have reported similar findings with regard to risk factors for invasive fungal infection.Citation47 Myelodysplastic syndrome compared with other underlying hematologic diseases (including acute myelogenous leukemia, chronic myelogenous leukemia, acute lymphocytic leukemia, and multiple myeloma) and unrelated donor hematopoietic cell transplantation compared with sibling donor transplantation were significant risk factors for invasive fungal infection. Grades 3–4 acute graft versus host disease and extensive chronic graft versus host disease were also found to be significant risk factors.Citation47,Citation48 T cell-depleting therapies (antithymocyte globulin or alemtuzumab) delay immune recovery and also increase the risk of invasive aspergillosis.Citation6,Citation48Citation51

Chronic treatment for graft versus host disease with corticosteroids places hematopoietic cell transplantation recipients at increased risk of infection. Risk was found to be associated with the duration and intensity of the corticosteroid regimen.Citation52 The greatest risk for infection was found to be within 2 weeks of high prednisone-equivalent doses of 1 mg/kg/day or greater. This extended to 4 weeks for doses of 0.25–1 mg/kg/day. Other immunosuppressants, such as daclizumab and infliximab, have been significantly associated with invasive fungal infection.Citation53,Citation54

Cytomegalovirus infection has been associated with risk for invasive fungal infection.Citation49,Citation52 The virus itself is marrow-suppressive, as is the drug therapy commonly used to treat cytomegalovirus, ie, ganciclovir. Cytomegalovirus suppresses cellular and humoral immunity, causes abnormalities in lymphocytes and monocytes, and suppresses antigen-specific cytotoxic T lymphocytes.Citation49 Ganciclovir (an antiviral agent with marrow-suppressive effects) has been associated with a significant risk for invasive aspergillosis, with a hazard ratio of 13.5, even higher than the use of high-dose corticosteroids, graft versus host disease, or neutropenia.Citation52

Genetic predisposition

The study of genetic risk factors as they relate to development of invasive fungal infection is becoming increasingly important to evaluate. This is not only to select those patients who are at high risk for invasive fungal infection for prophylaxis, but to illuminate the immunology and pathophysiology of invasive fungal infections. Invasive aspergillosis has been studied the most in this regard. Polymorphisms in toll-like receptors (TLRs) and tumor necrosis factor (TNF)-α are considered to be one of the more significant genetic factors associated with infection.Citation55,Citation56

TLRs are immune cell surface proteins that recognize fungal pathogens. TLR polymorphisms have been associated with different types of infections.Citation57 Two donor TLR4 haplotypes, S3 and S4, were found to have increased risk for invasive aspergillosis, with hazard ratios of 2.2 and 6.2, respectively.Citation55

TNF-α is secreted by macrophages and activated T lymphocytes during fungal infection.Citation56 TNF-α acts through TNF receptor 1 (TNFR1) to trigger a proinflammatory response. Single nucleotide polymorphisms in the TNFR1 gene have been associated with susceptibility to invasive aspergillosis, with odds ratios of 1.7–1.9. It was demonstrated that significantly lower TNFR1 mRNA expression occurred in patients with invasive aspergillosis compared with noninfected patients with single nucleotide polymorphisms in TNFR1.

Single nucleotide polymorphisms in the proximal region and haplotypes of the interleukin (IL)-10 promoter gene have also been evaluated. IL-10 is a typical Th2 regulator cytokine.Citation58 Increased production of IL-10 has been shown to be associated with invasive aspergillosis. Thus, single nucleotide polymorphisms may affect transcription of IL-10 genes and thus production of IL-10, as would certain haplotypes. One study found an increased incidence of invasive aspergillosis with increased occurrence (11.5–19.7%)Citation58 of single nucleotide polymorphisms, with a hazard ratio of 9.3.

Environmental factors

Environmental factors can play a role in the risk of invasive fungal infection in high-risk patients. In regards to hematopoietic cell transplantation, it was found that transplants that occurred outside laminar air flow rooms had an increased risk of invasive aspergillosis during the early posthematopoietic cell transplantation period, within 40 days after transplant.Citation46 The risk for infection was 5.6 times higher than for transplants occurring within a laminar air flow room. For infections occurring beyond 40 days posttransplant, environmental factors were also found to be significant. This is important because most hematopoietic cell transplant recipients are discharged from the hospital (and their HEPA [Health Enhancing Physical Activity]-filtered environment) by day 40 when they are at high risk for invasive mold infection. Hence, this may explain the peak incidence of invasive aspergillosis that was observed at day 99 in the recent TRANSNET data.Citation2 Construction placed patients at higher risk for infection by 1.8 times.Citation46 Seasonality can also play a role in the risk of invasive fungal infection.Citation46 One study found the summer months to be associated with the highest risk for invasive aspergillosis.Citation59

Invasive candidiasis

Another high-risk group for fungal infections is critically ill patients. These patients are mainly at increased risk of invasive candidiasis. There are multiple risk factors that have been associated with invasive candidiasis, ie, colonization, presence of a central venous catheter, hemodialysis, and surgery, particularly complicated and repeated abdominal surgery.Citation20,Citation60 Patients who are clinically unstable are at increased risk for invasive candidiasis, ie, those with acute renal failure, shock, and disseminated intravascular coagulation.Citation60 Certain medications have been associated with increased risk for candidemia. These include antianerobic antibiotics (2.2 relative risk) such as carbapenems, metronidazole, clindamycin, and piperacillin/tazobactam. However, there was no increased risk with individual antibiotics, such as aminoglycosides, cephalosporins, and quinolones. Of those patients who did not receive an antibacterial antibiotic, none developed candidemia. This is likely related to replacement of the normal gastrointestinal flora with Candida species. Other agents associated with invasive candidiasis are parenteral nutrition and intralipid agents.

Clinical presentation of invasive fungal infections

Manifestations of invasive fungal infection in the immunocompromised host may range from fever of unknown etiology to symptoms and signs referable to a specific organ system affected by the fungal pathogen.Citation61 At the other end of the spectrum are patients with no symptoms or signs, primarily due to the underlying immunosuppression, steroid use, and neutropenia.Citation62,Citation63

Candidemia and visceral (chronic disseminated) candidiasis

Fever persisting despite appropriate empiric antibacterial therapy during neutropenia is one of the most common manifestations of candidemia in immunocompromised patients; up to 88% of episodes in one seriesCitation64 and 99% in another.Citation65 Sepsis syndrome/septic shock can be an initial presentation of candidemia with multiorgan dysfunction. Skin and soft tissue involvement usually manifests as a rash that may have a variable presentation, ranging from maculopapular erythematous to nodular lesions, and may be painful. The lesions may appear similar to ecthyma gangrenosum.Citation66 Muscle pain/myositis may be present. Candida endophthalmitis may be asymptomatic (depending on location of lesions), but may manifest with blurred vision, creamy white retinal lesions that may evolve to retinal necrosis evident on funduscopic examination. Vitritis and uveitis can be seen.Citation67 Cardiac involvement can be in the form of infective endocarditis of a native or prosthetic valve, pericarditis,Citation68 and septic thrombophlebitis, usually in the setting of indwelling central venous catheters.

