Coronavirus Disease 2019-Associated Mucormycosis in France: A Rare but Deadly Complication

Epidemiology and prognostic factors of mucormycosis in France (2012-2022): a cross-sectional study nested in a prospective surveillance programme

Background

Mucormycosis is a deadly invasive fungal infection recently included in the WHO priority pathogen list. Here we sought to describe epidemiological trends of mucormycosis in France, and to evaluate factors associated with mortality.

Methods

From 2012 to 2022, we implemented a nationwide prospective surveillance programme for mucormycosis in France, focusing on epidemiology, species, seasonal variations. Factors associated with 3-month mortality were studied by univariable and multivariable logistic regression.

Findings

Among 550 cases of mucormycosis, the main underlying conditions were haematological malignancy (HM, 65.1%, 358/550), trauma (8%, 44/550), diabetes (7.5%, 41/550) and solid-organ transplants (6.5%, 36/550). Site of infection was pulmonary in 52.4% (288/550), rhinocerebral in 14.5% (80/550), and cutaneo-articular in 17.1% (94/550). Main species identified were Rhizopus arrhizus (21%, 67/316), Rhizopus microsporus (13.6%, 43/316), Lichtheimia corymbifera and Mucor circinelloides (13.3%, 42/316 each), Rhizomucor pusillus (12%, 38/316), and Lichtheimia ramosa (10.8%, 34/316). We found associations between underlying condition, site of infection, and infecting species, including a previously undescribed triad of trauma, cutaneo-articular localisations, and L. ramosa/M. circinelloides. Diagnostic contribution of Polymerase Chain Reaction (PCR) increased from 16% (4/25) in 2012 to 91% (61/67) in 2022, with more than 50% of diagnoses relying solely on PCR in 2022. We also found seasonal variations with relatively more cases in autumn. Ninety-day mortality was 55.8% (276/495). Independent prognostic factors were age, diagnosis in Intensive Care Unit (ICU), and HM while diagnosis after 2015 (i.e. large implementation of PCR) and surgery were associated with reduced mortality.

Interpretation

This study reveals major mucormycosis epidemiological changes in France, with a large predominance of HM patients, and a parallel between PCR multicentre implementation and improved prognosis. We also evidence new associations between species, localisations and risk factors, as well as seasonal variations.

Funding

Recurrent financial support from Santé Publique France and Institut Pasteur.

Epidemiology, Clinical Manifestations, Treatment, and Outcome of Mucormycosis: A Review of 77 Cases From a Single Center in France

Background

The aim of this study was to assess the epidemiology, clinical manifestations, and outcome of mucormycosis over 15 years in a single center in France.

Methods

We conducted a retrospective analysis of all mucormycosis cases in our institution from 1 January 2006 to 31 December 2020 and analyzed patients' medical records, laboratory results, and treatment to describe the epidemiology, clinical manifestations, diagnosis, treatment, and outcome. Mucorales quantitative polymerase chain reaction (qPCR) for the diagnosis was implemented in 2015.

Results

Seventy-seven mucormycosis cases were analyzed in 77 patients, with a median age of 54 years (60% male). Identified risk factors were hematological diseases (46 cases [60%]), solid malignancies (2 cases), solid organ transplants (3), burns (18), diabetes only (7), and trauma (1). Sites of infection were lungs (42%), sinus (36%), skin (31%), central nervous system (9%), liver (8%), others (6%), and disseminated (12%). Diagnosis remained difficult and qPCR contributed to mucormycosis diagnosis in 30% of cases. Among hematology patients, serum qPCR was the only positive test in 15% of cases. A mixed mold infection was diagnosed in 24 of 77 (31%) patients. Surgical treatment was undertaken in 43 (56%) cases. Most patients received liposomal amphotericin B (89%), with a combination therapy in 18 of 77 cases (23%). Three-month survival rate was 40% (95% confidence interval [CI], .30-.53]). As for treatment, adjunction of surgery (hazard ratio, 0.47 [95%CI, .25-.91); P = 0.02) was associated with lower mortality.

