SARS-CoV2 first emerged in Dec 2019 in Wuhan and rapidly developed into a COVID-19 pandemic since March 2020.
The clinical spectrum of COVID-19 ranges from asymptomatic infection, mild, moderate, severe to critical illness.
SARS-CoV2 is highly infectious with high viral loads peaking during day 2-4 of illness and the viral kinetics facilitate community transmission.
Patients in the asymptomatic or pre-symptomatic stage can transmit infection to others.
Common routes of transmission include respiratory droplets, contact with fomites, and short-range airborne transmission in environment with poor ventilation.
Low dose corticosteroid is the only treatment modality proven to reduce mortality while antiviral agent remdesivir can shorten duration of illness by 5 days in patients who have respiratory failure.
Vaccination is an important modality to control COVID-19 by reducing risk of symptomatic transmission.
Emergence of mutant viruses in recent months are of great concern as these would increase transmission potential of SARS-CoV2 and reduce effectiveness of COVID-19 vaccines.
