Kodamaea ohmeri: A rare yeast causing invasive infections in immunocompromised patients.

INTRODUCTION: Kodamaea ohmeri is a rare, recognized pathogen that has previously been isolated from environmental sources. The patients commonly affected by this yeast include immunocompromised as well as immunocompetent patients having several associated risk factors. METHODOLOGY: We report three cases in which K. ohmeri was isolated from blood using Bact T/ALERT. Identification was carried out by MALDI-TOF MS (Vitek-MS, BioMérieux, Marcy-l'Etoile, France) in addition to color characteristics on chromogenic media. The patients had diminished immune response on account of a multitude of comorbidities. RESULTS: K. ohmeri can be misidentified as Candida tropicalis, Candida albicans, or Candida hemolounii by conventional methods; correct and timely identification can be achieved by MALDI-TOF MS. Antifungal susceptibility breakpoints for K. ohmeri are currently not defined. An Echinocandin was added to the treatment regimen of all three of the cases. CONCLUSIONS: Identification of K. ohmeri using conventional methods is difficult and unusual yeasts should be carefully observed, especially upon prolonged incubation.

End-organ damage from neonatal invasive fungal infection: a 14-year retrospective study from a tertiary center in China.

BACKGROUND: Invasive fungal infection (IFI) has become an increasing problem in NICU neonates, and end-organ damage (EOD) from IFI is one of the leading causes of morbidity and mortality in neonates. This study was conducted to summarize clinical data on epidemiology, risk factors, causative pathogens, and clinical outcomes of IFI-associated EOD among neonates in a center in China for the sake of providing references for prevention and treatment of fungal infections in neonates in future. METHODS: The clinical data of IFI neonates who received treatment in a tertiary NICU of China from January 2009 to December 2022 were retrospectively analyzed, including causative pathogens and the incidence of EOD. The neonates were divided into EOD group and non-EOD (NEOD) group. The general characteristics, risk factors and clinical outcomes of the two groups were compared. RESULTS: Included in this study were 223 IFI neonates (137 male and 86 female) with a median gestational age (GA) of 30.71 (29,35) weeks and a median birth weight (BW) of 1470 (1120,2150) g. Of them, 79.4% were preterm infants and 50.2% were born at a GA of ≥ 28, <32 weeks, and 37.7% with BW of 1000-1499 g. Candida albicans (C. albicans) was the most common Candida spp. in these neonates, accounting for 41.3% of all cases, followed by C. parapsilosis (30.5%) and C. glabrata (7.2%). EOD occurred in 40 (17.9%) of the 223 cases. Fungal meningitis was the most common EOD, accounting for 13.5% of the 40 EOD cases. There was no significant difference in the premature birth rate, delivery mode, GA and BW between EOD and NEOD groups, but the proportion of male infants with EOD was higher than that without. There was no significant difference in antenatal corticosteroid use, endotracheal intubation, invasive procedures, use of antibiotics, total parenteral nutrition, blood transfusion, postnatal corticosteroid use, fungal prophylaxis and the incidence of necrotizing enterocolitis between the two groups, but the proportion of C. albicans infection cases in EOD group was higher than that in NEOD group (57.5% vs. 37.7%). Compared with NEOD group, the proportion of cured or improved infants in EOD group was significantly lower (P < 0.05), and the number of infants who died or withdrew from treatment was larger (P < 0.05). CONCLUSIONS: Our retrospective study showed that preterm infants were prone to fungal infection, especially very preterm infants. C. albicans was the most common Candida spp. for IFI, and was a high-risk factor for EOD. EOD can occur in both full-term and premature infants, so the possibility of EOD should be considered in all infants with IFI.

Dynamics and prognostic value of plasma cell-free DNA PCR in patients with invasive aspergillosis and mucormycosis.