Conclusions

Mucormycosis remained associated with high mortality, especially in the hematological and burn populations. Surgery in combination with antifungal treatment was associated with improved survival.

Severe mold fungal infections in critically ill patients with COVID-19

The SARS-CoV-2 pandemic put an unprecedented strain on modern societies and healthcare systems. A significantly higher incidence of invasive fungal co-infections was noted compared with the pre-COVID-19 era, adding new diagnostic and therapeutic challenges in the critical care setting. In the current narrative review, we focus on invasive mold infections caused by Aspergillus and Mucor species in critically ill COVID-19 patients. We discuss up-to-date information on the incidence, pathogenesis, diagnosis and treatment of these mold-COVID-19 co-infections, as well as recommendations on preventive and prophylactic interventions. Traditional risk factors were often not recognized in COVID-19-associated aspergillosis and mucormycosis, highlighting the role of other determinant risk factors. The associated patient outcomes were worse compared with COVID-19 patients without mold co-infection.

Risk factors, mortality, and predictors of survival in COVID-19-associated pulmonary mucormycosis: a multicentre retrospective study from India

OBJECTIVES

To compare COVID-19-associated pulmonary mucormycosis (CAPM) with COVID-19-associated rhino-orbital mucormycosis (CAROM), ascertain factors associated with CAPM among patients with COVID-19, and identify factors associated with 12-week mortality in CAPM.

METHODS

We performed a retrospective multicentre cohort study. All study participants had COVID-19. We enrolled CAPM, CAROM, and COVID-19 subjects without mucormycosis (controls; age-matched). We collected information on demography, predisposing factors, and details of COVID-19 illness. Univariable analysis was used to compare CAPM and CAROM. We used multivariable logistic regression to evaluate factors associated with CAPM (with hypoxemia during COVID-19 as the primary exposure) and at 12-week mortality.

RESULTS

We included 1724 cases (CAPM [n = 122], CAROM [n = 1602]) and 3911 controls. Male sex, renal transplantation, multimorbidity, neutrophil-lymphocyte ratio, intensive care admission, and cumulative glucocorticoid dose for COVID-19 were significantly higher in CAPM than in CAROM. On multivariable analysis, COVID-19-related hypoxemia (aOR, 2.384; 95% CI, 1.209-4.700), male sex, rural residence, diabetes mellitus, serum C-reactive protein, glucocorticoid, and zinc use during COVID-19 were independently associated with CAPM. CAPM reported a higher 12-week mortality than CAROM (56 of the 107 [52.3%] vs. 413 of the 1356 [30.5%]; p = 0.0001). Hypoxemia during COVID-19 (aOR [95% CI], 3.70 [1.34-10.25]) and Aspergillus co-infection (aOR [95% CI], 5.40 [1.23-23.64]) were independently associated with mortality in CAPM, whereas surgery was associated with better survival.

DISCUSSION

CAPM is a distinct entity with a higher mortality than CAROM. Hypoxemia during COVID-19 illness is associated with CAPM. COVID-19 hypoxemia and Aspergillus co-infection were associated with higher mortality in CAPM.

Rapid detection of Mucorales based on recombinase polymerase amplification and real-time PCR