Candidemia can be associated with dissemination to deep organs causing visceral (chronic disseminated) candidiasis, identified most commonly in the setting of resolving neutropenia after cytotoxic chemotherapy in acute leukemia and hematopoietic cell transplantation. This syndrome is associated with a low yield of fungal isolates on blood culture. With resolution of neutropenia, the patient may present with fever, right upper quadrant pain, palpable tender hepatomegaly, and elevated serum alkaline phosphatase. Diagnosis is often pursued based on a prior episode of documented candidemia. Other organs that are affected include the spleen and kidneys.Citation69 In a prospective study, 2019 episodes of candidemia were identified.Citation21 Distribution of the organs involved in those determined to have disseminated disease were abdomen in 95 (53%), lungs in 17 (9.5%), skin and soft tissue in 14 (7.8%), eyes in nine (5%), heart in seven (3.9%), tracheobronchial tree in seven (3.9%), skeleton in three (1.7%), and central nervous system in two (1.1%). Lung involvement is rare, but is manifested as innumerable nodules on imaging, usually in conjunction with dissemination to other sites, and is mostly asymptomatic. Skeletal involvement can manifest as vertebral osteomyelitis/discitis, and commonly manifests with progressive back pain and a relative lack of constitutional symptoms.Citation70 Central nervous system involvement can be in the form of meningitis or brain abscess.

Invasive mold infections

The most common clinical presentation of invasive mold infection is pneumonia, with Aspergillus species being the leading cause in patients with hematologic malignancy, hematopoietic cell transplantation (especially in association with graft versus host disease and corticosteroid therapy), and solid organ transplantation. The classic symptoms include fever, cough, pleuritic chest pain, and, at times, hemoptysis,Citation61 and on examination there may be a pleural rub. All of these symptoms are rarely present simultaneously. Aspergillus tracheobronchitis is seen more frequently in lung transplant recipients.Citation71 Non-Aspergillus septated mold infections (Scedosporium, Fusarium, and Acremonium species), and Zygomycetes may also present in a similar manner. Invasive sinusitis can manifest as headache/sinus pain, nasal stuffiness with or without discharge, fever, ptosis, proptosis, and cranial nerve deficits. Rapidly progressive disease may be suggestive of zygomycosis. The nasal examination may reveal a grayish discoloration of the mucosa early on, and necrotic turbinates or eschar later on. Intracranial extension of invasive sinusitis can result in central nervous system infection, manifesting as brain abscess, cavernous sinus thrombosis, and meningitis. Central nervous system infection may result from hematogenous dissemination with vascular thrombosis and infarction.Citation72 The angioinvasive molds have a propensity to cause brain abscesses.Citation73 The sudden appearance of mental status changes and/or focal neurologic deficits should alert one to central nervous system involvement. Other manifestations include skin lesions in the setting of disseminated infection (such as Fusarium species, Acremonium species, Aspergillus species, and Zygomycetes), ocular involvement (endophthalmitis with blindness), osteoarticular infections, and uncommonly, gastrointestinal involvement.

Diagnosis

The diagnosis of invasive fungal infections can be challenging, especially when associated with protean manifestations. The European Organization for Research and Treatment of Cancer/Mycoses Study GroupCitation74 diagnostic criteria are used primarily for research purposes, but can be applied in clinical practice. Currently, diagnosis relies upon the presence of risk factors (host characteristics, ie, underlying disease, immunosuppressive regimen, and transplantation), microbiology, serologic testing (AGM and β-1,3-D-glucan assay [BDG]), and imaging. The gold standard for establishing proven infection is to obtain tissue for histologic or cultural confirmation of invasive disease.

Candidemia/visceral candidiasis

Culturing of blood is readily available but lacks sensitivity (ranging between 50% and 70%), which may be enhanced by cell centrifugation. For visceral candidiasis, a high index of clinical suspicion should lead to a diagnostic workup that would include imaging. The yield of a positive blood culture is poor in visceral invasive candidiasis, with candidemia detected in only 20%–30% of cases.Citation70,Citation75 Imaging (computed axial tomography [CT], ultrasonography, and magnetic resonance imaging [MRI])Citation76 can be suggestive of this condition (hypodense lesions in liver, spleen, kidneys, and lungs). The pattern of radiographic abnormality suggesting different stages of infection has been described with ultrasonography, CT, and MRI.Citation77 MRI may be more sensitive than CT for detection of lesions and staging of disease.Citation76 Biopsy of the suspected lesion should be attempted, if feasible, for a definitive diagnosis, although sampling error is possible. BDG is an adjunctive test that can be useful, with sensitivity and specificity reported at >90% in invasive candidiasis.Citation78,Citation79 It can also be positive in a number of other invasive fungal infections (such as aspergillosis and fusariosis). Another issue with BDG is the high rate of false positive results. Various other antibodies and antigens, along with polymerase chain reaction, have been studied but have not been approved for clinical use.

Invasive mold infections

The diagnosis of invasive mold infection can be problematic and is often delayed due to the presence of nonspecific symptoms. CT scan of the chest is often the first diagnostic test, and should be performed promptly in those suspected to have pneumonia due to invasive mold infection. The radiographic appearance can be quite variable, from the solitary nodule with a halo sign to later consolidation (with or without cavitation, air crescent sign).Citation80,Citation81 It can also present just with diffuse infiltrates. The findings in zygomycosis can be similar, with a propensity to invade through the chest wall or extension through fissures. Radiographic findings due to molds other than Aspergillus species and Zygomycetes tend to be similar. Therefore, the specific fungal species causing the infection cannot be determined by radiographic appearance, and there is a need for further evaluation. Bronchoscopy with lavage, serologic testing (AGM, BDG), CT-guided biopsy of infiltrate, and open lung biopsy should be considered in sequence.

CT scan of the paranasal sinuses and orbits should be considered in those presenting with sinonasal symptoms. Endoscopic sinonasal examination with biopsies for microbiologic and histologic examination should be performed as necessary without delay. In situations where central nervous system disease is suspected, CT or MRI of the brain should be obtained, in conjunction with an assessment of the sinuses. The finding of a focal lesion suggestive of abscess or disseminated fungal infection, warrants consideration of a biopsy if feasible, unless there is another site proven to be involved. Cerebrospinal fluid should be sampled (if there are no contraindications) for diagnostic microbiologic, cytologic, antigen, and nucleic acid testing for invasive fungal infection and other opportunistic organisms.

Mold fungemia with positive blood cultures is observed frequently with infection due to Fusarium, Acremonium, and Scedosporium species, but rarely, if ever, with Aspergillus species. Skin is often involved, with multiple painful necrotic lesions, with Fusarium and Acremonium species,Citation82,Citation83 while lesions with Scedosporium are usually painless.

Serologic tests have been an important development as an adjunct in the diagnosis of invasive fungal infections. AGM and BDG have been incorporated into the European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria for diagnosis of fungal infection. The AGM test has low sensitivity in the setting of antimold prophylaxis,Citation84 rendering its utility in acute myelogenous leukemia/myelodysplastic syndrome and hematopoietic cell transplantation uncertain, and therefore cannot be used as a screening test for preemptive therapy. The application of AGM and BDG in the diagnosis of invasive aspergillosis was recently reviewed.Citation85 Polymerase chain reaction for diagnosis of invasive mold infection appears promising, but due to lack of standardization/validation, remains investigational.

