Respiratory Tract Infections - Covid-19

Question 1

SARS-Cov-2

Answer 1

Beta coronavirus
Identified December 2019
Sequenced in January 2020
Likely originated in bat
Droplet, aerosol, contact spread
Spike protein (S) binds ACE2 receptor on airway epithelial cells (or gut or other organs)

Question 2

Wide Range of Symptoms

Answer 2

New continuous dry cough, fever +37.8, change/loss of smell/taste.
Nausea, vomiting and abdominal pain more common with increasing age.
More severe symptoms develop later - hospital admissions usually day 8-10

Question 3

Clinical Syndrome

Answer 3

80% asymptomatic-moderate disease & recover without needing hospital treatment.
15% may get severe disease.
5% become critically unwell - shock/multi-organ failure.
Infection fatality rate: 0.9% (0.5% in 45-65 year olds, and 11.6% in people over 75).
80% of deaths have been in those 70+ years old.

Question 4

Risk Factors

Answer 4

Medical problems: hypertension, IHD, obesity, diabetes, male gender.
BAME groups have higher rates of infection, serious disease, mortality.
Societal factors increase susceptibility and worsen outcomes.

Question 5

Severe Disease

Answer 5

Admission to hospital if oxygen sats <90%; respiratory rate >30; signs of severe respiratory distress.
Complications: high risk of thromboembolism, glycaemic issues (hyperglycaemia/DKA), acute kidney injury, cardiac toxicity, delirium in elderly.

Question 6

Treatment and Prevention of severe disease

Answer 6

Treatment: supportive care, high flow oxygen, dexamethasone
Prevention: PPE, ventilation, reducing encounters/proximity/contact, hand-washing, immunisation