Mucormycosis, an invasive fungal disease with severe consequences, poses a significant threat to immunocompromised individuals. However, the timely and accurate identification of Mucorales infection continues to present difficulties. In this study, novel detection techniques utilizing recombinase polymerase amplification (RPA) and quantitative real-time polymerase chain reaction (qPCR) were developed, specifically targeting the mitochondrial rnl gene, in order to address this challenge. The specificity of the RPA and qPCR assay was assessed by adding genomic DNAs extracted from 14 non-targeted strains, as well as human and mouse blood. No false-positive results were observed. Additionally, genomic DNAs from 13 species in five genera of order Mucorales were tested and yielded positive results in both methods. To further evaluate the sensitivity of the assays, DNAs from Rhizopus oryzae, Mucor racemosus, Absidia glauca, Rhizomucor miehei, and Cunninghamella bertholletiae were utilized, with concentrations ranging from 1 ng/μL to 1 fg/μL. The limit of detection (LoD) for the RPA assay was determined to be 1 pg., with the exception of Rhizomucor miehei which had a LoD of 1 ng. The LoD for the qPCR assay varied between 10 fg and 1 pg., depending on the specific species being tested. Sensitivity analysis conducted on simulated clinical samples revealed that the LoD for RPA and qPCR assays were capable of detecting DNA extracted from 103 and 101 colony forming units (CFU) conidia in 200 μL of blood and serum, respectively. Consequently, the real-time RPA and qPCR assays developed in this study exhibited favorable sensitivity and specificity for the diagnosis of mucormycosis.

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

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

COVID-19-associated mucormycosis in India: Why such an outbreak?

An unprecedented mucormycosis outbreak occurred in India during the second COVID-19 wave in spring 2021. COVID-19-associated mucormycosis (CAM) was observed, mainly rhino-orbito-cerebral mucormycosis (ROCM), in patients with poorly controlled diabetes and treated with inappropriate doses of glucocorticoids. The aim of this mini-review was to compare the characteristics of the CAM epidemic in India with (i) mucormycosis cases before the COVID-19 pandemic and (ii) CAM in the rest of the world (particularly in France) in order to identify the reasons for this outbreak. In India, the major mucormycosis epidemiologic change during the COVID-19 pandemic was an increase in the percentage of patients treated with corticosteroids who developed CAM. Compared with the rest of the world, India reported a higher mucormycosis incidence even before the COVID-19 pandemic. Moreover, in India, patients with CAM were more likely to have diabetes mellitus and ROCM; conversely, mortality rates were lower. The reasons for such a localized epidemic in India have remained unclear, but some hypotheses can be put forward, particularly the combination of high prevalence of uncontrolled diabetes mellitus and frequent indiscriminate corticosteroid utilization in a country that already had a high mucormycosis burden before the COVID-19 pandemic.

A Repertoire of Clinical Non-Dermatophytes Moulds

Humans are constantly exposed to micromycetes, especially filamentous fungi that are ubiquitous in the environment. In the presence of risk factors, mostly related to an alteration of immunity, the non-dermatophyte fungi can then become opportunistic pathogens, causing superficial, deep or disseminated infections. With new molecular tools applied to medical mycology and revisions in taxonomy, the number of fungi described in humans is rising. Some rare species are emerging, and others more frequent are increasing. The aim of this review is to (i) inventory the filamentous fungi found in humans and (ii) provide details on the anatomical sites where they have been identified and the semiology of infections. Among the 239,890 fungi taxa and corresponding synonyms, if any, retrieved from the Mycobank and NCBI Taxonomy databases, we were able to identify 565 moulds in humans. These filamentous fungi were identified in one or more anatomical sites. From a clinical point of view, this review allows us to realize that some uncommon fungi isolated in non-sterile sites may be involved in invasive infections. It may present a first step in the understanding of the pathogenicity of filamentous fungi and the interpretation of the results obtained with the new molecular diagnostic tools.

What Is New in Pulmonary Mucormycosis?

