Epidemiology - Topic 2

Question 1

What is the rate of disease transmission?

Answer 1

The ability of a disease to spread, and how infectious it is measured by the basic reproductive number R0

Question 2

What does R0 measure?

Answer 2

Is a measure of how many people will contract a disease from the person who is the primary source

Question 3

What is R0 the number of?

Answer 3

The number of secondary infections produced by a single case of infection, in a population where the disease doesnt exist and the individuals are therefore vulnerable

Question 4

Example: If R0 is 7

Answer 4

It means that approx. seven people will become infected from coming into contact with a diseased person
Every new case would result in seven new secondary cases

Question 5

Pandemics: R0>1

Answer 5

Transmission is increasing and outbreak is possible

Question 6

Pandemics: R0 = 1

Answer 6

Transmission is stable

Question 7

Pandemics: R0<1

Answer 7

Transmission is decreasing (local extinction of disease is possible)

Question 8

Calculation for R0:

Answer 8

R0 = r x c x d

Question 9

What is r:

Answer 9

The transmissibility of the pathogen

Question 10

What is c:

Answer 10

The average rate of contact between susceptible and infected individuals

Question 11

What is d:

Answer 11

The duration of the infectious of the disease

Question 12

How to calculate the proportion of a population that needs to be vaccinated?

Answer 12

VT = 1 - 1/ R0

Question 13

What is VT:

Answer 13

The proportion of the population that needs to be vaccinated