COVID-19 associated mucormycosis - An emerging threat

Risk Factors of COVID-19 associated mucormycosis in Iranian patients: a multicenter study

BACKGROUND

To evaluate the demographic, clinical, and prognostic characteristics of patients diagnosed with COVID-19-associated mucormycosis (CAM) in Iranian patients.

METHODS

This prospective observational study was conducted in 8 tertiary referral ophthalmology centers in different provinces of Iran during the fifth wave of the COVID-19 pandemic. All patients were subjected to complete history taking and comprehensive ophthalmological examination and underwent standard accepted treatment strategy based on the disease stage.

RESULTS

Two hundred seventy-four CAM patients (most were males (150, 54.7%)) with a mean age of 56.8 ± 12.44 years were enrolled. Patients with a history of cigarette smoking (Adjusted Odds Ratio (AOR) = 4.36), Intensive Care Unit admission (ICU) (AOR = 16.26), higher stage of CAM (AOR = 2.72), and receiving endoscopic debridement and transcutaneous retrobulbar amphotericin B (AOR = 3.30) had higher odds of mortality. History of taking systemic corticosteroids during COVID-19 was significantly associated with reduced odds of mortality (AOR = 0.16). Generalized Estimating Equations analysis showed that the visual acuity of deceased patients (LogMAR: 3.71, 95% CI: 3.04-4.38) was worse than that of patients who were discharged from the hospital (LogMAR: 2.42, 95% CI: 2.16-2.68) (P < 0.001).

CONCLUSIONS

This study highlights significant risk factors for mortality in patients with CAM, such as cigarette smoking, ICU admission, advanced CAM stages, receiving transcutaneous retrobulbar amphotericin B and worser visual acuity. Conversely, a history of systemic corticosteroid use during COVID-19 was linked to reduced mortality. These findings underscore the critical need for early identification and targeted interventions for high-risk CAM patients to improve clinical outcomes.

Mucorales: A systematic review to inform the World Health Organization priority list of fungal pathogens

The World Health Organization, in response to the growing burden of fungal disease, established a process to develop a fungal priority pathogens list (FPPL). This systematic review aimed to evaluate the epidemiology and impact of invasive fungal disease due to Mucorales. PubMed and Web of Science were searched to identify studies published between January 1, 2011 and February 23, 2021. Studies reporting on mortality, inpatient care, complications and sequelae, antifungal susceptibility, risk factors, preventability, annual incidence, global distribution, and emergence during the study time frames were selected. Overall, 24 studies were included. Mortality rates of up to 80% were reported. Antifungal susceptibility varied across agents and species, with the minimum inhibitory concentrations lowest for amphotericin B and posaconazole. Diabetes mellitus was a common risk factor, detected in 65%-85% of patients with mucormycosis, particularly in those with rhino-orbital disease (86.9%). Break-through infection was detected in 13.6%-100% on azole or echinocandin antifungal prophylaxis. The reported prevalence rates were variable, with some studies reporting stable rates in the USA of 0.094-0.117/10 000 discharges between 2011 and 2014, whereas others reported an increase in Iran from 16.8% to 24% between 2011 and 2015. Carefully designed global surveillance studies, linking laboratory and clinical data, are required to develop clinical breakpoints to guide antifungal therapy and determine accurate estimates of complications and sequelae, annual incidence, trends, and global distribution. These data will provide robust estimates of disease burden to refine interventions and better inform future FPPL.

Transcutaneous retrobulbar amphotericin B for rhino-orbital-cerebral mucormycosis: a multi-center retrospective comparative study

PURPOSE

To assess whether transcutaneous retrobulbar amphotericin B injections (TRAMB) reduce exenteration rate without increasing mortality in rhino-orbital-cerebral mucormycosis (ROCM).

