Epidemiology of visceral mycoses: analysis of data in annual of the pathological autopsy cases in Japan

Mucormycosis and Its Upsurge During COVID-19 Epidemic: An Updated Review

Although mucormycosis may have reached an epidemic situation during the COVID-19 pandemic, the term was much more familiar even before the COVID-19 period. The year 2020 showed an outbreak of novel coronavirus (SARS-CoV-2) which affected millions of people all over the world. One of the noticeable complications observed to be associated with this disease is mucormycosis. It is an opportunistic infection caused by members of the Order Mucorales existing worldwide and has been commonly reported as a laboratory contaminant for a long time. However, nowadays due to the changes in the host environment, they have been emerging as potent opportunistic pathogens responsible for causing primary infections or coinfections with other diseases eventually resulting in morbidity and even mortality in severe cases. Although immunocompromised patients are more susceptible to this infection, few cases have been reported in immunocompetent individuals. Various risk factors which are responsible for the acquisition of mucormycosis include diabetes mellitus type 2, ketoacidosis, hematological malignancies, organ transplants, and chemotherapy recipients. Among the various etiological agents, Rhizopus is found to be the most common, and rhino-cerebral to be the most frequent clinical presentation. As far as pathogenesis is concerned, host cell invasion, thrombosis, and necrosis are the main events in the progression of this disease. The aim of the present review is to address a complete spectrum of mucormycosis and COVID-19-associated mucormycosis (CAM) in a single article. Both global and Indian scenarios of mucormycosis are taken into account while framing this review.

Surge of mucormycosis during the COVID-19 pandemic

Patients with respiratory viral infections are more likely to develop co-infections leading to increased fatality. Mucormycosis is an epidemic amidst the COVID-19 pandemic that conveys a 'double threat' to the global health fraternity. Mucormycosis is caused by the Mucorales group of fungi and exhibits acute angioinvasion generally in immunocompromised patients. The most familiar foci of infections are sinuses (39%), lungs (24%), and skin tissues (19%) where the overall dissemination occurs in 23% of cases. The mortality rate in the case of disseminated mucormycosis is found to be 96%. Symptoms are mostly nonspecific and often resemble other common bacterial or fungal infections. Currently, COVID-19-associated mucormycosis (CAM) is being reported from a number of countries such as the USA, Turkey, France, Mexico, Iran, Austria, UK, Brazil, and Italy, while India is the hotspot for this deadly co-infection, accounting for approximately 28,252 cases up to June 8, 2021. It strikes patients within 12-18 days after COVID-19 recovery, and nearly 80% require surgery. Nevertheless, the mortality rate can reach 94% if the diagnosis is delayed or remains untreated. Sometimes COVID-19 is the sole predisposing factor for CAM. Therefore, this study may provide a comprehensive resource for clinicians and researchers dealing with fungal infections, intending to link the potential translational knowledge and prospective therapeutic challenges to counter this opportunistic pathogen.

Focusing COVID-19-associated mucormycosis: a major threat to immunocompromised COVID-19

COVID-19 disease has been identified to cause remarkable increase of mucormycosis infection cases in India, with the majority of cases being observed in individuals recovering from COVID-19. Mucormycosis has emanated as an outcome of the recent COVID-19 pandemic outbreak as rapidly developing fatal illness which was acquired by Mucorales fungus which is a subcategory of molds known as mucormycetes. Mucormycosis is one of the serious, sporadic mycotic illnesses which is a great threat to immunocompromised COVID-19 patients and affects people of all ages, including children with COVID-19 infections. This is associated with tissue damaging property and, therefore, causes serious clinical complications and elevated death rate. The COVID-19-associated mucormycosis or "black fungus" are the terms used interchangeably. The rapid growth of tissue necrosis presenting as "rhino-orbital-cerebral, pulmonary, cutaneous, gastrointestinal, and disseminated disease" are various clinical forms of mucormycosis. The patient's prognosis and survival can be improved with proper surgeries using an endoscopic approach for local tissue protection in conjunction with course of appropriate conventional antifungal drug like Amphotericin-B and novel drugs like Rezafungin, encochleated Amphotericin B, Orolofim, and SCY-078 which have been explored in last few years. This review provides an overview of mucormycosis including its epidemiology, pathophysiology, risk factors, its clinical forms, and therapeutic approaches for disease management like antifungal therapy, surgical debridement, and iron chelators. The published patents and ongoing clinical trials related to mucormycosis have also been mentioned in this review.

New insights on mucormycosis and its association with the COVID-19 pandemic

COVID-19 continues to cause significant fatality worldwide. Glucocorticoids prove to play essential roles in COVID-19 management; however, the extensive use of steroids together with the virus immune dysregulation may increase the danger of secondary infections with mucormycosis, an angioinvasive fungal infection. Unfortunately, a definite correlation between COVID-19 and elevated mucormycosis infection cases is now clear worldwide. In this review, we discuss the historical record and epidemiology of mucormycosis as well as pathogenesis and associated host immune response, risk factors, clinical presentation, diagnosis and treatment. Special emphasis is given to its association with the current COVID-19 pandemic, including latest updates on COVID-19-associated mucormycosis cases globally, with recommendations for efficacious management.

