Recovery of a triazole-resistant Aspergillus fumigatus in respiratory specimen of COVID-19 patient in ICU - A case report

Coronavirus disease 2019 (COVID-19)-associated brain abscesses caused by Pseudomonas aeruginosa and Aspergillus fumigatus: two case and a review of the literature

BACKGROUND

Bacterial and fungal superinfections are commonly reported in patients with coronavirus disease 2019.

CASE PRESENTATION

We report the first case of brain and intramedullary abscesses caused by Pseudomonas aeruginosa and a rare case of brain abscesses caused by Aspergillus fumigatus in two post-coronavirus disease 2019 patients. The first patient-34-year-old Iranian woman-presented with weakness of the left upper limb, headaches, and lower limb paresthesia. She had a history of undiagnosed diabetes and had received corticosteroid therapy. The second patient-45-year-old Iranian man-presented with right-sided weakness and had a history of intensive care unit admission. Both patients passed away despite appropriate medical therapy.

CONCLUSION

The immune dysregulation induced by coronavirus disease 2019 and its' treatments can predispose patients, especially immunosuppressed ones, to bacterial and fungal infections with unusual and opportunistic pathogens in the central nervous system. Pseudomonas aeruginosa and Aspergillus fumigatus should be considered as potential causes of brain infection in any coronavirus disease 2019 patient presenting with neurological symptoms and evidence of brain abscess in imaging, regardless of sinonasal involvement. These patients should get started on appropriate antimicrobial therapy as soon as possible, as any delay in diagnosis or treatment can be associated with adverse outcomes.

Fungal pathogens and COVID-19

COVID-19 pandemic highlighted the complications of secondary fungal infections that occurred globally in severe cases of coronavirus disease managed in the intensive care units. Furthermore, varied underlying host factors, such as preexisting immunosuppression, the use of immunomodulatory agents, and invasive procedures predisposing lung tissues to fungal colonization and proliferation, caused increased susceptibility to fungal infections in COVID-19 patient populations. These invasive fungal infections directly impact the overall length of hospitalization and mortality. The most commonly reported fungal infections in patients with COVID-19 include aspergillosis, invasive candidiasis, and mucormycosis. An overall worldwide increase in the prevalence of candidiasis and aspergillosis was observed in COVID-19 patients , whereas outbreaks of mucormycosis were mainly recorded from India. Diagnostic challenges and limited antifungal treatment options make secondary fungal infections among COVID-19 patients more burdensome, which results in improper management and increased mortality.

Secondary fungal infections in SARS-CoV-2 patients: pathological whereabouts, cautionary measures, and steadfast treatments

The earliest documented COVID-19 case caused by the SARS-CoV-2 coronavirus occurred in Wuhan, China, in December 2019. Since then, several SARS-CoV-2 mutants have rapidly disseminated as exemplified by the community spread of the recent omicron variant. The disease already attained a pandemic status with ever-dwindling mortality even after two and half years of identification and considerable vaccination. Aspergillosis, candidiasis, cryptococcosis and mucormycosis are the prominent fungal infections experienced by the majority of SARS-CoV-2 high-risk patients. In its entirety, COVID-19's nexus with these fungal infections may worsen the intricacies in the already beleaguered high-risk patients, making this a topic of substantial clinical concern. Thus, thorough knowledge of the subject is necessary. This article focuses on the concomitant fungal infection(s) in COVID-19 patients, taking into account their underlying causes, the screening methods, manifested drug resistance, and long-term effects. The information and knowledge shared herein could be crucial for the management of critically ill, aged, and immunocompromised SARS-CoV-2 patients who have had secondary fungal infections (SFIs).

Aspergilloma in an Immunocompetent Host: A Case Report

Aspergillosis is a serious pathologic condition caused by Aspergillus that commonly affects immunocompromised patients. In recent years, it has been demonstrated that Aspergillus infection can cause a wide spectrum of pulmonary diseases, including allergic bronchopulmonary aspergillosis, chronic necrotizing aspergillosis, aspergilloma, and invasive aspergillosis. The characteristic computed tomography (CT) and pathologic findings of the various pulmonary manifestations of Aspergillus infection are illustrated and reviewed in this case report. Aspergillus niger is an infrequent infection that affects the lungs in severely immunosuppressed patients. In this paper, we report the case of a 50-year-old female with well-controlled type 2 diabetes mellitus who presented to the emergency department with a history of shortness of breath, cough, and weight loss. She denied any use of immunosuppressive medications. High-resolution CT revealed a large right upper lung cavitary lesion, and the sputum examination and bronchoalveolar lavage revealed Aspergillus niger and positive Aspergillus galactomannan. In conclusion, immunocompetent hosts are rarely affected by aspergilloma with lung cavities. We recommend conducting a retrospective data registry on unreported aspergilloma cases in immunocompetent patients to understand the clinicopathological behavior and improve management.

