Case Report: Nocardia amamiensis Infection Leading to Worsening of Chronic Obstructive Pulmonary Disease Symptoms in an Elderly Man.

Nocardiosis is a rare opportunistic infection mostly affecting the lungs, brain, or skin of immunocompromised individuals. Most pulmonary nocardiosis patients present with nonspecific clinical features such as productive cough, exertional dyspnea, and fever. The disease is uncommonly suspected, especially in tuberculosis-endemic regions, and clinical diagnosis is often delayed, resulting in high mortality. Pulmonary nocardiosis in apparently immunocompetent individuals is uncommon. Here, we present the case of an elderly gentleman with a background history of poorly controlled diabetes but no history of systemic steroid use who presented with worsening symptoms of chronic obstructive pulmonary disease in the form of productive cough and dyspnea. The patient had diffuse crepitations in bilateral lung fields and an arterial oxygen saturation of 86% at admission. Sputum microscopy revealed gram-positive filamentous bacteria that could be successfully cultured and identified as Nocardia amamiensis on 16S ribosomal RNA sequencing. Contrast-enhanced computed tomography of the lungs revealed cavitary nodules and consolidation. The patient responded well to treatment with specific antibiotics based on sensitivity patterns. Because of the nonspecific clinical and radiological findings in pulmonary nocardiosis, a high index of suspicion is required, especially in tuberculosis-endemic regions.

The Pathogenetic Dilemma of Post-COVID-19 Mucormycosis in India.

There has been a surge of mucormycosis cases in India in the wake of the second wave of COVID-19 with more than 40000 cases reported. Mucormycosis in patients of COVID-19 in India is at variance to other countries where Aspergillus, Pneumocystis, and Candida have been reported to be the major secondary fungal pathogens. We discuss the probable causes of the mucormycosis epidemic in India. Whereas dysglycaemia and inappropriate steroid use have been widely suggested as tentative reasons, we explore other biological, iatrogenic, and environmental factors. The likelihood of a two-hit pathogenesis remains strong. We propose that COVID-19 itself provides the predisposition to invasive mucormycosis (first hit), through upregulation of GRP78 and downregulation of spleen tyrosine kinase involved in anti-fungal defense, as also through inhibition of CD8+ T-cell mediated immunity. The other iatrogenic and environmental factors may provide the second hit which may have resulted in the surge.

Case Report: Rhino-orbital Mucormycosis Related to COVID-19: A Case Series Exploring Risk Factors.

There has been a surge of rhino-orbital mucormycosis cases in India in the wake of the second wave of the COVID-19 pandemic. It has been widely suggested that dysglycemia resulting from diabetes which is a common comorbidity in COVID-19 patients, and indiscriminate steroid use has resulted in this surge. We report a series of 13 cases of rhino-orbital mucormycosis in COVID-19 patients admitted to our center between mid-April and early June 2021. The cases showed a male preponderance, two patients had loss of vision, and four of them showed intracranial extension of disease. Twelve patients had received steroids and 12 had preexisting or newly diagnosed diabetes, both steroid use and diabetes being the most common identified risk factors. Considering other possible risk factors, immunosuppressed state, antiviral or ayurvedic (Indian traditional) medications, and oxygen therapy were not associated with a definite risk of mucormycosis, because they were not present uniformly in the patients. We propose that COVID-19 itself, through molecular mechanisms, predisposes to mucormycosis, with other factors such as dysglycemia or steroid use increasing the risk.