Aspergillus species and Mucorales agents are the primary etiologies of invasive fungal disease (IFD). Biomarkers that predict outcomes are needed to improve care. Patients diagnosed with invasive aspergillosis and mucormycosis using plasma cell-free DNA (cfDNA) PCR were retested weekly for 4 weeks. The primary outcome included all-cause mortality at 6 weeks and 6 months based on baseline cycle threshold (CT) values and results of follow-up cfDNA PCR testing. Forty-five patients with Aspergillus and 30 with invasive Mucorales infection were retested weekly for a total of 197 tests. Using the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium (EORTC/MSG) criteria, 30.7% (23/75), 25.3% (19/75), and 38.7% (29/75) had proven, probable, and possible IFD, respectively. In addition, 97.3% (73/75) were immunocompromised. Baseline CT increased significantly starting at week 1 for Mucorales and week 2 for Aspergillus. Aspergillosis and mucormycosis patients with higher baseline CT (CT >40 and >35, respectively) had a nonsignificantly higher survival rate at 6 weeks, compared with patients with lower baseline CT. Mucormycosis patients with higher baseline CT had a significantly higher survival rate at 6 months. Mucormycosis, but not aspergillosis patients, with repeat positive cfDNA PCR results had a nonsignificantly lower survival rate at 6 weeks and 6 months compared with patients who reverted to negative. Aspergillosis patients with baseline serum Aspergillus galactomannan index <0.5 and <1.0 had significantly higher survival rates at 6 weeks when compared with those with index ≥0.5 and ≥1.0, respectively. Baseline plasma cfDNA PCR CT can potentially be used to prognosticate survival in patients with invasive Aspergillus and Mucorales infections. IMPORTANCE: We show that Aspergillus and Mucorales plasma cell-free DNA PCR can be used not only to noninvasively diagnose patients with invasive fungal disease but also to correlate the baseline cycle threshold with survival outcomes, thus potentially allowing the identification of patients at risk for poor outcomes, who may benefit from more targeted therapies.

Increase in the incidence of invasive fungal infections due to Volvariella Volvacea.

PURPOSE: We aimed to show the increasing incidence of invasive fungal infections due to Volvariella Volvacea in patients with immunosuppression. METHODS: We present a case of an invasive fungal infection caused by Volvariella volvacea, and summarize the clinical and pathological features based on this case and a review of the literature. RESULTS: A total of seven patients with IFIs due to Volvariella Volvacea have been reported in the literature. The majority of cases have been obtained between 2019 and 2022. Including our case, they all had acquired immunosuppression. The lung and brain were the most commonly affected organs. All eight of these patients received antifungal therapy, but five still died one to seven months after occurrences of IFIs. CONCLUSION: The incidence of invasive fungal infections due to Volvariella Volvacea is increasing in recent years. It mainly occurred in patients with immunosuppression, especially in patients with malignant hematological cancers, and increased mortality.

Utility of an in-house real-time PCR in whole blood samples as a minimally invasive method for early and accurate diagnosis of invasive mould infections.

INTRODUCTION: Invasive mould infections (IMIs) are a leading cause of death in patients with compromised immune systems. Proven invasive mould infection requires detection of a fungus by histopathological analysis of a biopsied specimen, sterile culture, or fungal DNA amplification by PCR in tissue. However, the clinical performance of a PCR assay on blood samples taken from patients suspected of invasive mould disease has not been fully evaluated, particularly for the differential diagnosis of invasive aspergillosis (IA) and invasive Mucormycosis (IM). OBJECTIVES: To assess the diagnostic utility of our previously validated in-house real-time PCR in blood samples for diagnosis of invasive aspergillosis and mucormycosis in patients with suspected invasive mould infection. METHODS: All patients with suspected invasive mould infection were prospectively enrolled from May 2021 to July 2021. Conventional fungal diagnosis was performed using tissue and respiratory samples. In-house PCR was performed on blood samples and its diagnostic performance evaluated. RESULTS: A total of 158 cases of suspected invasive mould infection were enrolled in the study. The sensitivity and specificity of in-house PCR performed on blood samples was found to be 92.5% and 81.4% respectively for diagnosis of probable IA, and 65% and 84.62% respectively for diagnosis of proven and probable IM. It was also able to detect 3 out of 5 cases of possible IM where no other microbiological evidence of IM was obtained. CONCLUSIONS: This assay could be helpful in minimally invasive diagnosis of IMIs for patients in whom invasive sampling is not feasible, especially as a preliminary or screening test. It can help in early diagnosis, anticipating conventional laboratory confirmation by days or weeks. Possible correlation between fungal load and mortality can help in initiating aggressive treatment for patients with high initial fungal load.

Therapeutic drug monitoring of antifungal therapies: do we really need it and what are the best practices?