Managing the Next Wave of Influenza and/or SARS-CoV-2 in the ICU—Practical Recommendations from an Expert Group for CAPA/IAPA Patients

The aim of this study was to establish practical recommendations for the diagnosis and treatment of influenza-associated invasive aspergillosis (IAPA) based on the available evidence and experience acquired in the management of patients with COVID-19-associated pulmonary aspergillosis (CAPA). The CAPA/IAPA expert group defined 14 areas in which recommendations would be made. To search for evidence, the PICO strategy was used for both CAPA and IAPA in PubMed, using MeSH terms in combination with free text. Based on the results, each expert developed recommendations for two to three areas that they presented to the rest of the group in various meetings in order to reach consensus. As results, the practical recommendations for the management of CAPA/IAPA patients have been grouped into 12 sections. These recommendations are presented for both entities in the following situations: when to suspect fungal infection; what diagnostic methods are useful to diagnose these two entities; what treatment is recommended; what to do in case of resistance; drug interactions or determination of antifungal levels; how to monitor treatment effectiveness; what action to take in the event of treatment failure; the implications of concomitant corticosteroid administration; indications for the combined use of antifungals; when to withdraw treatment; what to do in case of positive cultures for Aspergillus spp. in a patient with severe viral pneumonia or Aspergillus colonization; and how to position antifungal prophylaxis in these patients. Available evidence to support the practical management of CAPA/IAPA patients is very scarce. Accumulated experience acquired in the management of CAPA patients can be very useful for the management of IAPA patients. The expert group presents eminently practical recommendations for the management of CAPA/IAPA patients.

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.

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.

Fungal Infection in Co-infected Patients With COVID-19: An Overview of Case Reports/Case Series and Systematic Review

Fungal co-infections are frequent in patients with coronavirus disease 2019 (COVID-19) and can affect patient outcomes and hamper therapeutic efforts. Nonetheless, few studies have investigated fungal co-infections in this population. This study was performed to assess the rate of fungal co-infection in patients with COVID-19 as a systematic review. EMBASE, MEDLINE, and Web of Science were searched considering broad-based search criteria associated with COVID-19 and fungal co-infection. We included case reports and case series studies, published in the English language from January 1, 2020 to November 30, 2021, that reported clinical features, diagnosis, and outcomes of fungal co-infection in patients with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Totally, 54 case reports and 17 case series were identified, and 181 patients (132 men, 47 women, and 2 not mentioned) co-infected with COVID-19 and fungal infection enrolled. The frequency of fungal co-infection among patients with COVID-19 was 49.7, 23.2, 19.8, 6.6, and 0.5% in Asia, America, Europe, Africa, and Australia, respectively. Diabetes (59.6%) and hypertension (35.9%) were found as the most considered comorbidities in COVID-19 patients with fungal infections. These patients mainly suffered from fever (40.8%), cough (30.3%), and dyspnea (23.7%). The most frequent findings in the laboratory results of patients and increase in C-reactive protein (CRP) (33.1%) and ferritin (18.2%), and lymphopenia (16%) were reported. The most common etiological agents of fungal infections were Aspergillus spp., Mucor spp., Rhizopus spp., and Candida spp. reported in study patients. The mortality rate was 54.6%, and the rate of discharged patients was 45.3%. Remdesivir and voriconazole were the most commonly used antiviral and antifungal agents for the treatment of patients. The global prevalence of COVID-19-related deaths is 6.6%. Our results showed that 54.6% of COVID-19 patients with fungal co-infections died. Thus, this study indicated that fungal co-infection and COVID-19 could increase mortality. Targeted policies should be considered to address this raised risk in the current pandemic. In addition, fungal infections are sometimes diagnosed late in patients with COVID-19, and the severity of the disease worsens, especially in patients with underlying conditions. Therefore, patients with fungal infections should be screened regularly during the COVID-19 pandemic to prevent the spread of the COVID-19 patients with fungal co-infection.

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.

Specific Zn(II)-binding site in the C-terminus of Aspf2, a zincophore from Aspergillus fumigatus

Aspergillus fumigatus, one of the most widespread opportunistic human fungal pathogens, adapts to zinc limitation by secreting a 310 amino acid Aspf2 zincophore, able to specifically bind Zn(II) and deliver it to a transmembrane zinc transporter, ZrfC. In this work, we focus on the thermodynamics of Zn(II) complexes with unstructured regions of Aspf2; basing on a variety of spectrometric and potentiometric data, we show that the C-terminal part has the highest Zn(II)-binding affinity among the potential binding sites, and Ni(II) does not compete with Zn(II) binding to this region. The 14 amino acid Aspf2 C-terminus coordinates Zn(II) via two Cys thiolates and two His imidazoles and it could be considered as a promising A. fumigatus targeting molecule.

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.

Pathogenesis of Respiratory Viral and Fungal Coinfections

Individuals suffering from severe viral respiratory tract infections have recently emerged as "at risk" groups for developing invasive fungal infections. Influenza virus is one of the most common causes of acute lower respiratory tract infections worldwide. Fungal infections complicating influenza pneumonia are associated with increased disease severity and mortality, with invasive pulmonary aspergillosis being the most common manifestation. Strikingly, similar observations have been made during the current coronavirus disease 2019 (COVID-19) pandemic. The copathogenesis of respiratory viral and fungal coinfections is complex and involves a dynamic interplay between the host immune defenses and the virulence of the microbes involved that often results in failure to return to homeostasis. In this review, we discuss the main mechanisms underlying susceptibility to invasive fungal disease following respiratory viral infections. A comprehensive understanding of these interactions will aid the development of therapeutic modalities against newly identified targets to prevent and treat these emerging coinfections.