Antifungal agents

Systemic antifungal agents available for the treatment of invasive fungal infections include the polyenes, azoles, echinocandins, and flucytosine (). The polyene class includes amphotericin B products.Citation86 Amphotericin B deoxycholate is the oldest, and with infusion-related side effects. Amphotericin B lipid complex, liposomal amphotericin B, and amphotericin B colloidal dispersion are lipid formulations developed in an attempt to decrease these side effects. However, the latter of these agents is used less frequently than the other formulations due to a higher rate of infusion-related reactions than with amphotericin B deoxycholate. Nephrotoxicity is another common adverse effect associated with all amphotericin B products. Their spectrum of activity is broad, and includes Aspergillus species (A. terreus is resistant), Zygomycetes, Candida species, and endemic fungi.Citation87Citation89

Table 3 Antifungal agents: uses, pros, and cons

The azoles used most commonly as systemic therapy in invasive fungal infection include fluconazole, itraconazole, voriconazole, and posaconazole. All azoles have activity against yeast such as Candida species; however, fluconazole has no mold activity.Citation90,Citation91 The azoles with mold activity are active against Aspergillus species. Voriconazole has no activity against Zygomycetes, while posaconazole does have activity against Zygomycetes. The most common adverse effects of azoles are raised hepatic enzymes, QTc prolongation, food-drug interactions, and interactions with concomitant drugs that are substrates for or alter cytochrome P450 isoenzymes.Citation92 Additionally, visual disturbances may occur with voriconazole. Therapeutic drug monitoring of azoles (except for fluconazole, given its limited drug-drug interactions and predictable bioavailability) would be beneficial to ensure adequate serum levels.Citation92Citation95

The echinocandins are the most recent antifungal class, and comprise caspofungin, micafungin, and anidulafungin. These agents have activity against yeasts, such as Candida species, and molds, such as Aspergillus species.Citation96,Citation97 However, activity against other molds, such as Zygomycetes, is lacking, and increased tolerance has been observed with C. parapsilosis and C. guillermondii.Citation18,Citation98 Echinocandins are well tolerated, with few side effects, and they lack renal toxicity. Echinocandins can be used in patients with hepatic impairment (with dose reduction, as for caspofungin).

Flucytosine is an antimetabolite with in vitro activity against a variety of fungi, most notably Candida and Cryptococcus species.Citation99 It is not used as monotherapy because resistance develops readily. Its main use is in combination therapy with amphotericin B for invasive candidiasis and cryptococcosis.

Invasive aspergillosis

Voriconazole has the best clinical activity against Aspergillus and Scedosporium species, and is considered first-line therapy for infections caused by these pathogens.Citation16,Citation91,Citation100 Amphotericin B products can be used as second-line agents in patients who cannot tolerate or are failing voriconazole therapy,Citation101 and echinocandins can be used as alternative or salvage therapy.Citation100,Citation102Citation104

Invasive candidiasis

In severe cases of invasive candidiasis, such as in critically ill patients, amphotericin B products can be used with or without flucytosine.Citation105 Echinocandins are effective against invasive candidiasis and are first-line therapy.Citation97,Citation105 Fluconazole and voriconazole are good choices for invasive candidiasis or stepdown therapy in severe cases of invasive candidiasis or candidemia after treatment with an amphotericin B product or an echinocandin.Citation105

Zygomycosis and other mold infections

Delay in the use of an amphotericin B product up front in zygomycosis has been associated with poor survival outcome.Citation106 Thus, the polyenes should be used first-line in invasive fungal infections caused by zygomycosis or unknown molds, because they have the broadest spectrum of coverage.Citation28 Among the azoles, posaconazole is the only azole having activity against Zygomycetes, and has proven efficacy as salvage therapy for zygomycosis.Citation91,Citation107Citation109

Combination therapy

Data for combination antifungal therapy varies depending on the invasive fungal infection involved. For invasive candidiasis, especially for infections that are deepseated or where penetration may be an issue, such as in the central nervous system or in endocarditis, an amphotericin B product in combination with flucytosine may be used.Citation99,Citation105 This combination allows for synergy, as well as better penetration into the central nervous system, synovial fluid, or valves. Other data suggest that combination of fluconazole and amphotericin B may be a useful alternative.Citation110

For other invasive fungal infections, data come mainly from in vitro studies, animal models, retrospective reviews, and case reports. Combination therapy for invasive aspergillosis is more controversial. Many in vitro and in vivo studies vary in methodology, but do suggest synergistic or additive effects when an echinocandin is combined with an amphotericin B product or an azole.Citation111Citation113 Combinations of amphotericin B and an azole can demonstrate antagonism and clinical failure if amphotericin B is given after itraconazole,Citation114 but also indifferent effects when given concurrently.Citation115,Citation116 Combining three classes (voriconazole, caspofungin, and amphotericin B) has shown variable results, depending on drug concentrations.Citation117,Citation118 Randomized, controlled studies are lacking in the evaluation of combination therapy. However, there is a study currently underway evaluating the clinical efficacy of voriconazole versus voriconazole plus anidulafungin in invasive aspergillosis.

For zygomycosis, data for combination therapy has shown some promise when iron chelators, such as deferiprone and deferasirox, are used in combination with liposomal amphotericin B.Citation119,Citation120 On the other hand, caution must be exercised when using other iron chelators, such as deferoxamine, which has been shown to aggravate zygomycosis by making siderophore iron-feroxamine complexes available to the pathogen.Citation121 A combination of posaconazole and amphotericin B has not demonstrated added benefit.Citation120 Data on combination therapy for other invasive mold infections are even more limited.

Surgical intervention

In certain situations, surgery may be warranted in order to resect the infected focus in invasive mold infection, particularly areas where antifungals have limited penetration. These may include solitary pulmonary lesions, invasion of the chest wall, osteomyelitis, pericardial infection, endocarditis, or fungal balls, such as aspergillomas.Citation100 Other situations where surgical intervention may be necessary include debridement of infected tissues as in rhinosinusitis, cerebral lesions, infected skin and soft tissue, or removal of prosthetic devices, and infected vascular catheters.Citation100,Citation105,Citation122 The latter is particularly important for candidemia. Candida species form a biofilm around catheters, and thus prevent complete eradication by antifungal agents alone and are associated with higher mortality.Citation123,Citation124 Timing of catheter removal, ie, 24 hours versus 48 hours, did not demonstrate significant differences in outcome, but removal versus no removal did.Citation124

Approaches to management

Different approaches have been described for management of invasive fungal infection and have been thoroughly reviewed in the literature, and therefore only a brief summary of these approaches is described here.Citation125,Citation126 These approaches include empiric, “preemptive”, prophylactic, and pathogen-specific therapy.Citation125,Citation126

Empiric therapy is an early approach in patients with febrile neutropenia, which usually entails starting or adjusting antifungal therapy in high-risk patients with unexplained fevers that are persistent or recurrent after 4–7 days of antibiotics.Citation127

The preemptive approach is also an early treatment as empiric therapy. Preemptive therapy has traditionally been applied towards viral infection (ie, cytomegalovirus) where treatment is started for evidence (such as polymerase chain reaction for viral load) of infection (or viremia) before disease onset. However, this is not practical for invasive fungal infection because there is no preemptive test available. That is, there is no diagnostic test that predicts infection ahead of disease. Hence, this approach would be better described as “empiric” or “presumptive”. Instead, it is based on suspicion for an invasive fungal infection that is already established, particularly mold infection.Citation125 Suspicion may include sero-positivity for AGM and supportive radiographic findings for invasive fungal infection in high-risk patients, and thus antimold agents are started.Citation128

Prophylaxis against invasive fungal infection in hematopoietic cell transplant recipients has been shown to improve outcomes, such as decreasing invasive fungal infection rates.Citation5,Citation10,Citation129Citation131 In hematopoietic cell transplantation, only prophylaxis with fluconazole has shown a survival benefit.Citation5,Citation132 Other antifungals have been compared with fluconazole, but none have demonstrated an improved survival benefit over fluconazole in hematopoietic cell transplantation.Citation129,Citation131 However, a survival benefit was demonstrated for posaconazole prophylaxis in neutropenic patients undergoing chemotherapy for acute myelogenous leukemia or myelo-dysplastic syndrome.Citation10

