Invasive fungal infection--laboratory diagnosis and antifungal treatment.

Invasive fungal infections (IFIs) have become increasingly prevalent in the recent decade along with the increasing populations of immunocompromised patients and widespread use of the broad-spectrum antibiotics. The morbidity and the mortality of IFIs remain high while the diagnosis and treatment of IFIs are highly challenging. Recent advances in diagnostic methods and antifungal agents provide the potential to improve the outcomes of these infections. Conventional diagnostic methods including microbiological cultures and histopathological diagnosis have the disadvantages of either insensitivity or requiring invasive procedures. The innovative techniques of detecting circulating fungal antigens and detecting fungal genomic DNA represent improvements in the diagnosis of invasive aspergillosis. Several antifungal agents have been developed in recent years, such as lipid formulations of amphotericin B, newer azoles, and echinocandins. These agents have either lower toxicities or greater activities against certain fungi compared with older treatments. With the availability of diverse antifungal agents, their use in combination has the potential to produce additive or synergistic effects, leading to better treatment outcomes. Large-scale randomized clinical trials are needed to confirm the efficacy of combination strategies.     

Cutaneous manifestations of systemic mycoses]

The systemic mycoses are increasing in importance as opportunistic infections. Cutaneous lesions resulting from systemic mycoses may first alert clinicians to the presence of a life-threatening disorder, or even the presence of an unsuspected immunodeficiency state. Skin involvement is generally uncommon in disseminated aspergillosis, zygomycosis but is more common in systemic candidiasis (candidemia) and cryptococcosis. The blanket terms, hyalohyphomycosis and phaeohyphomycosis, cover the infections caused by diverse fungal opportunists. A variety of manifestations of skin lesions of the systemic mycoses are reviewed. These specific and/or non-specific lesions require early recognition, diagnosis, and aggressive antifungal treatment.     

PCR based identification and discrimination of agents of mucormycosis and aspergillosis in paraffin wax embedded tissue

BACKGROUND: Invasive fungal infections are often diagnosed by histopathology without identification of the causative fungi, which show significantly different antifungal susceptibilities. AIMS: To establish and evaluate a system of two seminested polymerase chain reaction (PCR) assays to identify and discriminate between agents of aspergillosis and mucormycosis in paraffin wax embedded tissue samples. METHODS: DNA of 52 blinded samples from five different centres was extracted and used as a template in two PCR assays targeting the mitochondrial aspergillosis DNA and the 18S ribosomal DNA of zygomycetes. RESULTS: Specific fungal DNA was identified in 27 of 44 samples in accordance with a histopathological diagnosis of zygomycosis or aspergillosis, respectively. Aspergillus fumigatus DNA was amplified from one specimen of zygomycosis (diagnosed by histopathology). In four of 16 PCR negative samples no human DNA was amplified, possibly as a result of the destruction of DNA before paraffin wax embedding. In addition, eight samples from clinically suspected fungal infections (without histopathological proof) were examined. The two PCR assays detected a concomitant infection with Absidia corymbifera and A fumigatus in one, and infections with Rhizopus arrhizus and A fumigatus in another two cases. CONCLUSIONS: The two seminested PCR assays described here can support a histopathological diagnosis of mucormycosis or aspergillosis, and can identify the infective agent, thereby optimising antifungal treatment.     

A role for antibodies in the generation of memory antifungal immunity

Protective immunity to Candida albicans and Aspergillus fumigatus is mediated by antigen-specific Th1 cells. To define the role of B cells and antibodies in the generation of antifungal immune resistance, B cell-deficient (mu MT) mice were assessed for immune resistance to primary and secondary infections with both fungi. The results showed that, although passive administration of antibodies increased the fungal clearance, the innate and Th1-mediated resistance to the primary and secondary infections were both heightened in mu MT mice with candidiasis and aspergillosis. However, although capable of efficiently restricting the fungal growth, mu MT mice did not survive the re-infection with C. albicans, and this was concurrent with the failure to generate IL-10-producing dendritic cells and regulatory CD4(+)CD25(+) T cells. Antifungal opsonizing antibodies restored IL-10 production by dendritic cells from mu MT mice, a finding suggesting that the availability of opsonizing antibodies may condition the nature of the dendritic cell interaction with fungi, possibly impacting on the development of long-lasting antifungal immunity.     

