Covid 19

Question 1

What is covid 19

Answer 1

Corona virus disease is highly contagious disease caused by SARS CoV 2
Pandemic because new novel strain of coronavirus
Alpha beta gamma delta omicron
Natural reservoir in bats and pangolin

Question 2

How does coronavirus enter the cell

Answer 2

1st step- binding of Spike pr of virus to ACE-2 receptor( main receptor for SARS CoV2 on respiratory tract epithelium)

After binding, cell surface proteaseTMPRSS2 cleaves spike pr— fusion pr subunit— fusion of virus with cell membrane — enters cytoplasm

Ab elicited after natural infection or vaccine neutralize virus by preventing binding of spike pr to ACE2 receptor

Another receptor- neuropilin1 + spike pr of virus— enter cell

Question 3

Pathogenesis of coronavirus

Answer 3

2 pathogenetic mechanisms:

•killing of alveolar cellsby the virus.
Accumulated cell debris—blocks diffusion of oxygen into the capillaries —hypoxia

• killing of the endothelial cells of the capilaries lining the alveoli — blood clots and an immune-mediated “cytokine storm”(also known as cytokine release syndrome)__ further damage to alveolar membrane

High levels of proinflammatory cytokines such as IL-1, IL-6, bradykinin, and INF are found

Question 4

Clinical findings of coronavirus

Answer 4

Important diagnostic features
Anosmia loss of ability to smell
Dysgeusia loss of ability to taste
Fever dry cough shortness of breath sore throat fatigue shaking chills
Encephalopathy—blood clots— Thrombosis and embolism— stroke
nausea vomitting diarrhea
Not by virus directly but by cytokines storm( cytokines release syndrome)