INTRODUCTION: Despite advancements, invasive fungal infections (IFI) still carry high mortality rates, often exceeding 30%. The challenges in diagnosis, coupled with limited effective antifungal options, make managing IFIs complex. Antifungal drugs are essential for IFI management, but their efficacy can be diminished by drug-drug interactions and pharmacokinetic variability. Therapeutic Drug Monitoring (TDM), especially in the context of triazole use, has emerged as a valuable strategy to optimize antifungal therapy. AREAS COVERED: This review provides current evidence regarding the potential benefits of TDM in IFI management. It discusses how TDM can enhance treatment response, safety, and address altered pharmacokinetics in specific patient populations. EXPERT OPINION: TDM plays a crucial role in achieving optimal therapeutic outcomes in IFI management, particularly for certain antifungal agents. Preclinical studies consistently show a link between therapeutic drug levels and antifungal efficacy. However, clinical research in mycology faces challenges due to patient heterogeneity and the diversity of fungal infections. TDM's potential advantages in guiding Echinocandin therapy for critically ill patients warrant further investigation. Additionally, for drugs like Posaconazole, assessing whether serum levels or alternative markers like saliva offer the best measure of efficacy is an intriguing question.

Overview of invasive fungal infections in children in South America - the threat of resistant Candida species and the role of climate change in the new geographic distribution of endemic systemic mycosis.

PURPOSE OF REVIEW: Invasive fungal infection (IFI) in children is a growing problem with crescent morbidity and mortality, well recognized in developed countries, affecting mainly immunocompromised children, including neonates and children in intensive care units. The burden of IFI in South American children is less well comprehended. In addition, the current epidemiology of endemic systemic mycoses in children may have changed over time. RECENT FINDINGS: Candida spp. infections are very prevalent in South America hospitalized children, especially in neonates, in a rate far superior compared to developed countries. C. auris, has already been responsible for outbreaks in neonates and children in Venezuela and Colombia. Sporotrichosis is well established as an urban zoonosis in impoverish families. Paracoccidioidomycosis and histoplasmosis are affecting new areas of Brazil, probably due to climate change, deforestation, and human migration. SUMMARY: This review aims to unveil the real dimension of these infections in South American children. Hopefully, the awareness brought by this review will help healthcare professionals to recognize IFI more easily and it will provide support for getting more resources for IFI treatment and prevention.

Laboratory and clinical management capacity for invasive fungal infections: the Italian landscape.

BACKGROUND: We assessed the laboratory diagnosis and treatment of invasive fungal disease (IFD) in Italy to detect limitations and potential for improvement. METHODS: The survey was available online at www.clinicalsurveys.net/uc/IFI management capacity/, and collected variables such as (a) institution profile, (b) perceptions of IFD in the respective institution, (c) microscopy, (d) culture and fungal identification, (e) serology, (f) antigen detection, (g) molecular tests, (h) susceptibility testing and (i) therapeutic drug monitoring (TDM). RESULTS: The laboratory capacity study received responses from 49 Italian centres, with an equitable geographical distribution of locations. The majority of respondents (n = 36, 73%) assessed the occurrence of IFD as moderate-high, with Aspergillus spp. being the pathogen of highest concern, followed by Candida spp. and Mucorales. Although 46 (94%) of the institutions had access to microscopy, less than half of them performed direct microscopy on clinical specimens always when IFD was suspected. Cultures were available in all assessed laboratories, while molecular testing and serology were available in 41 (83%), each. Antigen detection tests and antifungal drugs were also generally accessible (> 90%) among the participating institutions. Nevertheless, access to TDM was limited (n = 31, 63%), with a significant association established between therapeutic drug monitoring availability and higher gross domestic product per capita. CONCLUSIONS: Apart from TDM, Italy is adequately prepared for the diagnosis and treatment of IFD, with no significant disparities depending on gross domestic product. Future efforts may need to focus on enhancing the availability and application of direct microscopic methods, as well as TDM, to promote optimal treatment and better patient outcomes.

[Enlightenment of World Health Organization fungal priority pathogens list].

The WHO established the first fungal priority pathogens list (FPPL) in October 2022 to focus on and promote further research and policy interventions to strengthen the global response to fungal infections and antifungal resistance. The FPPL and its formulation process provide new significant insights for managing pathogenic fungi and invasive fungal disease (IFD) in China, necessitating the following key actions: Strengthen public health interventions for IFD. Further, it improves the ability of laboratory testing and clinical supervision for IFD and pathogenic fungi. Increase targeted investment and support for innovative research and development in IFD diagnosis, treatment, and prevention.

[Research advances on invasive fungal infections after burns].