Incidence of zygomycosis in transplant recipients

Recently, a remarkable increase in the incidence of zygomycosis has been reported from institutions in the USA and Europe. The use of voriconazole for the treatment of aspergillosis and, less frequently, the use of echinocandins as empirical treatment for invasive fungal infections are thought to be responsible for the increase. In addition, an increased incidence of this infection has been observed in transplant recipients, including both haematopoietic stem cell transplant (HSCT) and solid organ transplant (SOT) patients. There are no global surveys on the prevalence or incidence of zygomycosis, but data from individual institutions and countries show that zygomycosis is an emerging infection. The increased incidence of zygomycosis most probably reflects a greater frequency of predisposing factors, such as higher numbers of patients undergoing HSCT and immunosuppressive chemotherapy. In addition, the emergence of rare pathogens as a result of the rise in the use of antifungal therapy against common species can be postulated. Further, the availability of antifungal agents with activity profiles that are more specific for selected fungi increases the necessity of identifying pathogenic fungi; the frequency of Zygomycetes infections may have been underestimated until now because therapeutic decisions did not depend on the precise identification of pathogenic fungi.     

Triple fungal infection in a patient with liver cirrhosis

The prevalence of invasive mycoses is increasing, especially among patients who are immunocompromised or hospitalized with serious underlying diseases. Such infections are associated with a high morbidity and significant mortality, requiring early diagnosis and appropriate treatment but also an optimal prophylaxis in patients with high risk factors. We report a case of triple fungal infection including an invasive pulmonary aspergillosis by Aspergillus fumigatus, a candidemia by Candida albicans and a Pneumocystis pneumonia. The overall clinical picture of this patient was liver cirrhosis with medical history of immunosuppressive treatment for Crohn disease and a non-hodgkin lymphoma. There was no antifungal prophylaxis for this patient. Under treatment, the issue was unfavourable with multivisceral failure.     

Evaluation of antimycotics in the elderly]

Incidence and risk factors were analyzed in elderly patients with deep-seated mycosis. Twenty cases with candidiasis or aspergillosis were found in 1,663 autopsy cases. Intravascular catheters and administration of antibiotics were prominent risk factors for candidiasis as was steroid therapy. Leukocytopenia due to anti-cancer drugs caused aspergillosis. Preventive use of AMPH in patients with hematological malignancies or with steroid therapy was effective against mycosis. Although AMPH is also effective for almost all kinds of deep-seated mycosis, we rarely administered it to elderly patients because of its nephrotoxicity. The safe use of antimycotics requires checking drug sensitivity of causative fungi in a laboratory, and establishing the optimal dosage for patients with impaired renal function.     

Evaluation of knowledge and experience of fungal infections (mycoses) among clinical doctors in Senegal

In order to assess the knowledge and experience of fungal infections (FIs) among clinicians in Senegal, a cross-sectional survey was carried out among medical practitioners in Senegal via a questionnaire designed with “Google Forms” between 24 January and 24 April 2022. A total of 100 clinicians responded to the questionnaire. Clinicians in the 31– 40-year-old age group formed the majority of respondents (51%). Male respondents were predominant (72%). Forty-one percent of respondents were general practitioners, 40% were specialist doctors, and the rest were residents. Dermatologists were the most common at 15% (6/40). In terms of clinicians’ general knowledge of fungi, FIs and their therapeutic management, an average of 70% correct answers was recorded. The majority (70%) of respondents cared for between two to four different categories of patients at risk of invasive FIs (IFIs) at a time, with diabetes predominating. Eighty percent confirmed that they had been confronted with FIs, including 43% with superficial FIs, 3% with subcutaneous FIs and 5% with IFIs. Thirty-four percent of doctors stated that they had never suspected an IFI. Candidiasis was the most commonly mentioned mycosis by doctors. To support the diagnosis of these FIs, 22% of the clinicians said that they had recourse only to the clinical diagnosis. In total, 79% of clinicians responded that they had never used an antifungal chemoprophylaxis. In addition, 28% and 22% of practicing physicians chose a combination of antifungals for the chemoprophylaxis of invasive candidiasis and invasive aspergillosis, respectively. This survey shows that both clinicians’ knowledge and experience of fungi, antifungals, FIs and their therapeutic management, as well as chemoprophylaxis, need to be improved. Indeed, half of the clinicians seem to be unaware of the incidence of FIs, in particular IFIs, which, nevertheless, represent some of the deadliest infectious diseases in the world.     

