Respiratory complication: Acute respiratory distress syndrome or ARDS is the predominant manifestation and most common complication of SARS-CoV-2 as lungs is the main target organ. Histopathology of ARDS lungs shows the diffuse alveolar damage, development of hyaline membrane, edema and interstitial infiltration. Damage to lungs occurs due to direct attack of virus to pneumocytes. The development of ARDS increases the mortality rate by 45%.

Cardiovascular involvement: COVID-19 patients have been reported to develop myocarditis, cardiomyopathy and arrhythmia during the disease process. High mortality rate has been found to be in patients with heart failure.

Kidney: Acute kidney injury is one of the significant factors for COVID-19 associated deaths. The epithelial cells of proximal tubular cells and podocytes are rich in ACE-2 receptor and thus are the direct target of SARS-CoV-2. In a meta-analysis study, the incidence of AKI has been found to be >30% in severe and critical cases and >50% in COVID-19 associated deaths.

Pancreas: Both islet cells and exocrine cells of pancreas express the ACE-2 receptor, hence are the direct target of SARS-CoV-2. Pancreatic injury may lead to hyperglycemia and may be responsible for precipitating the ketoacidosis.

Liver: Abnormal level of aminotransferase (AST and ALT) is often observed in up to 50% of COVID-19 patients. Significant increase in level of liver enzymes is more seen in severe patients than mild COVID-19 cases. However, liver injury has not been associated with bad prognosis.

Complication in pregnancy: Increased oxygen demand and physiologic anemia during pregnancy are the potential factors that could exacerbate the severity of COVID-19. The information on clinical implications of COVID-19 during pregnancy is limited to case reports and case series. In studies based on patient series, 14% COVID-19 infected pregnant women developed pre-eclampsia and about 6% required ICU admission.

Secondary Infections

 Bacterial infections are the most common secondary infections associated with COVID 19. However, systemic fungal infections in COVID-19 patients such as COVID associated mucormycosis (CAM) and COVID associated pulmonary aspergillosis (CAPA), have raised concern due to high mortality. The mortality rate is about 56% in COVID patients with secondary infection as compared to 10.6% in total COVID admitted patients as reported in a multicentric ICMR study.

COVID associated mucormycosis: Mucor mycosis is an angioinvasive disease caused by mold fungi of class—Zygomycetes and order— Mucorales. The genus Rhizopus, Mucor, Rhizomucor, Cunninghamella and Absidia are the common causes. This has been associated mostly with moderate-to-severe COVID-19, however, also been reported in mild COVID patients. The overall prevalence of CAM is <3% The prevalence in ICU patient is higher as compared to patients of general ward. CAM is reported more in male than females.

Multiple factors play role in facilitating the germination of mucorale spores in COVID-19 patients. The environment of low oxygen, hyperglycemia, acidic medium, immunosuppression and high iron level play the major risk factor. Hyperglycemia (high blood glucose) has been attributed as the prime predisposing factor of CAM. This can be present in patients with known diabetic, newly onset hyperglycemia or due to steroid induced hyperglycemia. SARS-CoV-2 itself has been shown to be diabetogenic by causing damage to the b cell of pancreas. High blood glucose level leads to the increased expression of endothelial receptor GRP78 resulting in polymorphonuclear dysfunction, decreased chemotaxis and defective intracellular killing. Steroid act as another major risk factor by inducing immunosuppression (particularly by impairing the neutrophil migration and inhibiting the phagolysosome fusion) and inducing hyperglycemia (steroid-induced hyperglycemia). COVID-19 disease process itself causes endothelial damage, thrombosis and lymphopenia which predisposes to secondary infections. Iron is one of the essential growth factors for Mucorales. Mucorales has the ability to acquire iron from the host. During the acidic medium in the host due to metabolic acidosis or diabetic ketoacidosis, free irons are available in the serum which are efficiently taken up by them through siderophores or iron permease which increases the virulence of these molds. The summary of the factors responsible for COVID associated mucormycosis is given in Table 1.

Table1. Risk factors for COVID-19 associated mucormycosis

Rhinocerebro-orbital is the most common type of mucormycosis in COVID patients followed by pulmonary variety. The spectrum of rhinocerebro-orbital involves sinonasal disease to limited rhino-orbital to rhino-orbital cerebral disease. The involvement of orbital and cranial nerves are ominous signs. The tissue necrosis leading to black necrotic lesion, eschar or black discharge are the clinical hallmark of disease. The diagnosis is confirmed by demonstration of fungal element (broad aseptate hyphal structures) from tissue samples by KOH or calcofluor fluorescent method and histopathology or by culture and molecular methods. Liposomal amphotericin B is the drug of choice. Isavuconazole and posaconazole are recommended as salvage therapy.

COVID associated pulmonary aspergillosis (CAPA) is another important superinfection which contributes to increased mortality due to COVID-19. Immunosuppression particularly decrease in T cell population and defective function is the major predisposing factor for CAPA or invasive fungal infection. The confirmation of diagnosis is often difficult as bronchoscopic sample is the most relevant specimen which is not usually recommended in a COVID 19 positive patients due to risk of transmission to health care workers. The diagnosis, therefore depends mostly on radiological features, demonstration of aspergillus-like fungal elements in sputum, tracheal aspirate and serum galactomannan and aspergillus PCR.

Secondary bacterial infections: Secondary bacterial infections in COVID patients have been reported mostly due to gram-negative bacilli. The overall incidence in admitted patients is less than 5% as reported in a multicentric ICMR network study in India. Multi-drug resistant Klebsiella pneumoniae and Acinetobacter baumannii are the predominant pathogens reported.

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قسم صناعة الشبابيك يشرع بإدامة شباكين قديمين لمرقد الإمامين العسكريين (عليهما السلام)

فرقة العباس (عليه السلام) تختتم خدماتها المقدمة للزائرين في سامراء

موكب العتبتين المقدستين يحيي ذكرى استشهاد الإمام الهادي (عليه السلام) في سامراء

العتبة العسكرية المقدسة تكرّم وفد العتبة العباسية المقدسة لمشاركته في تقديم الخدمات للزائرين

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كنز غذائي على طبقك.. ماذا تفعل السبانخ بجسمك؟

ما لا يتوقعه أحد.. "سر غذائي" في الجبن الدسم

لتحسين الهضم والنوم.. هذا أفضل وقت لتناول العشاء

10 طرق بسيطة وغير مألوفة لحرق المزيد من السعرات يوميا

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"الإنفلونزا الخارقة" تكتسح دول العالم.. وتثير قلقا كبيرا

مرحلة ما قبل الأعراض.. دواء جديد يستهدف "شرارة" الزهايمر

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مواضيع ذات صلة

Clinical Features of SARS-CoV-2 and COVID-19

Modes of Transmission SARS-CoV-2 and COVID-19

Papillomaviruses

Arenaviruses

Adenoviruses

Viral Serology: Immune Status Testing

Structure and Function of Hemagglutinin

Structure and Composition of influenza viruses

Filoviruses Diseases

Pathogenesis of SARS-CoV-2 and COVID-19

Viral Serology :General Principles

Virus detection methods: Cell Culture