Invasive fungal infection (IFI) is one of the serious complications in burn patients. The gradual development and application of broad-spectrum antibiotics in recent years has led to a serious dysbiosis of the flora, while the widespread prophylactic use of antifungal drugs has led to an increasing number of drug-resistant fungi. The clinical treatment of IFI is difficult and the prognosis is poor. The mortality of burn patients caused by IFI is increasing year by year. This paper reviews the epidemiologic characteristics, related risk factors, diagnostic methods, and treatment progress of IFI after burns, aiming to provide new ideas and reference for the prevention and treatment of IFI after burns.

An update on the global treatment of invasive fungal infections.

Fungal infections are a serious problem affecting many people worldwide, creating critical economic and medical consequences. Fungi are ubiquitous and can cause invasive diseases in individuals mostly living in developing countries or with weakened immune systems, and antifungal drugs currently available have important limitations in tolerability and efficacy. In an effort to counteract the high morbidity and mortality rates associated with invasive fungal infections, various approaches are being utilized to discover and develop new antifungal agents. This review discusses the challenges posed by fungal infections, outlines different methods for developing antifungal drugs and reports on the status of drugs currently in clinical trials, which offer hope for combating this serious global problem.

Antifungal therapy: Novel drug delivery strategies driven by new targets.

In patients with compromised immunity, invasive fungal infections represent a significant cause of mortality. Given the limited availability and drawbacks of existing first-line antifungal drugs, there is a growing interest in exploring novel targets that could facilitate the development of new antifungal agents or enhance the effectiveness of conventional ones. While previous studies have extensively summarized new antifungal targets inherent in fungi for drug development purposes, the exploration of potential targets for novel antifungal drug delivery strategies has received less attention. In this review, we provide an overview of recent advancements in new antifungal drug delivery strategies that leverage novel targets, including those located in the physio-pathological barrier at the site of infection, the infection microenvironment, fungal-host interactions, and the fungal pathogen itself. The objective is to enhance therapeutic efficacy and mitigate toxic effects in fungal infections, particularly in challenging cases such as refractory, recurrent, and drug-resistant invasive fungal infections. We also discuss the current challenges and future prospects associated with target-driven antifungal drug delivery strategies, offering important insights into the clinical implementation of these innovative approaches.

Primary prophylaxis of invasive fungal diseases in patients with haematological malignancies: 2022 update of the recommendations of the Infectious Diseases Working Party (AGIHO) of the German Society for Haematology and Medical Oncology (DGHO).

Patients with haematological malignancies (HM) are at high risk of developing invasive fungal disease (IFD) with high morbidity and attributable mortality. We reviewed data published until September 2021 to update the 2017 antifungal prophylaxis recommendations of the German Society of Haematology and Medical Oncology (DGHO). The strong recommendation to administer antifungal prophylaxis in patients with HM with long-lasting neutropenia, i.e. <500 cells/µL for >7 days remains unchanged. Posaconazole remains the drug of choice for mould-active prophylaxis in these patients. Novel treatment options in HM, such as CAR-T-cell treatment or novel targeted therapies for acute myeloid leukaemia (AML) were considered, however, data are insufficient to give general recommendations for routine antifungal prophylaxis in these patients. Major changes regarding specific recommendations compared to the 2017 edition are the now moderate instead of mild support for the recommendations of isavuconazole and voriconazole. Furthermore, published evidence on micafungin allows recommending it at moderate strength for its use in HM. For the first time we included recommendations for non-pharmaceutical measures regarding IFD, comprising the use of high-efficiency particulate air (HEPA) filters, smoking, measures during construction work and neutropenic diets. We reviewed the impact of antifungal prophylaxis with triazoles on drug-drug interactions with novel targeted therapies that are metabolized via cytochrome p450 where triazoles inhibit CYP3A4/5. The working group recommends reducing the dose of venetoclax when used concomitantly with strong CYP3A4 inhibiting antifungals. Furthermore, we reviewed data on the prophylactic use of novel antifungal agents. Currently there is no evidence to support their use in a prophylactic setting in clinical practice.

Post-hoc analysis of the safety and efficacy of isavuconazole in older patients with invasive fungal disease from the VITAL and SECURE studies.