Usefulness of animal models of aspergillosis in studying immunity against Aspergillus infections

Aspergillosis represents a spectrum of fungal diseases which are caused by fungi of the genus Aspergillus. Animal models have been developed and used to address immune-based mechanisms of defense against these fungi. Invertebrate models enabled mass screening of virulence attributes of Aspergillus species as well as mechanisms of acquired resistance to antifungal agents. This review represents a concise view of cellular and humoral participants in an immune response to Aspergillus gained mostly from rodent models of aspergillosis. The survey of immune defense mechanisms was given, including the role of innate immune cells (macrophages, neutrophils, monocytes, eosinophils, innate-like lymphocytes) and receptors in antifungal response, the significance of dendritic cells in activation of specific adaptive T cell-mediated immune responses and the regulatory mechanisms of excessive response. Insight into innate immune defense mechanisms gained using non-vertebrate models of infections with Aspergillus sp. was given as well. The contribution of animal models to the current knowledge of immune mechanisms of resistance or susceptibility to these fungi was stressed and the significance of data gained from these models in forming the basis for the design of therapeutic strategies in prevention and/or treatment of aspergillosis was pointed out.     

Aspergillus infections in lung transplant recipients: risk factors and outcome

This retrospective study of 251 lung transplant patients aimed to determine the prevalence, clinical presentation and mortality of Aspergillus infection in order to define specific risk factors and to compare survival in patients with and without infection. Aspergillus was isolated from 86 (33%) cases, which involved colonisation (n = 50), tracheobronchial lesions (n = 17) or invasive aspergillosis (n = 19). Overall, aspergillosis had an impact on survival (p < 0.05); in fact the 5-year mortality rate was substantially higher in single lung transplant recipients with bronchial anastomotic infection, and in those with late-onset infections and chronic rejection. A significant association (p < 0.05) was found between acute rejection and the time at which fungal infection was diagnosed. Aspergillus infection was not related to cytomegalovirus infection or treatment with corticosteroids. The mortality rate for invasive infections was 78% and was related to survival (p < 0.0001); invasive aspergillosis was also associated with chronic rejection (p < 0.05), but not with high corticosteroid doses (p 0.49) or use of tacrolimus (p 0.73). In conclusion, Aspergillus infection was associated with a reduction in the 5-year survival rate of lung transplant recipients, and this was particularly true for patients infected with the invasive forms and for patients with single lung transplants, bronchial anastomotic infection and chronic rejection. Isolation of Aspergillus spp. from respiratory samples preceded acute rejection, and may be a marker of graft dysfunction and/or airway inflammation. Close monitoring, or even pre-emptive antifungal therapy, is recommended for patients with chronic rejection or bronchial airway mechanical abnormalities and persistent Aspergillus colonisation.     

