The novel Coronavirus (COVID-19) is wide spreading virus that have ravaged the world health and economy in general.
There are three parameters to understand in order to assess the magnitude of the risk posed by this novel coronavirus:
- Transmission Rate (Ro) – number of newly infected people from a single case
- Case Fatality Rate (CFR) – percent of cases that result in death
- Determine whether asymptomatic transmission is possible
The attack rate or transmissibility (how rapidly the disease spreads) of a virus is indicated by its reproductive number (Ro, pronounced R-nought or r-zero), which represents the average number of people to which a single infected person will transmit the virus.
WHO’s estimated (on Jan. 23) Ro to be between 1.4 and 2.5.
Other studies have estimated a Ro between 3.6 and 4.0, and between 2.24 to 3.58.
Preliminary studies had estimated Ro to be between 1.5 and 3.5.
An outbreak with a reproductive number of below 1 will gradually disappear.
For comparison, the Ro for the common flu is 1.3 and for SARS it was 2.0.