A definite correlation between COVID-19 and elevated mucormycosis infection cases is now clear worldwide. This article can be used as comprehensive tool to help clinicians and the healthcare team in getting a clearer look on the historical record and epidemiology of mucormycosis as well as pathogenesis and associated host immune response. Risk factors, clinical presentation, diagnosis, treatment options and also the latest updates on COVID-19-associated mucormycosis are also discussed, which will help in the understanding of the fatal mucormycosis infection.

Antifungal susceptibilities of opportunistic filamentous fungal pathogens from the Asia and Western Pacific Region: data from the SENTRY Antifungal Surveillance Program (2011-2019)

Antifungal surveillance is an important tool to monitor the prevalence of uncommon fungal species and increasing antifungal resistance throughout the world, but data comparing results across several different Asian countries are scarce. In this study, 372 invasive molds collected in the Asia-Western Pacific region in 2011-2019 were susceptibility tested for mold-active triazoles (isavuconazole, posaconazole, voriconazole, and itraconazole). The collection includes 318 Aspergillus spp. isolates and 53 non-Aspergillus molds. The MIC values using CLSI methods for isavuconazole versus Aspergillus fumigatus ranged from 0.25 to 2 mg l^-1. Isavuconazole, itraconazole, posaconazole, and voriconazole acted similarly against A. fumigatus. The mold-active triazoles exhibited a wildtype phenotype to most of the Aspergillus spp. isolates tested (>94%), but poor activity against Fusarium solani species complex and Lomentospora prolificans. Voriconazole was most active against the Scedosporium spp. and posaconazole was most active against the Mucorales. In summary, isavuconazole displayed excellent activity against most species of Aspergillus and was comparable to other mold-active triazoles against non-Aspergillus molds.

Epidemiology of visceral mycoses in patients with acute leukemia and myelodysplastic syndrome: Analyzing the national autopsy database in Japan

Visceral mycoses (VM) are a deadly common infection in patients with acute leukemia and myelodysplastic syndrome (MDS). We retrospectively analyzed the data from the centralized "Annual Report of Autopsy Cases in Japan" that archives the national autopsy cases since 1989. Among the total of 175,615 archived autopsy cases, 7183 cases (4.1%) were acute leukemia and MDS patients. While VM was only found in 7756 cases (4.4% in total cases), we found VM had a disproportionally high prevalence among acute leukemia and MDS patients: 1562 VM cases (21.7%) and nearly sixfold higher in prevalence. Aspergillus spp. was the most predominant causative agent (45.0%), and Candida spp. was the second (22.7%) among confirmed single pathogen involved cases. The prevalence of Candida spp. infection decreased about 50% due to the widely use of fluconazole prophylaxis, which may skew toward doubling of the Mucormycetes incidence compared to 30 years ago. Complicated fungal infection (> one pathogen) was 11.0% in acute leukemia and MDS in 2015. It was 14.7 times higher than in other populations. Among 937 patients who received allogeneic hematopoietic cell transplantation (HCT), the prevalence of VM was 28.3% and 23.3% with GVHD. Aspergillus spp. was less prevalent, but Candida spp. was more associated with GVHD. Its prevalence remains stable. Although Aspergillus spp. was the primary causative agent, non-albicans Candida spp. was increasing as a breakthrough infection especially in GVHD cases. Complicated pathogen cases were more common in acute leukemia and MDS.

The Postmortem Features of Mucormycosis

Mucormycosis is a rare and severe invasive fungal infection caused by ubiquitous fungi of the order Mucorales. Infection often occurs in immunocompromised hosts and includes cutaneous, pulmonary, gastrointestinal, rhinocerebral, and disseminated forms of disease. Although the clinical characteristics of mucormycosis are well established, infection can be difficult to diagnose antemortem, resulting in frequent postmortem diagnoses. Despite this, the gross appearance of mucormycosis at autopsy has not been well described. In the present report we illustrate the gross and histologic findings in four autopsy cases of mucormycosis, including one case of pulmonary disease and three cases of disseminated mucormycosis with cerebral, pulmonary, hepatic, renal, and gastrointestinal involvement. In all cases autopsy examination demonstrated characteristic hemorrhagic infarcts with a targetoid appearance in the affected organs. These findings are secondary to fungal angioinvasion with subsequent thrombosis and tissue necrosis. Mucormycosis should be suspected at autopsy when these characteristic infarcts are identified within the proper clinical context, and a high suspicion for atypical infections should be maintained postmortem in immunosuppressed patients.