Isavuconazole is a triazole with broad-spectrum antifungal activity. In this post-hoc analysis of two prospective clinical trials (VITAL and SECURE), the safety and efficacy of isavuconazole in patients aged ≥ 65 years with invasive fungal diseases were evaluated. Patients were divided into two subgroups (≥ 65 and < 65 years). Adverse events (AEs); all-cause mortality; and overall, clinical, mycological, and radiological response were assessed. A total of 155 patients ≥ 65 years were enrolled in both trials. Most patients reported AEs. In the isavuconazole arm of both studies, serious AEs (SAEs) were greater in patients ≥ 65 versus < 65 years: 76.7% versus 56.9% (VITAL); 61.9% versus 49.0% (SECURE). In SECURE, SAE rates were similar in the ≥ 65 years subgroup of both treatment arms (61.9% vs 58.1%), while in the < 65 years subgroup the SAE rate was lower in the isavuconazole arm (49.0% vs 57.4%). In VITAL, all-cause mortality through day 42 (30.0% vs 13.8%) was higher, and overall response at end of treatment (27.6% vs 46.8%) was lower in patients ≥ 65 years versus < 65 years. In SECURE, all-cause mortality was similar between both subgroups, and isavuconazole (20.6% vs 17.9%) and voriconazole (22.6% vs 19.4%) treatment arms. The overall response was lower in the ≥ 65 years than the < 65 years subgroup in the isavuconazole (23.7% vs 39.0%) and voriconazole (32.0% vs 37.5%) arms. The safety and efficacy of isavuconazole were better in patients < 65 versus ≥ 65 years, and the safety profile was more favorable than that of voriconazole in both subgroups.Clinicaltrials.gov identifier NCT00634049 and NCT00412893.

Breakthrough invasive fungal infection in patients with myeloid malignancy receiving posaconazole tablet prophylaxis: Clinical features, risk factors, and posaconazole profiles.

Posaconazole (PSC) delayed-release tablet prophylaxis is the standard of care for preventing invasive fungal infection (IFI) in patients with acute myeloid leukemia undergoing myelosuppressive chemotherapy. The clinical features, risk factors, and PSC profiles of breakthrough IFI (bIFI) in patients receiving PSC tablet prophylaxis were investigated. A single-center retrospective cohort study was conducted, including adult patients with myeloid malignancy who received prophylactic PSC tablets while undergoing chemotherapy from June 2016 to June 2021. Logistic regression analysis was used to identify risk factors for bIFI. A receiver operating characteristic curve was used to predict the relationship between PSC trough level at steady state and bIFI. A total of 434 patients with myeloid malignancy who received PSC tablets were screened. A total of 10 patients with bIFI were compared with 208 non-IFI patients. There were four proven and six probable IFI cases, nine due to Aspergillus, and one due to Fusarium species. The bIFI patients had higher in-hospital mortality (30.0%) than the non-IFI patients (1.9%; P < 0.001). History of allogeneic hematopoietic stem cell transplantation (odds ratio [OR] 6.27; 95% confidence interval [CI] 1.63-24.09), prolonged neutropenia ≥28 days (OR 4.33; 95% CI 1.20-15.70), and low plasma PSC concentration <0.7 µg/ml (OR 16.33; 95% CI 4.15-64.26) were risk factors for bIFI. The optimal cutoff value of plasma PSC concentration predicting bIFI was 0.765 µg/ml (sensitivity, 60.0%; specificity, 91.3%; area under the curve, 0.746). bIFI was not uncommon in patients with myeloid malignancy receiving PSC tablet prophylaxis and associated with poor outcomes. Therapeutic drug monitoring may still be necessary, even in patients receiving PSC tablets.

Invasive fungal infections increase mortality in acute myeloid leukemia patients. This study investigated breakthrough invasive fungal infection cases in patients receiving posaconazole tablet prophylaxis. Our results will contribute to improving the outcome of patients with myeloid malignancy.

Physicians' knowledge of invasive fungal disease in China.

BACKGROUND: Invasive fungal disease (IFD) is associated with high morbidity and mortality. Data are lacking regarding physicians' perspectives on the diagnosis and management of IFD in China. OBJECTIVES: To evaluate physicians' perspectives on the diagnosis and management of IFD. METHODS: Based on current guidelines, a questionnaire was designed and administered to 294 physicians working in haematology departments, intensive care units, respiratory departments and infectious diseases departments in 18 hospitals in China. RESULTS: The total score and subsection scores for invasive candidiasis, invasive aspergillosis (IA), cryptococcosis and invasive mucormycosis (IM) were 72.0 ± 12.2 (maximum = 100), 11.1 ± 2.7 (maximum = 19), 43.0 ± 7.8 (maximum = 57), 8.1 ± 2.0 (maximum = 11) and 9.8 ± 2.3 (maximum = 13), respectively. Although the perspectives of the Chinese physicians were in good overall agreement with guideline recommendations, some knowledge gaps were identified. Specific areas in which the physicians' perspectives and guideline recommendations differed included use of the ß-D-glucan test to facilitate the diagnosis of IFD, relative utility of the serum galactomannan test and bronchoalveolar lavage fluid galactomannan test in patients with agranulocytosis, use of imaging in the diagnosis of mucormycosis, risk factors for mucormycosis, indications for initiating antifungal therapy in patients with haematological malignancies, when to start empirical therapy in mechanically ventilated patients, first-line drugs for mucormycosis and treatment courses for IA and IM. CONCLUSION: This study highlights the main areas that could be targeted by training programs to improve the knowledge of physicians treating patients with IFD in China.