Mucormycosis is a rare but life-threatening fungal infection due to molds of the order Mucorales. The incidence has been increasing over recent decades. Worldwide, pulmonary mucormycosis (PM) presents in the lungs, which are the third main location for the infection after the rhino-orbito-cerebral (ROC) areas and the skin. The main risk factors for PM include hematological malignancies and solid organ transplantation, whereas ROC infections are classically favored by diabetes mellitus. The differences between the ROC and pulmonary locations are possibly explained by the activation of different mammalian receptors—GRP78 in nasal epithelial cells and integrin β1 in alveolar epithelial cells—in response to Mucorales. Alveolar macrophages and neutrophils play a key role in the host defense against Mucorales. The diagnosis of PM relies on CT scans, cultures, PCR tests, and histology. The reversed halo sign is an early, but very suggestive, sign of PM in neutropenic patients. Recently, the serum PCR test showed a very encouraging performance for the diagnosis and follow-up of mucormycosis. Liposomal amphotericin B is the drug of choice for first-line therapy, together with correction of underlying disease and surgery when feasible. After a stable or partial response, the step-down treatment includes oral isavuconazole or posaconazole delayed release tablets until a complete response is achieved. Secondary prophylaxis should be discussed when there is any risk of relapse, such as the persistence of neutropenia or the prolonged use of high-dose immunosuppressive therapy. Despite these novelties, the mortality rate from PM remains higher than 50%. Therefore, future research must define the place for combination therapy and adjunctive treatments, while the development of new treatments is necessary.

Clinical profile of COVID-19-associated mucormycosis patients and the clinical suspects: a descriptive audit

Background

India witnessed a massive surge of rhino orbital cerebral mucormycosis (ROCM) cases during the second wave of COVID-19, recording the highest number of cases in the world, indeed, an epidemic within the pandemic.

Objectives

To describe the clinical profile of patients with COVID-19-associated mucormycosis (CAM) and the clinical suspects for mucormycosis.

Methods

This single-center descriptive, observational study/audit was done at Indira Gandhi Medical College, Pondicherry, South India. This study is about the clinical profile of 7 CAM patients and 14 COVID-19 patients who were suspects of CAM, based on their risk factors and clinical symptoms, and were referred to the ENT department.

Statistical analysis

All the descriptive variables were summarized as mean, frequency, and percentages for qualitative data.

Results

All 7 CAM patients were COVID-19 positive and were not vaccinated against COVID-19, All 7 were known diabetic, all 7 had steroid therapy for their COVID status, and 5 out of 7 (71%) had uncontrolled diabetes mellitus at the time of diagnosis. Facial pain, nasal discharge, and eye swelling were the presenting symptoms of CAM. Maxillary and ethmoid sinuses were the most commonly involved para nasal sinuses. Four out of seven (57.1%) CAM patients survived after 16 months of follow-up, after surgical and medical treatment for CAM. Of the 14 clinical suspects who were negative for CAM, 2 were negative for COVID-19, their risk factors were brought under control, 3 expired due to COVID complications, and 9 patients are alive till date.

Conclusion

Uncontrolled diabetes is a risk factor for ROCM/CAM, another possible risk factor is steroid therapy, and we hypothesize that COVID infection could also be a possible risk factor that needs to be studied more extensively in a larger sample. Early clinical suspicion, withdrawal of steroids, rapid control of diabetes mellitus, appropriate investigations, and early surgical intervention combined with medical treatment offers better outcome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s43163-023-00430-2.

Mucor and Malignancy: A Double-Hit Case of Intestinal Ischemia

Mucormycosis is an invasive fungal infection due to molds in the order Mucorales. These opportunistic pathogens found in soil or decaying organic matter mostly affect immunocompromised hosts. Rhino-orbital-cerebral, pulmonary, gastrointestinal, cutaneous, and disseminated patterns are possible. We describe a case of angioinvasive colonic mucormycosis in a patient with recent diabetic ketoacidosis and undiagnosed colon adenocarcinoma. The diagnosis was made on histopathology after the patient developed intestinal ischemia and underwent hemicolectomy. This case highlights the potentially diverse manifestations of Mucorales infections, typical and atypical risk factors, and the index of suspicion necessary for early diagnosis and outcome optimization.