Finally, from a practical point of view, the identity of the specific pathogen is rarely known. Therefore, a directed empirical approach to therapy should be employed using all the currently available information.Citation125 When invasive candidiasis is suspected, the choice of antifungal agent depends on the current clinical presentation of the patient, such as hemodynamic stability, prior antifungal exposure, and resistance patterns at a particular institution. One may choose an azole, echinocandin, or amphotericin B product ± flucytosine depending on the likelihood of an azole-resistant or echinocandin-resistant isolate and the risk of not adequately covering the pathogen. For suspicion of invasive mold infection, similar consideration can also determine the choice of antifungal. Choice can depend on the clinical presentation of the patient and likely focus of infection based on symptoms and radiographic data, prior prophylactic therapy, serology, and microbiologic/cytologic/histologic results. Most importantly, the choice of an antifungal agent will depend on whether one can exclude or confirm the diagnosis of zygomycosis.

Future horizons

New drugs and formulations

A number of new antifungal agents are examined each year. Most are studied in vitro or in animal models. However, none are in the immediate clinical pipeline. New echinocandins and azoles are being developed, such as enfumafungin and isavuconazole.Citation133,Citation134 There are also new antifungals with novel mechanisms of action. One example is E1210, a broad spectrum inhibitor of glycosylphosphatidylinositol biosynthesis.Citation135 It was found to inhibit fungal growth and biofilm formation, suppress some virulence factors in C. albicans, and have in vitro activity against A. fumigatus.Citation136 Another novel antifungal class includes FG3409, a small molecule antifungal with a proprietary “novel mechanism of action”. It was found to reduce tissue burden in a murine model of disseminated invasive aspergillosis with greater potency than the azoles and amphotericin B in vitro.Citation137 It also demonstrated greater potency than posaconazole or voriconazole against Scedosporium species, including S. prolificans, which is often resistant to current commercially available antifungals.Citation138 Other novel classes include phosphoinositide-dependent kinase 1 inhibitors which target the cell wall integrity signaling pathway,Citation139 and others that synergize with azoles. These include histone deacetylase inhibitors, which modulate genes involved in cell wall integrity,Citation140 and type II topoisomerase inhibitors.Citation141 In addition to new classes of antifungals, novel drug delivery technology has been applied to conventional antifungals, such as itraconazole. A nano-suspension formulation demonstrated improved itraconazole activity and less toxicity by eliminating its cardiac inotropic effects.Citation142 A new solid oral formulation of posaconazole with improved oral bioavailability over the current oral solution is currently under investigation.

Immunotherapy and vaccines

Despite the development of more active and less toxic antifungal agents, mortality rates for invasive fungal infection remain unacceptably high. There is a need for different approaches to both treatment and prevention. Recent efforts have focused on immunotherapy and vaccines.Citation143

In general, the primary protective defense mechanism against invasive fungal infection is T cell-mediated immunity, specifically, a robust Th1 response to fungal antigens.Citation144 In the immunocompromised host at risk of invasive fungal infection, T cell immunity is compromised due to a number of factors, including corticosteroid therapy. Cenci et al first demonstrated that passively transferred Aspergillus-specific Th1-committed CD4+ T cells could protect animals against invasive aspergillosis.Citation145 Beck et al has shown that Aspergillus-specific CD4+ T cells can be identified and expanded ex vivo to adequate numbers for infusion into patients.Citation146 Recently, Perruccio et al demonstrated use of Aspergillus-specific immunotherapy in hematopoietic cell transplantation that provided rapid immune recovery.Citation147

Vaccination to prevent invasive fungal infection in the immunocompromised host is a relatively new concept. It was not even attempted because of the assumption that severely immunocompromised patients (eg, hematopoietic cell transplantation recipients) cannot be vaccinated effectively within a year after their transplant.Citation39,Citation147 However, it was demonstrated in an animal model that a crude Aspergillus vaccine administered before immunosuppression (neutropenia or corticosteroid therapy) protected against subsequent invasive aspergillosis.Citation145,Citation148 Efforts are now focused on identifying epitope(s) with T cell immunogenic and protective properties. Also, work on adjuvantsCitation149 and dendritic cell vaccinationCitation150 have demonstrated promising results. Finally, there have been efforts toward developing Candida vaccines, and these has been thoroughly reviewed recently.Citation151

Conclusion

Over the past 20 years, the number of invasive fungal infections has continued to persist, due primarily to the increased numbers of patients we subject to severe immunosuppression. Despite the development of more active and less toxic anti-fungal agents and the standard use of antifungal prophylaxis, invasive fungal infection (especially invasive mold infection) continues to be a significant factor in hematopoietic cell and solid organ transplantation outcomes, resulting in high mortality rates. Since the advent of fluconazole as standard prophylaxis in the hematopoietic cell transplant setting, invasive candidiasis has come under control, but no mold-active antifungal agent (except for posaconazole in the acute myelogenous leukemia/myelodysplastic syndrome setting) has been shown to improve on the survival rate over fluconazole. With the introduction of new azole and echinocandin agents, we have seen the emergence of more azole-resistant and echinocandin-resistant fungi. The recent increase in zygomycosis seen in the hematopoietic cell transplant setting may be due to the increased use of voriconazole. This has implications for the empiric approach to pulmonary invasive mold infection when zygomycosis cannot be ruled out. It is imperative that an amphotericin B product, an antifungal that in over 50 years has never developed resistance, be initiated.

The clinical presentations of invasive mold infection and invasive candidiasis can be nonspecific and the diagnostic tests insensitive, so a high index of suspicion and immediate initiation of empiric therapy is required. Unfortunately, our currently available serologic tests do not predict infection ahead of disease, and, therefore, cannot be used to initiate “preemptive” therapy. Furthermore, the AGM test gives a false negative result in patients receiving antimold prophylaxis, ie, virtually all of our patients with hematologic malignancy and hematopoietic cell transplant recipients. We may eventually be able to select patients at highest risk for invasive fungal infections for prophylaxis by genetic testing. However, with our current armamentarium of antifungal agents and widespread use of prophylaxis in high-risk groups (hematologic malignancy, hematopoietic cell transplantation), we continue to see high incidence and mortality rates, and our future hope lies in reversing immunosuppression or augmenting the immune system in these severely immunocompromised hosts by developing and utilizing immunotherapy, immunoprophylaxis, and vaccines.

Disclosure

JII reports participating on speaker’s bureaus for Astellas, Merck, and Pfizer, and consulting for Sigma Tau. JK and SSD have no potential conflict of interest to report.

