Modelling Transmission and R0

Question 1

What determines spread of a disease?

Answer 1

The type of reservoir
Mode of transmission
Population density
Infectious likelihood from contact
Infectious period
Immunity in the population

Question 2

What is R0?

Answer 2

Basic Reproduction Number
Average number of secondary cases in fully susceptible population
A function of human behaviour and pathogen biology
An estimate defined as a range
Not a constant for a particular pathogen
Different in different areas/times

Question 3

What are the 3 parameters of R0?

Answer 3

Duration of contagiousness
Likelihood of infection per contact
Contact rate

Question 4

What is the latent period?

Answer 4

Period between exposure and shedding of pathogen

Question 5

What is the incubation period?

Answer 5

Period between exposure and onset of clinical symptoms

Question 6

What is the infectious period?

Answer 6

Period between shedding of pathogen to resolution/death

Question 7

What is the sub-clinical stage?

Answer 7

Period before onset of symptoms

Question 8

What is the clinical stage?

Answer 8

Period after onset of symptoms

Question 9

What is the calculation to determine percentage of herd immunity?

Answer 9

Herd immunity = 1-(1/R0)

or (R0-1)/R0