COVID-19 Associated Pulmonary Aspergillosis (CAPA)-From Immunology to Treatment

Aspergillosis ball graft as complication of Covid-19 infection: Case report

Invasive pulmonary aspergillosis is a severe presentation of aspergillosis fungal infection, with a high mortality rate. Many Covid-19-associated pulmonary aspergillosis cases have been described in the literature giving rise to a major dilemma for physicians: discriminate a simple colonization from an invasive infection. In this paper, we will describe the case of a 40-year-old immunocompetent man with no medical history was admitted to the intensive care unit for Covid-19 infection with lung damage initially estimated at 50%-75%. Two weeks later, patient condition got worse, with a thoracic CT showing a newly developed, well limited lung cavitation indicative of an aspergillosis fungus ball.

COVID-19-Associated Pulmonary Aspergillosis (CAPA) in Northern Greece during 2020-2022: A Comparative Study According to the Main Consensus Criteria and Definitions

Coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) has emerged as an important complication among patients with acute respiratory failure due to SARS-CoV-2 infection. Almost 2.5 years since the start of the COVID-19 pandemic, it continues to raise concerns as an extra factor that contributes to increased mortality, which is mostly because its diagnosis and management remain challenging. The present study utilises the cases of forty-three patients hospitalised between August 2020 and February 2022 whose information was gathered from ten ICUs and special care units based in northern Greece. The main aim was to describe the gained experience in diagnosing CAPA, according to the implementation of the main existing diagnostic consensus criteria and definitions, and present the different classification of the clinical cases due to the alternative algorithms.

COVID-19-associated pulmonary aspergillosis in immunocompetent patients: A virtual patient cohort study

Purpose

The opportunistic fungus Aspergillus fumigatus infects the lungs of immunocompromised hosts, including patients undergoing chemotherapy or organ transplantation. More recently however, immunocompetent patients with severe SARS-CoV2 have been reported to be affected by COVID-19 Associated Pulmonary Aspergillosis (CAPA), in the absence of the conventional risk factors for invasive aspergillosis. This paper explores the hypothesis that contributing causes are the destruction of the lung epithelium permitting colonization by opportunistic pathogens. At the same time, the exhaustion of the immune system, characterized by cytokine storms, apoptosis, and depletion of leukocytes may hinder the response to A. fumigatus infection. The combination of these factors may explain the onset of invasive aspergillosis in immunocompetent patients.

Methods

We used a previously published computational model of the innate immune response to infection with Aspergillus fumigatus . Variation of model parameters was used to create a virtual patient population. A simulation study of this virtual patient population to test potential causes for co-infection in immunocompetent patients.

Results

The two most important factors determining the likelihood of CAPA were the inherent virulence of the fungus and the effectiveness of the neutrophil population, as measured by granule half-life and ability to kill fungal cells. Varying these parameters across the virtual patient population generated a realistic distribution of CAPA phenotypes observed in the literature.

Conclusions

Computational models are an effective tool for hypothesis generation. Varying model parameters can be used to create a virtual patient population for identifying candidate mechanisms for phenomena observed in actual patient populations.

A Case Series Demonstrating the Difficulties in Diagnosing COVID-19 Associated Pulmonary Aspergillus

Many bacterial, viral, and fungal co-infections have been reported with COVID-19-associated acute respiratory distress syndrome (ARDS). Invasive Aspergillosis has been described with COVID-19 ARDS. However, it continues to evade diagnosis in critically ill patients admitted to the intensive care unit (ICU). The difficulty is discerning an actual infection from colonization. Unfortunately, a timely diagnosis is crucial since COVID-19-associated pulmonary Aspergillus (CAPA) has high morbidity and mortality. We present three ICU cases of CAPA to illustrate the difficulty in diagnosing and treating the disease. We hope to bring awareness and improve patient outcomes of CAPA.

COVID-19-associated pulmonary aspergillosis (CAPA) in Iranian patients admitted with severe COVID-19 pneumonia

PURPOSE

Bacterial or virus co-infections with SARS-CoV-2 have been reported in many studies; however, the knowledge on Aspergillus co-infection among patients with COVID-19 was limited. This study was conducted to identify and isolate fungal agents and to evaluate the prevalence of pulmonary aspergillosis (CAPA) as well as antifungal susceptibility patterns of Aspergillus species in patients with COVID-19 admitted to Shahid Beheshti Hospital, Kashan, Iran.

METHODS

The study involved 119 patients with severe COVID-19 pneumonia referred to the Shahid Beheshti Hospital, Kashan, Iran. A total of 17 Aspergillus spp. that were isolated from COVID-19 patients suspected of CAPA were enrolled in the study. CAPA was defined using ECMM/ISHAM consensus criteria. The PCR amplification of the β-tubulin gene was used to identify the species. The antifungal activities of fluconazole, itraconazole, voriconazole, amphotericin B against Aspergillus spp. were evaluated according to the Clinical and Laboratory Standards Institute manual (M38-A3).

RESULTS

From the 119 patients with severe COVID-19 pneumonia, CAPA was confirmed in 17 cases (14.3%). Of these, 12 (70.6%) were males and 5 (29.4%) were females; the mean age at presentation was 73.8 years (range: 45-88 years; median = 77; IQR = 18). Aspergillus fumigatus (9/17; 52.9%), Aspergillus flavus (5/17; 29.4%), Aspergillus oryzae (3/17, 17.6%), were identified as etiologic agents of CAPA, using the molecular techniques. Voriconazole and amphotericin B showed more activity against all isolates. Moreover, the MIC of fluconazole, itraconazole varied with the tested isolates. For 3 clinical isolates of A. fumigatus, 2 isolate of A. flavus and 3 A. oryzae, the MIC of fluconazole and itraconazole were ≥ 16 µg/mL.

CONCLUSIONS

We observed a high incidence (14.3%) of probable aspergillosis in 119 patients with COVID-19, which might indicate the risk for developing IPA in COVID-19 patients. When comparing patients with and without CAPA regarding baseline characteristics, CAPA patients were older (p =0 .024), had received more frequent systemic corticosteroids (p = 0.024), and had a higher mortality rate (p = 0.018). The outcome of CAPA is usually poor, thus emphasis shall be given to screening and/or prophylaxis in COVID-19 patients with any risk of developing CAPA.

Calcofluor white-cholesteryl hydrogen succinate conjugate mediated liposomes for enhanced targeted delivery of voriconazole into Candida albicans

A nano antifungal-drug delivery system is designed to increase voriconazole efficacy by specifically binding to chitin in the fungal cell wall.

Postinfluenza Environment Reduces Aspergillus fumigatus Conidium Clearance and Facilitates Invasive Aspergillosis In Vivo

Aspergillus fumigatus is a human fungal pathogen that is most often avirulent in immunecompetent individuals because the innate immune system is efficient at eliminating fungal conidia. However, recent clinical observations have shown that severe influenza A virus (IAV) infection can lead to secondary A. fumigatus infections with high mortality. Little is currently known about how IAV infection alters the innate antifungal immune response. Here, we established a murine model of IAV-induced A. fumigatus (IAV-Af) superinfection by inoculating mice with IAV followed 6 days later by A. fumigatus conidia challenge. We observed increased mortality in the IAV-Af-superinfected mice compared to mice challenged with either IAV or A. fumigatus alone. A. fumigatus conidia were able to germinate and establish a biofilm in the lungs of the IAV-Af superinfection group, which was not seen following fungal challenge alone. While we did not observe any differences in inflammatory cell recruitment in the IAV-Af superinfection group compared to single-infection controls, we observed defects in Aspergillus conidial uptake and killing by both neutrophils and monocytes after IAV infection. pHrodo Green zymosan bioparticle (pHrodo-zymosan) and CM-H2DCFDA [5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate] staining, indicators of phagolysosome maturation and reactive oxygen species (ROS) production, respectively, revealed that the fungal killing defect was due in part to reduced phagolysosome maturation. Collectively, our data demonstrate that the ability of neutrophils and monocytes to kill and clear Aspergillus conidia is strongly reduced in the pulmonary environment of an IAV-infected lung, which leads to invasive pulmonary aspergillosis and increased overall mortality in our mouse model, recapitulating what is observed clinically in humans. IMPORTANCE Influenza A virus (IAV) is a common respiratory virus that causes seasonal illness in humans, but can cause pandemics and severe infection in certain patients. Since the emergence of the 2009 H1N1 pandemic strains, there has been an increase in clinical reports of IAV-infected patients in the intensive care unit (ICU) developing secondary pulmonary aspergillosis. These cases of flu-Aspergillus superinfections are associated with worse clinical outcomes than secondary bacterial infections in the setting of IAV. To date, we have a limited understanding of the cause(s) of secondary fungal infections in immunocompetent hosts. IAV-induced modulation of cytokine production and innate immune cellular function generates a unique immune environment in the lung, which could make the host vulnerable to a secondary fungal infection. Our work shows that defects in phagolysosome maturation in neutrophils and monocytes after IAV infection impair the ability of these cells to kill A. fumigatus, thus leading to increased fungal germination and growth and subsequent invasive aspergillosis. Our work lays a foundation for future mechanistic studies examining the exact immune modulatory events occurring in the respiratory tract after viral infection leading to secondary fungal infections.

