Novel role of 18F- FDG PET/CT in rhinosinonasal mucormycosis in the era of covid-19 infection

Objectives: In the Covid-19 era, there was a surge in the cases of a life-threatening infection of rhinosinonasal mucormycosis. Mucormycosis, popularly known as black fungus, is an infection caused by mycetes mucorales, an aseptate hyphae. Presently, computed tomography (CT) and magnetic resonance imaging (MRI) are commonly used imaging modalities for the management of patients with rhinosinonasal mucormycosis. The present study was aimed to evaluate the role of 18F- FDG PET/CT in the detection of recurrent or residual disease in post-surgical or post antifungal therapy in these patients for further management. Method(s): A total of 10 patients were included in this pilot study of Covid-19 positive patients and histologically proven mucormycosis (by KOH mount). 18F- FDG PET/CT was performed to assess the disease status in 6 postoperative/ post debridement patients and response to antifungal therapy in 4 patients, at an interval of 40 (range = 27-66) days post intervention. Result(s): The mean age of the patients was 45.0 +/- 11.65 years. The male: female ratio was 9:1. The common clinical presentation was ipsilateral facial or orbital pain and swelling. Covid-19 infection was positive in all the patients except one who had CT finding with HRCT score of 10/25 and hence was considered as post Covid-19 infection. Six out of 10 patients were diabetic on oral hypoglycaemic agents or insulin. All patients had a baseline CT/MRI for staging the initial extent of the disease. Surgical debridement was done in 6 out of the 10 patients followed by antifungal therapy (Liposomal Amphotericin B and Pozaconazole). Remaining four patients were treated with antifungal therapy. PET/CTwas performed after an average of 40 days of surgical/medical intervention, in whom clinical symptoms persisted or worsened even on antifungal therapy. 18F-FDG PET/CT showed metabolically active residual disease in all the patients with a mean SUVmax of 9.78 +/- 4.03. Conclusion(s): In the era of ongoing Covid-19 infection, black fungus has been a debilitating disease with high mortality and morbidity. Present study demonstrated that 18F-FDG PET/CT can be an efficient imaging tool for an early surgical/ medical treatment response assessment and restaging.

Respiratory system resistance and reactance following recovery from non-critical COVID-19

Background: COVID-19-related lung injury may persist or require time to recover in some individuals. Objective(s): To better understand the post-acute pathophysiology of non-critical COVID-19 by evaluating respiratory system resistance and reactance in COVID-19 survivors 4-weeks and 6-months after recovery, compared to neverCOVID-19 controls. Method(s): Individuals with no history of lung disease who were hospitalized or home-isolated during the acute-phase of COVID-19, and age-matched never-COVID-19 controls, performed respiratory oscillometry (tremoFlo C-100) to measure resistance (Rrs5Hz, Rrs19Hz , Rrs5-19Hz ), reactance (Xrs5Hz ) and area of reactance (A ), Six Minute Walk Test, and completed the Borg Dyspnea Scale 4-weeks (visit 1) and 6-months (visit 2) post-recovery. Result(s): Hospitalized (n=9), home-isolated (n=20) and never-COVID-19 (n=17) cohorts were similar with respect to age (p=0.12), sex (p=0.89), and BMI (p=0.08). Figure 1 shows that Rrs5-19Hz (p=0.04) and A (p=0.009) were higher, and Xrs5Hz (p=0.007) was more negative, in the hospitalized cohort compared to control cohort at visit 1, but not visit 2. These measures were associated with greater dyspnea and decreased six-minute walk distance. Conclusion(s): Increased peripheral resistance and reactance following recovery from non-critical COVID-19 may only be prevalent among hospitalized COVID-19 survivors, within which these respiratory abnormalities may be temporary.

Diagnostic performance of MucorGenius® real-time polymerase chain reaction assay on tissue samples for the diagnosis of mucormycosis

