Histopathological Study of Mucormycosis in Post COVID-19 Patients and Factors Affecting it in a Tertiary Care Hospital

Mucormycosis, the Black Fungus in the Post-COVID-19 Pandemic: A Case Report with Review of Literature

Mucormycosis, a concerning and often fatal fungal infection, has shown a significant rise in cases following the COVID-19 pandemic in India, particularly affecting patients with uncontrolled comorbidities such as diabetes mellitus and other immunocompromised individuals. Our case series examines five instances of mucormycosis, supported by appropriate radiographic and histopathological evidence correlating with clinical observations. Our review indicated that patients were experiencing ailments or undergoing treatments that compromised their immune systems. We analyzed additional epidemiological data, including common infection sites, gender predispositions, and mortality rates. Treatments were tailored based on symptom severity, encompassing both surgical and medical approaches. The primary reason for the rise in cases was linked to elevated glycaemic levels and weakened immunity among post-COVID-19 patients. The report provides a detailed explanation of the factors contributing to this correlation. Our findings underscore the critical importance of timely surgical intervention and advocate for further investigation into treatment efficacy and symptom monitoring specific to mucormycosis in post-COVID-19 patients in India.

Diagnosis of Mucormycosis Using Frozen Section, Histopathology, Culture, and Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) Techniques: A Comparative Study

Mucormycosis usually occurs in immunocompromised patients or those with uncontrolled diabetes. Along the third wave of SARS-CoV-2, an associated angioinvasive opportunistic infection with Mucor, a life-threatening fungal infection, was rampant and emerging. With an increase in the usage of steroids in the COVID scenario, the rate of mucormycosis did take a rapid and alarming increase in King Edward Memorial Hospital, Pune, India. Any delay in the diagnosis and management of the disease was life-threatening. The most conventional methods to diagnose mucormycosis are microbiological culture and histopathology of the tissue. The microbiological culture method plays an important role in the diagnosis of mucormycosis. However, the technique is labour-intensive, taking seven to eight days. Histopathology leads to false-negative reports if the tissue is not biopsied from representative sites. On the other hand, molecular methods are rapid, reliable, and applicable to different body samples, such as tissue, paraffin-embedded tissue blocks, plasma, and urine. We aimed to use a reverse transcriptase polymerase chain reaction (RT-PCR) method to detect Mucor in plasma samples. Due to a lack of availability of fresh samples, nucleic acid was extracted from the tissue sections of 69 cases diagnosed as Mucor by histopathology. These samples were subjected to RT-PCR using the MucorGenius kit (Pathonostics, Maastricht, Netherlands). A total of 57 tissue samples were sent for culture, and 49% of our cases were positive by culture and equally by RT-PCR. There was 80% sensitivity and 76% specificity between culture and PCR techniques. However, the use of blood/plasma for RT-PCR for early diagnosis of mucormycosis will be the method of choice.

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.

Fungal infections in patients after recovering from COVID-19: a systematic review

Background and aims

The presence of fungal infections has been described in patients after recovering from COVID-19. This study aims to conduct a systematic review of studies that reported fungal infections (Mucor spp., Pneumocystis jirovecii, or Aspergillus spp.) in adults after recovering from COVID-19.

Methods

We performed a systematic review through PubMed, Web of Science, OVID-Medline, Embase, and Scopus. The study selection process was performed independently and by at least two authors. We performed a risk of bias assessment using the Newcastle-Ottawa Scale for cohort and case-control studies, and the Joanna Briggs Institute's Checklists for Case Series and Case Reports.

Results

The systematic search found 33 studies meeting all inclusion criteria. There was a total population of 774 participants, ranging from 21 to 87 years. From them, 746 developed a fungal infection. In 19 studies, Mucor spp. was reported as the main mycosis. In 10 studies, P. jirovecii was reported as the main mycosis. In seven studies, Aspergillus spp. was reported as the main mycosis. Regarding the quality assessment, 12 studies were classified as low risk of bias and the remaining studies as high risk of bias.

Conclusion

Patients' clinical presentation and prognosis after recovering from COVID-19 with fungal infection differ from those reported patients with acute COVID-19 infection and those without COVID-19 infection.

Role of histopathology in severity assessments of post-COVID-19 rhino-orbital cerebral mucormycosis - A case-control study

BACKGROUND

There was an upsurge in rhino-orbital-cerebral mucormycosis (ROCM) during the second wave of the COVID-19 pandemic in India. Histopathological examination of the biopsies witnessed greater tissue invasion in these cases. The present study aimed to evaluate the histopathological scoring system in the severity assessment and to compare the scores between ROCM that required orbital exenteration (cases) and those that were treated conservatively (controls).

MATERIAL AND METHODS

A retrospective study was conducted to analyze the histopathological features using a scoring system in patients diagnosed with mucormycosis on sino nasal biopsies. The scoring was based on the following parameters: the extent of necrosis (score 1 <50% and score 2 >50%), degree of angioinvasion (score 1 <3 vessels in 10 fields and score 2 > 3 vessels in 10 fields), degree of inflammation (mild, moderate or severe), and fungal load(score 1 to 4), based on which three grades (I to III) were given. The scores were compared between the case group and the control group. The data obtained were analyzed statistically.

RESULTS

The study included 40 controls and 10 cases. The median age of patients in the control group was 52 with 82.5%males (n = 43) and 17.5 % females (n = 7) while in the case group, the median age was 51 years, and all were males. The predominant inflammatory response was of mixed suppurative type (70 %, n = 28). The degree of necrosis was scored 2 in 57.5 % (n = 23) of controls and 70 %(n = 7) in the case group. All the samples in the case group showed scores of 2 for angioinvasion and scores of 3 and 4 for fungal load. There was a statistically significant difference in the degree of necrosis, angioinvasion, the severity of neutrophilic infiltrates, and fungal load between the cases and controls (p-value <0.05).

CONCLUSION

The present study analyses the predictive role of histopathology in invasive mucormycosis. Higher fungal load, degree of angioinvasion, and the absence of granulomas are associated with advanced disease in sinonasal mucormycosis. The study findings recommend incorporating the histopathological scoring criteria in evaluating patients with sinonasal mucormycosis.

Histopathological significance of necrosis in oral lesions: A review

Necrosis is a localized area of tissue death followed by degradation of tissue by hydrolytic enzymes released from the dead cells, resulting in swelling of organelles, rupture of the plasma membrane, eventual cell lysis, and leakage of intracellular contents into the surrounding tissue. It is always accompanied by an inflammatory reaction. Necrosis is caused by various factors such as hypoxia, physical factors, chemical agents, immunological agents, and microbial agents. Still now, there is no literature review regarding the necrotic lesions of the oral cavity. In this paper, the oral lesions associated with necrosis are categorized under the headings such as odontogenic cysts, odontogenic tumors, salivary gland pathology, and epithelial malignancies. In addition, the histopathological significance of necrosis in oral lesions has been discussed. By suggesting that spotting necrosis in the histopathology aids in determining the diagnosis, tumor behavior, and prognosis of oral lesions.

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.