Clinical and Microbiological Characteristics of Aspergillosis at a Chinese Tertiary Teaching Hospital

BACKGROUND

Aspergillus spp. infection in immunocompromised patients results in increasing morbidity and mortality. This study investigated clinical and microbiological characteristics of aspergillosis in a Chinese tertiary teaching hospital.

METHODS

A total of 114 patients with aspergillosis were included over a 5-year period at Ruijin Hospital. In sum, 114 Aspergillus strains were isolated and identified at species level using matrix-assisted laser desorption ionization time-of-flight mass spectrometry, confirmed by ITS gene region and β-tubulin (BenA) gene sequencing. Sensititre YeastOne was used in vitro to test susceptibility to antifungal drugs: amphotericin B, itraconazole, voriconazole, posaconazole, isavuconazole, micafungin, anidulafungin, and caspofungin.

RESULTS

The median age of the patients was 61 (19) years, men accounted for 53.5% (n=61) of the sample, about 64% were immunocompromised, and 36% had underlying diseases. Pulmonary diseases accounted for 27.2%. Aspergillus isolates were mainly isolated from sputum (n=42, 36.8%). Antifungal therapy was administered to 106 (93.0%) patients and voriconazole (n=76, 66.7%) was the most frequently used as empirical therapy. Aspergillus fumigatus (n=69, 60.5%) was the most common species. There was a 73.7% concordance between MALDI-TOF MS and molecular identification. All Aspergillus isolates showed good susceptibility to anidulafungin and caspofungin.

CONCLUSION

Immunocompromised patients are an at-risk population for aspergillosis, and voriconazole was used as empirical therapy in Ruijin Hospital, China. A. fumigatus was the predominant Aspergillus species causing aspergillosis, and A. flavus - as non-A. fumigatus species are increasing - the second-leading cause of aspergillosis. Anidulafungin and caspofungin were the most active in vitro against the Aspergillus isolates tested. The MALDI-TOF MS method showed good accuracy for identification of common Aspergillus spp. In vitro antifungal-susceptibility testing is crucially important for decisions on effective therapy with aspergillosis.

Dual Fungal Infection of Aspergillosis and Mucormycosis in a COVID-19 Patient: A Rare Case Report

Coronavirus disease 2019 (COVID-19) infections can be related to vast spectrum of co-existent bacterial and fungal infections. A 49-year-old diabetic male was admitted with a history of fever, cough and breathlessness since 5 days. He developed persistent headache with right sided purulent nasal discharge. Relevant histo-pathological, biochemical, microbiological and imaging studies were performed which proved it to be a dual infection of Aspergillosis and Mucormycosis. We present one such case in a COVID-19 patient to highlight its unusual clinical features along with the diagnostic and therapeutic challenges.

N-chlorotaurine is highly active against respiratory viruses including SARS-CoV-2 (COVID-19) in vitro

N-chlorotaurine (NCT) a long-lived oxidant generated by leukocytes, can be synthesized chemically and applied topically as an anti-infective to different body sites, including the lung via inhalation. Here, we demonstrate the activity of NCT against viruses causing acute respiratory tract infections, namely severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza viruses, and respiratory syncytial virus (RSV). Virucidal activity of NCT was tested in plaque assays, confirmed by RT-qPCR assays. Attack on virus proteins was investigated by mass spectrometry. NCT revealed broad virucidal activity against all viruses tested at 37°C and pH 7. A significant reduction in infectious particles of SARS-CoV-2 isolates from early 2020 by 1 log₁₀ was detected after 15 min of incubation in 1% NCT. Proteinaceous material simulating body fluids enhanced this activity by transchlorination mechanisms (1 −2 log₁₀ reduction within 1–10 min). Tested SARS-CoV-2 variants B.1.1.7 (Alpha) und B.1.351 (Beta) showed a similar susceptibility. Influenza virus infectious particles were reduced by 3 log₁₀ (H3N2) to 5 log₁₀ (H1N1pdm), RSV by 4 log₁₀ within a few min. Mass spectrometry of NCT-treated SARS-CoV-2 spike protein and 3C-like protease, influenza virus haemagglutinin and neuraminidase, and RSV fusion glycoprotein disclosed multiple sites of chlorination and oxidation as the molecular mechanism of action. Application of 1.0% NCT as a prophylactic and therapeutic strategy against acute viral respiratory tract infections deserves comprehensive clinical investigation.

Siderophores: a potential role as a diagnostic for invasive fungal disease

PURPOSE OF REVIEW

Invasive fungal diseases (IFDs) such as invasive aspergillosis continue to be associated with high morbidity and mortality while presenting significant diagnostic challenges. Siderophores are high-affinity Fe 3+ chelators produced by Aspergillus spp. and other fungi capable of causing IFD. Previously evaluated as a treatment target in mucormycosis, siderophores have recently emerged as new diagnostic targets for invasive aspergillosis and scedosporiosis. Here, we review the diagnostic potential of siderophores for diagnosing IFD, with a particular focus on invasive aspergillosis.

RECENT FINDINGS

The major secreted siderophore of A. fumigatus , triacetylfusarinine C (TAFC), has been successfully detected by mass spectrometry in serum, BALF and urine of patients with invasive aspergillosis, with promising sensitivities and specificities in single-centre studies. Intracellular uptake of siderophores has also been utilized for imaging, wherein fungal siderophores have been conjugated with the easy-to-produce radioactive isotope gallium-68 ( 68 Ga) to visualize infected body sites in PET. For the Scedosporium apiospermum complex, another siderophore N(α)-methyl coprogen B has been shown promising as a marker for airway colonization in early studies.

SUMMARY

Siderophores and particular TAFC have the potential to revolutionize diagnostic pathways for invasive aspergillosis and other mould infections. However, larger multicentre studies are needed to confirm these promising performances. Methods that allow rapid and cost-effective measurements in routine clinical practice need to be developed, particularly when TAFC is used as a biomarker in patient specimens.

Early CT and MRI signs of invasive fungal sinusitis complicating COVID-19 infection: case report

Background

Corticosteroids are usually prescribed for severe cases with SARS-CoV-2 (COVID-19). Despite their importance to decrease patients’ mortality, they can cause serious side effects like fulminant fungal infection that can damage lungs or invade the sinuses then rapidly spread to the orbit and even intra-cranially. Unless early diagnosed and properly managed, patients can lose their vision or die from cavernous sinus thrombosis or other intracranial complications.

