Lecture 19

Question 1

Zika pandemic

Answer 1

1920s - Africa

1940s - Spread from East Africa to South East Asia and India

2007 - Prevalent in South East Asia

2013 - 32,000 cases in French Polynesia

2014 - Spread to South America

2015 - Spread to Mexico

Question 2

Smallpox spread

Answer 2

1 case leads to 7 on average

R = 7

Question 3

Pandemic Influenza spread

Answer 3

1 case leads to 2-3 others

R=2.5

Question 4

Seasonal influenza spread

Answer 4

1 case leads to 1-2 others
R=1.28

Question 5

Ebola spread

Answer 5

One case leads to 1-3 others on average

R is 1.5 to 2.8

Question 6

Zika (Polynesia)

Answer 6

1 case lead to 1-2 others

R=1.8-2

Question 7

Zika (Micronesia)

Answer 7

1 case leads to about 5 others

R = 4.2-5.8

Question 8

Zika (Colombia)

Answer 8

1 case leads to about 3-6 others

R = 3-6.6

Question 9

Zika in Rio

Answer 9

1 case leads to about 2-3 others on average

R = 2.33

Question 10

SARS-CoV2

Answer 10

1 case leads to 2-3 others on average

R = 2.63

Question 11

New variant SARS

Answer 11

1 case leads to around 3-4 others on average

Question 12

What is Ps

Answer 12

Proportion susceptible

Question 13

What is Pst

Answer 13

Proportion susceptible at time t

Question 14

How to calculate Rt?

Answer 14

R0 x Pst

Question 15

How to calculate Pr

Answer 15

1 - Ps

Question 16

Prt

Answer 16

Proportion resistant at time t

Question 17

HET

Answer 17

Herd immunity threshold

HET = (R0 - 1)/R0

Question 18

Calculating proportion to vaccinate

Answer 18

HET/Vaccine efficacy