METHODS

In this retrospective case-control study, 46 patients (51 eyes) with biopsy-proven ROCM were evaluated at 9 tertiary care institutions from 1998 to 2021. Patients were stratified by radiographic evidence of local orbital versus extensive involvement at presentation. Extensive involvement was defined by MRI or CT evidence of abnormal or loss of contrast enhancement of the orbital apex with or without cavernous sinus, bilateral orbital, or intracranial extension. Cases (+TRAMB) received TRAMB as adjunctive therapy while controls (-TRAMB) did not. Patient survival, globe survival, and vision/motility loss were compared between +TRAMB and -TRAMB groups. A generalized linear mixed effects model including demographic and clinical covariates was used to evaluate the impact of TRAMB on orbital exenteration and disease-specific mortality.

RESULTS

Among eyes with local orbital involvement, exenteration was significantly lower in the +TRAMB group (1/8) versus -TRAMB (8/14) (p = 0.04). No significant difference in mortality was observed between the ±TRAMB groups. Among eyes with extensive involvement, there was no significant difference in exenteration or mortality rates between the ±TRAMB groups. Across all eyes, the number of TRAMB injections correlated with a statistically significant decreased rate of exenteration (p = 0.048); there was no correlation with mortality.

CONCLUSIONS

Patients with ROCM with local orbital involvement treated with adjunctive TRAMB demonstrated a lower exenteration rate and no increased risk of mortality. For extensive involvement, adjunctive TRAMB does not improve or worsen these outcomes.

COVID-19-Associated Rhinocerebral Mucormycosis, an Incidental Finding or a Matter of Concern - Mixed-Method Systematic Review

With the advent of COVID-19, the number of patients diagnosed with mucormycosis has increased, especially in developing countries. The reason behind this increase is that COVID-19 causes hypoxia that promotes the growth of fungus. To identify the association between mucormycosis and COVID-19, in critically ill or immunocompromised COVID-19 patients. The literature included in the review was researched from October 1, 2021, to November 1, 2022, by using the Google Scholar database as the search engine. Of the 20 articles included, there were 4 case reports, 2 case series, 10 narrative reviews, and 4 quantitative studies. Mucormycetes growth is caused by several factors, including hyperglycemia owing to previously existing diabetes or excessive use of steroids, increased ferritin levels owing to the inflammatory cascade initiated by COVID-19, and immunosuppression caused by the use of steroids or other immunosuppressive therapy. Reduced white-cell count and activity in COVID-19 leads to increased germination of fungal spores hence developing a catastrophic picture of rhinocerebral mucormycosis. Considering that the hematological patient is frequently treated with cortisone, immunosuppressed due to the underlying condition, but also through the administered therapy, the association with a possible diabetes makes this patient susceptible to developing rhinocerebral mucormycosis during COVID-19 infection. Despite being severe, the association between mucormycosis and COVID-19 is specific and treatable. Development of mucormycosis in hematological patients suffering from severe COVID-19 disease is dangerous, yet not compulsory and can be prevented. Using a common steroid-dose protocol with hyperbaric oxygen and necessary preventive measure reveals the disease as a superadded infection. Hypoxia, poor glycemic control and overuse of steroids or immunosuppressive drugs cause it.

Integrated bioinformatics approaches to investigate alterations in transcriptomic profiles of monkeypox infected human cell line model

BACKGROUND

The recent re-emergence of the monkeypox (mpox) epidemic in nonendemic regions has raised concerns regarding a potential global outbreak. The mpox virus (MPV) is a smallpox-like virus belonging to the genus Orthopoxvirus (family: Poxviridae). Although studies suggest that MPV infection suppresses the Toll-like receptor-3- and tumor necrosis factor-α-related signaling pathways, whether MPV regulates other immune-related pathways remains unclear.

METHODS

In this study, two distinct temporal patterns were used for establishing an MPV-infected human immortal epithelial cancer cell line (HeLa). These two durations 2 and 12 h of incubation were selected to identify the coregulated genes and pathways affected by MPV infection.

