Notes from the Field: COVID-19-Associated Mucormycosis - Arkansas, July-September 2021

Fungal Infections of the Sinonasal Tract and Their Differential Diagnoses

Fungal rhinosinusitis is a broad group of diseases that includes noninvasive and invasive forms with overlapping clinical presentations. While most cases of fungal rhinosinusitis follow an indolent clinical course, surgical pathologists play a crucial role in early identification of life-threating subtypes, specifically invasive fungal rhinosinusitis. This review describes fungal infections of the sinonasal tract and their histopathologic mimickers. Clinical, gross, and microscopic features that are important for diagnosis, as well as available ancillary studies, are discussed.

Factors influencing mortality in COVID-19-associated mucormycosis: The international ID-IRI study

The emergence of COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), triggered a global pandemic. Concurrently, reports of mucormycosis cases surged, particularly during the second wave in India. This study aims to investigate mortality factors in COVID-19-associated mucormycosis (CAM) cases, exploring clinical, demographic, and therapeutic variables across mostly Asian and partly African countries. A retrospective, cross-sectional analysis of CAM patients from 22 medical centers across eight countries was conducted, focusing on the first 3 months post-COVID-19 diagnosis. Data collected through the ID-IRI included demographics, comorbidities, treatments, and outcomes. A total of 162 CAM patients were included. The mean age was 54.29 ± 13.04 years, with 54% male. Diabetes mellitus (85%) was prevalent, and 91% had rhino-orbital-cerebral mucormycosis. Surgical debridement was performed in 84% of the cases. Mortality was 39%, with advanced age (hazard ratio [HR] = 1.06, [P < .001]), rituximab use (HR = 21.2, P = .05), and diabetic ketoacidosis (HR = 3.58, P = .009) identified as risk factors. The mortality risk increases by approximately 5.6% for each additional year of age. Surgical debridement based on organ involvement correlated with higher survival (HR = 8.81, P < .001). The utilization of rituximab and diabetic ketoacidosis, along with advancing age, has been associated with an increased risk of mortality in CAM patients. A combination of antifungal treatment and surgical intervention has demonstrated a substantial improvement in survival outcomes.

Post-transcriptional control of antifungal resistance in human fungal pathogens

Global estimates suggest that over 300 million individuals of all ages are affected by serious fungal infections every year, culminating in about 1.7 million deaths. The societal and economic burden on the public health sector due to opportunistic fungal pathogens is quite significant, especially among immunocompromised patients. Despite the high clinical significance of these infectious agents, treatment options are limited with only three major classes of antifungal drugs approved for use. Clinical management of fungal diseases is further compromised by the emergence of antifungal resistant strains. Transcriptional and genetic mechanisms that control drug resistance in human fungal pathogens are well-studied and include drug target alteration, upregulation of drug efflux pumps as well as changes in drug affinity and abundance of target proteins. In this review, we highlight several recently discovered novel post-transcriptional mechanisms that control antifungal resistance, which involve regulation at the translational, post-translational, epigenetic, and mRNA stability levels. The discovery of many of these novel mechanisms has opened new avenues for the development of more effective antifungal treatment strategies and new insights, perspectives, and future directions that will facilitate this process are discussed.

Invasive Fungal Infections Associated with COVID-19

The COVID-19 pandemic caused >6 million deaths worldwide, often from respiratory failure. Complications frequently occurred in hospitalized patients, particularly in the intensive care unit. Among these, fungal infections were a cause of high morbidity and mortality. Invasive aspergillosis, candidiasis and mucormycosis were the most serious of these infections. Risk factors included alterations in immune defense mechanisms by COVID-19 itself, as well as immunosuppression due to various therapies utilized in severely ill patients. Diagnosis was often challenging due to lack of sensitivity of current testing. Outcomes were generally poor, due to significant co-morbidities and delayed diagnosis, with mortality rates >50% in some studies. High index of clinical suspicion is needed to facilitate early diagnosis and initiation of appropriate antifungal therapy.

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.

Is the production of reactive oxygen and nitrogen species by macrophages associated with better infectious control in female mice with experimentally disseminated and pulmonary mucormycosis?

Different levels of resistance against Rhizopus oryzae infection have been observed between inbred (BALB/c) and outbred (Swiss) mice and are associated with the genetic background of each mouse strain. Considering that macrophages play an important role in host resistance to Rhizopus species, we used different infectious outcomes observed in experimental mucormycosis to identify the most efficient macrophage response pattern against R. oryzae in vitro and in vivo. For this, we compared BALB/c and Swiss macrophage activity before and after intravenous or intratracheal R. oryzae infections. The production of hydrogen peroxide (H2O2) and nitric oxide (NO) was determined in cultures of peritoneal (PMΦ) or alveolar macrophages (AMΦ) challenged with heat-killed spores of R. oryzae. The levels of tumor necrosis factor-alpha (TNF-α) and interleukin-10 (IL-10) were measured to confirm our findings. Naïve PMΦ from female BALB/c mice showed increased production of H2O2, TNF-α, and IL-10 in the presence of heat-killed spores of R. oryzae. Naïve PMΦ from female Swiss mice were less responsive. Naïve AMΦ from the two strains of female mice were less reactive to heat-killed spores of R. oryzae than PMΦ. After 30 days of R. oryzae intravenous infection, lower fungal load in spleen from BALB/c mice was accompanied by higher production of H2O2 by PMΦ compared with Swiss mice. In contrast, AMΦ from BALB/c mice showed higher production of NO, TNF-α, and IL-10 after 7 days of intratracheal infection. The collective findings reveal that, independent of the female mouse strain, PMΦ is more reactive against R. oryzae upon first contact than AMΦ. In addition, increased PMΦ production of H2O2 at the end of disseminated infection is accompanied by better fungal clearance in resistant (BALB/c) mice. Our findings further the understanding of the parasite-host relationship in mucormycosis.