Case presentation

A 71-year-old diabetic male patient presented with dry cough, fever, and dyspnea for 6 days. PCR test for COVID-19 was ordered and declared positive. The oxygen saturation on day 7 started to decline to reach 90%. Eight ampules of intra-muscular dexamethasone were prescribed. The patient’s dyspnea improved, and the oxygen saturation reached 94% by day 13. Oral prednisone was prescribed in a withdrawal protocol. Unfortunately, on day 15, the patient complained of mild left-sided cheek swelling and noticeably dropped left angle of mouth. Neurological consultation suspected facial palsy and asked for brain MRI examination. Limited lower cuts of the MRI study that covered the left maxillary antrum revealed mild fullness of the pre-maxillary fat planes with mucosal thickening. Complimentary dedicated MRI and CT cuts over the left maxillary sinus showed localized signs of invasive fungal sinusitis without orbital or intracranial complications. The patient received antifungal therapy even before evident endoscopic findings appeared. He underwent endoscopic debridement few days after and he had an excellent outcome without any progression or significant morbidities.

Conclusion

Early CT/MRI radiological signs of invasive fungal sinusitis that complicated COVID-19 infection aid in the diagnosis and proper timely management of this fatal disease.

Gut Microbial Disruption in Critically Ill Patients with COVID-19-Associated Pulmonary Aspergillosis

OBJECTIVES

COVID-19 disease can be exacerbated by Aspergillus superinfection (CAPA). However, the causes of CAPA are not yet fully understood. Recently, alterations in the gut microbiome have been associated with a more complicated and severe disease course in COVID-19 patients, most likely due to immunological mechanisms. The aim of this study was to investigate a potential association between severe CAPA and alterations in the gut and bronchial microbial composition.

METHODS

We performed 16S rRNA gene amplicon sequencing of stool and bronchial samples from a total of 16 COVID-19 patients with CAPA and 26 patients without CAPA. All patients were admitted to the intensive care unit. Results were carefully tested for potentially confounding influences on the microbiome during hospitalization.

RESULTS

We found that late in COVID-19 disease, CAPA patients exhibited a trend towards reduced gut microbial diversity. Furthermore, late-stage patients with CAPA superinfection exhibited an increased abundance of Staphylococcus epidermidis in the gut which was not found in late non-CAPA cases or early in the disease. The analysis of bronchial samples did not yield significant results.

CONCLUSIONS

This is the first study showing that alterations in the gut microbiome accompany severe CAPA and possibly influence the host's immunological response. In particular, an increase in Staphylococcus epidermidis in the intestine could be of importance.

Liposomal amphotericin B—the future

Advances in medicine have led to a growing number of people with compromised or suppressed immune systems who are susceptible to invasive fungal infections. In particular, severe fungal infections are becoming increasingly common in ICUs, affecting people within and outside of traditional risk groups alike. This is exemplified by the emergence of severe viral pneumonia as a significant risk factor for invasive pulmonary aspergillosis, and the recognition of influenza-associated pulmonary aspergillosis and, more recently, COVID-19-associated pulmonary aspergillosis.

The treatment landscape for haematological malignancies has changed considerably in recent years, and some recently introduced targeted agents, such as ibrutinib, are increasing the risk of invasive fungal infections. Consideration must also be given to the risk of drug–drug interactions between mould-active azoles and small-molecule kinase inhibitors.

At the same time, infections caused by rare moulds and yeasts are increasing, and diagnosis continues to be challenging. There is growing concern about azole resistance among both moulds and yeasts, mandating continuous surveillance and personalized treatment strategies.

It is anticipated that the epidemiology of fungal infections will continue to change and that new populations will be at risk. Early diagnosis and appropriate treatment remain the most important predictors of survival, and broad-spectrum antifungal agents will become increasingly important. Liposomal amphotericin B will remain an essential therapeutic agent in the armamentarium needed to manage future challenges, given its broad antifungal spectrum, low level of acquired resistance and limited potential for drug–drug interactions.

Lateral flow assay (LFA) in the diagnosis of COVID-19-associated pulmonary aspergillosis (CAPA): a single-center experience

BACKGROUND

Invasive pulmonary aspergillosis (IPA) is seen during coronavirus-2019 (COVID-19), has been reported in different incidences, and is defined as COVID-19-associated pulmonary aspergillosis (CAPA). Detection of galactomannan antigen is an important diagnostic step in diagnosing IPA. Enzyme-linked immunoassay (ELISA) is the most frequently used method, and lateral flow assay (LFA) is increasingly used with high sensitivity and specificity for rapid diagnosis. The present study aimed to compare the sensitivity of LFA and ELISA in the diagnosis of CAPA in COVID-19 patients followed in our hospital's ICU for pandemic (ICU-P).

METHODS

This study included patients with a diagnosis of COVID-19 cases confirmed by polymerase chain reaction and were followed up in ICU-P between August 2021 and February 2022 with acute respiratory failure. The diagnosis of CAPA was based on the European Confederation of Medical Mycology (ECMM) and the International Society for Human and Animal Mycology 2020 (ECMM/ ISHAM) guideline. Galactomannan levels were determined using LFA and ELISA in serum samples taken simultaneously from the patients.

RESULTS

Out of the 174 patients followed in the ICU-P, 56 did not meet any criteria for CAPA and were excluded from the analysis. The rate of patients diagnosed with proven CAPA was 5.7% (10 patients). A statistically significant result was obtained with LFA for the cut-off value of 0.5 ODI in the diagnosis of CAPA (p < 0.001). The same significant statistical relationship was found for the cut-off value of 1.0 ODI for the ELISA (p < 0.01). The sensitivity of LFA was 80% (95% CI: 0.55-1.05, p < 0.05), specificity 94% (95% CI: 0.89-0.98, p < 0.05); PPV 53% (95% CI: 0.28-0.79, p > 0.05) and NPV was 98% (95% CI: 0.95-1.01, p < 0.05). The risk of death was 1.66 (HR: 1.66, 95% CI: 1.02-2.86, p < 0.05) times higher in patients with an LFA result of ≥ 0.5 ODI than those with < 0.5 (p < 0.05).

CONCLUSIONS

It is reckoned that LFA can be used in future clinical practice, particularly given its effectiveness in patients with hematological malignancies and accuracy in diagnosing CAPA.

Genome-wide scan for potential CD4+ T-cell vaccine candidates in Candida auris by exploiting reverse vaccinology and evolutionary information

Candida auris is a globally emerging fungal pathogen responsible for causing nosocomial outbreaks in healthcare associated settings. It is known to cause infection in all age groups and exhibits multi-drug resistance with high potential for horizontal transmission. Because of this reason combined with limited therapeutic choices available, C. auris infection has been acknowledged as a potential risk for causing a future pandemic, and thus seeking a promising strategy for its treatment is imperative. Here, we combined evolutionary information with reverse vaccinology approach to identify novel epitopes for vaccine design that could elicit CD4+ T-cell responses against C. auris. To this end, we extensively scanned the family of proteins encoded by C. auris genome. In addition, a pathogen may acquire substitutions in epitopes over a period of time which could cause its escape from the immune response thus rendering the vaccine ineffective. To lower this possibility in our design, we eliminated all rapidly evolving genes of C. auris with positive selection. We further employed highly conserved regions of multiple C. auris strains and identified two immunogenic and antigenic T-cell epitopes that could generate the most effective immune response against C. auris. The antigenicity scores of our predicted vaccine candidates were calculated as 0.85 and 1.88 where 0.5 is the threshold for prediction of fungal antigenic sequences. Based on our results, we conclude that our vaccine candidates have the potential to be successfully employed for the treatment of C. auris infection. However, in vivo experiments are imperative to further demonstrate the efficacy of our design.