RESULTS

The use of the Gene Ontology framework, Kyoto Encyclopedia of Genes and Genome database, and MetaCore software yielded valuable insights. Specifically, various pathways were found to be enriched in HeLa cells infected with MPV for 2 and 12 h. These pathways included Notch, CD40, CD95, hypoxia-inducible factor-1-α, interleukin (IL)- 1, IL-6, phosphoinositide 3-kinase, nuclear factor-κB, mitogen-activated protein kinase, and oxidative stress-induced signalling pathways. Clusters and pathways of metabolism and viral replication cycles were significantly associated with the 2-hour infection group. This association was identified based on the regulation of genes such as HSPG2, RHPN2, MYL1, ASPHD2, CA9, VIPR1, SNX12, MGC2752, SLC25A1, PEX19, and AREG. Furthermore, clusters and pathways related to immunity and cell movement were found to be associated with the 12-hour infection group. This association was identified based on the regulation of genes such as C1orf21, C19orf48, HRK, IL8, GULP1, SCAND2, ATP5C1, FEZ1, SGSH, TACC2, CYP4X1, MMP1, CPB1, P2RY13, WDR27, PRPF4, and ENDOD1.

CONCLUSIONS

This study can improve our understanding of the mechanisms underlying the pathophysiology and post-infection sequelae of mpox. Our findings provide valuable insights into the various modes of MPV infection.

Causal associations and genetic overlap between COVID-19 and intelligence

OBJECTIVE

COVID-19 might cause neuroinflammation in the brain, which could decrease neurocognitive function. We aimed to evaluate the causal associations and genetic overlap between COVID-19 and intelligence.

METHODS

We performed Mendelian randomization (MR) analyses to assess potential associations between three COVID-19 outcomes and intelligence (N = 269 867). The COVID phenotypes included severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (N = 2 501 486), hospitalized COVID-19 (N = 1 965 329) and critical COVID-19 (N = 743 167). Genome-wide risk genes were compared between the genome-wide association study (GWAS) datasets on hospitalized COVID-19 and intelligence. In addition, functional pathways were constructed to explore molecular connections between COVID-19 and intelligence.

RESULTS

The MR analyses indicated that genetic liabilities to SARS-CoV-2 infection (odds ratio [OR]: 0.965, 95% confidence interval [CI]: 0.939-0.993) and critical COVID-19 (OR: 0.989, 95% CI: 0.979-0.999) confer causal effects on intelligence. There was suggestive evidence supporting the causal effect of hospitalized COVID-19 on intelligence (OR: 0.988, 95% CI: 0.972-1.003). Hospitalized COVID-19 and intelligence share 10 risk genes within 2 genomic loci, including MAPT and WNT3. Enrichment analysis showed that these genes are functionally connected within distinct subnetworks of 30 phenotypes linked to cognitive decline. The functional pathway revealed that COVID-19-driven pathological changes within the brain and multiple peripheral systems may lead to cognitive impairment.

CONCLUSIONS

Our study suggests that COVID-19 may exert a detrimental effect on intelligence. The tau protein and Wnt signaling may mediate the influence of COVID-19 on intelligence.

COVID-19 associated Mucormycosis among ICU patients: risk factors, control, and challenges

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic is still difficult to be controlled. The spread of this virus and the emergence of new variants are considered a great challenge worldwide. Disturbance in infection control guidelines implementation, use of steroids, antibiotics, hospital crowdedness, and repeated use of oxygen masks during the management of critically ill COVID-19 patients lead to an increase in the rate of opportunistic infections. So, patients need to fight both the virus with its different variants and opportunistic pathogens including bacteria and fungi especially patients with diabetes mellitus, malignancy, or those who undergo hemodialysis and receive deferoxamine. During the pandemic, many cases of Mucormycosis associated with COVID-19 infection were observed in many countries. In this review, we discuss risk factors that increase the chance of infection by opportunistic pathogens, especially fungal pathogens, recent challenges, and control measures.

COVID-19-associated candidiasis and the emerging concern of Candida auris infections

The incidence of COVID-19-associated candidiasis (CAC) is increasing, resulting in a grave outcome among hospitalized patients with COVID-19. The most alarming condition is the increasing incidence of multi-drug resistant Candida auris infections among patients with COVID-19 worldwide. The therapeutic strategy towards CAC caused by common Candida species, such as Candida albicans, Candida tropicalis, and Candida glabrata, is similar to the pre-pandemic era. For non-critically ill patients or those with a low risk of azole resistance, fluconazole remains the drug of choice for candidemia. For critically ill patients, those with a history of recent azole exposure or with a high risk of fluconazole resistance, echinocandins are recommended as the first-line therapy. Several novel therapeutic agents alone or in combination with traditional antifungal agents for candidiasis are potential options in the future. However, for multidrug-resistant C. auris infection, only echinocandins are effective. Infection prevention and control policies, including strict isolation of the patients carrying C. auris and regular screening of non-affected patients, are suggested to prevent the spread of C. auris among patients with COVID-19. Whole-genome sequencing may be used to understand the epidemiology of healthcare-associated candidiasis and to better control and prevent these infections.

