Clinical and mycological investigations of post-COVID-19 acute invasive fungal sinusitis

Invasive fungal rhinosinusitis: current evidence and research opportunities

PURPOSE OF REVIEW

To summarize the evidence surrounding diagnosis, treatment, prognosis, and surveillance of patients with acute invasive fungal sinusitis (AIFS) and discuss future research needs.

RECENT FINDINGS

New risk factors for AIFS such as COVID have been identified, and a new prognostic staging system has been developed.

SUMMARY

Most patients who develop AIFS are immunocompromised, with the majority having a history of diabetes or a hematologic malignancy. Unfortunately, there are not any highly sensitive and specific diagnostic tools. Therefore, a combination of signs and symptoms, imaging, endoscopy, biopsy, and labs should be used to diagnosis AIFS. Although surgery and systemic antifungals are known to improve outcomes, there is limited data on time to intervention, duration of antifungals, and surveillance patterns. There is also limited information on factors that can predict outcomes in AIFS patients. However, sensory/perceptual changes, prolonged neutropenia duration, and comorbidity burden may be associated with a poor prognosis.

Invasive Fungal Rhinosinusitis: The First Histopathological Study in Vietnam

BACKGROUND

Invasive fungal rhinosinusitis (IRFS) is a rare but highly fatal disease. The two primary groups of pathogens, Mucorales and Aspergillus, require different treatments and have distinct prognoses.

PURPOSE

This study aimed to analyze the histopathological features of IFRS.

METHODS

We conducted a retrospective study involving 57 IFRS cases. Demographic and comorbid characteristics were obtained from clinical records. Two pathologists independently examined the histopathological features using H&E, PAS, and GMS-stained slides. Fungal groups were identified with PCR under the guidance of histopathology.

RESULTS

The mean age of IFRS was 58.9 ± 13.4. The male-to-female ratio was 1.4:1. 100% of cases had diabetes comorbidity. Mucorales, Aspergillus, and other fungi were found in 61.4%, 33.3%, and 5.3% of cases, respectively. No Aspergillus and Mucorales co-infections were detected. Histopathology and PCR results were strongly concordant in classifying pathogens (Cohen's kappa = 84.2%, 95% CI 60.1% - 100%, p < 0.001). Mucormycosis exhibited higher rates of extensive necrosis and vascular invasion, and lower rates of pigment and spore presence than the non-Mucormycosis group (p < 0.001, p = 0.01, p = 0.02, p = 0.03, respectively). Extensive necrosis and vascular invasion were statistically significantly correlative (OR = 13.03, 95% CI 2.62-64.75, p = 0.002).

CONCLUSIONS

IFRS predominantly affects older adults and males. Histopathology is a reliable method for differentiating between Mucorales and Aspergillus. When extensive necrosis is detected, it is critical to investigate for vascular invasion carefully. The vascular invasion, degree of necrosis, pigments, and spores are valuable factors for distinguishing fungal agents of IFRS.

Post COVID-19 mucormycosis in critical care settings: A prospective cohort study in a tertiary care center in Egypt

BACKGROUND

The emergence of mucormycosis as a life-threatening fungal infection after the coronavirus disease of 2019 (COVID-19) is a major concern and challenge, but there is limited information on the risk factors for mortality in patients.

METHODS

We conducted a prospective cohort study from May 2021 to April 2022 to determine the in-hospital outcomes of post-COVID-19 mucormycosis during the intensive care unit (ICU) stay. The sample of the study was collected as consecutive sampling using all accessible patients in the study period. The Statistical Package for Social Sciences (SPSS), version 25 (IBM, Chicago, Illinois, USA) was used for statistical analysis.

RESULTS

Among 150 patients with post-COVID-19 mucormycosis, the majority had a primary sinus infection (86.0 %), while 11.3 % had both sinus and ocular infections, and 2.7 % had sinus and cutaneous infections. Around 21 % (n = 31) of patients deceased after staying in the ICU for a median (range) of 45.0 (10.0-145.0) days. The majority of the patients who deceased had pneumonia patches on computed tomography (CT) (90.3 %) while none of the patients who were discharged had pneumonia patches (p < 0.001). The deceased group had higher rates of pulmonary embolism (93.5 %) compared to the surviving groups (21.8 %). In a multivariate Cox regression analysis, the risk of death was higher in older patients above 60 years old (hazard ratio (95 %CI): 6.7 (1.73-15.81)), increase among patient with history of steroid administration (hazard ratio (95 %CI): 5.70 (1.23-10.91)), who had facial cutaneous infection with mucormycosis (hazard ratio (95 %CI): 8.76 (1.78-25.18)), patients with uncontrolled diabetes (hazard ratio (95 %CI): 10.76 (1.78, 65.18)), and total leukocytic count (TLC>10 ×103 mcL) (hazard ratio (95 %CI): 10.03 (3.29-30.61)).