References

  • BaddleyJWAndesDRMarrKAFactors associated with mortality in transplant patients with invasive aspergillosisClin Infect Dis201050121559156720450350
  • KontoyiannisDPMarrKAParkBJProspective surveillance for invasive fungal infections in hematopoietic stem cell transplant recipients, 2001–2006: Overview of the Transplant-Associated Infection Surveillance Network (TRANSNET) DatabaseClin Infect Dis20105081091110020218877
  • ParkBJPappasPGMarrKARecent epidemiology of zygomycosis among organ transplant and stem cell transplant recipients: Results from the TRANSNET surveillance networkAbstract M-618 presented at the 47th Interscience Conference on Antimicrobial Agents and ChemotherapyChicago, ILSeptember 17–20, 2007
  • PappasPGAlexanderBDAndesDRInvasive fungal infections among organ transplant recipients: Results of the Transplant-Associated Infection Surveillance Network (TRANSNET)Clin Infect Dis20105081101111120218876
  • SlavinMAOsborneBAdamsREfficacy and safety of fluconazole prophylaxis for fungal infections after marrow transplantation – a prospective, randomized, double-blind studyJ Infect Dis19951716154515527769290
  • TomblynMChillerTEinseleHGuidelines for preventing infectious complications among hematopoietic cell transplantation recipients: A global perspectiveBiol Blood Marrow Transplant200915101143123819747629
  • MarrKACarterRACrippaFWaldACoreyLEpidemiology and outcome of mould infections in hematopoietic stem cell transplant recipientsClin Infect Dis200234790991711880955
  • BraymanKLStephanianEMatasAJAnalysis of infectious complications occurring after solid-organ transplantationArch Surg1992127138471734849
  • PayaCVFungal infections in solid-organ transplantationClin Infect Dis19931656776888507760
  • CornelyOAMaertensJWinstonDJPosaconazole vs fluconazole or intraconazole prophylaxis in patients with neutropeniaN Engl J Med2007356434835917251531
  • MattiuzziGNKantarjianHFaderlSAmphotericin B lipid complex as prophylaxis of invasive fungal infections in patients with acute myelogenous leukemia and myelodysplastic syndrome undergoing induction chemotherapyCancer2004100358158914745876
  • VreugdenhilGVan DijkeBJDonnellyJPEfficacy of itraconazole in the prevention of fungal infections among neutropenic patients with hematologic malignancies and intensive chemotherapy. A double blind, placebo controlled studyLeuk Lymphoma1993115–63533588124207
  • MenichettiFDel FaveroAMartinoPItraconazole oral solution as prophylaxis for fungal infections in neutropenic patients with hematologic malignancies: A randomized, placebo-controlled, double-blind, multicenter trial. GIMEMA Infection Program. Gruppo Italiano Malattie Ematologiche dell’ AdultoClin Infect Dis199928225025510064240
  • LehrnbecherTFrankCEngelsKKrienerSGrollAHSchwabeDTrends in the postmortem epidemiology of invasive fungal infections at a university hospitalJ Infect201061325926520624423
  • VincentJLRelloJMarshallJInternational study of the prevalence and outcomes of infection in intensive care unitsJAMA2009302212323232919952319
  • HerbrechtRDenningDWPattersonTFBennettJEGreeneREVoriconazole versus amphotericin B for primary therapy of invasive aspergillosisN Engl J Med2002347640841512167683
  • SteinbachWJBenjaminDKJrKontoyiannisDPInfections due to Aspergillus terreus: A multicenter retrospective analysis of 83 casesClin Infect Dis200439219219815307028
  • PfeifferCDGarcia-EffronGZaasAKPerfectJRPerlinDSAlexanderBDBreakthrough invasive candidiasis in patients on micafunginJ Clin Microbiol20104872373238020421445
  • VazquezJAInvasive fungal infections in the intensive care unitSemin Respir Crit Care Med2010311798620101550
  • ArendrupMCEpidemiology of invasive candidiasisCurr Opin Crit Care201016544545220711075
  • HornDLNeofytosDAnaissieEJEpidemiology and outcomes of candidemia in 2019 patients: Data from the prospective antifungal therapy alliance registryClin Infect Dis200948121695170319441981
  • HidronAIEdwardsJRPatelJNHSN annual update: Antimicrobial-resistant pathogens associated with healthcare-associated infections: Annual summary of data reported to the National Healthcare Safety Network at the Centers for Disease Control and Prevention, 2006–2007Infect Control Hosp Epidemiol20082911996101118947320
  • NeumannPRRakowerSRThe risk of positive cultures for Candida in the critically ill patientCrit Care Med1978627376639536
  • KettDHAzoulayEEcheverriaPMVincentJLCandida bloodstream infections in intensive care units: Analysis of the extended prevalence of infection in a intensive care unit studyCrit Care Med12162010 [Epub ahead of print].
  • NeofytosDHornDAnaissieEEpidemiology and outcome of invasive fungal infection in adult hematopoietic stem cell transplant recipients: Analysis of Multicenter Prospective Antifungal Therapy (PATH) Alliance registryClin Infect Dis200948326527319115967
  • AmbrosioniJBouchuiguir-WafaKGarbinoJEmerging invasive zygomycosis in a tertiary care center: Epidemiology and associated risk factorsInt J Infect Dis201014Suppl 3e100e10320335060
  • TrifilioSSinghalSWilliamsSBreakthrough fungal infections after allogeneic hematopoietic stem cell transplantation in patients on prophylactic voriconazoleBone Marrow Transplant200740545145617589527
  • TrifilioSMBennettCLYarnoldPRBreakthrough zygomycosis after voriconazole administration among patients with hematologic malignancies who receive hematopoietic stem-cell transplants or intensive chemotherapyBone Marrow Transplant200739742542917310132
  • SuzukiKSugawaraYSekineTNakaseKKatayamaNBreakthrough disseminated zygomycosis induced massive gastrointestinal bleeding in a patient with acute myeloid leukemia receiving micafunginJ Infect Chemother2009151424519280300
  • Espinel-IngroffAMechanisms of resistance to antifungal agents: Yeasts and filamentous fungiRev Iberoam Micol2008252101106 Spanish.18473504
  • Chapeland-LeclercFHennequinCPaponNAcquisition of flucytosine, azole, and caspofungin resistance in Candida glabrata bloodstream isolates serially obtained from a hematopoietic stem cell transplant recipientAntimicrob Agents Chemother20105431360136220038613
  • LawDMooreCBWardleHMGanguliLAKeaneyMGDenningDWHigh prevalence of antifungal resistance in Candida spp. from patients with acquired immunodeficiency syndromeJ Antimicrob Chemother19943456596687706161
  • WestbrookSDWiederholdNPVallorACLoss of in vitro resistance in Candida glabrata following discontinuation of fluconazole prophylaxis in a hematopoietic stem cell transplantation patientMed Mycol201048355756020370365
  • LaverdièreMLalondeRGBarilJGSheppardDCParkSPerlinDSProgressive loss of echinocandin activity following prolonged use for treatment of Candida albicans oesophagitisJ Antimicrob Chemother200657470570816464893
  • MelladoEGarcia-EffronGAlcazar-FuoliLA new Aspergillus fumigatus resistance mechanism conferring in vitro cross-resistance to azole antifungals involves a combination of cyp51A alterationsAntimicrob Agents Chemother20075161897190417371828
  • RajendranRMowatEMcCullochEAzole resistance of Aspergillus fumigatus biofilms is partly associated with efflux pump activityAntimicrob Agents Chemother2142011 [Epub ahead of print].