Genomic and Molecular Identification of Genes Contributing to the Caspofungin Paradoxical Effect in Aspergillus fumigatus

Aspergillus fumigatus is a deadly opportunistic fungal pathogen responsible for ~100,000 annual deaths. Azoles are the first line antifungal agent used against A. fumigatus, but azole resistance has rapidly evolved making treatment challenging. Caspofungin is an important second-line therapy against invasive pulmonary aspergillosis, a severe A. fumigatus infection. Caspofungin functions by inhibiting β-1,3-glucan synthesis, a primary and essential component of the fungal cell wall. A phenomenon termed the caspofungin paradoxical effect (CPE) has been observed in several fungal species where at higher concentrations of caspofungin, chitin replaces β-1,3-glucan, morphology returns to normal, and growth rate increases. CPE appears to occur in vivo, and it is therefore clinically important to better understand the genetic contributors to CPE. We applied genomewide association (GWA) analysis and molecular genetics to identify and validate candidate genes involved in CPE. We quantified CPE across 67 clinical isolates and conducted three independent GWA analyses to identify genetic variants associated with CPE. We identified 48 single nucleotide polymorphisms (SNPs) associated with CPE. We used a CRISPR/Cas9 approach to generate gene deletion mutants for seven genes harboring candidate SNPs. Two null mutants, ΔAfu3g13230 and ΔAfu4g07080 (dscP), resulted in reduced basal growth rate and a loss of CPE. We further characterized the dscP phosphatase-null mutant and observed a significant reduction in conidia production and extremely high sensitivity to caspofungin at both low and high concentrations. Collectively, our work reveals the contribution of Afu3g13230 and dscP in CPE and sheds new light on the complex genetic interactions governing this phenotype. IMPORTANCE This is one of the first studies to apply genomewide association (GWA) analysis to identify genes involved in an Aspergillus fumigatus phenotype. A. fumigatus is an opportunistic fungal pathogen that causes hundreds of thousands of infections and ~100,000 deaths each year, and antifungal resistance has rapidly evolved in this species. A phenomenon called the caspofungin paradoxical effect (CPE) occurs in some isolates, where high concentrations of the drug lead to increased growth rate. There is clinical relevance in understanding the genetic basis of this phenotype, since caspofungin concentrations could lead to unintended adverse clinical outcomes in certain cases. Using GWA analysis, we identified several interesting candidate polymorphisms and genes and then generated gene deletion mutants to determine whether these genes were important for CPE. Two of these mutant strains (ΔAfu3g13230 and ΔAfu4g07080/ΔdscP) displayed a loss of the CPE. This study sheds light on the genes involved in clinically important phenotype CPE.

Checkpoint inhibitors as immunotherapy for fungal infections: Promises, challenges, and unanswered questions

Opportunistic fungal infections have high mortality in patients with severe immune dysfunction. Growing evidence suggests that the immune environment of invasive fungal infections and cancers share common features of immune cell exhaustion through activation of immune checkpoint pathways. This observation gave rise to several preclinical studies and clinical case reports describing blockade of the Programmed Cell Death Protein 1 and Cytotoxic T-Lymphocyte Antigen 4 immune checkpoint pathways as an adjunct immune enhancement strategy to treat opportunistic fungal infections. The first part of this review summarizes the emerging evidence for contributions of checkpoint pathways to the immunopathology of fungal sepsis, opportunistic mold infections, and dimorphic fungal infections. We then review the potential merits of immune checkpoint inhibitors (ICIs) as an antifungal immunotherapy, including the incomplete knowledge of the mechanisms involved in both immuno-protective effects and toxicities. In the second part of this review, we discuss the limitations of the current evidence and the many unknowns about ICIs as an antifungal immune enhancement strategy. Based on these gaps of knowledge and lessons learned from cancer immunology studies, we outline a research agenda to determine a "sweet spot" for ICIs in medical mycology. We specifically discuss the importance of more nuanced animal models, the need to study ICI-based combination therapy, potential ICI resistance, the role of the immune microenvironment, and the impact of ICIs given as part of oncological therapies on the natural immunity to various pathogenic fungi.

Aspergillus-SARS-CoV-2 Coinfection: What Is Known?

COVID-19-associated pulmonary aspergillosis (CAPA) has had a high incidence. In addition, it has been associated with prolonged hospital stays, as well as several predisposing risk factors, such as fungal factors (nosocomial organism, the size of the conidia, and the ability of the Aspergillus spp. of colonizing the respiratory tract), environmental factors (remodeling in hospitals, use of air conditioning and negative pressure in intensive care units), comorbidities, and immunosuppressive therapies. In addition to these factors, SARS-CoV-2 per se is associated with significant dysfunction of the patient's immune system, involving both innate and acquired immunity, with reduced CD4+ and CD8+ T cell counts and cytokine storm. Therefore, this review aims to identify the factors influencing the fungus so that coinfection with SARS-CoV-2 can occur. In addition, we analyze the predisposing factors in the fungus, host, and the immune response alteration due to the pathogenicity of SARS-CoV-2 that causes the development of CAPA.

Biogeography of Black Mold Aspergillus niger: Global Situation and Future Perspective under Several Climate Change Scenarios Using MaxEnt Modeling

Climate change impacts represent one of the most important ecological and medical issues during this century. Several fungal species will change their distribution through space and time as a response to climate changes. This will rearrange many fungal diseases throughout the world. One of the most important and very common fungi is the black mold Aspergillus niger. The COVID-19 pandemic reforms the way in which mycologists think about this fungus as an emerging healthy issue. Through this work, about one thousand records of Aspergillus niger were used to model its current and future global distribution using 19 bioclimatic variables under several climate change scenarios. Maximum entropy implemented in Maxent was chosen as the modeling tool, especially with its accuracy and reliability over the other modeling techniques. The annual mean temperature (bio 1) forms the most contributed climatological parameter to black mold distribution. The produced current distribution model came compatible with the real distribution of the species with a cosmopolitan range. The rise of temperature due to global warming will form a limitation to Aspergillus niger through several parts of its range. The generated maps of the future status of this fungus under two different RCPs for 2050 and 2070, indicate several parts that become free from black mold due to temperature limitations. The present results need more intensive future evaluation using data science and GIS, especially on a local scale including more ecological parameters other than climatological data.

COVID-19-associated pulmonary aspergillosis: an underdiagnosed or overtreated infection?

PURPOSE OF REVIEW

Coronavirus disease (COVID-19)-associated pulmonary aspergillosis (CAPA) may concern up to one third of intensive care unit (ICU) patients. The purpose of this review is to discuss the diagnostic criteria, the pathogenesis, the risk factors, the incidence, the impact on outcome, and the diagnostic and therapeutic management of CAPA in critically ill patients.

RECENT FINDINGS

The incidence of CAPA ranges 3--28% of critically ill patients, depending on the definition used, study design, and systematic or triggered screening. COVID-19 is associated with direct damage of the respiratory epithelium, immune dysregulation, and common use of immunosuppressive drugs which might promote Aspergillus respiratory tract colonization and invasion. Positive Aspergillus tests among COVID-19 critically patients might reflect colonization rather than invasive disease. CAPA usually appears during the second week after starting invasive mechanical ventilation and is independently associated with ICU mortality.

SUMMARY

Further studies are needed to validate CAPA case definitions, to determine the accurate incidence of CAPA in comparison to adequate controls, and its evolution during the pandemic. A pro-active diagnostic strategy, based on risk stratification, clinical assessment, and bronchoalveolar lavage could be recommended to provide early antifungal treatment in patients with high probability of CAPA and clinical deterioration.

CAR T cells targeting Aspergillus fumigatus are effective at treating invasive pulmonary aspergillosis in preclinical models

Aspergillus fumigatus is a ubiquitous mold that can cause severe infections in immunocompromised patients, typically manifesting as invasive pulmonary aspergillosis (IPA). Adaptive and innate immune cells that respond to A. fumigatus are present in the endogenous repertoire of patients with IPA but are infrequent and cannot be consistently isolated and expanded for adoptive immunotherapy. Therefore, we gene-engineered A. fumigatus-specific chimeric antigen receptor (Af-CAR) T cells and demonstrate their ability to confer antifungal reactivity in preclinical models in vitro and in vivo. We generated a CAR targeting domain AB90-E8 that recognizes a conserved protein antigen in the cell wall of A. fumigatus hyphae. T cells expressing the Af-CAR recognized A. fumigatus strains and clinical isolates and exerted a direct antifungal effect against A. fumigatus hyphae. In particular, CD8⁺ Af-CAR T cells released perforin and granzyme B and damaged A. fumigatus hyphae. CD8⁺ and CD4⁺ Af-CAR T cells produced cytokines that activated macrophages to potentiate the antifungal effect. In an in vivo model of IPA in immunodeficient mice, CD8⁺ Af-CAR T cells localized to the site of infection, engaged innate immune cells, and reduced fungal burden in the lung. Adoptive transfer of CD8⁺ Af-CAR T cells conferred greater antifungal efficacy compared to CD4⁺ Af-CAR T cells and an improvement in overall survival. Together, our study illustrates the potential of gene-engineered T cells to treat aggressive infectious diseases that are difficult to control with conventional antimicrobial therapy and support the clinical development of Af-CAR T cell therapy to treat IPA.