Fungal brain infection-no longer a death sentence

The aim of this case series was to provide a modern cohort of patients with cerebral aspergillosis and show the effectiveness of modern treatment concepts. In a 10-year period from January 2009 to January 2019, we identified 10 patients (6 male, 4 female) who received surgery or frameless stereotactic drainage of a cerebral aspergilloma at our center. Patients’ and disease characteristics were recorded. The median age was 65 (range 45 to 83). We conducted 133 cranial surgeries in 100 patients due to cerebral brain abscess (BA) during that time, which leads to a percentage of 10% of aspergilloma within BAs in our patient sample. We performed 3.1 surgeries per patient followed by antifungal treatment for 6 months (= median) according to the microbiological findings. Regarding comorbidities, the mean Charlson comorbidity index (CCI) at the time of admission was 5, representing an estimated 10-year survival of 21%. Six (60%) of 10 patients showed conditions of immunosuppression, one suffered endocarditis after replacement of aortic valves. Four patients showed associated frontobasal bone destruction, mycotic aneurysms, or thromboses. The mean duration of hospital stay was 37 days. Mortality was much lower than in literature. Sixty percent of the patients died during the follow-up period. The outcome of the two immunocompetent patients was more favorable. Cerebral aspergillosis is a rare, but still life-threatening, condition, which predominantly occurs in immunosuppressive conditions. Due to radical surgical and antifungal therapy for several months, mortality can be reduced dramatically.

Rapid and Low-Cost Culture-Based Method for Diagnosis of Mucormycosis Using a Mouse Model

Prompt and targeted antifungal treatment has a positive impact on the clinical outcome of mucormycosis; however, current diagnostic tools used in histopathology laboratories often fail to provide rapid results. Rapid culture-based strategies for early diagnosis of Mucorales infections, which may influence treatment decisions, are urgently needed. Herein, we evaluated a microculture assay for the early diagnosis of mucormycosis in an immunocompetent murine model of disseminated infection, by comparing it with traditional diagnostic methods. The assay specificity was assessed using blood (n = 90) and tissue (n = 90) specimens obtained from mice infected with Rhizopus arrhizus using different inoculum sizes [1 × 10⁴, 1 × 10⁵, and 1 × 10⁶ colony forming units (CFUs)/mouse] and blood (n = 15) and tissue specimens (n = 15) from uninfected mice. Surprisingly, 26 of 90 (28.9%) blood samples revealed positive results by microculture, whereas all blood samples were negative when assayed by conventional culture. The overall positive conventional culture rate for the mouse tissue (kidney) samples was 31.1% (28/90). The calculated sensitivity for kidney microculture was 98.8% [95% confidence interval (CI) 96.6–100], with an assay specificity of 100%. Hence, the microculture assay may be useful for rapid culturing and diagnosis of mucormycosis caused by R. arrhizus directly in blood and tissue samples. Hence, this method may allow for the timely administration of an appropriate treatment.

Microsatellite analysis of the population structure in Rhizopus arrhizus

OBJECTIVES

Rhizopus arrhizus is recognized as an emergent agent of superficial and invasive mucormycosis. Despite an increasing number of these infections, the molecular epidemiology of Rhizopus species has not been well studied.

MATERIALS AND METHODS

In this study, 43 R. arrhizus strains (25 environmental and 18 clinical isolates) were genotyped using six novel panels of microsatellite markers.

RESULTS

Upon the analysis of 43 isolates, 4-8 distinct alleles were detected for each marker. The discriminatory power for the individual markers ranged from 0·522 to 0·830. The combination of all six markers yielded 33 different haplotypes with a high degree of discrimination (0·989 D value). A four-marker combination were selected as the most parsimonious panel achieving D > 0·95. One clinical isolate and one environmental isolate shared the same genotype suggesting the possible nosocomial outbreak of mucormycosis in hospitalized patients. We have noted that the strains isolated from cutaneous mucormycosis were different from the strains isolated from rhino-orbito-cerebral mucormycosis. Then, the hypothesis of particular tropism of infectious strains for a given site is not excluded. The standardized indices of association IA and rBarD were significantly different from zero (P < 0·01), suggesting a prevailing clonal reproduction. The environmental population was significantly differentiated from clinical populations (Fst = 0·2249).

CONCLUSIONS

Microsatellite typing method described in our study showed an excellent degree of discriminatory power. It is a promising tool for illuminating the molecular epidemiology of R. arrhizus species, including strain relatedness and transmission pathways.

Global Epidemiology of Mucormycosis

Mucormycosis is an angio-invasive fungal infection, associated with high morbidity and mortality. A change in the epidemiology of mucormycosis has been observed in recent years with the rise in incidence, new causative agents and susceptible population. The rise has been perceived globally, but it is very high in the Asian continent. Though diabetes mellitus overshadow all other risk factors in Asia, post-tuberculosis and chronic renal failure have emerged as new risk groups. The rhino-cerebral form of mucormycosis is most commonly seen in patients with diabetes mellitus, whereas, pulmonary mucormycosis in patients with haematological malignancy and transplant recipients. In immunocompetent hosts, cutaneous mucormycosis is commonly seen following trauma. The intriguing clinical entity, isolated renal mucormycosis in immunocompetent patients is only reported from China and India. A new clinical entity, indolent mucormycosis in nasal sinuses, is recently recognized. The causative agents of mucormycosis vary across different geographic locations. Though Rhizopusarrhizus is the most common agent isolated worldwide, Apophysomycesvariabilis is predominant in Asia and Lichtheimia species in Europe. The new causative agents, Rhizopus homothallicus, Mucor irregularis, and Thamnostylum lucknowense are reported from Asia. In conclusion, with the change in epidemiology of mucormycosis country-wise studies are warranted to estimate disease burden in different risk groups, analyse the clinical disease pattern and identify the new etiological agents.