Antifungal Development and the Urgency of Minimizing the Impact of Fungal Diseases on Public Health

Fungal infections are a major public health problem resulting from the lack of public policies addressing these diseases, toxic and/or expensive therapeutic tools, scarce diagnostic tests, and unavailable vaccines. In this Perspective, we discuss the need for novel antifungal alternatives, highlighting new initiatives based on drug repurposing and the development of novel antifungals.

COVID-19-associated mucormycosis: A systematic review and meta-analysis of 958 cases

BACKGROUND

Mucormycosis, a rare fungal infection, has shown an increase in the number of reported cases during the COVID-19 pandemic.

OBJECTIVES

To provide a comprehensive insight into the characteristics of COVID-19-associated mucormycosis (CAM), through a systematic review and meta-analysis.

DATA SOURCES

PubMed, Scopus, Web of Science, Cochrane, CINAHL, Ovid MEDLINE, and FungiSCOPE.

STUDY ELIGIBILITY CRITERIA

Studies reporting individual-level information in adult CAM patients between January 1, 2020 and December 28, 2022.

PARTICIPANTS

Adults who developed mucormycosis during or after COVID-19.

ASSESSMENT OF RISK OF BIAS

Quality assessment was performed based on the National Institutes of Health Quality Assessment Tool for Case Series Studies.

METHODS OF DATA SYNTHESIS

Demographic information and clinical features were documented for each patient. Logistic regression analysis was used to predict the risk of mortality.

RESULTS

958 individual cases reported from forty-five countries were eligible. 88.1% (844/958) were reported from low- or middle-income countries (LMIC). Corticosteroid use for COVID-19 (78.5%, 619/789) and diabetes (77.9%, 738/948) were common. Diabetic ketoacidosis (p<0.001), history of malignancy (p<0.001), underlying pulmonary (p=0.017) or renal disease (p<0.001), obesity (p<0.001), hypertension (p=0.040), age (>65 years) (p=0.001), Aspergillus co-infection (p=0.037), and tocilizumab use during COVID-19 (p=0.018) increased the mortality. CAM occurred on average 22 days after COVID-19 and 8 days after hospitalization. Diagnosis of mucormycosis in patients with Aspergillus co-infection and pulmonary mucormycosis was made on average 15.4 days (range 0-35) and 14.0 days (range 0-53) after hospitalization, respectively. Cutaneous mucormycosis accounted for <1% of cases. The overall mortality rate was 38.9% (303/780).

CONCLUSION

Mortality of CAM was high, and most reports were from LMIC countries. We detected novel risk factors for CAM such as older age, specific comorbidities, Aspergillus co-infection and tocilizumab use, in addition to previously identified factors.

Coronavirus disease 2019 rebounds following nirmatrelvir/ritonavir treatment

Nirmatrelvir/ritonavir (NMV-r) is an effective anti-SARS-CoV-2 agent and has been recommended in the treatment of nonhospitalized patients with COVID-19. In rare occasions, some patients experience virologic and symptomatic rebound after initial resolution, which we call COVID-19 rebound after NMV-r. Although COVID rebound can also occur after molnupiravir treatment or even no antiviral treatment, we have more serious concern about the rebound after NMV-r, which remains the most effective antiviral. Due to a lack of information about its frequency, mechanism, outcomes, and management, we conducted this review to provide comprehensive and updated information to address these questions. Based on the limited evidence, the incidence of COVID-19 rebound after NMV-r was less than 2%, and most cases developed 5-15 days after initiating NMV-r treatment. Almost all reported cases had mild symptoms, and the clinical condition gradually subsided without additional treatment. Overall, the clinical outcome was favorable, and only a small number of patients required emergency department visits or hospitalization. Regarding virologic rebound, culturable SARS-CoV-2 with possible transmission was observed, so re-isolation may be needed.