Clinical Phenotypes of COVID-19 Associated Mucormycosis (CAM): A Comprehensive Review

A mucormycosis surge was reported during the COVID-19 pandemic in India. A literature search until 14 July 2022, with the aim of updating COVID-19-associated mucormycosis (CAM), identified 663 studies and 88 met inclusion criteria (8727 patients). India reported 8388 patients, Egypt 208 and Europe 40. Rhino-orbito-cerebral mucormycosis (ROCM) was identified among 8082 (98.3%) patients, followed by 98 (1.2%) with pulmonary. In India, 82.6% of patients had diabetes mellitus, with 82% receiving corticosteroids. In Europe, 75% presented pulmonary CAM, 32.5% had diabetes and 40% were immunocompromised. CAM was identified at a median of 17.4 days (IQR 7.5 days) post COVID-19 diagnosis, and PCR was performed in five studies. Rhino-orbital invasion is clinically obvious, while cerebral involvement presents with cavernous sinus thrombosis, meningitis and cerebrovascular disease. Symptoms of pulmonary CAM usually overlap with severe COVID-19 pneumonia. High-dose liposomal Amphotericin B (and early surgical debridement in ROCM) are the mainstay of therapy. The median mortality rate was estimated to be 21.4% (IQR 31.9%), increased by the presence of pulmonary (80% (IQR 50%) or cerebral involvement (50% (IQR 63.9%). In summary, different CAM clinical phenotypes need to be distinguished, influenced by geographical presentation. Opportunities exist for diagnosis and therapy optimization, based on earlier high-dose antifungal therapy, early source control, strict glycemic control and restriction of steroids to COVID-19 patients with oxygen requirements.

Influence of transitional care on the clinical manifestations among patients with COVID‑19: A single‑center, double‑blinded, randomized survey

Pneumonia and acute respiratory distress syndrome are the major complications of coronavirus disease 2019 (COVID-19). Transitional care is indispensable in successfully transitioning patients with COVID-19 from hospital to home and preventing adverse events of this disease. The purpose of the present study was to analyze the effects of transitional care on improvements in inflammation and pulmonary function in patients with COVID-19. Data of all hospitalized patients with COVID-19 (n=242) discharged from Mudanjiang Medical University (Mudanjiang, China) between May 2020 and October 2020 were retrospectively collected. Patients with COVID-19 had been hospitalized and assigned to receive transitional care (n=126) or usual care (n=116) and were followed up for 12 months. Hospital stay, inflammation and pulmonary function were compared in patients with COVID-19 between the transitional care and usual care group. Transitional care significantly improved physical symptoms, anxiety, depression and empathy of the patients for other patients affected. Compared to the usual care group, marked improvements in typical symptoms, including dyspnea, asthenia, cough, nausea, chest pain, myalgia, headache, fever, diarrhea, chest pain, dizziness, conjunctivitis, as well as disorders of smell and taste, were observed in the transitional care group. Patients in the transitional care group had a shorter hospital stay than those patients in the usual care group. Furthermore, transitional care decreased inflammation and ameliorated pulmonary function in patients with COVID-19. In conclusion, transitional care has an essential role in the improvement of physical symptoms, inflammation and pulmonary function in patients with COVID-19 [Chinese Clinical Trial Registry (ChiCTR) registration no. ChiCTR2200060295; 26.05.2022].

Alterations in the respiratory tract microbiome in COVID-19: current observations and potential significance

SARS-CoV-2 infection causes COVID-19 disease, which can result in consequences ranging from undetectable to fatal, focusing attention on the modulators of outcomes. The respiratory tract microbiome is thought to modulate the outcomes of infections such as influenza as well as acute lung injury, raising the question to what degree does the airway microbiome influence COVID-19? Here, we review the results of 56 studies examining COVID-19 and the respiratory tract microbiome, summarize the main generalizations, and point to useful avenues for further research. Although the results vary among studies, a few consistent findings stand out. The diversity of bacterial communities in the oropharynx typically declined with increasing disease severity. The relative abundance of Haemophilus and Neisseria also declined with severity. Multiple microbiome measures tracked with measures of systemic immune responses and COVID outcomes. For many of the conclusions drawn in these studies, the direction of causality is unknown-did an alteration in the microbiome result in increased COVID severity, did COVID severity alter the microbiome, or was some third factor the primary driver, such as medication use. Follow-up mechanistic studies can help answer these questions. Video Abstract.