COVID-19 Associated Pulmonary Aspergillosis: Diagnostic Performance, Fungal Epidemiology and Antifungal Susceptibility

Coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) raises concerns as to whether it contributes to an increased mortality. The incidence of CAPA varies widely within hospitals and countries, partly because of difficulties in obtaining a reliable diagnosis. We implemented a routine screening of respiratory specimens in COVID-19 ICU patients for Aspergillus species using culture and galactomannan (GM) detection from serum and/or bronchoalveolar lavages (BAL). Out of 329 ICU patients treated during March 2020 and April 2021, 23 (7%) suffered from CAPA, 13 of probable, and 10 of possible. In the majority of cases, culture, microscopy, and GM testing were in accordance with CAPA definition. However, we saw that the current definitions underscore to pay attention for fungal microscopy and GM detection in BALs, categorizing definitive CAPA diagnosis based on culture positive samples only. The spectrum of Aspergillus species involved Aspergillus fumigatus, followed by Aspergillus flavus, Aspergillus niger, and Aspergillus nidulans. We noticed changes in fungal epidemiology, but antifungal resistance was not an issue in our cohort. The study highlights that the diagnosis and incidence of CAPA is influenced by the application of laboratory-based diagnostic tests. Culture positivity as a single microbiological marker for probable definitions may overestimate CAPA cases and thus may trigger unnecessary antifungal treatment.

Coronavirus Disease 2019-Associated Invasive Fungal Infection

Coronavirus disease 2019 (COVID-19) can become complicated by secondary invasive fungal infections (IFIs), stemming primarily from severe lung damage and immunologic deficits associated with the virus or immunomodulatory therapy. Other risk factors include poorly controlled diabetes, structural lung disease and/or other comorbidities, and fungal colonization. Opportunistic IFI following severe respiratory viral illness has been increasingly recognized, most notably with severe influenza. There have been many reports of fungal infections associated with COVID-19, initially predominated by pulmonary aspergillosis, but with recent emergence of mucormycosis, candidiasis, and endemic mycoses. These infections can be challenging to diagnose and are associated with poor outcomes. The reported incidence of IFI has varied, often related to heterogeneity in patient populations, surveillance protocols, and definitions used for classification of fungal infections. Herein, we review IFI complicating COVID-19 and address knowledge gaps related to epidemiology, diagnosis, and management of COVID-19-associated fungal infections.

COVID-19-Associated Pulmonary Aspergillosis: A Single-Center Experience in Central Valley, California, January 2020-March 2021

Reports of coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) have been widely published across the world since the onset of the pandemic with varying incidence rates. We retrospectively studied all patients with severe COVID-19 infection who were admitted to our tertiary care center′s intensive care units between January 2020 and March 2021, who also had respiratory cultures positive for Aspergillus species. Among a large cohort of 970 patients admitted to the ICU with severe COVID-19 infections during our study period, 48 patients had Aspergillus species growing in respiratory cultures. Based on the 2020 European Confederation of Medical Mycology and the International Society for Human and Animal Mycology (ECMM/ISHAM) consensus criteria, 2 patients in the study had proven CAPA, 9 had probable CAPA, and 37 had possible CAPA. The incidence of CAPA was 5%. The mean duration from a positive COVID-19 test to Aspergillus spp. being recovered from the respiratory cultures was 16 days, and more than half of the patients had preceding fever or worsening respiratory failure despite adequate support and management. Antifungals were given for treatment in 44% of the patients for a mean duration of 13 days. The overall mortality rate in our study population was extremely high with death occurring in 40/48 patients (83%).

COVID-19-Associated Pulmonary Aspergillosis, Fungemia, and Pneumocystosis in the Intensive Care Unit: a Retrospective Multicenter Observational Cohort during the First French Pandemic Wave

The aim of this study was to evaluate diagnostic means, host factors, delay of occurrence, and outcome of patients with COVID-19 pneumonia and fungal coinfections in the intensive care unit (ICU). From 1 February to 31 May 2020, we anonymously recorded COVID-19-associated pulmonary aspergillosis (CAPA), fungemia (CA-fungemia), and pneumocystosis (CA-PCP) from 36 centers, including results on fungal biomarkers in respiratory specimens and serum. We collected data from 154 episodes of CAPA, 81 of CA-fungemia, 17 of CA-PCP, and 5 of other mold infections from 244 patients (male/female [M/F] ratio = 3.5; mean age, 64.7 ± 10.8 years). CA-PCP occurred first after ICU admission (median, 1 day; interquartile range [IQR], 0 to 3 days), followed by CAPA (9 days; IQR, 5 to 13 days), and then CA-fungemia (16 days; IQR, 12 to 23 days) (P < 10-4). For CAPA, the presence of several mycological criteria was associated with death (P < 10-4). Serum galactomannan was rarely positive (<20%). The mortality rates were 76.7% (23/30) in patients with host factors for invasive fungal disease, 45.2% (14/31) in those with a preexisting pulmonary condition, and 36.6% (34/93) in the remaining patients (P = 0.001). Antimold treatment did not alter prognosis (P = 0.370). Candida albicans was responsible for 59.3% of CA-fungemias, with a global mortality of 45.7%. For CA-PCP, 58.8% of the episodes occurred in patients with known host factors of PCP, and the mortality rate was 29.5%. CAPA may be in part hospital acquired and could benefit from antifungal prescription at the first positive biomarker result. CA-fungemia appeared linked to ICU stay without COVID-19 specificity, while CA-PCP may not really be a concern in the ICU. Improved diagnostic strategy for fungal markers in ICU patients with COVID-19 should support these hypotheses. IMPORTANCE To diagnose fungal coinfections in patients with COVID-19 in the intensive care unit, it is necessary to implement the correct treatment and to prevent them if possible. For COVID-19-associated pulmonary aspergillosis (CAPA), respiratory specimens remain the best approach since serum biomarkers are rarely positive. Timing of occurrence suggests that CAPA could be hospital acquired. The associated mortality varies from 36.6% to 76.7% when no host factors or host factors of invasive fungal diseases are present, respectively. Fungemias occurred after 2 weeks in ICUs and are associated with a mortality rate of 45.7%. Candida albicans is the first yeast species recovered, with no specificity linked to COVID-19. Pneumocystosis was mainly found in patients with known immunodepression. The diagnosis occurred at the entry in ICUs and not afterwards, suggesting that if Pneumocystis jirovecii plays a role, it is upstream of the hospitalization in the ICU.