Opportunistic Candida Infections in Critical COVID-19 Patients

The frequency of opportunistic fungal infections in critically ill patients whose intensive care unit stays are prolonged due to coronavirus disease 2019 (COVID-19) is higher than in the period before COVID-19. We planned this study to improve the management of Candida infections by defining the Candida species, the etiology of infections caused by Candida species, and the antifungal susceptibility of the species. This retrospective study included patients older than 18 hospitalized in the intensive care unit (ICU) with a definitive diagnosis of COVID-19 for seven months (from March 2021 to September 2021). All study data that we recorded in a standard study form were analyzed with TURCOSA (Turcosa Analytics Ltd. Co., Turkey, www.turcosa.com.tr) statistical software. The patients were evaluated in four groups as group 1 (candidemia patients, n = 78), group 2 (candiduria patients, n = 189), group 3 (control patients, n = 57), and group 4 (patients with candidemia in urine cultures taken before Candida was detected in blood culture, n = 42). Candida species were identified using both conventional and VITEK® 2 (BioMérieux, France) methods. The antifungal susceptibility of fungi was determined using the E test method. Of the 5,583 COVID-19 patients followed during the study period, 78 developed candidemia, and 189 developed candiduria. The incidence of candidemia (per 1,000 admissions) was determined to be 1.6. As a result of statistical analysis, we found that Candida albicans was the dominant strain in candidemia and candiduria, and there was no antifungal resistance except for naturally resistant strains. Candida strains grown in blood and urine were the same in 40 of 42 patients. Mortality was 69.2% for group 1, 60.4% for group 2, and 57.8% for group 3. Antifungals were used in 34 (43.5%) patients from group 1, and 95 (50.2%) from group 2. In the candidemia group without antifungal use, mortality was quite high (77.2%). Antifungal use reduced mortality in the group 2 (p < 0.05). Length of ICU stays, comorbidity, broad-spectrum antibiotics, and corticosteroids are independent risk factors for candidemia in critically ill COVID-19 patients. Our study contributes to the knowledge of risk factors for developing COVID-19-related candida infections. The effect of candiduria on the development of candidemia in critically ill COVID-19 patients should be supported by new studies.

SARS-CoV-2 pneumonia and bacterial pneumonia patients differ in a second hit immune response model

Secondary infections have been shown to complicate the clinical course and worsen the outcome of critically ill patients. Severe Coronavirus Disease 2019 (COVID-19) may be accompanied by a pronounced cytokine release, and immune competence of these patients towards most pathogenic antigens remains uncompromised early in the disease. Patients with bacterial sepsis also exhibit excessive cytokine release with systemic hyper-inflammation, however, typically followed by an anti-inflammatory phase, causing immune paralysis. In a second hit immune response model, leukocyte activation capacity of severely ill patients with pneumonia caused by SARS-CoV-2 or by bacteria were compared upon ICU admission and at days 4 and 7 of the ICU stay. Blood cell count and release of the pro-inflammatory cytokines IL-2, IFNγ and TNF were assessed after whole-blood incubation with the potent immune stimulus pokeweed mitogen (PWM). For comparison, patients with bacterial sepsis not originating from pneumonia, and healthy volunteers were included. Lymphopenia and granulocytosis were less pronounced in COVID-19 patients compared to bacterial sepsis patients. After PWM stimulation, COVID-19 patients showed a reduced release of IFNγ, while IL-2 levels were found similar and TNF levels were increased compared to healthy controls. Interestingly, concentrations of all three cytokines were significantly higher in samples from COVID-19 patients compared to samples from patients with bacterial infection. This fundamental difference in immune competence during a second hit between COVID-19 and sepsis patients may have implications for the selection of immune suppressive or enhancing therapies in personalized medicine.

Penicillium digitatum, First Clinical Report in Chile: Fungal Co-Infection in COVID-19 Patient

Penicillium digitatum is one of the most important phytopathogens. It causes deterioration and rotting of citrus fruits, generating significant economic losses worldwide. As a human pathogen, it is extremely rare. We present a case of pulmonary co-infection in a patient diagnosed with pneumonia due to SARS-CoV-2. A 20-year-old female patient, primigravid, 36 weeks of gestation, without comorbidities, and diagnosed with severe pneumonia due to the SARS-CoV-2, showed rapid lung deterioration for which their pregnancy was interrupted by surgery. The patient was hospitalized in the Intensive Care Unit (ICU), connected to mechanical ventilation and receiving corticosteroids and antibiotics. The diagnosis of pulmonary fungal infection was made through bronchoalveolar lavage (BAL) culture, and the species identification was performed by sequencing of β-tubulin. Phylogenetic analysis with related species was performed for the confirmation of species identification. Antifungal susceptibility tests were performed for itraconazole (4 µg/mL), voriconazole (2 µg/mL), and amphotericin B (2 µg/mL). The patient was successfully treated with itraconazole. This is the second worldwide report of pulmonary infection by P. digitatum and the first in Chile. Although it is a fungus that rarely infects humans, it could represent an emerging opportunistic fungal pathogen, with associated risk factors that should be considered in the differential diagnosis of Penicillium species isolated from infections in humans.

Comparative risk assessment of COVID-19 associated mucormycosis and aspergillosis: A systematic review

COVID-19 is not only limited to a defined array but also has expanded with several secondary infections. Two uncommon opportunistic fungal infections, COVID-19 associated mucormycosis (CAM) and aspergillosis (CAA), have recently been highly acquainted by many worldwide cases. Two immune response deteriorating factors are considered to be responsible for immunosuppression: comorbidities and medication. Due to unlike infection sites and patterns, CAM and CAA-associated factors deflect a few degrees of proximity, and the present study is for its assessment. The study evaluated 351 CAM cases and 191 CAA cases retrieved from 65 and 53 articles based on inclusion criteria, respectively. Most of the CAM reported from India and CAA were from four South-European and West-European neighbor countries. The mean ages of CAM and CAA were 52.72 ± 13.74 and 64.81 ± 11.14, correspondingly. Mortality of CAA (56.28%) was two times greater than CAM (26.02%). Nevertheless, the count of diabetes cases was very high in CAM compared to CAA. The main comorbidities of CAM were diabetes (nearly 80%) and hypertension (more than 38%). All noticeable complications were higher in CAA except diabetes, and these were diabetes (34.55%), hypertension (45.03%), and obesity (18.32%). Moreover, pre-existing respiratory complications like asthma and chronic obstructive pulmonary disease are visible in CAA. The uses of steroids in CAM and CAA were nearly 70% and 66%, respectively. Almost one-fourth of CAA cases were reported using immunosuppressant monoclonal antibodies, whereas only 7.69% were for CAM. The overall finding highlights diabetes, hypertension, and steroids as the risk factors for CAM, whereas obesity, chronic pulmonary disease, and immunosuppressants for CAA.

The impact of COVID-19 pandemic on invasive fungal infections in Africa: What have we learned?

Invasive fungal infections (IFIs) have been described as diseases of the poor. The mortality rate of the infections is comparable to that of malaria, HIV, and TB, yet the infections remain poorly funded, neglected in research, and policy at all levels of human resources. The Coronavirus Disease 2019 (COVID-19) pandemic has further worsened the current state of management for IFIs. At the same time, response to COVID-19 has stirred and boosted vaccine production, vaccine substance manufacturing, and building of next-generation sequencing capacity and genomics data sharing network in the continent. Through collaboration and transdisciplinary research effort, these network and technology can be extended to encourage fungal research to address health issues of existing and emerging fungal pathogens.

