Key Knowledge Points


  • Coronaviruses are a large family of viruses. They get their name from the crown-like spikes that can be seen on their surface with electron microscopy. They were first identified in the middle of the 1960s, and they can cause very mild symptoms like a common cold, or in some cases the viruses can cause severe disease.
  • There are many coronaviruses circulating in animals, and some that are circulating in humans. Rarely, one of the viruses infecting animals may evolve to infect humans and spread. The virus causing the disease Severe Acute Respiratory Syndrome - SARS - in 2002 originated from bats, but then passed through Civet cats and onto humans.
  • Evidence indicates that Covid 19 human transmission occurs via close contact with respiratory droplets produced when a person exhales, sneezes, or coughs, or via contact with contaminated surfaces.
  • Airborne transmission has not been reported; however, it may be possible during aerosol-generating procedures (AGPs) performed in clinical care.
  • Estimate for the incubation period range from one to 14 days. The median incubation period is estimated at approximately five days. Most are asymptomatic.
  • Transmission may be possible during the incubation period before symptoms appear, although transmission is believed to be greatest around the time of symptom onset. Module 2: The COVID-19 Virus Its epidemiology, risk factors, definitions and symptoms Covid 19 tracker Module 2 Covid 19 tracker link.
  • Four transmission scenarios of Covid-19: No case > sporadic cases > cluster of cases > increased community transmission.

Last modified: Wednesday, 18 November 2020, 8:27 PM