  • HowardSJCerarDAndersonMJFrequency and evolution of azole resistance in Aspergillus fumigatus associated with treatment failureEmerg Infect Dis20091571068107619624922
  • SchelenzSAbdallahSGrayGEpidemiology of oral yeast colonization and infection in patients with hematological malignancies, head neck and solid tumorsJ Oral Pathol Med2011401838920923440
  • StorekJDawsonMALimLCEfficacy of donor vaccination before hematopoietic cell transplantation and recipient vaccination both before and early after transplantationBone Marrow Transplant200433333734614647254
  • FishmanJAIssaNCInfection in organ transplantation: Risk factors and evolving patterns of infectionInfect Dis Clin North Am201024227328320466270
  • EgererGGeistMJPosaconazole prophylaxis in patients with acute myelogenous leukaemia – results from an observational studyMycoses201154Suppl 171121126266
  • OraschCWeisserMMertzDComparison of infectious complications during induction/consolidation chemotherapy versus allogeneic hematopoietic stem cell transplantationBone Marrow Transplant201045352152619668238
  • BodeyGPInfectious complications of acute leukemiaMed Times1966949107610855946471
  • PaganoLAkovaMDimopoulosGHerbrechtRDrgonaLBlijlevensNRisk assessment and prognostic factors for mould-related diseases in immunocompromised patientsJ Antimicrob Chemother201166Suppl 1514
  • PortugalRDGarnicaMNucciMIndex to predict invasive mold infection in high-risk neutropenic patients based on the area over the neutrophil curveJ Clin Oncol200927233849385419597026
  • WaldALeisenringWvan BurikJABowdenRAEpidemiology of Aspergillus infections in a large cohort of patients undergoing bone marrow transplantationJ Infect Dis19971756145914669180187
  • JantunenERuutuPNiskanenLIncidence and risk factors for invasive fungal infections in allogeneic BMT recipientsBone Marrow Transplant19971988018089134172
  • Van BurikJACarterSLFreifeldAGHigher risk of cytomegalovirus and aspergillus infections in recipients of T cell-depleted unrelated bone marrow: Analysis of infectious complications in patients treated with T cell depletion versus immunosuppressive therapy to prevent graft-versus-host diseaseBiol Blood Marrow Transplant200713121487149818022579
  • De La RosaGRChamplinREKontoyiannisDPRisk factors for the development of invasive fungal infections in allogeneic blood and marrow transplant recipientsTranspl Infect Dis2002413912123420
  • SchmeiserTWiesnethMBunjesDInfectious complications after allogeneic bone marrow transplantation with and without T-cell depletion of donor marrowInfection19891731241302661437
  • PirschJDMakiDGInfectious complications in adults with bone marrow transplantation and T-cell depletion of donor marrow. Increased susceptibility to fungal infectionsAnn Intern Med198610456196313516042
  • ThurskyKByrnesGGriggASzerJSlavinMRisk factors for post-engraftment invasive aspergillosis in allogeneic stem cell transplantationBone Marrow Transplant200434211512115156166
  • LabbeACSuSHLaverdiereMHigh incidence of invasive aspergillosis associated with intestinal graft-versus-host disease following nonmyeloablative transplantationBiol Blood Marrow Transplant200713101192120017889356
  • AldersonJWVan DinterTGJrOpatowskyMJBurtonECDisseminated aspergillosis following infliximab therapy in an immunosuppressed patient with Crohn’s disease and chronic hepatitis C: A case study and review of the literatureMed Gen Med2005737
  • BochudPYChienJWMarrKAToll-like receptor 4 polymorphisms and aspergillosis in stem-cell transplantationN Engl J Med2008359171766177718946062
  • SainzJSalas-AlvaradoILopez-FernandezETNFR1 mRNA expression level and TNFR1 gene polymorphisms are predictive markers for susceptibility to develop invasive pulmonary aspergillosisInt J Immunopathol Pharmacol201023242343620646338
  • CarvalhoACunhaCCarottiAPolymorphisms in Toll-like receptor genes and susceptibility to infections in allogeneic stem cell transplantationExp Hematol20093791022102919539691
  • SeoKWKimDHSohnSKProtective role of interleukin-10 promoter gene polymorphism in the pathogenesis of invasive pulmonary aspergillosis after allogeneic stem cell transplantationBone Marrow Transplant200536121089109516247433
  • PanackalAALiHKontoyiannisDPGeoclimatic influences on invasive aspergillosis after hematopoietic stem cell transplantationClin Infect Dis201050121588159720450414
  • BlumbergHMJarvisWRSoucieJMRisk factors for candidal bloodstream infections in surgical intensive care unit patients: The NEMIS prospective multicenter study. The National Epidemiology of Mycosis SurveyClin Infect Dis200133217718611418877
  • SegalBHAspergillosisN Engl J Med2009360181870188419403905
  • BodeyGBueltmannBDuguidWFungal infections in cancer patients: An international autopsy surveyEur J Clin Microbiol Infect Dis1992112991091396746
  • SicklesEAGreeneWHWiernikPHClinical presentation of infection in granulocytopenic patientsArch Intern Med197513557157191052668
  • ViscoliCGirmeniaCMarinusACandidemia in cancer patients: A prospective, multicenter surveillance study by the Invasive Fungal Infection Group (IFIG) of the European Organization for Research and Treatment of Cancer (EORTC)Clin Infect Dis19992851071107910452637
  • PaganoLAntinoriAAmmassariARetrospective study of candidemia in patients with hematological malignancies. Clinical features, risk factors and outcome of 76 episodesEur J Haematol1999632778510480286
  • FineJDMillerJAHarristTJHaynesHACutaneous lesions in disseminated candidiasis mimicking ecthyma gangrenosumAm J Med1981705113311357234879
  • KanskiJPavesioCTuftSEndophthalmitisOcular Inflammatory DiseasePhiladelphia, PAElsevier2006
  • RabinoviciRSzewczykDOvadiaPGreenspanJRSivalingamJJCandida pericarditis: Clinical profile and treatmentAnn Thorac Surg1997634120012049124944
  • PaganoLMeleLFianchiLChronic disseminated candidiasis in patients with hematologic malignancies. Clinical features and outcome of 29 episodesHaematologica200287553554112010669
  • MillerDJMejicanoGCVertebral osteomyelitis due to Candida species: Case report and literature reviewClin Infect Dis200133452353011462190
  • SinghNHusainSAspergillus infections after lung transplantation: Clinical differences in type of transplant and implications for managementJ Heart Lung Transplant200322325826612633692
  • Kleinschmidt-DeMastersBKCentral nervous system aspergillosis: A 20-year retrospective seriesHum Pathol200233111612411823982
  • WalshTJHierDBCaplanLRFungal infections of the central nervous system: comparative analysis of risk factors and clinical signs in 57 patientsNeurology19853511165416574058755
  • De PauwBWalshTJDonnellyJPRevised Definitions of Invasive Fungal Disease from the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) Consensus GroupClin Infect Dis200846121813182118462102
  • AnaissieEBodeyGPKantarjianHFluconazole therapy for chronic disseminated candidiasis in patients with leukemia and prior amphotericin B therapyAm J Med19919121421501867240
  • SamuelsBIPaganiJJLibshitzHIRadiographic features of candida infectionsBodeyGPCandidiasis: Pathogenesis, Diagnosis and TreatmentsNew York, NYRaven Press1993
  • SemelkaRCShoenutJPGreenbergHMBowEJDetection of acute and treated lesions of hepatosplenic candidiasis: Comparison of dynamic contrast-enhanced CT and MR imagingJ Magn Reson Imaging1992233413451627870