COVID-19 and Fungal Infections: A Double Debacle

Fungal infections remain hardly treatable because of unstandardized diagnostic tests, limited antifungal armamentarium, and more specifically, potential toxic interactions between antifungals and immunosuppressants used during anti-inflammatory therapies, such as those set up in critically ill COVID-19 patients. Taking into account pre-existing difficulties in treating vulnerable COVID-19 patients, any co-occurrence of infectious diseases like fungal infections constitutes a double debacle for patients, healthcare experts, and the public economy. Since the first appearance of SARS-CoV-2, a significant rise in threatening fungal co-infections in COVID-19 patients has been testified in the scientific literature. Better management of fungal infections in COVID-19 patients is, therefore, a priority and requires highlighting common risk factors, relationships with immunosuppression, as well as challenges in fungal diagnosis and treatment. The present review attempts to highlight these aspects in the three most identified causative agents of fungal co-infections in COVID-19 patients: Aspergillus, Candida, and Mucorales species.

Comparison of mucormycosis infection between patients with and without a history of COVID-19 infection: a retrospective cohort study

BACKGROUND

Mucormycosis infection is a complication seen in some coronavirus disease 2019 (COVID-19) patients. This study compares the characteristics of mucormycosis infection between COVID-19 and non-COVID-19 patients.

METHODS

This retrospective cohort comprised 87 patients with mucormycosis divided into two groups. The first included 44 patients who had COVID-19 recently before hospitalization due to mucormycosis at Namazi Hospital, Shiraz, Iran, between February 2019 and August 2021. The second group included all 43 patients hospitalized at the same hospital due to mucormycosis between 2010 and 2019 (pre-pandemic).

RESULTS

Mucormycosis patients with a history of recent COVID-19 infection had a higher rate of diabetes mellitus, fewer malignancies and higher blood glucose, erythrocyte sedimentation rate and C-reactive protein levels (p<0.05). Glucocorticoid use was common (77%) in the COVID-19 group.

CONCLUSIONS

In the pre-COVID-19 era, mucormycosis mainly affected immunodeficient patients like those receiving chemotherapy due to malignancy but now seems to affect COVID-19 patients with uncontrolled blood glucose and glucocorticoids use. Special care must be taken in prescribing glucocorticoids and controlling the blood glucose levels of COVID-19 patients.

COVID-19 patients share common, corticosteroid-independent features of impaired host immunity to pathogenic molds

Patients suffering from coronavirus disease-2019 (COVID-19) are susceptible to deadly secondary fungal infections such as COVID-19-associated pulmonary aspergillosis and COVID-19-associated mucormycosis. Despite this clinical observation, direct experimental evidence for severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2)-driven alterations of antifungal immunity is scarce. Using an ex-vivo whole blood stimulation assay, we challenged blood from twelve COVID-19 patients with Aspergillus fumigatus and Rhizopus arrhizus antigens and studied the expression of activation, maturation, and exhaustion markers, as well as cytokine secretion. Compared to healthy controls, T-helper cells from COVID-19 patients displayed increased expression levels of the exhaustion marker PD-1 and weakened A. fumigatus- and R. arrhizus-induced activation. While baseline secretion of proinflammatory cytokines was massively elevated, whole blood from COVID-19 patients elicited diminished release of T-cellular (e.g., IFN-γ, IL-2) and innate immune cell-derived (e.g., CXCL9, CXCL10) cytokines in response to A. fumigatus and R. arrhizus antigens. Additionally, samples from COVID-19 patients showed deficient granulocyte activation by mold antigens and reduced fungal killing capacity of neutrophils. These features of weakened anti-mold immune responses were largely decoupled from COVID-19 severity, the time elapsed since diagnosis of COVID-19, and recent corticosteroid uptake, suggesting that impaired anti-mold defense is a common denominator of the underlying SARS-CoV-2 infection. Taken together, these results expand our understanding of the immune predisposition to post-viral mold infections and could inform future studies of immunotherapeutic strategies to prevent and treat fungal superinfections in COVID-19 patients.

COVID-19-Associated Pulmonary Fungal Infection among Pediatric Cancer Patients, a Single Center Experience

Patients with COVID-19 are at risk of developing secondary complications such as invasive pulmonary aspergillosis and mucormycosis. This is a retrospective study including all cancer children diagnosed with COVID-19-associated pulmonary fungal infection (CAPFI) during the period 2020–2021. A total of 200 patients were diagnosed with COVID-19, out of which 21 (10%) patients were diagnosed with CAPFI, 19 patients (90%) with COVID-aspergillosis (CAPA), and 2 (10%) patients with COVID-mucormycosis (CAM). Patients with CAPFI were classified using the “2020 ECMM/ISHAM consensus criteria”; proven in 2 (10%) patients, probable in 12 (57%), and possible in 7 (33%) patients. Although the hematological malignancy patients were already on antifungal prophylaxis, breakthrough fungal infection was reported in 16/21 (75%), 14 (65%) patients had CAPA while on echinocandin prophylaxis, while 2 (10%) patients had CAM while on voriconazole prophylaxis. Overall mortality was reported in 8 patients (38%) while CAPFI-attributable mortality was reported in 4 patients (20%). In conclusion, clinicians caring for pediatric cancer patients with COVID-19 should consider invasive pulmonary fungal infection, even if they are on antifungal prophylaxis, especially with worsening of the clinical chest condition. A better understanding of risk factors for adverse outcomes may improve clinical management in these patients.

Atypical Presentation of Aspergillus niger Infection in the Oral Cavity as a Prediction of Invasive Pulmonary Aspergillosis in a Patient with COVID-19: Case Report and Literature Review

Coinfections between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory pathogens such as Aspergillus have become challenging, as well as being associated with high morbidity and mortality in patients with COVID-19. Aspergillus niger is a common environmental mold. Before the emergence of COVID-19, it was considered a very rare cause of invasive pulmonary aspergillosis (IPA), occurring mainly in immunocompromised patients. The aim of this study was to describe a very rare case of IPA caused by A. niger found in the oral cavity of a mechanically ventilated COVID-19 patient. A. niger detected in the gingival pocket was diagnosed earlier than in the bronchial lavage, and without treatment, passed into the lungs of the patient, causing serious complications. The swab from the oral cavity of mechanically ventilated COVID-19 patients can be a predictor of the subsequent severity of inflammatory lesions and the development of suspected IPA.

Spectrum of Mucormycosis Before and During COVID-19: Epidemiology, Diagnosis, and Current Therapeutic Interventions

Purpose of Review

More than half a billion people have been infected and 6.2 million killed by the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) since the start of the pandemic in 2019. Systemic glucocorticoids are a double-edged sword, on the one hand, life-saving in treating COVID-19 complications while on the other hand, potentially leading to life-and-limb-threatening opportunistic fungal infections. Mucormycosis (MM) is caused by the mucormycetes family. Although rare, it is characterized by high mortality and significant morbidity. The gross similarities observed with other fungal infections which respond to different treatment regimens have made it all the more imperative to quickly and sensitively diagnose and treat MM. This review discusses the epidemiology of MM before and during the COVID-19 pandemic, associated risk factors, COVID-19-associated MM, diagnosis, and current therapeutic interventions.

Recent Findings

There has been a widespread and worrisome trend of rising in cases of MM, worldwide, but more so in the Indian subcontinent, where it is nicknamed the “black fungus.” This upsurge has picked up the pace ever since the start of the COVID-19 pandemic. Necrosis is secondary to the angio-invasive and pro-thrombotic nature of the mold resulting in extensive lesions presenting mostly as rhino-orbital MM (ROM) and rhino-orbito-cerebral MM (ROCM). Infection is mostly observed in subjects with underlying risk factors such as uncontrolled diabetes, those receiving hematopoietic stem cell transplant, and/or on corticosteroid or immunosuppressive therapy, although it is widely suspected that other factors such as iron and zinc may play a role in the pathogenesis of MM. The “One world one guideline” strategy advocates both prophylactic anti-fungal therapy along with aggressive, prompt, and individualized treatment with anti-fungal drugs such as amphotericin B in addition to vigorous surgical intervention. High-risk groups need particularly rapid diagnosis although empirical anti-fungal therapy may not be delayed. Speeding diagnostic turnaround times are essential to institute early therapy, and there is much scope for newer modalities such as PCR, matrix-assisted laser desorption ionization-time of flight mass spectrometry, and whole-genome sequencing in such endeavors. The results of strict monitoring of blood glucose levels along with rational and limited use of steroids and immunomodulatory drugs have proven to be a significant preventive measure.