Epidemiology and clinical characteristics of invasive mould infections: A multicenter, retrospective analysis in five Asian countries

Formal, large-scale, multicenter studies of invasive mould infection (IMI) in Asia are rare. This 1-year, retrospective study was designed to assess the incidence and clinical determinants of IMI in centers in five countries (Thailand, Taiwan, Singapore, China, India). Patients treated in a single year (2012) were identified through discharge diagnoses, microbiology, and histopathology logs, and entered based on published definitions of IMI. A total of 155 cases were included (median age 54 years; 47.7% male). Of these, 47.7% had proven disease; the remainder had probable IMI. The most frequent host factors were prolonged steroid use (39.4%) and recent neutropenia (38.7%). Common underlying conditions included diabetes mellitus (DM; 30.9%), acute myeloid leukemia (19.4%), and rheumatologic conditions (11.6%). DM was more common in patients with no recent history of neutropenia or prolonged steroid use (P = .006). The lung was the most frequently involved site (78.7%), demonstrating a range of features on computed tomography (CT). Aspergillus was the most common mould cultured (71.6%), primarily A. fumigatus and A. flavus, although proportions varied in different centers. The most often used antifungal for empiric therapy was conventional amphotericin. Ninety-day mortality was 32.9%. This is the first multicenter Asian study of IMI not limited to specific patient groups or diagnostic methods. It suggests that DM and rheumatologic conditions be considered as risk factors for IMI and demonstrates that IMI should not be ruled out in patients whose chest features on CT do not fit the conventional criteria.

Identification of Candida albicans and Candida dubliniensis Species Isolated from Bronchoalveolar Lavage Samples Using Genotypic and Phenotypic Methods

Background

Candida dubliniensis is a newly diagnosed species very similar to Candida albicans phenotypically and first discovered in the mouth of people with AIDS in 1995. Among the different phenotypic and genotypic methods, a cost-effective method should be selected which makes it possible to differentiate these similar species.

Materials and Methods

Polymerase chain reaction (PCR)-restriction fragment length polymorphism with MspI enzyme and the Duplex-PCR method were done by DNA extraction using boiling. The sequencing of the amplified ribosomal region was used to confirm the C. dubliniensis species. Direct examination and colony count of the yeasts were applied for bronchoalveolar lavage (BAL) samples and the growth rate of the yeasts were studied at 45°C. To understand the ability formation of chlamydoconidia in yeast isolates, they were separately cultured on the sunflower seed agar, wheat flour agar, and corn meal agar media.

Results

Fifty-nine (49.2%) yeast colonies were identified from the total of 120 BAL specimens. Twenty-nine isolated yeasts; including 17 (58.6%) of C. albicans/dubliniensis complex and 12 (41.4%) of nonalbicans isolates produced pseudohypha or blastoconidia in direct smear with a mean colony count of 42000 CFU/mL. C. albicans with the frequency of 15 (42.9%) were the most common isolated yeasts, whereas C. dubliniensis was identified in two nonHIV patients.

Conclusion

Sequencing of the replicated gene fragment is the best method for identifying the yeasts, but the determination of the species by phenotypic methods such as the creation of chlamydoconidia in sunflower seeds agar and wheat flour agar media can be cost-effective, have sensitivity and acceptable quality.

Infectious diseases in solid organ transplant recipients: Analysis of autopsied cases in Japan

BACKGROUND

With the improvements in immunosuppressive agents and graft survival, infections such as mycoses have become major complications after solid organ transplantation (SOT).

METHODS

Our group has continuously updated an epidemiological database of visceral mycoses (VM) among autopsy cases in Japan since 1989. Data on infectious agents and clinical information were complied using similar procedures.

RESULTS

Among the all autopsied cases studied, 356 undergone SOT. Of these, 214 (60.1%) suffered from one or more types of infections, including 51 (14.3%) with VM. Thus, the incidence of VM was higher in SOT recipients than in non-transplanted cases (P < 0.0001). Aspergillus spp. (Asp) was the most predominant agent and Candida spp. was second. Specifically, among SOT recipients, Asp was the most predominant in liver and lung transplant recipients. Among the 217 autopsied liver transplants cases, the incidence of VM was highest in those with fulminant hepatitis (FH, P = 0.01). The incidence of cytomegalovirus infection tended to be higher in cases with mycosis (P = 0.06). Multivariate logistic regression analysis identified FH (odds ratio, 3.61, 95% confidence interval 1.34-9.75; P = 0.03) as an independent risk factor for mycosis in liver transplant recipients.