Serious fungal infections in Korea

Information on the incidence and prevalence of fungal infections is of critical value in public health policy. However, nationwide epidemiological data on fungal infections are scarce, due to a lack of surveillance and funding. The objective of this study was to estimate the disease burden of fungal infections in the Republic of Korea. An actuarial approach using a deterministic model was used for the estimation. Data on the number of populations at risk and the frequencies of fungal infections in those populations were obtained from national statistics reports and epidemiology papers. Approximately 1 million people were estimated to be affected by fungal infections every year. The burdens of candidemia (4.12 per 100,000), cryptococcal meningitis (0.09 per 100,000), and Pneumocystis pneumonia (0.51 per 100,000) in South Korea were estimated to be comparable to those in other countries. The prevalence of chronic pulmonary aspergillosis (22.4 per 100,000) was markedly high, probably due to the high burden of tuberculosis in Korea. The low burdens of allergic bronchopulmonary aspergillosis (56.9 per 100,000) and severe asthma with fungal sensitization (75.1 per 100,000) warrant further study. Oral candidiasis (539 per 100,000) was estimated to affect a much larger population than noted in previous studies. Our work provides valuable insight on the epidemiology of fungal infections; however, additional studies are needed.     

Opportunistic fungal infections in the Asia-Pacific region

With more than half the world's population, many Asia-Pacific countries still lack resources for adequate infection control and diagnostics. Opportunistic invasive fungal infections (IFIs) have a significant impact on public health in the region, and early diagnosis and appropriate treatment remain important. The incidence of IFI in the Asia-Pacific region is increasing because of the expanded population of immunosuppressed patients resulting from advances in medical technology, such as treatments for cancer and transplantation, as well as the impact of human immunodeficiency virus. Even so, the epidemiology of IFIs is not well described in the Asia-Pacific region. Prevalence of some infections, such as mucormycosis, is particularly related to undiagnosed or untreated diabetes, which is likely to be a continuing problem with the epidemic of diabetes in the region. In addition, despite some effective treatment options, IFIs are associated with high morbidity and mortality. In an attempt to increase recognition of invasive mycoses in this large area, this paper reviews recent findings on the epidemiology of the most clinically significant opportunistic mould and yeast infections in the Asia-Pacific region, i.e., aspergillosis, mucormycosis, pythiosis, scedosporiosis, fusariosis, candidiasis, trichosporonosis, and cryptococcosis.     

Clinical efficacy of micafungin for chronic pulmonary aspergillosis.

The rising incidence of pulmonary aspergillosis is a major clinical concern. However, only a limited number of antifungal drugs are available in Japan that are effective for pulmonary Aspergillus infections. Micafungin (MCFG), a newly developed echinocandin family antifungal drug, has potent antifungal activity in vitro, but few reports detailing its clinical effectiveness have been published to date. A retrospective study was performed using data from nine patients (seven males and two females) with chronic invasive forms of pulmonary aspergillosis, who were treated with either MCFG alone or together with other antifungal drugs between April 2003 and March 2004. The overall efficacy of the treatments was evaluated in the terms of clinical, mycological, serological and radiological responses. The average age of the patients was 61.9 (20-83) years old. Four patients received only MCFG and the remaining five patients were treated with MCFG in combination with amphotericin B (AMB) only (1 patient), itraconazole (ITC) only (2 patients) or AMB backed up by ITC during AMB discontinuation periods (2 patients). The mean duration of MCFG administration was 59.2 (28-96) days. Overall, the treatment was judged to have been effective for seven of nine patients. No patient's condition deteriorated in response to treatment. Administration of MCFG alone was judged to have been effective in three of four patients. No notable adverse effects were documented during MCFG administration. These data suggest that MCFG may be an effective and safe antifungal drug for the treatment of chronic invasive forms of pulmonary aspergillosis.     

Mucormycosis after Coronavirus disease 2019 infection in a heart transplant recipient – Case report and review of literature

Mucormycosis is an invasive fungal infection (IFI) due to several species of saprophytic fungi, occurring in patients with underlying co-morbidities (including organ transplantation). During the ongoing Coronavirus disease 2019 (COVID-19) pandemic, there have been increasing reports of bacterial and fungal co-infections occurring in COVID-19 patients, including COVID-19 associated pulmonary aspergillosis (CAPA). We describe a case of mucormycosis occurring after COVID-19, in an individual who received a recent heart transplant for severe heart failure. Two months after heart transplant, our patient developed upper respiratory and systemic symptoms and was diagnosed with COVID-19. He was managed with convalescent plasma therapy and supportive care. Approximately three months after COVID-19 diagnosis, he developed cutaneous mucormycosis at an old intravascular device site. He underwent extensive surgical interventions, combined with broad-spectrum antifungal therapy. Despite the aggressive therapeutic measures, he died after a prolonged hospital stay. In this case report, we also review the prior well-reported cases of mucormycosis occurring in COVID-19 patients and discuss potential mechanisms by which COVID-19 may predispose to IFIs. Similar to CAPA, mucormycosis with COVID-19 may need to be evaluated as an emerging disease association. Clinicians should be vigilant to evaluate for invasive fungal infections such as mucormycosis in patients with COVID-19 infection.     