  • SemelkaRCKelekisNLSallahSWorawattanakulSAscherSMHepatosplenic fungal disease: Diagnostic accuracy and spectrum of appearances on MR imagingAJR Am J Roentgenol19971695131113169353448
  • Ostrosky-ZeichnerLAlexanderBDKettDHMulticenter clinical evaluation of the (1 ≥ 3) beta-D-glucan assay as an aid to diagnosis of fungal infections in humansClin Infect Dis200541565465916080087
  • LoganPMPrimackSLMillerRRMullerNLInvasive aspergillosis of the airways: Radiographic, CT, and pathologic findingsRadiology199419323833887972747
  • KuhlmanJEFishmanEKSiegelmanSSInvasive pulmonary aspergillosis in acute leukemia: Characteristic findings on CT, the CT halo sign, and the role of CT in early diagnosisRadiology198515736116143864189
  • NucciMAnaissieECutaneous infection by Fusarium species in healthy and immunocompromised hosts: Implications for diagnosis and managementClin Infect Dis200235890992012355377
  • KrcmeryVJrKunovaEJesenskaZInvasive mold infections in cancer patients: 5 years’ experience with Aspergillus, Mucor, Fusarium and Acremonium infectionsSupport Care Cancer19964139458771293
  • MarrKALaverdiereMGugelALeisenringWAntifungal therapy decreases sensitivity of the Aspergillus galactomannan enzyme immunoassayClin Infect Dis200540121762176915909264
  • WheatLJApproach to the diagnosis of invasive aspergillosis and candidiasisClin Chest Med2009302367377viii19375641
  • Wong-BeringerAJacobsRAGuglielmoBJLipid formulations of amphotericin B: Clinical efficacy and toxicitiesClin Infect Dis19982736036189770163
  • MesserSAMoetGJKirbyJTJonesRNActivity of contemporary antifungal agents, including the novel echinocandin anidulafungin, tested against Candida spp., Cryptococcus spp., and Aspergillus spp.: Report from the SENTRY Antimicrobial Surveillance Program (2006 to 2007)J Clin Microbiol20094761942194619386851
  • DannaouiEMeletiadisJMoutonJWMeisJFVerweijPEEurofung Network. In vitro susceptibilities of zygomycetes to conventional and new antifungalsJ Infect Dis20035114552
  • BaddleyJWMarrKAAndesDRPatterns of susceptibility of Aspergillus isolates recovered from patients enrolled in the Transplant-Associated Infection Surveillance NetworkJ Clin Microbiol200947103271327519692558
  • PfallerMAZhangJMesserSAIn vitro activities of voriconazole, fluconazole, and itraconazole against 566 clinical isolates of Cryptococcus neoformans from the United States and AfricaAntimicrob Agents Chemother19994311691709869586
  • DiekemaDMesserSAHollisRJJonesRNPfallerMAActivities of caspofungin, itraconazole, posaconazole, ravuconazole, voricaonzole, and amphotericin B against 448 recent clinical isolates of filamentous fungiJ Clin Microbiol20034183623362612904365
  • Dodds AshleyESLewisRLewisJSMarinCAndesDPharmacology of systemic antifungal agentsClin Infect Dis200643SupplS28S39
  • TrifilioSOrtizRPennickGVoriconazole therapeutic drug monitoring in allogeneic hematopoietic stem cell transplant recipientsBone Marrow Transplant200535550951315654347
  • SummersKKHardinTCGoreSJGraybillJRTherapeutic drug monitoring of systemic antifungal therapyJ Antimicrob Chemother19974067537649462426
  • PascualACalandraTBolaySBuclinTBilleJMarchettiOVoriconazole therapeutic drug monitoring in patients with invasive mycoses improves efficacy and safety outcomesClin Infect Dis200846220121118171251
  • Mora-DuarteJBettsRRotsteinCComparison of caspofungin and amphotericin B for invasive candidiasisN Engl J Med2002347252020202912490683
  • PappasPGRotsteinCMBettsRFMicafungin versus caspofungin for treatment of candidemia and other forms of invasive candidiasisClin Infect Dis200745788389317806055
  • MooreCBDenningDWTolerance and fungicidality in vitro of caspofungin, micafungin and anidulafungin against Candida guilliermondiiAbstract M-230 presented at the 42nd Annual Interscience Conference on Antimicrobial Agents and ChemotherapySeptember 27–30, 2002San Diego, CA
  • ThompsonGR3rdCadenaJPattersonTFOverview of antifungal agentsClin Chest Med2009302203215v19375628
  • WalshTJAnaissieEJDenningDWTreatment of aspergillosis: Clinical practice guidelines of the Infectious Diseases Society of AmericaClin Infect Dis20084632760
  • WalshTJRaadIPattersonTFTreatment of invasive aspergillosis with posaconazole in patients who are refractory to or intolerant of conventional therapy: An externally controlled trialClin Infect Dis200744121217143808
  • DenningDWMarrKALauWMMicafungin (FK463), alone or in combination with other systemic antifungal agents, for the treatment of acute invasive aspergillosisJ Infect200653533734916678903
  • BettsRGlasmacherAMaertensJEfficacy of caspofungin against invasive Candida or invasive Aspergillus infections in neutropenic patientsCancer2006106246647316353208
  • MaertensJRaadIPetrikkosGEfficacy and safety of caspofungin for treatment of invasive aspergillosis in patients refractory to or intolerant of conventional antifungal therapyClin Infect Dis200439111563157115578352
  • PappasPGKauffmanCAAndesDClinical practice guidelines for the management of candidiasis: 2009 update by the Infectious Diseases Society of AmericaClin Infect Dis200948550353519191635
  • ChamilosGLewisREKontoyiannisDPDelaying amphotericin B-based frontline therapy significantly increases mortality among patients with hematologic malignancy who have zygomycosisClin Infect Dis200847450350918611163
  • ManavathuEKCutrightJLChandrasekarPHOrganism-dependent fungicidal activities of azolesAntimicrob Agents Chemother19984211301830219797246
  • Lass-FlorlCMayrAPerkhoferSActivities of antifungal agents against yeasts and filamentous fungi: Assessment according to the Methodology of the European Committee on Antimicrobial Susceptibility TestingAntimicrob Agents Chemother200852103637364118694949
  • Van BurikJAHareRSSolomonHFCorradoMLKontoyiannisDPPosaconazole is effective as salvage therapy in zygomycosis: A retrospective summary of 91 casesClin Infect Dis2006427e61e6516511748
  • RexJHPappasPGKarchmerAWA randomized and blinded multicenter trial of high-dose fluconazole plus placebo versus fluconazole plus amphotericin B as therapy for candidemia and its consequences in nonneutropenic subjectsClin Infect Dis200336101221122812746765
  • MarrKABoeckhMCarterRAKimHWCoreyLCombination antifungal therapy for invasive aspergillosisClin Infect Dis200439679780215472810
  • CaillotDThiebautAHerbrechtRLiposomal amphotericin B in combination with caspofungin for invasive aspergillosis in patients with hematologic malignancies: A randomized pilot study (Combistrat trial)Cancer2007110122740274617941026
  • Cuenca-EstrellaMGomez-LopezAGarcia-EffronGCombined activity in vitro of caspofungin, amphotericin B, and azole agents against itraconazole-resistant clinical isolates of Aspergillus fumigatusAntimicrob Agents Chemother20054931232123515728937
  • SchaffnerAAnnetteBAmphotericin B refractory aspergillosis after itraconazole: Evidence for significant antagonismMycoses19933611–124214247935575
  • PoppAIWhiteMHQuadriTWalsheLArmstrongDAmphotericin B with and without itraconazole for invasive aspergillosis: A three-year retrospective studyInt J Infect Dis19993315716010460928