CONCLUSION

This epidemiological analysis of autopsied cases provides a strong incentive to intensify efforts to diagnose and treat post-SOT infectious diseases.

Fungistatic effect of hydroxychloroquine, lessons from a case

A 50-year-old male was prescribed with hydroxychloroquine (HCQ) after osteoarthritis was diagnosed. He had an old nail infection of Aspergillus niger. A remarkable improvement of the symptoms of fungal nail infection was seen after about four weeks of treatment with HCQ. It was very hard to detect the symptoms in the end of the second month of the treatment, both in the finger and toe nails. The symptoms were clearly recurred after HCQ was discontinued.

Rare complication of bronchoesophageal fistula due to pulmonary mucormycosis after induction chemotherapy for acute myeloid leukemia: a case report

Background

Mucormycosis is a rare and life-threatening invasive fungal infection. Pulmonary mucormycosis commonly occurs in patients with severe neutropenia. Typically, pulmonary mucormycosis causes tissue necrosis resulting from angioinvasion and subsequent thrombosis, so most cases can occur with necrotizing pneumonia and/or hemoptysis. Some complex cases may invade adjacent organs, such as the mediastinum, pericardium, and chest wall. However, to the best our knowledge there is little known regarding bronchoesophageal fistula due to pulmonary mucormycosis after induction chemotherapy for acute myeloid leukemia. We present a case report about this unusual presentation.

Case presentation

A 51-year-old Korean man was diagnosed as having acute myeloid leukemia and received induction chemotherapy. After prolonged severe neutropenia, he complained of coughing with aspiration. Imaging showed a bronchoesophageal fistula with extensive necrotizing pneumonia in the middle and lower lobes of his right lung. Bronchoscopy showed near total tissue necrosis in the middle lobe of his right lung, creating an orifice. A bronchial scope was passed through and was able to be connected with his esophagus; a bronchial wall biopsy was performed. Esophagoscopy revealed a large linear defect of his esophageal wall 30 cm from the incision that may have connected with the bronchus. A bronchial biopsy showed typical hyphae with necrotic tissue, indicating pulmonary mucormycosis. He was given amphotericin B, and a wide excision of lung and esophagus was planned. However, he suddenly died due to massive hemoptysis.

Conclusion

Here we present an extremely rare case of bronchoesophageal fistula with severe necrotizing pneumonia due to pulmonary mucormycosis.

Food preparation with mucoralean fungi: A potential biosafety issue?

Mucorales have been used for production of fermented food in Asia and Africa since time immemorial. Particularly Rhizopus species are rapidly growing, active producers of lipases and proteases and occur naturally during the first stages of soybean fermentation. Two biosafety issues have been raised in recent literature: (1) pathogenicity, Rhizopus species being prevalent opportunists causing erosive infections in severely compromised patients, and (2) toxicity, strains harbouring endosymbiotic Burkholderia producing toxic secondary metabolites. At the molecular level, based on different gene markers, species identity was found between strains used for food processing and clinical strains. In this study, we screened for bacterial symbionts in 64 Rhizopus strains by light microscopy, 16S rRNA sequencing, and HPLC. Seven strains (11 %) carried bacteria identified as Burkholderia rhizoxinica and Burkholderia endofungorum, and an unknown Burkholderia species. The Burkholderia isolates proved to be able to produce toxic rhizoxins. Strains with endosymbionts originated from food, soil, and a clinical source, and thus their presence could not be linked to particular habitats. The presence of Burkholderia in Rhizopus producing toxins could not be excluded as a potential risk for human health. In contrast, given the type of diseases caused by Rhizopus species, we regard the practical risk of infection via the food industry as negligible.

Epidemiology and clinical manifestations of mucormycosis

Mucormycosis is an emerging angioinvasive infection caused by the ubiquitous filamentous fungi of the Mucorales order of the class of Zygomycetes. Mucormycosis has emerged as the third most common invasive mycosis in order of importance after candidiasis and aspergillosis in patients with hematological and allogeneic stem cell transplantation. Mucormycosis also remains a threat in patients with diabetes mellitus in the Western world. Furthermore, this disease is increasingly recognized in recently developed countries, such as India, mainly in patients with uncontrolled diabetes or trauma. Epidemiological data on this type of mycosis are scant. Therefore, our ability to determine the burden of disease is limited. Based on anatomic localization, mucormycosis can be classified as one of 6 forms: (1) rhinocerebral, (2) pulmonary, (3) cutaneous, (4) gastrointestinal, (5) disseminated, and (6) uncommon presentations. The underlying conditions can influence clinical presentation and outcome. This review describes the emerging epidemiology and the clinical manifestations of mucormycosis.