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PM:   Objectives: To assess the diagnostic utility of MucorGenius® real-time PCR in tissue samples for the diagnosis of mucormycosis in patients suspected of having invasive mucormycosis (IM) during the second wave of the COVID-19 pandemic. Methods: A total of 193 clinically suspected cases of IM presenting at our tertiary care center from May to July 2021 were included and defined as proven, probable, possible, or negative for invasive fungal disease (IFD) according to EORTC/MSGERC guidelines. One sample from each patient (nasal/sinus biopsy, nasal crust, or orbital tissue) was subjected to conventional methods for diagnosis of IM and MucorGenius® real-time PCR (hereafter called ‘the assay’). Results: A total of 5 (1.92%), 124 (47.6%), and 44 (16.9%) cases respectively were classified as having proven, probable, and possible IM. The remaining 20 (7.69%) were classified as not having invasive fungal infections and were used as controls to calculate the specificity of the test. The majority of cases were classified as ‘probable’ because specimens received included biopsy from the nasal or sinus cavity.According to radiological findings, sino-nasal involvement was seen in 26/173 (15.02%), sino-orbital involvement in 122/173 (70.5%), and additional intracranial extension in 25/173 (14.4%) of the 173 cases of IM.Among 129 proven and probable cases, direct microscopy of samples showed only aseptate hyphae in 70 cases, and both aseptate and septate hyphae in 36 cases;the assay was positive in 53 and 13 of these cases respectively. In the remaining 23 cases, direct microscopy of samples showed only septate hyphae and the assay was negative.Additionally, the assay was able to detect the presence of Mucorales among 44 possible cases of IM in which direct microscopy of samples showed no fungal elements, but the patients displayed clinical and radiological features of IM and improved with antifungal therapy.The overall sensitivity and specificity of the assay were 63.21% and 90.48% respectively.The sensitivity of the assay in proven and probable cases of IM was 60% and 66.7% respectively, while specificity was 90% for both, using the presence of aseptate hyphae in direct microscopy as a gold standard. Sensitivity and specificity in possible cases were 27.27% and 90% respectively, using the presence of clinical and radiological features of IM and response to antifungal treatment as a reference.When sensitivity and specificity were determined independently in cases of mucormycosis and mixed infection (mucormycosis + aspergillosis), they increased to 75.71% and 90.48% respectively in the former, and both decreased to 38% in the latter. Conclusion: The MucorGenius® real-time PCR performs well in detecting IM as a single infection, especially in cases of possible IM which are not detected by conventional methods. However, it is inefficient in detecting co-infections of invasive mucormycosis and aspergillosis, possibly because Aspergillus can suppress the growth of Mucorales. With further studies using the results to guide clinical intervention and measuring the impact on the outcome, it can be a useful tool to make an early diagnosis of mucormycosis in patients with a high index of clinical suspicion.

Facial neuritis in coronavirus disease 2019 associated mucormycosis: study on clinico-radiological correlates.

OBJECTIVE: To elucidate the aetiopathogenesis of facial neuritis in coronavirus disease 2019 associated mucormycosis. METHODS: A retrospective review was conducted of coronavirus disease 2019 associated mucormycosis patients who presented with peripheral facial nerve palsy from January 2021 to July 2021. The clinico-radiological details of four patients were assessed to examine the potential mechanism of facial nerve involvement. RESULTS: Serial radiological evaluation with contrast-enhanced computed tomography and contrast-enhanced magnetic resonance imaging revealed infratemporal fossa involvement in all cases, with the inflammation extending along fascial planes to reach the stylomastoid foramen. Ascending neuritis with an enhancement of the facial nerve was demonstrated in all cases. CONCLUSION: The likely explanation for facial palsy in patients with coronavirus disease 2019 associated mucormycosis, backed by radiology, is the disease abutting the facial nerve at the stylomastoid foramen and causing ascending neuritis of the facial nerve.

COVID-19-associated mucormycosis presenting to the Emergency Department-an observational study of 70 patients.

BACKGROUND: Mucormycosis (MM) is a deadly opportunistic fungal infection and a large surge in COVID-19-associated mucormycosis (CAM) is occurring in India. AIM: Our aim was to delineate the clinico-epidemiological profile and identify risk factors of CAM patients presenting to the Emergency Department (ED). DESIGN: This was a retrospective, single-centre, observational study. METHODS: We included patients who presented with clinical features or diagnosed MM and who were previously treated for COVID-19 in last 3 months of presentation (recent COVID-19) or currently being treated for COVID-19 (active COVID-19). Information regarding clinical features of CAM, possible risk factors, examination findings, diagnostic workup including imaging and treatment details were collected. RESULTS: Seventy CAM patients (median age: 44.5 years, 60% males) with active (75.7%) or recent COVID-19 (24.3%) who presented to the ED in between 6 May 2021 and 1 June 2021, were included. A median duration of 20 days (interquartile range: 13.5-25) was present between the onset of COVID-19 symptoms and the onset of CAM symptoms. Ninety-three percent patients had at least one risk factor. Most common risk factors were diabetes mellitus (70%) and steroid use for COVID-19 disease (70%). After clinical, microbiological and radiological workup, final diagnosis of rhino-orbital CAM was made in most patients (68.6%). Systemic antifungals were started in the ED and urgent surgical debridement was planned. CONCLUSION: COVID-19 infection along with its medical management have increased patient susceptibility to MM.