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.

Secondary infections worsen the outcome of COVID-19 in patients with hematological malignancies: A report from the ITA-HEMA-COV

The impact of secondary infections (SI) on COVID-19 outcome in patients with hematological malignancies (HM) is scarcely documented. To evaluate incidence, clinical characteristics, and outcome of SI, we analyzed the microbiologically documented SI in a large multicenter cohort of adult HM patients with COVID-19. Among 1741 HM patients with COVID-19, 134 (7.7%) had 185 SI, with a 1-month cumulative incidence of 5%. Median time between COVID-19 diagnosis and SI was 16 days (IQR: 5-36). Acute myeloid leukemia (AML) and lymphoma/plasma cell neoplasms (PCN) were more frequent diagnoses in SI patients compared to patients without SI (AML: 14.9% vs. 7.1%; lymphoma/PCN 71.7% vs. 65.3%). Patients with SI were older (median age 70 vs. 66 years, p = 0.002), with more comorbidities (median Charlson Comorbidity Index 5 vs. 4, p < 0.001), higher frequency of critical COVID-19 (19.5% vs. 11.5%, p = 0.046), and more frequently not in complete remission (75% vs. 64.7% p = 0.024). Blood and bronchoalveolar lavage were the main sites of isolation for SI. Etiology of infections was bacterial in 80% (n = 148) of cases, mycotic in 9.7% (n = 18) and viral in 10.3% (n = 19); polymicrobial infections were observed in 24 patients (18%). Escherichia coli represented most of Gram-negative isolates (18.9%), while coagulase-negative Staphylococci were the most frequent among Gram-positive (14.2%). The 30-day mortality of patients with SI was higher when compared to patients without SI (69% vs. 15%, p < 0.001). The occurrence of SI worsened COVID-19 outcome in HM patients. Timely diagnosis and adequate management should be considered to improve their prognosis.

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.

Isavuconazole for COVID-19-Associated Invasive Mold Infections

Isavuconazole is a broad-spectrum antifungal drug recently approved as a first-line treatment for invasive aspergillosis and as a first or alternative treatment for mucormycosis. The purpose of this review was to report and discuss the use of isavuconazole for the treatment of COVID-19-associated aspergillosis (CAPA), and COVID-19-associated mucormycosis (CAM). Among all studies which reported treatment of CAPA, approximately 10% of patients were reportedly treated with isavuconazole. Considering 14 identified studies that reported the use of isavuconazole for CAPA, isavuconazole was used in 40% of patients (95 of 235 treated patients), being first-line monotherapy in over half of them. We identified six studies that reported isavuconazole use in CAM, either alone or in combination therapy. Overall, isavuconazole was used as therapy in 13% of treated CAM patients, frequently as combination or sequential therapy. The use of isavuconazole in CAPA and CAM is complicated by the challenge of achieving adequate exposure in COVID-19 patients who are frequently obese and hospitalized in the ICU with concomitant renal replacement therapy (RRT) or extracorporeal membrane oxygenation (ECMO). The presence of data on high efficacy in the treatment of aspergillosis, lower potential for drug-drug interactions (DDIs) and for subtherapeutic levels, and no risk of QT prolongation compared to other mold-active azoles, better safety profile than voriconazole, and the possibility of using an intravenous formulation in the case of renal failure are the advantages of using isavuconazole in this setting.

