Quote:
Originally Posted by AndrewM
That’s good it was the exception rather than the norm. Don’t know transmissivity of other viruses or diseases but those numbers don’t seem that high. Hopefully it stays that way.
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Those numbers are plenty high, possible exponential growth. Anything greater than 1 means it's spreading. That 1.4-2.5 would be it's
effective reproduction number.
A population will rarely be totally susceptible to an infection in the real world. Some contacts will be immune. Therefore, not all contacts will become infected, and the average number of secondary cases per infectious case will be lower than the basic reproduction number. The
effective reproductive number (R) is the average number of secondary cases per infectious case in a population made up of both susceptible and non-susceptible hosts.
If R>1, the number of cases will increase, such as at the start of an epidemic. Where R=1, the disease is endemic, and where R<1 there will be a decline in the number of cases.
If R=2, that means if one contact infects 2, then 2 infect 4, then 4 infect 8. Not exponential, but growing linearly. If R>2, then it becomes exponential growth