Invasive Fungal Infections Complicating COVID-19: A Narrative Review

Invasive fungal infections (IFIs) can complicate the clinical course of COVID-19 and are associated with a significant increase in mortality, especially in critically ill patients admitted to an intensive care unit (ICU). This narrative review concerns 4099 cases of IFIs in 58,784 COVID-19 patients involved in 168 studies. COVID-19-associated invasive pulmonary aspergillosis (CAPA) is a diagnostic challenge because its non-specific clinical/imaging features and the fact that the proposed clinically diagnostic algorithms do not really apply to COVID-19 patients. Forty-seven observational studies and 41 case reports have described a total of 478 CAPA cases that were mainly diagnosed on the basis of cultured respiratory specimens and/or biomarkers/molecular biology, usually without histopathological confirmation. Candidemia is a widely described secondary infection in critically ill patients undergoing prolonged hospitalisation, and the case reports and observational studies of 401 cases indicate high crude mortality rates of 56.1% and 74.8%, respectively. COVID-19 patients are often characterised by the presence of known risk factors for candidemia such as in-dwelling vascular catheters, mechanical ventilation, and broad-spectrum antibiotics. We also describe 3185 cases of mucormycosis (including 1549 cases of rhino-orbital mucormycosis (48.6%)), for which the main risk factor is a history of poorly controlled diabetes mellitus (>76%). Its diagnosis involves a histopathological examination of tissue biopsies, and its treatment requires anti-fungal therapy combined with aggressive surgical resection/debridement, but crude mortality rates are again high: 50.8% in case reports and 16% in observational studies. The presence of other secondary IFIs usually diagnosed in severely immunocompromised patients show that SARS-CoV-2 is capable of stunning the host immune system: 20 cases of Pneumocystis jirovecii pneumonia, 5 cases of cryptococcosis, 4 cases of histoplasmosis, 1 case of coccidioides infection, 1 case of pulmonary infection due to Fusarium spp., and 1 case of pulmonary infection due to Scedosporium.

Impact of SARS-CoV-2 Epidemic on Antimicrobial Resistance: A Literature Review

Antimicrobial resistance is an urgent threat to public health and global development; in this scenario, the SARS-CoV2 pandemic has caused a major disruption of healthcare systems and practices. A narrative review was conducted on articles focusing on the impact of COVID-19 on multidrug-resistant gram-negative, gram-positive bacteria, and fungi. We found that, worldwide, multiple studies reported an unexpected high incidence of infections due to methicillin-resistant S. aureus, carbapenem-resistant A. baumannii, carbapenem-resistant Enterobacteriaceae, and C. auris among COVID-19 patients admitted to the intensive care unit. In this setting, inappropriate antimicrobial exposure, environmental contamination, and discontinuation of infection control measures may have driven selection and diffusion of drug-resistant pathogens.

COVID-19-Associated Invasive Pulmonary Aspergillosis in the Intensive Care Unit: A Case Series in a Portuguese Hospital

Invasive pulmonary aspergillosis (IPA) has become a recognizable complication in coronavirus disease 2019 (COVID-19) patients admitted to intensive care units (ICUs). Alveolar damage in the context of acute respiratory distress syndrome (ARDS) appears to be the culprit in facilitating fungal invasion in COVID-19 patients, leading to a COVID-19-associated pulmonary aspergillosis (CAPA) phenomenon. From November 2020 to 15 February 2021, 248 COVID-19 patients were admitted to our ICUs, of whom ten patients (4% incidence) were classified as either probable (six) or possible (four) CAPA cases. Seven patients had positive cultural results: Aspergillus fumigatus sensu stricto (five), A. terreus sensu stricto (one), and A. welwitschiae (one). Five patients had positive bronchoalveolar lavage (BAL) and galactomannan (GM), and two patients had both positive cultural and GM criteria. All but two patients received voriconazole. Mortality rate was 30%. Strict interpretation of classic IPA definition would have resulted in eight overlooked CAPA cases. Broader diagnostic criteria are essential in this context, even though differentiation between Aspergillus colonization and invasive disease might be more challenging. Herein, we aim to raise awareness of CAPA in view of its potential detrimental outcome, emphasizing the relevance of a low threshold for screening and early antifungal treatment in ARDS patients.

COVID-19-Associated Pulmonary Aspergillosis (CAPA)