Microbial and clinical epidemiology of invasive fungal rhinosinusitis in hospitalized COVID-19 patients, the divergent causative agents.

Since COVID-19 spread worldwide, invasive fungal rhinosinusitis (IFRS) has emerged in immunocompromised patients as a new clinical challenge. In this study, clinical specimens of 89 COVID-19 patients who presented clinical and radiological evidence suggestive of IFRS were examined by direct microscopy, histopathology, and culture, and the isolated colonies were identified through DNA sequence analysis. Fungal elements were microscopically observed in 84.27% of the patients. Males (53.9%) and patients over 40 (95.5%) were more commonly affected than others. Headache (94.4%) and retro-orbital pain (87.6%) were the most common symptoms, followed by ptosis/proptosis/eyelid swelling (52.8%), and 74 patients underwent surgery and debridement. The most common predisposing factors were steroid therapy (n = 83, 93.3%), diabetes mellitus (n = 63, 70.8%), and hypertension (n = 42, 47.2%). The culture was positive for 60.67% of the confirmed cases, and Mucorales were the most prevalent (48.14%) causative fungal agents. Different species of Aspergillus (29.63%) and Fusarium (3.7%) and a mix of two filamentous fungi (16.67%) were other causative agents. For 21 patients, no growth was seen in culture despite a positive result on microscopic examinations. In PCR-sequencing of 53 isolates, divergent fungal taxons, including 8 genera and 17 species, were identified as followed: Rhizopus oryzae (n = 22), Aspergillus flavus (n = 10), A. fumigatus (n = 4), A. niger (n = 3), R. microsporus (n = 2), Mucor circinelloides, Lichtheimia ramosa, Apophysomyces variabilis, A. tubingensis, A. alliaceus, A. nidulans, A. calidoustus, Fusarium fujikuroi/proliferatum, F. oxysporum, F. solani, Lomentospora prolificans, and Candida albicans (each n = 1). In conclusion, a diverse set of species involved in COVID-19-associated IFRS was observed in this study. Our data encourage specialist physicians to consider the possibility of involving various species in IFRS in immunocompromised and COVID-19 patients. In light of utilizing molecular identification approaches, the current knowledge of microbial epidemiology of invasive fungal infections, especially IFRS, may change dramatically.

Invasive fungal rhinosinusitis (IFRS) may infect people with diabetes, cancer, or COVID-19. In this study, various types of fungi were identified from COVID-19-associated-IFRS, encouraging physicians to consider specific treatments.

Diagnosis of invasive respiratory mycoses in the immunocompromised host.

PURPOSE OF REVIEW: The burden of invasive fungal infection is increasing worldwide, largely due to a growing population at-risk. Most serious human fungal pathogens enter the host via the respiratory tract. Early identification and treatment of invasive fungal respiratory infections (IFRIs) in the immunocompromised host saves lives. However, their accurate diagnosis is a difficult challenge for clinicians and mortality remains high. RECENT FINDINGS: This article reviews IFRIs, focussing on host susceptibility factors, clinical presentation, and mycological diagnosis. Several new diagnostic tools are coming of age including molecular diagnostics and point-of-care antigen tests. As diagnosis of IFRI relies heavily on invasive procedures like bronchoalveolar lavage and lung biopsy, several novel noninvasive diagnostic techniques are in development, such as metagenomics, 'volatilomics' and advanced imaging technologies. SUMMARY: Where IFRI cannot be proven, clinicians must employ a 'weights-of-evidence' approach to evaluate host factors, clinical and mycological data. Implementation studies are needed to understand how new diagnostic tools can be best applied within clinical pathways. Differentiating invasive infection from colonization and identifying antifungal resistance remain key challenges. As our diagnostic arsenal expands, centralized clinical mycology laboratories and efforts to ensure access to new diagnostics in low-resource settings will become increasingly important.