Serum glucose-regulated protein 78 (GRP78) levels in COVID-19-associated mucormycosis: results of a case-control study

BACKGROUND

In experimental models, the expression of glucose-regulated protein 78 (GRP78) in endothelial cells played a role in the pathogenesis of mucormycosis. However, the role of GRP78 in COVID-19-associated mucormycosis (CAM) has not been studied. We hypothesized that serum GRP78 levels are elevated in subjects with CAM.

OBJECTIVE

To compare the serum GRP78 levels in subjects with CAM and COVID-19 controls without mucormycosis.

DESIGN AND SETTING

We performed a hospital-based, case-control study between 1 April 2021 and 31 May 2021.

PARTICIPANTS

We enrolled 24 subjects each of CAM and COVID-19 subjects without mucormycosis. We also measured serum GRP78 levels in ten healthy controls.

EXPOSURE

The primary exposure studied was serum GRP78 concentration, estimated using a commercially available ELISA kit in stored serum samples.

RESULTS

We found the mean ± standard deviation (SD) serum GRP78 levels significantly higher (p = 0.0001) among the CAM (374.3 ± 127.3 pg/mL) than the COVID-19 (246.4 ± 67.0 pg/mL) controls. The proportion of subjects with an abnormal GRP78 level (> mean [184.8 pg/mL] plus two SD [23.2 pg/mL] of GRP78 from healthy participants) was 87.5% and 45.8% in the CAM group and COVID-19 controls, respectively. Serum GRP78 level was independently associated with CAM (odds ratio 1.011; 95% confidence interval [1.002-1.019]) after adjusting for diabetes mellitus and hypoxemia during acute COVID-19.

CONCLUSION

Serum GRP78 levels were significantly higher in CAM than in COVID-19 controls. Further studies are required to the role of GRP78 in the pathogenesis of CAM.

Recent Developments in the Diagnosis of Mucormycosis

Mucormycosis is a potentially fatal infection that presents in different clinical forms and occurs in patients with various risk factors. Recently, the COVID-19 epidemic has been responsible for an increase in the incidence of mucormycosis, particularly in India. As with other invasive filamentous fungal infections, there are no specific clinical or radiological signs, and we have fewer diagnostic tools available than for other invasive fungal infections. Therefore, the diagnosis of Mucormycosis remains difficult. Nevertheless, for optimal management, early and accurate diagnosis is important. According to the latest recommendations, diagnosis is based on direct examination of clinical specimens, and/or histopathology, and culture. There are also molecular tools for direct detection from clinical specimens, but these techniques are moderately recommended. The main problems with these molecular techniques are that, until now, they were not very well standardized; there was a great heterogeneity of DNA targets and methods, which resulted in variable sensitivity. It is in this field that most advances have been made in the last two years. Indeed, recent studies have evaluated the performance and kinetics of Mucorales qPCR in serum and have shown good sensitivity and specificity. Large inter-laboratory evaluations of qPCR in serum have also been performed and have demonstrated good qualitative and quantitative reproducibility. These new results suggest the use of Mucorales qPCR as part of the diagnostic strategy for mucormycosis. One way to achieve better reproducibility could be to use commercial methods. Currently, there are at least three commercial qPCRs for Mucorales (MucorGenius from PathoNostics, MycoGenie from Ademtech, and Fungiplex from Bruker) that can be used to test serum, respiratory samples, or biopsies. However, to date, there has been little evaluation of these methods. Overall, Mucorales PCR in tissue samples, in respiratory samples, and in serum is promising and its addition as a diagnostic tool in the definitions of invasive mucormycosis should be discussed.

Are Unique Regional Factors the Missing Link in India's COVID-19-Associated Mucormycosis Crisis?