  • ChandrasekarPHCutrightJLManavathuEKEfficacy of voriconazole plus amphotericin B or micafungin in a guinea-pig model of invasive pulmonary aspergillosisClin Microbiol Infect2004101092592815373889
  • O’ShaughnessyEMMeletiadisJStergiopoulouTDemchokJPWalshTJAntifungal interactions within the triple combination of amphotericin B, caspofungin and voriconazole against Aspergillus speciesJ Antimicrob Chemother20065861168117617071635
  • MeletiadisJStergiopoulouTO’ShaughnessyEMPeterJWalshTJConcentration-dependent synergy and antagonism within a triple antifungal drug combination against Aspergillus species: Analysis by a new response surface modelAntimicrob Agents Chemother20075162053206417387150
  • IbrahimASEdwardsJEJrFuYSpellbergBDeferiprone iron chelation as a novel therapy for experimental mucormycosisJ Antimicrob Chemother20065851070107316928702
  • SpellbergBWalshTJKontoyiannisDPEdwardsJJrIbrahimASRecent advances in the management of mucormycosis: From bench to bedsideClin Infect Dis200948121743175119435437
  • BoelaertJRde LochtMVan CutsemJMucormycosis during deferoxamine therapy is a siderophore-mediated infection. In vitro and in vivo animal studiesJ Clin Invest1993915197919868486769
  • KasapogluFCoskunHOzmenOAAkalinHEnerBAcute invasive fungal rhinosinusitis: Evaluation of 26 patients treated with endonasal or open surgical proceduresOtolaryngol Head Neck Surg2010143561462020974328
  • TumbarelloMPosteraroBTrecarichiEMBiofilm production by Candida species and inadequate antifungal therapy as predictors of mortality for patients with candidemiaJ Clin Microbiol20074561843185017460052
  • NucciMAnaissieEBettsRFEarly removal of central venous catheter in patients with candidemia does not improve outcome: Analysis of 842 patients from 2 randomized clinical trialsClin Infect Dis201051329530320578829
  • ItoJIKriengkauykiatJDadwalSSArfonsLMLazarusHMApproaches to the early treatment of invasive fungal infectionLeuk Lymphoma20105191623163120629521
  • MichalletMItoJIApproaches to the management of invasive fungal infections in hematologic malignancy and hematopoietic cell transplantationJ Clin Oncol200927203398340919487382
  • FreifeldAGBowEJSepkowitzKAClinical practice guideline for the use of antimicrobial agents in neutropenic patients with cancer: 2010 update by the Infectious Diseases Society of AmericaClin Infect Dis2011524e56e9321258094
  • MaertensJTheunissenKLodewyckTLagrouKVan EldereJAdvances in the serological diagnosis of invasive Aspergillus infections in patients with haematological disordersMycoses200750Suppl 121717394605
  • UllmannAJLiptonJHVesoleDHPosaconazole or fluconazole for prophylaxis in severe graft-versus-host diseaseN Engl J Med2007357433534717251530
  • MarrKACrippaFLeisenringWItraconazole versus fluconazole for prevention of fungal infections in patients receiving allogeneic stem cell transplantsBlood200410341527153314525770
  • Van BurikJARatanatharathornVStepanDEMicafungin versus fluconazole for prophylaxis against invasive fungal infections during neutropenia in patients undergoing hematopoietic stem cell transplantationClin Infect Dis200439101407141615546073
  • MarrKASeidelKSlavinMAProlonged fluconazole prophylaxis is associated with persistent protection against candidiasis-related death in allogeneic marrow transplant recipients: Long-term follow-up of a randomized, placebo-controlled trialBlood20009662055206110979947
  • PeelMMamaiAFanWNew beta-1,3-glucan synthase (GS) inhibitors with potent antifungal activityAbstract presented at the 49th Interscience Conference on Antimicrobial Agents and ChemotherapySan Francisco, CASeptember 12–15, 2009
  • PerkhoferSLechnerVLass-FlorlCIn vitro activity of isavuconazole against Aspergillus species and zygomycetes according to the methodology of the European Committee on Antimicrobial Susceptibility TestingAntimicrob Agents Chemother20095341645164719164153
  • WatanabeNHoriiTMiyazakiMHataKE1210, a new broad-spectrum antifungal, inhibits glycosylphosphatidylinositol (GPI) biosynthesis and effects Candida albicans cell characteristicsAbstract F1-841 presented at the 50th Interscience Conference on Antimicrobial Agents and ChemotherapyBoston, MASeptember 12–15, 2010
  • MiyazakiMHoriiTHataKWatanabeNIn vitro antifungal activity of E1210: A novel antifungal with activity against clinically important yeasts and mouldsAbstract F1-840 presented at the 50th Interscience Conference on Antimicrobial Agents and ChemotherapyBoston, MASeptember 12–15, 2010
  • WarnPASharpAGouldJEfficacy of FG3409 a new antifungal agent, in reducing tissue burden in murine models of disseminated aspergillosisAbstract F1-1182 presented at the 48th Interscience Conference on Antimicrobial Agents and ChemotherapyWashington, DCOctober 25–28, 2008
  • LawDFothergrillAWChenSCSorrellTCBirchMThe activity of FG3622 and FG3409 against Scedosporium sppAbstract F1-858 presented at the 50th Interscience Conference on Antimicrobial Agents and ChemotherapyBoston, MASeptember 12–15, 2010
  • KrysanDBaxterBKDidoneLPhosphoinositide-dependent kinase 1 (PDK1) inhibitors are a novel class of cell wall-targeted antifungal small moleculesAbstract F1-859 presented at the 50th Interscience Conference on Antimicrobial Agents and ChemotherapyBoston, MASeptember 12–15, 2010
  • NguyenDLiJAkacheBMGCD290: A novel small molecule, modulates azole antifungal activity through specific inhibition of the histone deacetylase HOS2Abstract M-1919 presented at the 49th Interscience Conference on Antimicrobial Agents and ChemotherapySan Francisco, CASeptember 12–15, 2009
  • Krishnan-NatesanSSwaminathanSChandrasekarPExtended spectrum triazole plus type II topoisomerase inhibitor (TI) against azole-resistant (R) isolates of Aspergillus: Synergistic interaction in vitroAbstract M-396 presented at 50th Interscience Conference on Antimicrobial Agents and ChemotherapyBoston, MASeptember 12–15, 2010
  • McKeeJRabinowBCookCGassJNanosuspension formulation of itraconazole eliminates the negative inotropic effect of Sporanox in dogsJ Med Toxicol20106333133620238196
  • SegalBHKwon-ChungJWalshTJImmunotherapy for fungal infectionsClin Infect Dis200642450751516421795
  • RomaniLCell mediated immunity to fungi: A reassessmentMed Mycol200846651551919180748
  • CenciEMencacciABacciABistoniFKurupVPRomaniLT cell vaccination in mice with invasive pulmonary aspergillosisJ Immunol2000165138138810861075
  • BeckOKoehlUTramsenLEnumeration of functionally active anti-Aspergillus T-cells in human peripheral bloodJ Immunol Methods20083351–2414518395221
  • PerruccioKTostiABurchielliETransferring functional immune responses to pathogens after haploidentical hematopoietic transplantationBlood2005106134397440616123217
  • ItoJILyonsJMVaccination of corticosteroid immunosuppressed mice against invasive pulmonary aspergillosisJ Infect Dis2002186686987112198627
  • BozzaSGazianoRLipfordGBVaccination of mice against invasive aspergillosis with recombinant Aspergillus proteins and CpG oligode-oxynucleotides as adjuvantsMicrobes Infect20024131281129012443892
  • BozzaSMontagnoliCGazianoRDendritic cell-based vaccination against opportunistic fungiVaccine200422785786415040938
  • CassoneAFungal vaccines: Real progress from real challengesLancet Infect Dis20088211412418222162