Epidemiology of Visceral Mycoses: Analysis of Data in Annual of the Pathological Autopsy Cases in Japan

The data on visceral mycoses that had been reported in the Annual of the Pathological Autopsy Cases in Japan from 1969 to 1994 by the Japanese Society of Pathology were analyzed epidemiologically. The frequency of visceral mycoses among the annual total number of pathological autopsy cases increased noticeably from 1.60% in 1969 to a peak of 4.66% in 1990. Among them, the incidences of candidiasis and aspergillosis increased the most. After 1990, however, the frequency of visceral mycoses decreased gradually. Until 1989, the predominant causative agent was Candida, followed in order by Aspergillus and Cryptococcus. Although the rate of candidiasis decreased by degrees from 1990, the rate of aspergillosis increased up to and then surpassed that of candidiasis in 1991. Leukemia was the major disease underlying the visceral mycoses, followed by solid cancers and other blood and hematopoietic system diseases. Severe mycotic infection has increased over the reported 25-year period, from 6.6% of the total visceral mycosis cases in 1969 to 71% in 1994. The reasons for this decrease of candidiasis combined with an increase of aspergillosis or of severe mycotic infection might be that (i) nonsevere (not disseminated) infections were excluded from the case totals, since they have become controllable by antifungal drugs such as fluconazole, but (ii) the available antifungal drugs were not efficacious against severe infections such as pulmonary aspergillosis, and (iii) the number of patients living longer in an immunocompromised state had increased because of developments in chemotherapy and progress in medical care.     

Monitoring and prophylaxis]

Invasive deep mycoses following bone marrow and solid-organ transplantation remain a major cause of morbidity and mortality. Species of Candida and Aspergillus account for more than 80% of these mycoses. Because these infections are often difficult to diagnose and treat successfully, antifungal prophylaxis is recommended in high-risk patients. Fluconazole is useful in patients who are at risk of invasive candidiasis, including bone marrow transplants, liver and pancreatic transplants. Although invasive aspergillosis is frequent in patients with bone marrow, lung and heart transplantation, no established methods have been available for its prophylaxis. Recently, efforts to improve the efficiency of diagnostic tests have been directed toward the detection of fungal components or metabolites. The requirements for clinical use (monitoring) are as follows: capability of early diagnosis, quantitative measurement, and easy sampling and simple assay procedure. The detection of plasma (1-3)-beta-D-glucan (BDG), a characteristic cell wall component of almost all fungi, is widely used in Japan. Twenty-seven episodes of fungemia were observed in our hematology ward and all were positive with BDG. Positive results were observed before the documentation of fungemia in 14 patients (51.9%). Although the positive rate of BDG also was 100% in 17 patients with invasive aspergillosis, it rose slightly at an early stage of the disease in 13 patients (76.5%). The determination of plasma BDG appears useful in the monitoring of deep fungal infection, but its usefulness for early diagnosis remains to be determined. The utility of detection of Aspergillus galactomannan by ELISA and fungal DNA by polymerase chain reaction are also discussed.     

