epidemiology

Question 1

What are the types of transmission?

Answer 1

• airborne
• contact and faeces
• contaminated water
• tissues and blood stream via needles
• insects

Question 2

what are stages of evolution of transmission of infection

Answer 2

1: agent only in animals
2. primary outbreak
3. long outbrea
4. exclusive human agent

Question 3

What is the difference in direct and indirect transmission?

Answer 3

direct: from human to human
indirect: human to mosquito to human

Question 4

What is the chain of infection?

Answer 4

reservoir > mode of transmission > susceptible host

Question 5

what determines efficacy of transmission?

Answer 5

• mode of transmission
• host factors
• microbial factors

Question 6

what can be non-biological factors for transmission?

Answer 6

• insufficient screening
• lack of access to healthcare
• multiple sex partners

Question 7

What determines whether infectivity occur?

Answer 7

1. infectivity(how easy it is to transmit it)
2. virulence (how severe is a disease?)
3. pathogenicity (how good is it to produce a disease)

Question 8

What is the definition of the following terms:
true carrier
incubatory carrier
convalescent carrier

Answer 8

true carrier: transmittable pathogen while not showing clinical signs of disease
incubatory carrier: transmittable pathogen while still in incubation phase
convalescent phase: transmittable pathogen while clinical signs of disease have disappeared

Question 9

What are the stages of infectiousness?

Answer 9

susceptibe > latent > infectious> non-infectious

Question 10

what are the stages of disease?

Answer 10

susceptible>incubation > clinical symptoms> non-diseased

Question 11

What happens wheen the latency stage is shorter than the incubation stage?

Answer 11

the infectious stage can occur earlier than the clinical symptoms, meaning that it is already infectious in incubation phase

Question 12

What does SIR mean?

Answer 12

S > susceptible
I > infected
R > recovered

Question 13

How to calculate the R effective?

Answer 13

basic reproduction rate multiplied by the ratio of susceptible population

Question 14

What influences the R0?

Answer 14

• duration of infectiousness
• rate of contact population
• propability of infection being transmitted

Question 15

What is the definition of the following terms?
- epidemic
- pandemic
- endemic

Answer 15

epidemic: occurence of casees in excess of normal expectancy
pandemic: epidemic occuring crossing international boundaries
endemic: infection maintained without need for external inputs

Question 16

What is the difference between point source outbreak and propagated outbreak?

Answer 16

point source outbreak: e.g. a food poisining outbreak from a restaurant. One source only and peak will dissappear quickly
propagated outbreak: several peaks e.g. covid

Question 17

what is backward tracing?

Answer 17

tracing from who you got the disease from?

Question 18

What is forward tracing?

Answer 18

tracing to who you spread the disease to? e.g. people from work