CONCLUSIONS

Identifying high-risk patients especially old diabetic patients with corticosteroid administration and detecting their deterioration quickly is crucial in reducing post-COVID-19 mucormycosis mortality rates, and these factors must be considered when developing treatment and quarantine strategies.

COVID-19-Associated Rhino-Orbital Mucormycosis: Histological and Electron Microscopy Characteristics

COVID-19-associated rhino-orbital mucormycosis has become a new clinical entity. This study's aim was to evaluate the histopathological and ultramicroscopic morphological aspects of this fungal infection. This was an observational retrospective study on eight patients from three tertiary centers in Romania. The tissue samples collected during functional endoscopic sinus surgery were studied through histopathological examination, scanning electron microscopy, and transmission electron microscopy. In the histopathological examination, the morphological aspects characteristic of mucormycosis in all cases were identified: wide aseptate hyphae with right-angle ramifications, which invade blood vessels. One case presented perineural invasion into the perineural lymphatics. And in another case, mucormycosis-aspergillosis fungal coinfection was identified. Through scanning electron microscopy, long hyphae on the surface of the mucosa surrounded by cells belonging to the local immune system were identified in all samples, and bacterial biofilms were identified in half of the samples. Through transmission electron microscopy, aseptate hyphae and bacterial elements were identified in the majority of the samples. Rhino-orbital-cerebral mucormycosis associated with COVID-19 produces nasal sinus dysbiosis, which favors the appearance of bacterial biofilms. The way in which the infection develops depends on the interaction of the fungi with cells of the immune system.

Part 2: Mucormycosis: Focus on Therapy

INTRODUCTION

Mucormycosis (MCR) a rare but life-threatening infection occurs primarily in immunocompromised hosts. Mortality rates with invasive MCR are high (>30-50%), up to 90% with disseminated disease, but lower (10-30%) with localized cutaneous disease. Due to the rarity of MCR, randomized, controlled therapeutic trials are lacking. Lipid formulations of amphotericin B (LFAB) are the mainstay of therapy but oral triazoles (posaconazole and isavuconazole) may be effective as step-down therapy or in MCR cases refractory to or intolerant of LFAB. Early surgical debridement or excision play important adjunctive roles in localized invasive disease. Control of hyperglycemia in diabetic patients, correction of neutropenia and reduction of immunosuppressive therapy is critical for optimal survival.

AREAS COVERED

The authors discuss various therapeutic options for mucormycosis. A literature search of mucormycosis therapies was performed via PubMed (up to December 2022), using the key words: invasive fungal infections; mold; mucormycosis; Mucorales; amphotericin B; isavuconazole; posaconazole.

EXPERT OPINION

Randomized, controlled therapeutic trials are lacking. Lipid formulations of amphotericin B (LFAB) are the mainstay of therapy but oral triazoles (posaconazole and isavuconazole) may be effective as step-down therapy, in MCR cases refractory to or intolerant of LFAB. We encourage early surgical debridement or excision as adjunctive measures.

Is low dose of liposomal amphotericin B effective in management of acute invasive fungal rhinosinusitis? Our conclusions from Al-Mowassat University Hospital, Syria: a prospective observational study

BACKGROUND

Acute invasive fungal rhinosinusitis (AIFRS) is a fatal infection associated with high morbidity and mortality. Although it is a rare disease, upsurge of AIFRS was noticed during the second wave of COVID-19 disease. Early diagnosis and management is the cornerstone for good outcomes. However, management of AIFRS is challengeable especially in developing countries due to limited resources and high prices of antifungal agents. No previous studies have been conducted to evaluate the outcomes of management of AIFRS in Syria. The purpose of this study is to report the results of management of AIFRS with low doses of liposomal amphotericin B in our tertiary hospital in Syria.

METHODS

The outcomes of management of AIFRS cases were followed through a prospective observational study between January 2021 and July 2022. The required medical data were collected for each individual. Three-month mortality rate was studied. SPSS v.26 was used to perform the statistical analysis. Pearson Chi-square test was used to study the associations between different variables and mortality. Survival curves were plotted by the Kaplan-Meier to compare the survival probability. Log Rank (Mantel-Cox) test and Cox regression were conducted to evaluate the factors affecting survival within the follow up period.

RESULTS

Of 70 cases, 36 (51.4%) were males and 34 (48.6%) were females. The mean age of patients was 52.5 years old. The most common underlying risk factor was diabetes mellitus (84.3%). The used dose of liposomal amphotericin B ranged between 2-3 mg/kg per day. The overall 3-month mortality rate was 35.7%. Significant association was found between survival and the following variables: Age, orbital involvement, stage, and comorbidity.

CONCLUSION

The overall mortality rate was close to other studies. However, survival rate was worse than comparable studies in selected cases of AIFRS (older ages, involved orbits, advanced stages, and chronic immunodeficiency). Therefore, low doses of liposomal amphotericin B could be less effective in such cases and high doses are recommended.