Trends in the prevalence of invasive fungal infections from an analysis of annual records of autopsy cases of Toho University

Clinical diagnosis of invasive fungal infections (IFIs) is sometimes difficult, and obtaining an accurate assessment of trends concerning the prevalence of IFIs is a challenge. The aim of this study was to determine trends in the prevalence of IFIs from an autopsy survey. The retrospective review of autopsy records stored in Toho University was performed on all documented cases with fungal infection from 1955 to 2006. A total of 411 cases of IFIs were detected among 10 297 autopsies. The prevalence of candidiasis decreased from 3.6% (1981-93) to 2.0% (1994-2006), and that of aspergillosis increased throughout the 52-year period and reached 2.0% (1994-2006). The prevalence of IFIs in the patient group comprising haematological disorders was significantly higher (19.9%) than in other patient groups (2.9%), of which the odds ratio was 18.4 for mucormycosis and 10.0 for aspergillosis. The lung was the most common organ involved irrespective of major fungal species, and most cases with candidiasis showed multiple-organ infection. Results confirmed the increasing prevalence of aspergillosis and high risk of IFIs in the patient group with haematological disorders. IFIs were also detected in an immunocompromised state caused not only by primary disease but also by treatment with anti-tumour drugs and corticosteroids.

In vitro activity of isavuconazole against 140 reference fungal strains and 165 clinically isolated yeasts from Japan

The in vitro susceptibilities of 140 laboratory reference strains of fungi, including type strains, and 165 clinical yeast isolates from Japan towards isavuconazole compared with fluconazole (FLC), itraconazole (ITC), voriconazole and amphotericin B were measured. Broth microdilution methods based on Clinical and Laboratory Standards Institute (CLSI) methods were used for yeasts, and RPMI-MOPS medium semi-solidified with 0.2% low-melting-point agarose based on CLSI guidelines was used for moulds. The range of isavuconazole minimum inhibitory concentrations (MICs) was 0.0004-0.21 mg/L for Candida albicans, 0.0036-0.4 mg/L for Candida glabrata, 0.023-0.058 mg/L for Candida krusei, 0.0026-0.032 mg/L for Cryptococcus neoformans, 0.1-0.39mg/L for Aspergillus fumigatus and 0.2-0.39 mg/L for Aspergillus terreus. Isavuconazole was as active as ITC against the dimorphic true pathogenic fungi, with a range of MICs from <0.0004 mg/L to 0.0063 mg/L for Blastomyces dermatitidis and Histoplasma capsulatum. It was also active against uncommon dematiaceous fungi such as Exophiala spp. and Phialophora spp. as well as against dermatophytic species. Isavuconazole showed very good in vitro antifungal activity with a broad spectrum, including against FLC-resistant Candida spp., Aspergillus spp. and uncommon opportunistic fungal species. This is the first report of the in vitro susceptibility of Japanese clinical yeast isolates to isavuconazole. No cross-resistance was found to isavuconazole amongst FLC-resistant strains.

Histopathological study of candidal infection in the central nervous system

In recent years, incidence of invasive fungal infection has been increasing, mostly due to advances in + medicine that may produce immunocompromised individuals. Candidial infection in the central nervous system (CNS) is one of the most serious forms of blood stream infection of Candida sp. and mortality is known to be more than 50%. In this research, we employed 27 autopsies with confirmed in vasive CNS yeast infection which were confirmed. In addition to detailed morphological analysis of yeast cells in lesions, in situ hybridization was carried out with an originally designed Candida-specific peptide nucleic acid (PNA) probe to identify the candidial infection of each patient. This was followed by histopathological investigation: invasiveness, shape, and distribution of yeast or yeasts with pseudohyphal growth, and a study regarding the correlation between histological characteristics and number of leukocytes in the peripheral blood just before death. Results showed that the, supratentorial region was the most common area of disseminated candidial infection in CNS, and that density was highest in the cerebral gray matter followed by the white matter and basal ganglia. On the other hand, regarding the lesions developed in the cortical area, the average distance from the brain surface was 4.026 mm. This area corresponding to the deeper cortex has a characteristic arterial structure that refers hairpin curving reverse. The structure may contribute to the high incidence of candidial foci in the deeper cortex, because of the increase in shear stress.

Cerebral aspergillosis: tissue penetration is the key

Cerebral aspergillosis is increasingly recognized in severely immunocompromised patients and, until recently, this type of fungal infection was associated with a mortality approaching 100%. The central nervous system is a protected environment and penetration of drugs across the blood-brain barrier is mainly limited by their molecular size and physicochemical properties, as well as drug interaction with transporter systems (e.g., P-glycoprotein) at the blood-brain barrier. Most antifungal agents are large molecules (>700 Da), which makes sufficient penetration into the central nervous system unlikely. In fact, the available data indicate low levels of most antifungal agents in cerebrospinal fluid and brain tissue, except for fluconazole and voriconazole. Concentrations of voriconazole exceeding inhibitory concentrations for Aspergillus species were found repeatedly in cerebrospinal fluid and brain tissue, including brain abscess material. A recent retrospective study confirmed that voriconazole treatment resulted in improved response and survival rates in patients with cerebral aspergillosis. Data from animal models, which explored escalated doses or combinations of antifungal agents in experimental neuroaspergillosis, suggest that selected combination or dose-escalated therapies might further improve the still unsatisfactory prognosis in this particular type of Aspergillus infection.