Summary

The significant rise in cases of MM worldwide has necessitated viewing each case with a strong index of suspicion. Adoption of rapid diagnostics, early antifungal therapy, and prompt surgical interventions are essential, while high-risk groups need particular focused care which may include prophylactic anti-fungal therapy, limited steroid use, and meticulous control of the underlying disease. Developing quicker and more sensitive diagnostic modalities has great potential to improve the detection and management of MM.

COVID-19-associated fungal infections

Coronavirus disease 2019 (COVID-19)-associated invasive fungal infections are an important complication in a substantial number of critically ill, hospitalized patients with COVID-19. Three groups of fungal pathogens cause co-infections in COVID-19: Aspergillus, Mucorales and Candida species, including Candida auris. Here we review the incidence of COVID-19-associated invasive fungal infections caused by these fungi in low-, middle- and high-income countries. By evaluating the epidemiology, clinical risk factors, predisposing features of the host environment and immunological mechanisms that underlie the pathogenesis of these co-infections, we set the scene for future research and development of clinical guidance.

Hoenigl and colleagues review the epidemiology, immunology and clinical risk factors contributing to COVID-19-associated fungal infections.

Possible Alterations of Imaging Patterns in Computed Tomography for Delta-VOC of SARS-CoV-2

BACKGROUND

 So far, typical findings for COVID-19 in computed tomography (CT) have been described as bilateral, multifocal ground glass opacities (GGOs) and consolidations, as well as intralobular and interlobular septal thickening. On the contrary, round consolidations with the halo sign are considered uncommon and are typically found in fungal infections, such as invasive pulmonary aspergillosis. The authors recently observed several patients with COVID-19 pneumonia presenting with round, multifocal consolidations accompanied by a halo sign. As this may indicate alterations of CT morphology based on the virus variant, the aim of this study was to investigate this matter in more detail.

METHODS

 161 CT scans of patients with confirmed SARS-CoV-2 infection (RT-PCR within 2 days of CT) examined between January 2021 and September 15, 2021 were included. Follow-up examinations, patients with invasive ventilation at the time of CT, and patients with insufficient virus typing for variants of concern (VOC) were excluded. CT scans were assessed for vertical and axial distribution of pulmonary patterns, degree of involvement, uni- vs. bilaterality, reticulations, and other common findings. The mean density of representative lesions was assessed in Hounsfield units. Results were compared using Mann-Whitney U-tests, Student's t-rests, descriptive statistics, and Fisher's exact tests.

RESULTS

 75 patients did not meet the inclusion criteria. Therefore, 86/161 CT scans of unique patients were analyzed. PCR VOC testing confirmed manifestation of the Delta-VOC SARS-CoV-2 in 22 patients, 39 patients with Alpha-VOC and the remaining 25 patients with Non-VOC SARS-CoV-2 infections. Three patients with the Delta-VOC demonstrated multiple pulmonary masses or nodules with surrounding halo sign, whereas no patients with either Alpha-VOC (p = 0.043) or non-VOC (p = 0.095) demonstrated these findings. All three patients were admitted to normal wards and had no suspicion of a pulmonary co-infection. Patients with Delta-VOC were less likely to have ground glass opacities compared to Alpha-VOC (7/22 or 31.8 % vs. 4/39 or 10.3 %; p < 0.001), whereas a significant difference has not been observed between Delta-VOC and non-VOC (5/25 or 20 %; p = 0.348). The mean representative density of lesions did not show significant differences between the studied cohorts.

CONCLUSION

 In this study 3 out of 22 patients (13.6 %) with Delta-VOC presented with bilateral round pulmonary masses or nodules with surrounding halo signs, which has not been established as a notable imaging pattern in COVID-19 pneumonia yet. Compared to the other cohorts, a lesser percentage of patients with Delta-VOC presented with ground glass opacities. Based on these results Delta-VOC might cause a divergence in CT-morphologic phenotype.

KEY POINTS

· Until recently, CT-morphologic signs of COVID-19 pneumonia have been presumed to be uncontroversially understood. Yet, recently the authors observed diverging pulmonary alterations in patients infected with Delta-VOC.. · These imaging alterations included round pulmonary masses or nodules with surrounding halo sign.. · These imaging alterations have not yet been established as typical for COVID-19 pneumonia, yet.. · Based on these results, Delta-VOC could impose a divergence of CT-morphologic phenotype..

CITATION FORMAT

· Yüksel C, Sähn M, Kleines M et al. Possible Alterations of Imaging Patterns in Computed Tomography for Delta-VOC of SARS-CoV-2 . Fortschr Röntgenstr 2022; DOI: 10.1055/a-1826-0436.

Overview of COVID-19-Associated Invasive Fungal Infection

Purpose of Review

Invasive fungal infections are a complication of COVID-19 disease. This article reviews literature characterizing invasive fungal infections associated with COVID-19.

Recent Findings

Multiple invasive fungal infections including aspergillosis, candidiasis, pneumocystosis, other non-Aspergillus molds, and endemic fungi have been reported in patients with COVID-19. Risk factors for COVID-19-associated fungal disease include underlying lung disease, diabetes, steroid or immunomodulator use, leukopenia, and malignancy. COVID-19-associated pulmonary aspergillosis (CAPA) and COVID-19-associated mucormycosis (CAM) are the most common fungal infections described. However, there is variability in the reported incidences related to use of differing diagnostic algorithms.

Summary

Fungal pathogens are important cause of infection in patients with COVID-19, and the diagnostic strategies continue to evolve. Mortality in these patients is increased, and providers should operate with a high index of suspicion. Further studies will be required to elucidate the associations and pathogenesis of these diseases and best management and prevention strategies.

COVID-19-associated fungal infections in Iran: A systematic review

Objectives

This systematic review aims to summarize the mycological and clinical features of COVID-19-associated fungal infections (CAFIs) in Iran.

Methods

PubMed, Web of Science, Scopus, Cochrane Library, SID, Magiran, IranDoc, and Google Scholar were searched for Persian and English articles published from January 1, 2020, to November 5, 2021, using a systematic search strategy. Studies on Iranian patients suffering from CAFIs were included in the review.

Results

Twenty-two studies comprising 169 patients were retrieved. Reported CAFIs included candidiasis (85, 50.30%), mucormycosis (35, 20.71%), aspergillosis (29, 17.16%), fusariosis (6, 3.55%), three cases caused by rare pathogens (Rhodotorula mucilaginosa, Diaporthe foeniculina, and Sarocladium kiliense) and 11 (6.51%) uncharacterized mold infections. The most common underlying diseases were diabetes (67/168, 39.88%), cardiovascular diseases (55/168, 32.74%), and hypertension (43/168, 25.59%). The use of antibiotics (111/124, 89.52%), corticosteroids (93/132, 70.44%), and mechanical ventilation (66, 51.16%) were the most common predisposing factors. Totally, 72 (50.35%) of 143 patients with CAFIs died (data were not available for 26 patients).

Conclusion

Fungal infections are evident to be a complication of COVID-19 in Iran; thus, clinicians should consider them as a differential diagnosis, especially in patients with comorbidities and previous antibiotic or corticosteroid use.