Timeline,Epidemiology, and Risk Factors for Bacterial,Fungal, and Viral Infections in Children and Adolescents after Allogeneic Hematopoietic Stem Cell Transplantation

Advances made in the field of hematopoietic stem cell transplantations (HSCT) over the past 20 years may have had an impact on the distribution of posttransplantation infections. We sought to retrospectively analyze the epidemiology and risk factors for bacterial, fungal, and viral infections in children after allogeneic HSCT in a cohort of 759 children who underwent allogeneic HSCT in a single institution between 1990 and 2009. The association between infections and risk factors of interest at 0 to 30 days, 31 to 100 days, and 101 days to 2 years posttransplantation was evaluated using logistic regression. Difference among the subtypes within each category was studied. There were 243 matched-related donors, 239 matched-unrelated donors (MUDs), and 176 haploidentical donor transplantations. Era of transplantation (0-30 days), peripheral blood stem cell product, acute graft-versus-host disease (aGVHD; 31-100 days), and chronic GVHD (cGVHD; 101-730 days) were associated with higher risk for bacterial infections at the respective time periods. Patients with aGVHD (31-100 days), cGVHD, and older age (101-730 days) were at higher risk for fungal infections. Cytomegalovirus (CMV) donor/recipient (D/R) serostatus (0-100 days), era of transplantation, MUD HSCT (31-100 days), and cGVHD (101-730 days), influenced viral infections. Gram-positive outnumbered gram-negative bacterial infections; aspergillosis and candidemia were equally prevalent in all time periods. Haploidentical donor HSCT was not associated with an increased risk of infections. There seems to be a continuum in the timeline of infections posttransplantation, with bacterial, fungal, and viral infections prevalent in all time periods, particularly late after the transplantation, the risk affected by GVHD, CMV, D/R status, product type, older age, and use of unrelated donors.     

Antifungal activity and clinical efficacy of micafungin (funguard)]

Micafungin (MCFG) is a new lipopeptide antifungal agent of the echinocandin class. MCFG inhibits 1,3-beta-D-glucan synthesis in C. albicans and A. fumigatus in a non-competitive manner, and has antifungal activity against both Aspergillus and Candida species. In neutropenic mouse models of disseminated candidiasis and pulmonary aspergillosis, the efficacy of MCFG was superior to that of fluconazole and itraconazole, but comparable to that of amphotericin B. The efficacy and safety of MCFG were investigated in 70 patients with deep-seated mycosis caused by Candida and Aspergillus species. The overall clinical response rates were 57.1% in aspergillosis and 78.6% in candidiasis. The incidence of adverse events related to micafungin was 17.9%, and there was no dose-related occurrence of any adverse events. The results from this study indicated that micafungin was effective in aspergillosis and candidiasis, with no tolerability problems.     

三种常见肺部真菌感染CT表现比较

目的 探究肺部三种真菌感染的CT表现并进行比较研究。方法 对2014年3月~2017年4月宜丰县人民医院确诊的肺部真菌感染患者90例的临床资料展开比较分析。其中20例念珠菌病,40例隐球菌病,以及30例侵入性肺曲霉病,对上述三种临床常见的肺部真菌感染的CT表现对比研究。结果 念珠菌病和侵入性肺曲霉病比较,单纯性隐球菌病患者发生率、支气管充气征以及聚集性结节发生率较高,组间对比,差异有统计学意义（P＜0.05）;念珠菌病和隐球菌病者比较,侵入性肺曲霉病空洞发生率较高,组间对比,差异有统计学意义（P＜0.05）。结论 支气管充气征和结节密集型分布是肺隐球菌病的主要特点,空气半月征和空洞是侵入性肺曲霉病的主要特点,而磨玻璃影则为肺念珠菌病的主要特点。     

Combination Antifungals as an Effective Means of Salvage in Paediatric Leukaemia Patients with Invasive Fungal Infections

Invasive fungal infections (IFIs) are an important cause of morbidity and mortality in paediatric leukaemias. Antifungal combinations to treat these patients are being explored. Fourteen children with leukaemias and IFIs were treated with a combination of antifungal agents at our centre. The first antifungal was amphotericin-B in 13 children and voriconazole in one child. In view of no improvement and clinical deterioration, in nine patients, voriconazole was added as the second antifungal agent and in four, it was caspofungin. All patients completed 4–6 weeks of antifungal therapy. The overall mortality attributable to IFI for the cohort was 4/14 (28%).