Invasive Pulmonary Aspergillosis (IPA) has been recognized as a possible secondary infection complicating Coronavirus disease 2019 (COVID-19) and increasing mortality. The aim of this review was to report and summarize the available data in the literature concerning the incidence, pathophysiology, diagnosis, and treatment of COVID-19-Associated Pulmonary Aspergillosis (CAPA). Currently, the incidence of CAPA is unclear due to different definitions and diagnostic criteria used among the studies. It was estimated that approximately 8.6% (206/2383) of mechanically ventilated patients were diagnosed with either proven, probable, or putative CAPA. Classical host factors of invasive aspergillosis are rarely recognized in patients with CAPA, who are mainly immuno-competent presenting with comorbidities, while the role of steroids warrants further investigation. Direct epithelial injury and diffuse pulmonary micro thrombi in combination with immune dysregulation, hyper inflammatory response, and immunosuppressive treatment may be implicated. Discrimination between two forms of CAPA (e.g., tracheobronchial and parenchymal) is required, whereas radiological signs of aspergillosis are not typically evident in patients with severe COVID-19 pneumonia. In previous studies, the European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) criteria, a clinical algorithm to diagnose Invasive Pulmonary Aspergillosis in intensive care unit patients (AspICU algorithm), and influenza-associated pulmonary aspergillosis (IAPA) criteria were used for the diagnosis of proven/probable and putative CAPA, as well as the differentiation from colonization, which can be challenging. Aspergillus fumigatus is the most commonly isolated pathogen in respiratory cultures. Bronchoalveolar lavage (BAL) and serum galactomannan (GM), β-d-glucan (with limited specificity), polymerase chain reaction (PCR), and Aspergillus-specific lateral-flow device test can be included in the diagnostic work-up; however, these approaches are characterized by low sensitivity. Early treatment of CAPA is necessary, and 71.4% (135/189) of patients received antifungal therapy, mainly with voriconazole, isavuconazole, and liposomal amphotericin B . Given the high mortality rate among patients with Aspergillus infection, the administration of prophylactic treatment is debated. In conclusion, different diagnostic strategies are necessary to differentiate colonization from bronchial or parenchymal infection in intubated COVID-19 patients with Aspergillus spp. in their respiratory specimens vs. those not infected with severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2). Following confirmation, voriconazole or isavuconazole should be used for the treatment of CAPA.

Overview on the Prevalence of Fungal Infections, Immune Response, and Microbiome Role in COVID-19 Patients

Patients with severe COVID-19, such as individuals in intensive care units (ICU), are exceptionally susceptible to bacterial and fungal infections. The most prevalent fungal infections are aspergillosis and candidemia. Nonetheless, other fungal species (for instance, Histoplasma spp., Rhizopus spp., Mucor spp., Cryptococcus spp.) have recently been increasingly linked to opportunistic fungal diseases in COVID-19 patients. These fungal co-infections are described with rising incidence, severe illness, and death that is associated with host immune response. Awareness of the high risks of the occurrence of fungal co-infections is crucial to downgrade any arrear in diagnosis and treatment to support the prevention of severe illness and death directly related to these infections. This review analyses the fungal infections, treatments, outcome, and immune response, considering the possible role of the microbiome in these patients. The search was performed in Medline (PubMed), using the words "fungal infections COVID-19", between 2020-2021.

Aspergillus fumigatus and aspergillosis: From basics to clinics

The airborne fungus Aspergillus fumigatus poses a serious health threat to humans by causing numerous invasive infections and a notable mortality in humans, especially in immunocompromised patients. Mould-active azoles are the frontline therapeutics employed to treat aspergillosis. The global emergence of azole-resistant A. fumigatus isolates in clinic and environment, however, notoriously limits the therapeutic options of mould-active antifungals and potentially can be attributed to a mortality rate reaching up to 100 %. Although specific mutations in CYP 51A are the main cause of azole resistance, there is a new wave of azole-resistant isolates with wild-type CYP 51A genotype challenging the efficacy of the current diagnostic tools. Therefore, applications of whole-genome sequencing are increasingly gaining popularity to overcome such challenges. Prominent echinocandin tolerance, as well as liver and kidney toxicity posed by amphotericin B, necessitate a continuous quest for novel antifungal drugs to combat emerging azole-resistant A. fumigatus isolates. Animal models and the tools used for genetic engineering require further refinement to facilitate a better understanding about the resistance mechanisms, virulence, and immune reactions orchestrated against A. fumigatus. This review paper comprehensively discusses the current clinical challenges caused by A. fumigatus and provides insights on how to address them.

COVID-19 and fungal infections: Etiopathogenesis and therapeutic implications

Invasive fungal infection often complicates patients with severe viral infection, especially those admitted to critical care units. Severe SARS-CoV-2 infection has been no exception and a significant association with Aspergillus spp. has been documented, resulting in high patient mortality. In this summary we describe the clinical presentation, the underlying diseases most commonly linked with this association, radiological manifestations and therapeutic management of CAPA.

Epidemiology of Systemic Mycoses in the COVID-19 Pandemic

The physiopathologic characteristics of COVID-19 (high levels of inflammatory cytokines and T-cell reduction) promote fungal colonization and infection, which can go unnoticed because the symptoms in both diseases are very similar. The objective of this work was to study the current epidemiology of systemic mycosis in COVID-19 times. A literature search on the subject (January 2020–February 2021) was performed in PubMed, Embase, Cochrane Library, and LILACS without language restrictions. Demographic data, etiological agent, risk factors, diagnostic methods, antifungal treatment, and fatality rate were considered. Eighty nine publications were found on co-infection by COVID-19 and pneumocystosis, candidiasis, aspergillosis, mucormycosis, coccidioidomycosis, or histoplasmosis. In general, the co-infections occurred in males over the age of 40 with immunosuppression caused by various conditions. Several species were identified in candidiasis and aspergillosis co-infections. For diagnosis, diverse methods were used, from microbiological to molecular. Most patients received antifungals; however, the fatality rates were 11–100%. The latter may result because the clinical picture is usually attributed exclusively to SARS-CoV-2, preventing a clinical suspicion for mycosis. Diagnostic tests also have limitations beginning with sampling. Therefore, in the remainder of the pandemic, these diagnostic limitations must be overcome to achieve a better patient prognosis.