Long COVID: An inevitable sequela of SARS-CoV-2 infection

At present, there are more than 560 million confirmed cases of the coronavirus disease 2019 (COVID-19) worldwide. Although more than 98% of patients with severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection can survive acute COVID, a significant portion of survivors can develop residual health problems, which is termed as long COVID. Although severe COVID-19 is generally associated with a high risk of long COVID, patients with asymptomatic or mild disease can also show long COVID. The definition of long COVID is inconsistent and its clinical manifestations are protean. In addition to general symptoms, such as fatigue, long COVID can affect many organ systems, including the respiratory, neurological, psychosocial, cardiovascular, gastrointestinal, and metabolic systems. Moreover, patients with long COVID may experience exercise intolerance and impaired daily function and quality of life. Long COVID may be caused by SARS-CoV-2 direct injury or its associated immune/inflammatory response. Assessment of patients with long COVID requires comprehensive evaluation, including history taking, physical examination, laboratory tests, radiography, and functional tests. However, there is no known effective treatment for long COVID. Based on the limited evidence, vaccines may help to prevent the development of long COVID. As long COVID is a new clinical entity that is constantly evolving, there are still many unknowns, and further investigation is warranted to enhance our understanding of this disease.

Hemorrhagic Fever with Renal Syndrome Complicated with Rhino Mucormycosis: A Case Report

Mucormycosis (MCR) is a rare but aggressive fungal disease. Rhino-orbito-cerebral mucormycosis is the most common clinical form of MCR infection, and sinonasal inoculation is the primary site of infection. The morbidity and mortality rates associated with MCR remain high. In this case report, we describe the successful use of amphotericin B in a 40-year-old male with hemorrhagic fever with renal syndrome (HFRS) complicated by rhinomucormycosis. This case report provides evidence for the successful treatment of HFRS.

Editorial: The World Health Organization (WHO) Fungal Priority Pathogens List in Response to Emerging Fungal Pathogens During the COVID-19 Pandemic

The COVID-19 pandemic, climate change, increased resistance to antifungal drugs, and an increased number of immunocompromised patients have driven a recent global surge in pathogenic fungal infections, including aspergillosis, candidiasis, and mucormycosis. On 25 October 2022, the World Health Organization (WHO) released a list of 19 fungal priority pathogens identified as having the greatest threat to public health. The WHO Fungal Priority Pathogens List represents the first global response to identify and prioritize fungal pathogens and their impact on global public health and to consider the unmet research and development needs. The WHO has grouped the priority fungal pathogens into those of critical, high, and medium priority. This Editorial aims to highlight the importance of identifying and prioritizing fungal pathogens and identifying emerging fungal pathogens and the global factors driving changing patterns of infection.

COVID-19 Associated with Cryptococcosis: A New Challenge during the Pandemic

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a great threat to global health. In addition to SARS-CoV-2 itself, clinicians should be alert to the possible occurrence of co-infection or secondary infection among patients with COVID-19. The possible co-pathogens include bacteria, viruses, and fungi, but COVID-19-associated cryptococcosis is rarely reported. This review provided updated and comprehensive information about this rare clinical entity of COVID-19-associated cryptococcosis. Through an updated literature search till 23 August 2022, we identified a total of 18 culture-confirmed case reports with detailed information. Half (n = 9) of them were elderly. Fifteen (83.3%) of them had severe COVID-19 and ever received systemic corticosteroid. Disseminated infection with cryptococcemia was the most common type of cryptococcosis, followed by pulmonary and meningitis. Except one case of C. laurentii, all other cases are by C. neoformans. Liposomal amphotericin B and fluconazole were the most commonly used antifungal agents. The overall mortality was 61.1% (11/18) and four of them did not receive antifungal agents before death. Improving the poor outcome requires a physician's high suspicion, early diagnosis, and prompt treatment.

