Pathophysiology of COVID-19

21-Aug-2021

The pandemic COVID-19, unfortunately, have only supportive therapy as the treatment option. Preventive measures to reduce community transmission are equally important as the vaccines against this disease. Let us consider the disease progression in patients once infected by novel Coronavirus.

Pathophysiology
Coronaviruses are enveloped positive strand RNA viruses which mean that the viral RNA acts as mRNA once it enters human host and starts synthesizing viral proteins. The envelope plays an important role in viral pathogenesis. The viral assembly and release is promoted by the envelope proteins.

Severe Acute Respiratory Syndrome
There seems to be a complex pathogenic mechanism involved resulting in pneumonia. The patients initially suffered from fever, dry cough, weakness and uneasiness which are typical symptoms of a viral infection. The onset of initial symptoms varied among population depending upon the age of the patient and their immune system’s capability to fight the disease starting from 6 days to 41 days until death. The average time the infection took to show symptoms was 14 days. Chest CT (Computerized Tomography) scans showed pneumonia. The disease progresses with difficulty in breathing (dyspnea) leading to respiratory failure. At this stage mechanical ventilation and intensive care unit (ICU) support becomes necessary. The patient afterward showed systemic symptoms like sepsis, septic shock and multiple organ dysfunction/failure leading to death.

Sepsis
A dysregulated host response to infection leading to multiple organ dysfunctions resulting in a life threatening condition is called sepsis. The COVID-19 patients with sepsis showed signs and symptoms which include dyspnea and hypoxemia (abnormally low level of oxygen in blood), altered mental status, kidney injury and tachycardia (a condition in which heart beats more than 100 times per minute).

Management of the Disease
No specific antiviral treatment is currently available. Major treatment is oxygen therapy. In case of respiratory failure, mechanical ventilation is provided. Septic shock is managed by hemodynamic support.

With a huge population, countries like India saved lives by National Lock Down in the first wave of COVID 19. Still people were not serious about following social distancing religiously and the second wave of Coronavirus had devastating effects on Indian population. What do you think are the possible reasons for this kind of irresponsible behavior among citizens of the country?

Figure Source: https://www.cdc.gov/coronavirus/2019-ncov/downloads/COVID19-symptoms.pdf

For more information please read: https://www.ncbi.nlm.nih.gov/books/NBK554776/

By:
Dr Vigi Chaudhary
Assistant Professor
Amity Institute of Biotechnology

Amity University Rajasthan