A review of significance of Aspergillus detection in airways of ICU COVID-19 patients

It is now well known that patients with SARS-CoV-2 infection admitted in ICU and mechanically ventilated are at risk of developing invasive pulmonary aspergillosis (IPA). Nevertheless, symptomatology of IPA is often atypical in mechanically ventilated patients, and radiological aspects in SARS-CoV-2 pneumonia and IPA are difficult to differentiate. In this context, the significance of the presence of Aspergillus in airway specimens (detected by culture, galactomannan antigen or specific PCR) remains to be fully understood. To decipher the relevance of the detection of Aspergillus, we performed a comprehensive review of all published cases of respiratory Aspergillus colonisation and IPA in COVID-19 patients. The comparison of patients receiving or not antifungal treatment allowed us to highlight the most important criteria for the decision to treat. The comparison of surviving and non-surviving patients made it possible to unveil criteria associated with mortality that should be taken into account in the treatment decision.

Taskforce report on the diagnosis and clinical management of COVID-19 associated pulmonary aspergillosis

Purpose

Invasive pulmonary aspergillosis (IPA) is increasingly reported in patients with severe coronavirus disease 2019 (COVID-19) admitted to the intensive care unit (ICU). Diagnosis and management of COVID-19 associated pulmonary aspergillosis (CAPA) are challenging and our aim was to develop practical guidance.

Methods

A group of 28 international experts reviewed current insights in the epidemiology, diagnosis and management of CAPA and developed recommendations using GRADE methodology.

Results

The prevalence of CAPA varied between 0 and 33%, which may be partly due to variable case definitions, but likely represents true variation. Bronchoscopy and bronchoalveolar lavage (BAL) remain the cornerstone of CAPA diagnosis, allowing for diagnosis of invasive Aspergillus tracheobronchitis and collection of the best validated specimen for Aspergillus diagnostics. Most patients diagnosed with CAPA lack traditional host factors, but pre-existing structural lung disease and immunomodulating therapy may predispose to CAPA risk. Computed tomography seems to be of limited value to rule CAPA in or out, and serum biomarkers are negative in 85% of patients. As the mortality of CAPA is around 50%, antifungal therapy is recommended for BAL positive patients, but the decision to treat depends on the patients’ clinical condition and the institutional incidence of CAPA. We recommend against routinely stopping concomitant corticosteroid or IL-6 blocking therapy in CAPA patients.

Conclusion

CAPA is a complex disease involving a continuum of respiratory colonization, tissue invasion and angioinvasive disease. Knowledge gaps including true epidemiology, optimal diagnostic work-up, management strategies and role of host-directed therapy require further study.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-021-06449-4.

Coalescence of co-infection and antimicrobial resistance with SARS-CoV-2 infection: The blues of post-COVID-19 world

In viral respiratory infections, bacterial co-pathogens are widely known to co-infect, and they significantly increase the morbidity and mortality rate. During the influenza season, the advent of 2019-nCoV (novel coronavirus) has led to the widespread use of oral and intravenous antibiotics and inhibitors of neuraminidase enzyme. Owing to causes such as extended intubation, the ubiquitous use of intrusive catheters, and compromised host immunity, coronavirus disease (COVID-19) patients are at heightened risk of secondary bacterial and fungal infections, leading to the difficulty in their treatment. Apart from the pandemic, the primary risk is a likely surge in multidrug resistance. In this work, we evaluated the coalescence of present co-infection alongside the COVID-19 and post-pandemic antimicrobial resistance due to high ongoing drug use for the treatment of COVID-19. We found that while there is currently limited evidence of bacterial infections in COVID-19, available proof supports the restricted use of antibiotics from an antibiotic stewardship viewpoint, primarily upon entry. Paramount attempts should be made to collect sputum and blood culture samples as well as pneumococcal urinary antigen monitoring in order to endorse stringent antibiotic usage. For antimicrobial stewardship, inflammatory markers like procalcitonin have been added, but such biomarkers are typically upraised in COVID-19. Antimicrobials cannot be completely removed in wastewater treatment plants (WWTPs) and once they enter the water environment, possesses a great risk of inducing resistance to drugs in microbes. Hence, their prescription and administrations should be regulated and alternate solutions such as vaccines, preventive measures and personal hygiene should be given top priority. It is imperative to establish an antimicrobial strategy discrete to COVID-19, as this pandemic has caused an outbreak of numerous other associated diseases and has the potential to drive microbial resistance. Coordinated plans are essential for this at the citizen, health-care and policy levels.

Incidence, diagnosis and outcomes of COVID-19-associated pulmonary aspergillosis (CAPA): a systematic review

COVID-19-associated pulmonary aspergillosis (CAPA) is defined as invasive pulmonary aspergillosis occurring in COVID-19 patients. The purpose of this review was to discuss the incidence, characteristics, diagnostic criteria, biomarkers, and outcomes of hospitalized patients diagnosed with CAPA. A literature search was performed through Pubmed and Web of Science databases for articles published up to 20^th March 2021. In 1421 COVID-19 patients, the overall CAPA incidence was 13.5% (range 2.5-35.0%). The majority required invasive mechanical ventilation (IMV). The time to CAPA diagnosis from illness onset varied between 8.0 and 16.0 days. However, the time to CAPA diagnosis from intensive care unit (ICU) admission and IMV initiation ranged between 4.0-15.0 days and 3.0-8.0 days. The most common diagnostic criteria were the modified AspICU-Dutch/Belgian Mycosis Study Group and IAPA-Verweij et al. A total of 77.6% of patients had positive lower respiratory tract cultures, other fungal biomarkers of bronchoalveolar lavage and serum galactomannan were positive in 45.3% and 18.2% of patients. The CAPA mortality rate was high at 48.4%, despite the widespread use of antifungals. Lengthy hospital and ICU stays ranging between 16.0-37.5 days and 10.5-37.0 days were observed. CAPA patients had prolonged IMV duration of 13.0-20.0 days. The true incidence of CAPA likely remains unknown as the diagnosis is limited by the lack of standardized diagnostic criteria that rely solely on microbiological data with direct or indirect detection of Aspergillus in respiratory specimens, particularly in clinical conditions with a low pretest probability. A well-designed, multi-centre study to determine the optimal diagnostic approach for CAPA is required.