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.

Increased Deaths From Fungal Infections During the Coronavirus Disease 2019 Pandemic-National Vital Statistics System, United States, January 2020-December 2021

BACKGROUND

Coronavirus disease 2019 (COVID-19)-associated fungal infections cause severe illness, but comprehensive data on disease burden are lacking. We analyzed US National Vital Statistics System (NVSS) data to characterize disease burden, temporal trends, and demographic characteristics of persons dying of fungal infections during the COVID-19 pandemic.

METHODS

Using NVSS's January 2018-December 2021 Multiple Cause of Death Database, we examined numbers and age-adjusted rates (per 100 000 population) of deaths due to fungal infection by fungal pathogen, COVID-19 association, demographic characteristics, and year.

RESULTS

Numbers and age-adjusted rates of deaths due to fungal infection increased from 2019 (n = 4833; rate, 1.2 [95% confidence interval, 1.2-1.3]) to 2021 (n = 7199; rate, 1.8 [1.8-1.8] per 100 000); of 13 121 such deaths during 2020-2021, 2868 (21.9%) were COVID-19 associated. Compared with non-COVID-19-associated deaths (n = 10 253), COVID-19-associated deaths more frequently involved Candida (n = 776 [27.1%] vs n = 2432 [23.7%], respectively) and Aspergillus (n = 668 [23.3%] vs n = 1486 [14.5%]) and less frequently involved other specific fungal pathogens. Rates of death due to fungal infection were generally highest in nonwhite and non-Asian populations. Death rates from Aspergillus infections were approximately 2 times higher in the Pacific US census division compared with most other divisions.

CONCLUSIONS

Deaths from fungal infection increased during 2020-2021 compared with previous years, primarily driven by COVID-19-associated deaths, particularly those involving Aspergillus and Candida. Our findings may inform efforts to prevent, identify, and treat severe fungal infections in patients with COVID-19, especially in certain racial/ethnic groups and geographic areas.

Severe Acute Respiratory Syndrome Coronavirus 2 Infections in Children

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in children generally have milder presentations, but severe disease can occur in all ages. MIS-C and persistent post-acute COVID-19 symptoms can be experienced by children with previous infection and emphasize the need for infection prevention. Optimal treatment for COVID-19 is not known, and clinical trials should include children to guide therapy. Vaccines are the best tool at preventing infection and severe outcomes of COVID-19. Children suffered disproportionately during the pandemic not only from SARS-CoV-2 infection but because of disruptions to daily life, access to primary care, and worsening income inequalities.

Clinical Characteristics, Healthcare Utilization, and Outcomes among Patients in a Pilot Surveillance System for Invasive Mold Disease—Georgia, United States, 2017–2019

Background

Invasive mold diseases (IMD) cause severe illness, but public health surveillance data are lacking. We describe data collected from a laboratory-based, pilot IMD surveillance system.

Methods

During 2017–2019, the Emerging Infections Program conducted active IMD surveillance at three Atlanta-area hospitals. We ascertained potential cases by reviewing histopathology, culture, and Aspergillus galactomannan results and classified patients as having an IMD case (based on European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group [MSG] criteria) or a non-MSG IMD case (based on the treating clinician’s diagnosis and use of mold-active antifungal therapy). We described patient features and compared patients with MSG versus non-MSG IMD cases.

Results

Among 304 patients with potential IMD, 104 (34.2%) met an IMD case definition (41 MSG, 63 non-MSG). The most common IMD types were invasive aspergillosis (n = 66, 63.5%), mucormycosis (n = 8, 7.7%), and fusariosis (n = 4, 3.8%); the most frequently affected body sites were pulmonary (n = 66, 63.5%), otorhinolaryngologic (n = 17, 16.3%), and cutaneous/deep tissue (n = 9, 8.7%). Forty-five (43.3%) IMD patients received intensive care unit-level care, and 90-day all-cause mortality was 32.7%; these outcomes did not differ significantly between MSG and non-MSG IMD patients.

Conclusions

IMD patients had high mortality rates and a variety of clinical presentations. Comprehensive IMD surveillance is needed to assess emerging trends, and strict application of MSG criteria for surveillance might exclude &gt; one-half of clinically significant IMD cases.

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.