Comparison of Transcriptomic Signatures between Monkeypox-Infected Monkey and Human Cell Lines

Monkeypox virus (MPV) is a smallpox-like virus belonging to the genus Orthopoxvirus of the family Poxviridae. Unlike smallpox with no animal reservoir identified and patients suffering from milder symptoms with less mortality, several animals were confirmed to serve as natural hosts of MPV. The reemergence of a recently reported monkeypox epidemic outbreak in nonendemic countries has raised concerns about a global outburst. Since the underlying mechanism of animal-to-human transmission remains largely unknown, comprehensive analyses to discover principal differences in gene signatures during disease progression have become ever more critical. In this study, two MPV-infected in vitro models, including human immortal epithelial cancer (HeLa) cells and rhesus monkey (Macaca mulatta) kidney epithelial (MK2) cells, were chosen as the two subjects to identify alterations in gene expression profiles, together with co-regulated genes and pathways that are affected during monkeypox disease progression. Using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and MetaCore analyses, we discovered that elevated expression of genes associated with interleukins (ILs), G protein-coupled receptors (GPCRs), heat shock proteins (HSPs), Toll-like receptors (TLRs), and metabolic-related pathways play major roles in disease progression of both monkeypox-infected monkey MK2 and human HeLa cell lines. Interestingly, our analytical results also revealed that a cluster of differentiation 40 (CD40), plasmin, and histamine served as major regulators in the monkeypox-infected monkey MK2 cell line model, while interferons (IFNs), macrophages, and neutrophil-related signaling pathways dominated the monkeypox-infected human HeLa cell line model. Among immune pathways of interest, apart from traditional monkeypox-regulated signaling pathways such as nuclear factor- (NF-κB), mitogen-activated protein kinases (MAPKs), and tumor necrosis factors (TNFs), we also identified highly significantly expressed genes in both monkey and human models that played pivotal roles during the progression of monkeypox infection, including CXCL1, TNFAIP3, BIRC3, IL6, CCL2, ZC3H12A, IL11, CSF2, LIF, PTX3, IER3, EGR1, ADORA2A, and DUOX1, together with several epigenetic regulators, such as histone cluster family gene members, HIST1H3D, HIST1H2BJ, etc. These findings might contribute to specific underlying mechanisms related to the pathophysiology and provide suggestions regarding modes of transmission, post-infectious sequelae, and vaccine development for monkeypox in the future.

Immunohistochemical expression of angiotensin-converting enzyme 2 in superficial and deep maxillofacial tissues: A cross-sectional study

Background and Aims

The involvement of maxillofacial tissues in SARS-CoV-2 infections ranges from mild dysgeusia to life-threatening tissue necrosis, as seen in SARS-CoV-2-associated mucormycosis. Angiotensin-converting enzyme 2 (ACE2) which functions as a receptor for SARS-CoV-2 was reported in the epithelial surfaces of the oral and nasal cavities; however, a complete understanding of the expression patterns in deep oral and maxillofacial tissues is still lacking.

Methods

The immunohistochemical expression of ACE2 was analyzed in 95 specimens from maxillofacial tissues and 10 specimens of pulmonary alveolar tissue using a semiquantitative immunohistochemical scoring procedure, taking into account all superficial and deep maxillofacial tissue cells. We also explored the associations of age, gender, and anatomical site with expression scores.

Results

ACE2 was detected in keratinized epithelia (57.34%), non-keratinized epithelia (46.51%), nasal respiratory epithelial cells (73.35%), pulmonary alveolar cells (82.54%), fibroblasts (63.69%), vascular endothelial cells (58.43%), mucous acinar cells (59.88%), serous acinar cells (79.49%), salivary duct cells (86.26%) skeletal muscle fibers (71.01%), neuron support cells (94.25%), and bone marrow cells (72.65%). Age and gender did not affect the expression levels significantly in epithelial cells (p = 0.76, and p = 0.7 respectively); however, identical cells expressed different protein levels depending on the site from which the specimens were obtained. For example, dorsal tongue epithelia expressed significantly lower ACE2 scores than alveolar epithelia (p < 0.001). A positive correlation was found between ACE2 expression in fibroblasts and epithelial cells (r = 0.378, p = 0.001), and between vascular endothelial and epithelial cells (r = 0.395, p = 0.001).