State-of-the-art review of secondary pulmonary infections in patients with COVID-19 pneumonia

Background

The incidence of secondary pulmonary infections is not well described in hospitalized COVID-19 patients. Understanding the incidence of secondary pulmonary infections and the associated bacterial and fungal microorganisms identified can improve patient outcomes.

Objective

This narrative review aims to determine the incidence of secondary bacterial and fungal pulmonary infections in hospitalized COVID-19 patients, and describe the bacterial and fungal microorganisms identified.

Method

We perform a literature search and select articles with confirmed diagnoses of secondary bacterial and fungal pulmonary infections that occur 48 h after admission, using respiratory tract cultures in hospitalized adult COVID-19 patients. We exclude articles involving co-infections defined as infections diagnosed at the time of admission by non-SARS-CoV-2 viruses, bacteria, and fungal microorganisms.

Results

The incidence of secondary pulmonary infections is low at 16% (4.8–42.8%) for bacterial infections and lower for fungal infections at 6.3% (0.9–33.3%) in hospitalized COVID-19 patients. Secondary pulmonary infections are predominantly seen in critically ill hospitalized COVID-19 patients. The most common bacterial microorganisms identified in the respiratory tract cultures are Pseudomonas aeruginosa, Klebsiella species, Staphylococcus aureus, Escherichia coli, and Stenotrophomonas maltophilia. Aspergillus fumigatus is the most common microorganism identified to cause secondary fungal pulmonary infections. Other rare opportunistic infection reported such as PJP is mostly confined to small case series and case reports. The overall time to diagnose secondary bacterial and fungal pulmonary infections is 10 days (2–21 days) from initial hospitalization and 9 days (4–18 days) after ICU admission. The use of antibiotics is high at 60–100% involving the studies included in our review.

Conclusion

The widespread use of empirical antibiotics during the current pandemic may contribute to the development of multidrug-resistant microorganisms, and antimicrobial stewardship programs are required for minimizing and de-escalating antibiotics. Due to the variation in definition across most studies, a large, well-designed study is required to determine the incidence, risk factors, and outcomes of secondary pulmonary infections in hospitalized COVID-19 patients.

COVID-19-associated pulmonary aspergillosis: a prospective single-center dual case series

Background

COVID‐19–associated pulmonary aspergillosis (CAPA) has emerged as an invasive fungal disease, often affecting previously immunocompetent, mechanically ventilated, intensive care unit (ICU) patients. Incidence rates of 3.8%–33.3% have been reported depending on the geographic area, with high (47%) mortality.

Objectives

Here, we describe a single‐centre prospective case series with CAPA cases from both the first (March‐May, n = 5/33) and second (mid‐September through mid‐December, n = 8/33) COVID‐19 wave at a 500‐bed teaching hospital in the Netherlands.

Patients/Methods

In the first COVID‐19 wave, a total of 265 SARS‐CoV‐2 PCR‐positive patients were admitted to our hospital of whom 33 needed intubation and mechanical ventilation. In the second wave, 508 SARS‐CoV‐2 PCR‐positive patients were admitted of whom 33 needed mechanical ventilation. Data were prospectively collected.

Results

We found a significant decrease in COVID‐19 patients needing mechanical ventilation in the ICU in the second wave (p < .01). From these patients, however, a higher percentage were diagnosed with CAPA (24.2% vs 15.2%), although not significant (p = .36). All CAPA patients encountered in the second wave received dexamethasone. Mortality between both groups was similarly high (40%–50%). Moreover, we found environmental TR₃₄/L98H azole‐resistant Aspergillus fumigatus isolates in two separate patients.

Conclusions

In this series, 19.7% (n = 13/66) of mechanically ventilated SARS‐CoV‐2 patients were diagnosed with CAPA. In addition, we found a significant reduction in COVID‐19 patients needing mechanical ventilation on the ICU in the second wave. Numbers are too small to determine whether there is a true difference in CAPA incidence in mechanically ventilated patients between the two waves, and whether it could be attributed to dexamethasone SARS‐CoV‐2 therapy.

COVID-19-Associated Pulmonary Aspergillosis, March-August 2020

Pneumonia caused by severe acute respiratory syndrome coronavirus 2 emerged in China at the end of 2019. Because of the severe immunomodulation and lymphocyte depletion caused by this virus and the subsequent administration of drugs directed at the immune system, we anticipated that patients might experience fungal superinfection. We collected data from 186 patients who had coronavirus disease-associated pulmonary aspergillosis (CAPA) worldwide during March-August 2020. Overall, 182 patients were admitted to the intensive care unit (ICU), including 180 with acute respiratory distress syndrome and 175 who received mechanical ventilation. CAPA was diagnosed a median of 10 days after coronavirus disease diagnosis. Aspergillus fumigatus was identified in 80.3% of patient cultures, 4 of which were azole-resistant. Most (52.7%) patients received voriconazole. In total, 52.2% of patients died; of the deaths, 33.0% were attributed to CAPA. We found that the cumulative incidence of CAPA in the ICU ranged from 1.0% to 39.1%.