The emergence of COVID-19 associated mucormycosis: a review of cases from 18 countries

Reports of COVID-19-associated mucormycosis have been increasing in frequency since early 2021, particularly among patients with uncontrolled diabetes. Patients with diabetes and hyperglycaemia often have an inflammatory state that could be potentiated by the activation of antiviral immunity to SARS-CoV2, which might favour secondary infections. In this Review, we analysed 80 published and unpublished cases of COVID-19-associated mucormycosis. Uncontrolled diabetes, as well as systemic corticosteroid treatment, were present in most patients with COVID-19-associated mucormycosis, and rhino-orbital cerebral mucormycosis was the most frequent disease. Mortality was high at 49%, which was particularly due to patients with pulmonary or disseminated mucormycosis or cerebral involvement. Furthermore, a substantial proportion of patients who survived had life-changing morbidities (eg, loss of vision in 46% of survivors). Our Review indicates that COVID-19-associated mucormycosis is associated with high morbidity and mortality. Diagnosis of pulmonary mucormycosis is particularly challenging, and might be frequently missed in India.

Air Sampling for Fungus around Hospitalized Patients with Coronavirus Disease 2019

The risk of developing coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) depends on factors related to the host, virus, and treatment. However, many hospitals have modified their existing rooms and adjusted airflow to protect healthcare workers from aerosolization, which may increase the risk of Aspergillus exposure. This study aimed to quantitatively investigate airborne fungal levels in negative and slightly negative pressure rooms for COVID-19 patients. The air in neutral pressure rooms in ordinary wards and a liver intensive care unit with high-efficiency particulate air filter was also assessed for comparison. We found the highest airborne fungal burden in recently renovated slightly negative air pressure rooms, and a higher airborne fungal concentration in both areas used to treat COVID-19 patients. The result provided evidence of the potential environmental risk of CAPA by quantitative microbiologic air sampling, which was scarcely addressed in the literature. Enhancing environmental infection control measures to minimize exposure to fungal spores should be considered. However, the clinical implications of a periodic basis to determine indoor airborne fungal levels and further air sterilization in these areas remain to be defined.

COVID-19-Associated Fungal Infections: An Urgent Need for Alternative Therapeutic Approach?

Secondary fungal infections may complicate the clinical course of patients affected by viral respiratory diseases, especially those admitted to intensive care unit. Hospitalized COVID-19 patients are at increased risk of fungal co-infections exacerbating the prognosis of disease due to misdiagnosis that often result in treatment failure and high mortality rate. COVID-19-associated fungal infections caused by predominantly Aspergillus and Candida species, and fungi of the order Mucorales have been reported from several countries to become significant challenge for healthcare system. Early diagnosis and adequate antifungal therapy is essential to improve clinical outcomes, however, drug resistance shows a rising trend highlighting the need for alternative therapeutic agents. The purpose of this review is to summarize the current knowledge on COVID-19-associated mycoses, treatment strategies and the most recent advancements in antifungal drug development focusing on peptides with antifungal activity.

COVID-19 and Fungal Diseases

Coronavirus Disease-2019 (COVID-19) can cause secondary bacterial and fungal infections by affecting the expression of pro-inflammatory markers, such as tumor necrosis alpha and certain cytokines, as well as the numbers of CD₄ and CD₈ cells. In particular, in the head and neck, various fungal species are naturally present, making it the main route of secondary infection. It is difficult to clearly distinguish whether secondary infection is caused by COVID-19 directly or indirectly as a result of the immunocompromised state induced by drugs used to treat the disease. However, the risk of fungal infection is high in patients with severe COVID-19, and lymphopenia is observed in most patients with the disease. Patients with COVID-19 who are immunosuppressed or have other pre-existing comorbidities are at a significantly higher risk of acquiring invasive fungal infections. In order to reduce morbidity and mortality in these patients, early diagnosis is required, and treatment with systemic antifungal drugs or surgical necrotic tissue resection is essential. Therefore, this review aimed to examine the risk of fungal infection in the head and neck of patients with COVID-19 and provide information that could reduce the risk of mortality.

Targeting immunometabolism in host-directed therapies to fungal disease

Fungal infections affect over a billion people and are responsible for more than 1.5 million deaths each year. Despite progress in diagnostic and therapeutic approaches, the management of severe fungal infections remains a challenge. Recently, the reprogramming of cellular metabolism has emerged as a central mechanism through which the effector functions of immune cells are supported to promote antifungal activity. An improved understanding of the immunometabolic signatures that orchestrate antifungal immunity, together with the dissection of the mechanisms that underlie heterogeneity in individual immune responses, may therefore unveil new targets amenable to adjunctive host-directed therapies. In this review, we highlight recent advances in the metabolic regulation of host-fungus interactions and antifungal immune responses, and outline targetable pathways and mechanisms with promising therapeutic potential.

An overview of COVID-19 related to fungal infections: what do we know after the first year of pandemic?

In 2019, severe acute respiratory syndrome caused by CoV-2 virus became a pandemic worldwide, being the fast spread of the disease due to the movement of infected people from one country to another, from one continent to another, or within the same country. Associated comorbidities are important factors that predispose to any fungal coinfections. Because of the importance of fungal infections in COVID-19 patients, the aim of this work was to collect data of the more encountered mycoses related to patients undergoing this disease. Aspergillosis was the first COVID-19-related fungal infection reported, being A. fumigatus the most frequent species for CAPA. Other fungal infections related include mainly candidiasis and mucormycosis, being Rhizopus spp. the more prevalent species found. Influenza-associated pulmonary aspergillosis is well documented; thus, similar complications are expected in severe forms of COVID-19 pneumonia. Therefore, in patients with COVID-19, it is important to take special attention to the surveillance and suspicion of fungal coinfections that might worsen the patient's prognosis.

Human Fungal Infection, Immune Response, and Clinical Challenge-a Perspective During COVID-19 Pandemic

Fungi are a small but important part of the human microbiota and several fungi are familiar to the immune system, yet certain can cause infections in immunocompromised hosts and referred as opportunistic pathogens. The fungal coinfections in COVID-19 hosts with predisposing conditions and immunosuppressive medications are posing higher severity and death. The immunological counteraction (innate/adaptive immunity) is triggered when the PRRs on the host cells recognize the fungal PAMPs. However, in simultaneous infections (COVID-19 and fungal coinfection), the synergism of TLR and NLR may hyperactivate the immune cells which dramatically increase the cytokine level and generate cytokine storm. Fungal colonization in the human gut assists the development of microbiome assembly, ecology, and shaping immune response. However, SARS-CoV-2 infection represented unstable mycobiomes and long-term dysbiosis in a large proportion in COVID-19 patients. Normally, amphotericin B is considered as first-line treatment for invasive fungal infection. So, amphotericin B therapy is recommended in COVID-19 hosts with serious fungal infections. Still, the long-term corticosteroid supplementation prescribed in case of severe pneumonia and lower oxygen levels may result in systemic fungal infection in COVID-19 patients, eventually limiting the lifesaving benefits of available medications. Also, due to the evolution of fungal resistance to available antibiotics, the current treatments are becoming ineffective. Therefore, this review summarizes the concerns, needed to deal with the impending crises.

Cytokine Profile of Invasive Pulmonary Aspergillosis in Severe COVID-19 and Possible Therapeutic Targets

During the SARS-CoV-2 pandemic, a higher incidence of invasive pulmonary aspergillosis was observed in patients affected by Coronavirus disease 2019 (COVID-19), leading to the delineation of a new entity named COVID-19 associated pulmonary aspergillosis (CAPA). A predisposition to invasive infection caused by Aspergillus spp. in SARS-CoV-2 infected patients can be ascribed either to the direct viral-mediated damage of the respiratory epithelium, as already observed in influenza H1N1 virus infections, or to the dysregulated immunity associated with COVID-19. This narrative review focuses on the impact of immune impairment, particularly due to cytokine dysregulation caused by Aspergillus spp. superinfection in COVID-19 for a more in-depth understanding of the molecular pathways implicated in CAPA. As immune competence has proven to be essential in protecting against CAPA onset, a role already threatened by SARS-CoV-2 infection itself, preventive strategies should focus on reducing factors that could further target the host immune system. We also aimed to focus on well-known and less-known risk factors for IPA in COVID-19 patients, related to the main causes of immune suppression, both virus-mediated and iatrogenic, including treatments currently indicated for COVID-19. Lastly, possible preventive strategies aimed at reducing morbidity and mortality due to CAPA could be implemented.