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Flashcards in Surveillance Deck (41)
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1

Define monitoring

Continous efforts to collect data to detect changes or trends in the occourence of disease in order to inform decisisons

2

Define passive surveillance

Surveillance = monitoring with the view to intervene if prevalence rises above a certain theshold

3

Define incident

The first isolation and all subsequent isolations of the same serovar from an animal OR epidemiologiclaly distinct group of animals on a single premises wihtin a 30d period

4

How has salmonella incidence in humans and livestock changed over recent years?

parallell

5

Give an example of surveillance whre the threshold is 0

FMD

6

What is the target level of clinical mastitis?

30 cases/100 cows/year

7

How may surveillance be used?

- monitoring diseases deemed to be of importance
- checking for effectiveness of control measures
- if eradication is achieved, demonstrating freedom from infection

8

Give an example of a disease where the aim of surveillance is to prove freedom of disease

Brucellosis

9

What was the first animal disease to be officiallly declared eradicated

rinderpest

10

What do farm level surveillance systems focus on?

- diseases controllable by the farmer
- focus on productivity
- rely on farm records

11

Give egs. of monitoring/surveillance objectives at a natinoal level

- demonstrate freedom from disease (eg. brucellosis)
- outbreak detection
- diseas control/eradication
- monitor zoonoses (eg. salmonella)
- pregress of hazard reduction programmes
- detect emerging disease

12

Give egs. of monitoring/surveillance objectives at an industrial level

- freedom from disease
- outbreaks
- define herd health status
- monitor production diseases
- monitor zoonoses and food bourne pathogens
- document acceptable risk levels

13

Give egs. of monitoring/surveillance objectives at a prodcer levle

- monitor production diseases
- outbreak detection
- assure freedom from food safetly hazard
- define herd/product status
- documnet aceptable risk levels

14

Give egs. of monitoring/surveillance objectives at a wildlife levle

establish disease status

15

How may cases be defined?

- clinical criteria: suspect cases that become confirmed following lab work (lab criteria added)
- epidemiological criteria eg. FMD control: farms defined as potental cases on the bases of location with repect to infected farms or dangerous contact with infected farms

16

What are the varying levels of disease prevalence?

- case
- outbreak
- epidemic
- pandemic

17

How are incidence and prevalence different?

- incidence = rate (no. new cases/ population at risk*time at risk)
- prevalence = proportion (no. existing cases/population at risk)

18

Define internal and external validity

- internal : measuring what is happening on farm, valid for that farm
- external validity: extrapolating to general population

19

What is the difference between active and passice monitoring or surveillance? Which is more susceptable to bias?

- passive: waiting, reliant on case reporting, awareness and motivation to report [most biased]
- active: searching, surveys, testing

20

How does systematic error differ from random error?

- systematic error: error due to the design, implementation or analysis of the surveillance programme
- random error: due to samping variation due to a random sampe of the popuation being studeied to make inferences about the whole popuation

21

Give 3 types of bias

- case detection: case ascertainment
- selection bias: in surveys if participation is voluntary, if not all famrs listed in sampking frame
- information bias: case definition, diagnositc tests

22

How may underrerporting skew surveillance statistics?

The "clinical iceberg" means deaths, severe disease and moderate disease [likely to be admitted to hosptial] but mild disease and sub-clinical infection not often reported so no cases actually ^ than recorded.

23

What is important regarding defining cases for epidemiology?

deifnition must be specific so that all cases are recorded correctly

24

What is important following detection of a case?

Dissemination of information quickly and efficiently to those who require it

25

How may lab tests introduce bias to results?

Differing sensitivity and specificity of lab tests

26

How may sampling introduce bias?

Picking a non random group of subjects

27

What are the 2 types of farm level monitoring and surveillance?

- statutory eg. TB, Brucella
- coluntary industry led eg. JD, BVD

28

Define a notifiable disease

statutory requirement to report suspicion of a clinical case of disease

29

Define a reportable disease

statutory requirement to report a lab confirmed isolation of organisms (ie. Salmonella nad Brucella) Under Zoonoses order 1989. Report made by lab that isolated the organism from animal dervied sample.

30

Who should notifiable disease be reported to?

- local animal health DVM
- now APHVLA