The exact cause of the disproportionate increase in COVID-19-associated mucormycosis (CAM) cases in India remains unknown. Most researchers consider the major cause of India's CAM epidemic to be the conjunction of the COVID-19 pandemic and associated corticosteroid treatment with the enormous number of Indians with diabetes mellitus (DM). However, excess CAM cases were not seen to the same extent in the Western world, where diabetes is prevalent and corticosteroids are also used extensively for COVID-19 treatment. Herein, we hypothesize that previously overlooked environmental factors specific to India were important contributors to the country's CAM epidemic. Specifically, we propose that the spread of fungal spores, mainly through fumes generated from the burning of Mucorales-rich biomass, like cow dung and crop stubble, caused extensive environmental exposure in the context of a large population of highly vulnerable patients with DM and COVID-19. Testing this hypothesis with epidemiologic studies, phylogenetic analyses, and strategic environmental sampling may have implications for preventing future epidemics.

Invasive Respiratory Fungal Infections in COVID-19 Critically Ill Patients

Patients with coronavirus disease 19 (COVID-19) admitted to the intensive care unit (ICU) often develop respiratory fungal infections. The most frequent diseases are the COVID-19 associated pulmonary aspergillosis (CAPA), COVID-19 associated pulmonary mucormycosis (CAPM) and the Pneumocystis jirovecii pneumonia (PCP), the latter mostly found in patients with both COVID-19 and underlying HIV infection. Furthermore, co-infections due to less common mold pathogens have been also described. Respiratory fungal infections in critically ill patients are promoted by multiple risk factors, including epithelial damage caused by COVID-19 infection, mechanical ventilation and immunosuppression, mainly induced by corticosteroids and immunomodulators. In COVID-19 patients, a correct discrimination between fungal colonization and infection is challenging, further hampered by sampling difficulties and by the low reliability of diagnostic approaches, frequently needing an integration of clinical, radiological and microbiological features. Several antifungal drugs are currently available, but the development of new molecules with reduced toxicity, less drug-interactions and potentially active on difficult to treat strains, is highly warranted. Finally, the role of prophylaxis in certain COVID-19 populations is still controversial and must be further investigated.

Prevalence of COVID-19 Associated Mucormycosis in a German Tertiary Care Hospital

Due to Coronavirus disease (COVID-19) a new group of patients at risk emerged with COVID-19-associated mucormycosis (CAM). Systematic studies, evaluating the prevalence of CAM are missing. To assess CAM prevalence in a tertiary care hospital in Germany, we applied direct microscopy, fungal culture and quantitative realtime in-house PCR targeting Mucorales-specific fragments of 18S and 28S rRNA on respiratory specimens of 100 critically ill COVID-19 patients. Overall, one Mucorales-PCR positive bronchoalevolar lavage was found whereas direct microscopy and fungal culture were negative in all cases. We conclude that a routine screening for CAM in Germany is not indicated.

A Clustered Case Series of Mucorales Detection in Respiratory Samples from COVID-19 Patients in Intensive Care, France, August to September 2021

While COVID-19-associated pulmonary aspergillosis is now well described in developed countries, COVID-19-associated mucormycosis (CAM) has seemed to remain quite rare in Europe. A retrospective study was performed between March 2020 to September 2021 among COVID-19 adult patients in the intensive care unit (ICU) at Toulouse Hospital (Southern France). PCR screening on respiratory samples, which target Aspergillus or Mucorales DNA, were performed, and the number of fungal detections was evaluated monthly during the study period. During the 19 months of the study, 44 (20.3%) COVID-19 ICU patients had a positive PCR for Aspergillus, an overall rate in keeping with the incidence of ICU COVID-19 patients. Ten patients (7.1%) had a positive Mucorales PCR over the same period. Surprisingly, 9/10 had a positive Mucor/Rhizopus PCR in August-September 2021, during the fourth Delta SARS-CoV-2 variant wave. Epidemic investigations have identified a probable environmental cause linked to construction works in the vicinity of the ICU (high levels of airborne spores due to the mistaken interruption of preventive humidification and summer temperature). Even if CAM are apparently rare in Europe, a cluster can also develop in industrialised countries when environmental conditions (especially during construction work) are associated with a high number of COVID-19 patients in the ICU.