Infectious Disease Epidemiology

Question 1

What is the difference between microparasites and macroparasites?

Answer 1

Microparasites are small and multiply in-host whereas macroparasites are large and multiply out of host

Question 2

Name some properties of macroparasites

Answer 2

• Age related exposure
• No immunity
• High morbidity, low mortality
• Endemic
• Continual reinfection

Question 3

What are the two types of transmission routes?

Answer 3

• 1-1 (direct, indirect, droplet)
• no contact (airborne, vehicle, vector borne)

Question 4

State the equation to work out the DALY

Answer 4

DALY = years lived with disability + years of life lost

Question 5

How was the plague spread?

Answer 5

Aerosol

Question 6

What is a vector?

Answer 6

Living organism which transmits infectious disease between humans or animals to humans (WHO)

Question 7

What is vertical transmission?

Answer 7

Transmission from mother to offspring

Question 8

Define an epidemic

Answer 8

An increase in incidence of disease

Question 9

What is the R0 and when does an epidemic occur?

Answer 9

R0 is the basic case reproduction number and an epidemic occurs when it is >1

Question 10

What is the equation for the R0?

Answer 10

R0 = p x c x D

Question 11

What is the Re and its formula?

Answer 11

The restrained growth rate
Re = R0 x fraction of ‘s’

Question 12

What is the Pc?

Answer 12

Percent of population likely to get the disease in a fully susceptible population

Question 13

What is the formula for effective contact rate?

Answer 13

effective contact rate = p x c

Question 14

What is the incubation period?

Answer 14

Time between infection and clinical onset of disease

Question 15

What is the latent period?

Answer 15

Time from infection to infectiousness

Question 16

In which population are endemic diseases most common?

Answer 16

Animals

Question 17

What is the CCS equation?

Answer 17

Minimum host population size required for the pathogen to persist

Question 18

What does an increased infectious period cause?

Answer 18

A slower moving infection

Question 19

What is a ‘reservoir host’ and a ‘carrier’?

Answer 19

A reservoir host refers to a population or a species and a carrier refers to an individual

Question 20

What are the 4 aims of intervention?

Answer 20

1) control
2) eliminate
3) eradicate
4) extinct

Question 21

What are the 2 easy ways to prevent transmission?

Answer 21

• vaccination
• reduction in contact

Question 22

What are the 2 intervention strategies of intervention?

Answer 22

• tracing + isolation
• culling

Question 23

Define vectoral capacity

Answer 23

Average number of potentially infective bites that will be delivered by all the vectors feeding upon a host in one day

Question 24

What is the equation for vectoral capacity?

Answer 24

C = (V/N)(ah)^2 x p^n / -ln(p)

Question 25

What is the difference between anthroponotic and zoonotic diseases?

Answer 25

Anthrophonotic goes from human to anthropod to human whereas zoonotic goes from animal to anthropod to human

Question 26

What natural event can affect spread of disease?

Answer 26

Climate change, temperature

Question 27

What 2 factors can affect BTV transmission?

Answer 27

- temperature - precipitation

Question 28

What event offers evidence that climate change can alter disease?

Answer 28

El nino

Question 29

What is vaccine efficacy?

Answer 29

The % of people who are immunised

Question 30

Where did SARS-COV-2 originate?

Answer 30

Wuhan, China

Question 31

How many coronas infect humans?

Answer 31

1/6 of them