Conclusion

ACE2 is expressed by epithelial cells and subepithelial tissues including fibroblasts, vascular endothelia, skeletal muscles, peripheral nerves, and bone marrow. No correlation was detected between ACE2 expression and patient age or sex while the epithelial expression scores were correlated with stromal scores.

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.

Mucormycosis and COVID-19-Associated Mucormycosis: Insights of a Deadly but Neglected Mycosis

The ongoing COVID-19 pandemic has quickly become a health threat worldwide, with high mortality and morbidity among patients with comorbidities. This viral infection promotes the perfect setting in patients for the development of opportunistic infections, such as those caused by fungi. Mucormycosis, a rare but deadly fungal infection, has recently increased its incidence, especially in endemic areas, since the onset of the pandemic. COVID-19-associated mucormycosis is an important complication of the pandemic because it is a mycosis hard to diagnose and treat, causing concern among COVID-19-infected patients and even in the already recovered population. The risk factors for the development of mucormycosis in these patients are related to the damage caused by the SARS-CoV-2 itself, the patient's overstimulated immune response, and the therapy used to treat COVID-19, causing alterations such as hyperglycemia, acidosis, endothelial and lung damage, and immunosuppression. In this review, the molecular aspects of mucormycosis and the main risk factors for the development of COVID-19-associated mucormycosis are explained to understand this virus-fungi-host interaction and highlight the importance of this neglected mycosis.

Changing Epidemiology of Respiratory Tract Infection during COVID-19 Pandemic

The outbreak of COVID-19 has significantly changed the epidemiology of respiratory tract infection in several ways. The implementation of non-pharmaceutical interventions (NPIs) including universal masking, hand hygiene, and social distancing not only resulted in a decline in reported SARS-CoV-2 cases but also contributed to the decline in the non-COVID-19 respiratory tract infection-related hospital utilization. Moreover, it also led to the decreased incidence of previous commonly encountered respiratory pathogens, such as influenza and Streptococcus pneumoniae. Although antimicrobial agents are essential for treating patients with COVID-19 co-infection, the prescribing of antibiotics was significantly higher than the estimated prevalence of bacterial co-infection, which indicated the overuse of antibiotics or unnecessary antibiotic use during the COVID-19 pandemic. Furthermore, inappropriate antimicrobial exposure may drive the selection of drug-resistant microorganisms, and the disruption of infection control in COVID-19 setting measures may result in the spread of multidrug-resistant organisms (MDROs). In conclusion, NPIs could be effective in preventing respiratory tract infection and changing the microbiologic distribution of respiratory pathogens; however, we should continue with epidemiological surveillance to establish updated information, antimicrobial stewardship programs for appropriate use of antibiotic, and infection control prevention interventions to prevent the spread of MDROs during the COVID-19 pandemic.

Fungal Colonization and Infections-Interactions with Other Human Diseases

Candida albicans is a commensal fungus that asymptomatically colonizes the skin and mucosa of 60% of healthy individuals. Breaches in the cutaneous and mucosal barriers trigger candidiasis that ranges from asymptomatic candidemia and mucosal infections to fulminant sepsis with 70% mortality rates. Fungi influence at least several diseases, in part by mechanisms such as the production of pro-carcinogenic agents, molecular mimicking, and triggering of the inflammation cascade. These processes impact the interactions among human pathogenic and resident fungi, the bacteriome in various organs/tissues, and the host immune system, dictating the outcomes of invasive infections, metabolic diseases, and cancer. Although mechanistic investigations are at stages of infancy, recent studies have advanced our understanding of host-fungal interactions, their role in immune homeostasis, and their associated pathologies. This review summarizes the role of C. albicans and other opportunistic fungi, specifically their association with various diseases, providing a glimpse at the recent developments and our current knowledge in the context of inflammatory-bowel disease (IBD), cancers, and COVID-19. Two of the most common human diseases where fungal interactions have been previously well-studied are cancer and IBD. Here we also discuss the emerging role of fungi in the ongoing and evolving pandemic of COVID-19, as it is relevant to current health affairs.