Pulmonary cryptococcosis in late pregnancy and review of published literature

Naturally occurring maternal immunosuppression increases the risk of infection by a variety of pathogens during pregnancy and the postpartum period. Pulmonary cryptococcosis during pregnancy is relatively rare. Here, we report on two cases of pulmonary cryptococcosis during pregnancy and puerperium. Both cases were successfully treated using oral fluconazole after parturition to avoid fetal toxicity. For the two patients, the placentas were checked and found to be pathologically normal, and the cryptococcal serum antigen in both infants was negative. Pulmonary cryptococcosis should be considered during differential diagnosis as a possible cause of abnormal chest shadow in pregnant patients.

Workload and clinical significance of the isolation of zygomycetes in a tertiary general hospital

Several reports of increases in invasive zygomycosis (IZ) at individual institutions across the USA and Europe have contributed to a generalized concept that IZ is an increasing problem and the overestimation of the clinical significance of the isolation of zygomycetes in microbiology departments. We assessed the workload and clinical significance of zygomycetes isolates recovered from clinical samples in our institution over a 19-year period (1988-2006). We retrospectively reviewed the charts of those patients from who isolates of zygomycetes were obtained and calculated the workload of its isolation, the incidence of IZ during this period and the positive predictive value (PPV) of a positive culture. Zygomycetes were recovered from 210 samples (176 patients), i.e., 0.086/1,000 clinical samples processed and 6.3/1,000 samples submitted for fungal isolation. Zygomycetes represented 0.6% of the total fungi recovered. The mean incidence of the disease was 1.2 cases/100,000 admissions (range 0-20). Only 16 of the samples which grew zygomycetes (7.6%) were from infected patients. The workload generated by zygomycetes in our institution and the PPV for IZ of their isolation in our laboratory were very low and the disease was not found to have significantly increased in recent years in our institution. Data from specific institutions cannot be generalized.

[Spectrum and risk factors of invasive fungal infection]

In recent years, invasive fungal infection has become a growing problem in immunosuppressed patients. Simultaneously, changes in medical practice, such as the use of anti-Candida prophylaxis with azoles, has led to a shift in the epidemiology of these infections from Candida spp. to Aspergillus and other filamentous molds. Moreover, new risk factors for invasive fungal infection have been identified and the time of onset is different from that seen a decade ago. Recognition of these trends in patients receiving novel immunosuppressive regimens has important implications for the clinical management of fungal infection in this population.

Invasive aspergillosis: epidemiology, diagnosis and management in immunocompromised patients

Morbidity and mortality caused by invasive Aspergillus infections are increasing. This is because of the higher number of patients with malignancies treated with intensive immunosuppressive therapy regimens as well as their improved survival from formerly fatal bacterial infections, and the rising number of patients undergoing allogeneic haematopoietic stem cell or organ transplantation. Early initiation of effective systemic antifungal treatment is essential for a successful clinical outcome in these patients; however, clinical clues for diagnosis are sparse and early microbiological proof of invasive aspergillosis (IA) is rare. Clinical diagnosis is based on pulmonary CT scan findings and non-culture based diagnostic techniques such as galactomannan or DNA detection in blood or bronchoalveolar lavage samples. Most promising outcomes can be expected in patients at high risk for aspergillosis in whom antifungal treatment has been started pre-emptively, backed up by laboratory and imaging findings. The gold standard of systemic antifungal treatment is voriconazole, which has been proven to be significantly superior to conventional amphotericin B and has led to a profound improvement of survival rates in patients with cerebral aspergillosis. Liposomal amphotericin B at standard dosages appears to be a suitable alternative for primary treatment, while caspofungin, amphotericin B lipid complex or posaconazole have shown partial or complete response in patients who had been refractory to or intolerant of primary antifungal therapy. Combination therapy with two antifungal compounds may be a promising future strategy for first-line treatment. Lung resection helps to prevent fatal haemorrhage in single patients with pulmonary lesions located in close proximity to larger blood vessels, but is primarily considered for reducing the risk of relapse during subsequent periods of severe immunosuppression. Strict reverse isolation appears to reduce the incidence of aspergillosis in allogeneic stem cell transplant recipients and patients with acute myeloid leukaemia undergoing aggressive anticancer therapy. Well designed, prospective randomised studies on infection control measures effective to prevent aspergillosis are lacking. Prophylactic systemic antifungal treatment with posaconazole significantly improves survival and reduces IA in acute myeloid leukaemia patients and reduces aspergillosis incidence rates in patients with intermediate-to-severe graft-versus-host reaction emerging after allogeneic haematopoietic stem cell transplantation. Voriconazole prophylaxis may be suitable for prevention of IA as well; however, the results of large clinical trials are still awaited.

