Epidemiology and Spread of Infectious Disease (L38) Flashcards Preview

CELS191 > Epidemiology and Spread of Infectious Disease (L38) > Flashcards

Flashcards in Epidemiology and Spread of Infectious Disease (L38) Deck (27):
1

what are the sources of infection for humans? (3)

- animal reservoirs (zoonotic disease)
- non-living reservoirs
- human carriers/cases
- nosocomial infection

2

what is the term for when there is an animal reservoir of disease?

zoonotic disease

3

what are some examples of zoonotic diseases?

rabies, anthrax, ringworm, giardia

4

what are fomites?

physical objects which become infected and can transmit infection to humans

5

how can infection be transmitted?

- contact: direct, indirect, droplet
- vectors: mechanical, biological

6

what are the 5 stages of an infectious disease?

- incubation period
- prodromal period
- illness
- decline
- convalescence

7

what occurs during the incubation period?

- individual has been exposed to the organism which is growing in tissues
- showing no signs or symptoms

8

how long does the incubation period last for and what determines this length of time?

may take a short or long time
depends on:
- virulence
- dose
-immune defences
- pathogen characteristics
- site of infection

9

what occurs during the prodromal period?

- show vague, general symptoms
- symptoms are non-specific and if infectious during this stage, may spread disease before you know you have it

10

why is the prodromal period an important stage of infectious disease?

because treatment during this stage may intercept the development of the disease
also may be important for differential diagnosis

11

what is the illness stage of infectious disease?

- the stage where the most characteristic signs and symptoms of the disease are evident
- most infectious stage

12

what is the decline stage of infectious disease?

- when immune response or medical intervention resolves infection which leads to decrease in pathogen numbers -> declining signs and symptoms
- immune parameters peak

13

what occurs during the convalescence period of infectious disease?

- no signs or symptoms
- tissues repaired as recovering from damage caused by infectious organism

14

what does the time period of convalescence depend on?

- amount of damage
- nature of pathogen
- infection site (CNS = lifelong effects)
- patient health and immune competence

15

what are nosocomial infections?

infections that occur in health care facilities

16

what are the types of nosocomial infection?

- exogenous
- endogenous
- iatrogenic

17

what are exogenous nosocomial infections caused by?

infection from someone else

18

what are endogenous nosocomial infections caused by?

infection from opportunistic pathogens on own body due to catheters (tubes inserted into body)

19

what are iatrogenic nosocomial infections caused by?

infection from someone else due to not using sterile instruments or washing hands

20

what are the 3 ways in which infectious diseases can be classified?

- body system
- taxonomic group
- longevity and severity

21

what are the categories within the infectious disease classification of longevity and severity?

- acute
will start and end within days
will either die or get better
- chronic
go on for months or years
- subacute
largely secondary infections
- latent

22

what are some examples of all the categories within the infectious disease classification of longevity and severity?

- acute
common cold
- chronic
TB
- subacute
subacute endocarditis
- latent
chicken pox -> shingles, herpes

23

what does it mean if a disease is epidemic?

occurs in a large number of people in a population at the same time

24

what does it mean if a disease is pandemic?

disease is widespread, usually worldwide

25

what does is mean if a disease is endemic?

the disease is constantly present in a population, usually at low incidences

26

what does it mean if a disease is sporadic?

disease only occurs in a few scattered cases

27

outline the experimental approach to epidemiology studies (4)

- reporting of clinical cases attending hospitals or medical practices
- diagnostic follow up to confirm disease incidence/prevalence
- monitor disease incidence following therapy/vaccination
- monitor case histories/patient records