Aspergillosis Complicating Severe Coronavirus Disease

Aspergillosis complicating severe influenza infection has been increasingly detected worldwide. Recently, coronavirus disease-associated pulmonary aspergillosis (CAPA) has been detected through rapid reports, primarily from centers in Europe. We provide a case series of CAPA, adding 20 cases to the literature, with review of pathophysiology, diagnosis, and outcomes. The syndromes of pulmonary aspergillosis complicating severe viral infections are distinct from classic invasive aspergillosis, which is recognized most frequently in persons with neutropenia and in other immunocompromised persons. Combined with severe viral infection, aspergillosis comprises a constellation of airway-invasive and angio-invasive disease and results in risks associated with poor airway fungus clearance and killing, including virus- or inflammation-associated epithelial damage, systemic immunosuppression, and underlying lung disease. Radiologic abnormalities can vary, reflecting different pathologies. Prospective studies reporting poor outcomes in CAPA patients underscore the urgent need for strategies to improve diagnosis, prevention, and therapy.

Defining and managing COVID-19-associated pulmonary aspergillosis: the 2020 ECMM/ISHAM consensus criteria for research and clinical guidance

Severe acute respiratory syndrome coronavirus 2 causes direct damage to the airway epithelium, enabling aspergillus invasion. Reports of COVID-19-associated pulmonary aspergillosis have raised concerns about it worsening the disease course of COVID-19 and increasing mortality. Additionally, the first cases of COVID-19-associated pulmonary aspergillosis caused by azole-resistant aspergillus have been reported. This article constitutes a consensus statement on defining and managing COVID-19-associated pulmonary aspergillosis, prepared by experts and endorsed by medical mycology societies. COVID-19-associated pulmonary aspergillosis is proposed to be defined as possible, probable, or proven on the basis of sample validity and thus diagnostic certainty. Recommended first-line therapy is either voriconazole or isavuconazole. If azole resistance is a concern, then liposomal amphotericin B is the drug of choice. Our aim is to provide definitions for clinical research and up-to-date recommendations for clinical management of the diagnosis and treatment of COVID-19-associated pulmonary aspergillosis.

Invasive Pulmonary Aspergillosis in Patients with SARS-CoV-2 Infection: A Systematic Review of the Literature

In this systematic review, we investigate the epidemiology, pathogenesis, risk factors, clinical manifestations, diagnosis and treatment of COVID-19-associated pulmonary aspergillosis (CAPA). We identified 85 cases from 22 studies. The frequency of CAPA is currently unknown but ranges between <5% to >30% in different case series; the possibility of colonization rather than invasive disease is the most important confounder. The vast majority of patients with CAPA did not have any of the classic host risk factors, such as immunosuppression from organ transplant or neutropenia, although a significant proportion (46%) had received corticosteroids. Age, pulmonary comorbidities and male sex were associated with higher mortality. Patients treated with voriconazole had numerically lower case-fatality rate. Clinical vigilance for CAPA is advisable in critically ill patients with COVID-19 who are not improving, even those who do not meet classic host criteria for invasive mycoses, especially if they are receiving corticosteroids. A thorough, multi-faceted diagnostic work-up and early initiation of a mold-active triazole may be lifesaving. Further research studies using standardized, uniform definitions of invasive disease and colonization are urgently needed.

Fatal Coronavirus Disease 2019-associated Pulmonary Aspergillosis; A Report of Two Cases and Review of the Literature

Coronavirus Disease 2019 (COVID-19)-associated pulmonary aspergillosis is an emerging entity. We report two fatal cases of putative COVID-19-associated pulmonary aspergillosis. Both cases were diagnosed on the basis of respiratory tract cultures yielding Aspergillus species and otherwise unexplained clinical and radiological deterioration. Existing published literature on COVID-19-associated pulmonary aspergillosis indicate poor outcomes and high mortality. CAPA should be considered in patients with critical COVID-19 who have unexplained progressive respiratory failure despite optimized supportive care. Diagnostic work-up should be initiated as early as possible and should ideally include fungal cultures, galactomannan detection and Aspergillus PCR on tracheal aspirates or broncho-alveolar lavage fluid. Empiric systemic antifungal therapy may be justified in selected cases, pending diagnostic work up results. Large, multi-center studies are required to further understand the pathogenesis of invasive aspergillosis in COVID-19, and the optimal diagnostic and treatment strategies.

COVID-19 Associated Invasive Pulmonary Aspergillosis: Diagnostic and Therapeutic Challenges

Aspergillus co-infection in patients with severe coronavirus disease 2019 (COVID-19) pneumonia, leading to acute respiratory distress syndrome, has recently been reported. To date, 38 cases have been reported, with other cases most likely undiagnosed mainly due to a lack of clinical awareness and diagnostic screening. Importantly, there is currently no agreed case definition of COVID-19 associated invasive pulmonary aspergillosis (CAPA) that could aid in the early detection of this co-infection. Additionally, with the global emergence of triazole resistance, we emphasize the importance of antifungal susceptibility testing in order to ensure appropriate antifungal therapy. Herein is a review of 38 published CAPA cases, which highlights the diagnostic and therapeutic challenges posed by this novel fungal co-infection.