CNS aspergillosis: recognition, diagnosis and management

Early diagnosis of CNS aspergillosis requires a high degree of clinical suspicion, because there are no typical clinical symptoms or CSF findings. Clinical features are usually dramatic and tend to progress rapidly. Changes in mental status, hemiparesis and seizures are most common, but other nonspecific neurological features may occur and should always be an indication for neuroradiological examination in high-risk patients, in order to allow early initiation of antifungal therapy. Low density lesions with little or no mass effect and minimal or no contrast enhancement on CT scans that are usually more numerous on MRI and show intermediate signal intensity within high-signal areas on T2-weighted images, may suggest CNS aspergillosis. Cerebral lesions in CNS aspergillosis are often located not only in the cerebral hemispheres but also in the basal ganglia, thalami, corpus callosum and perforator artery territories. There is frequently a lack of contrast enhancement or perifocal oedema, due to the immunosuppressed status of the patient. A definite diagnosis requires brain tissue for histopathological analysis. However, neurosurgery is often not feasible, so that any of the neuroradiological findings mentioned above should raise the suspicion of CNS aspergillosis in immunocompromised patients and lead to early initiation of antifungal therapy. In the past, amphotericin B-based therapy was the treatment of choice for CNS aspergillosis, but this treatment produced negligible effects. Recently, voriconazole has been reported to be more effective than amphotericin B in the treatment of invasive aspergillosis. Response rates of about 35% have been achieved with voriconazole in patients with CNS aspergillosis. Combination therapy with antifungal agents, such as voriconazole plus caspofungin or liposomal amphotericin B, is being investigated in vitro and in animal models, and optimistic results have been observed. A combined medical and neurosurgical treatment should be considered in all patients with this disease.

Indicaciones actuales de voriconazol en pacientes onco-hematológicos

Invasive fungal infections (IFI) are the main cause of infectious death in cancer patients, especially in hematological malignancies and hematopoietic transplant recipients. Current epidemiology is characterized by a predominance of IFI caused by molds, mainly aspergillosis, along with a emergence of hard-to-treat fungi such are Zygomicetes, Fusarium and Scedosporium. Voriconazole is a broad spectrum antifungal agent with oral and intravenous formulations, approved by the EMEA for the treatment of invasive aspergillosis, candidemia in non-neutropenic patients, IFI caused by fluconazole-resistant species of Candida as well as Scedosporium and Fusarium infections. However, its use in clinical practice is broader, as empirical antifungal treatment and as secondary prophylaxis. It should be kept in mind the possibility of breakthrough IFI, particularly zygomycosis, in patients treated with voriconazole for long periods.

Diagnosis of invasive aspergillosis and mucormycosis in immunocompromised patients by seminested PCR assay of tissue samples

Aspergillosis and mucormycosis are the most common mold infections in patients with hematological malignancies. Infections caused by species of the genus Aspergillus and the order Mucorales require different antifungal treatments depending on the in vitro susceptibility of the causative strain. Cultures from biopsy specimens frequently do not grow fungal pathogens, even from histopathologically proven cases of invasive fungal infection. Two seminested PCR assays were evaluated by amplifying DNA of zygomycetes and Aspergillus spp. from organ biopsies of 21 immunocompromised patients. The PCR assays correctly identified five cases of invasive aspergillosis and six cases of mucormycosis. They showed evidence of double mold infection in two cases. Both assays were negative in five negative controls and in two patients with yeast infections. Sequencing of the PCR products was in accordance with culture results in all culture-positive cases. In six patients without positive cultures but with positive histopathology, sequencing suggested a causative organism. Detection of fungal DNA from biopsy specimens allows rapid identification of the causative organism of invasive aspergillosis and mucormycosis. The use of these PCR assays may allow guided antifungal treatment in patients with invasive mold infections.

Impact of zygomycosis on microbiology workload: a survey study in Spain

This multicenter, population-based study evaluated the laboratory workload produced by zygomycetes and the number of cases of zygomycosis in Spain during 2005. Less than 8% of the patients who harbored zygomycete isolates had zygomycosis. The incidence of zygomycosis (6 cases) was 0.43 cases/1,000,000 inhabitants and 0.62 cases/100,000 hospital admissions.

Nosocomial fungal infections: epidemiology, diagnosis, and treatment

Invasive fungal infections are increasingly common in the nosocomial setting. Furthermore, because risk factors for these infections continue to increase in frequency, it is likely that nosocomial fungal infections will continue to increase in frequency in the coming decades. The predominant nosocomial fungal pathogens include Candida spp., Aspergillus spp., Mucorales, Fusarium spp., and other molds, including Scedosporium spp. These infections are difficult to diagnose and cause high morbidity and mortality despite antifungal therapy. Early initiation of effective antifungal therapy and reversal of underlying host defects remain the cornerstones of treatment for nosocomial fungal infections. In recent years, new antifungal agents have become available, resulting in a change in standard of care for many of these infections. Nevertheless, the mortality of nosocomial fungal infections remains high, and new therapeutic and preventative strategies are needed.