Healthy Pop- Problem Investigation/Surveillance

Block 2

What is the purpose of a problem investigation?

to conduct a targeted assessment of a group of animals to investigate and address a specific problem

When are problem investigations initiated?

1. A increase in disease frequency

2. Production issues

3. Husbandry or population management issues

What are the steps for problem investigation?

1. Gather information

2. Verify a problem exists

3. Establish a case definition

4. Plan an investigation

5. Formulate hypotheses

6. Test the hypothesis

7. Design an intervention

What would be an immediate cause in a calf diarrhea outbreak?

Detection of an organism like Cryptosporidia

What would be an upstream cause of calf diarrhea? 

Protocol drift- leads to an increase in production of calves with Failure of Passive Transfer of Immunity, if protocol drift is addressed it improves host resistance 

How would you improve host resistance?

Colostrum protocols, nutrition, and treatment protocols

How would you decrease the infectious challenge?

Sanitation, bedding, amd housing management

What are the questions to ask for initial information gathering?

Who, What, When, Where

How many

Why is evidence gathered?

to verify a problem exists by comparing the “How Many” data against the farm’s accepted standards

How is evidence gathered?

by performing a physical exam

How is a case definition established?

based on the clinical signs and characteristics 

How are herd level diagnostics decided?

sampling is planned based on the case definition and intended use of the results

What are on-farm associations?

evidence is gathered to demonstrate the link between a suspected upstream cause and the disease outcome

What is surveillance?

defined as the systematic collection, analysis, and interpretation of data

What is the objective of surveillance?

intervention in defined populations

What is monitoring?

essentially surveillance without an intervention threshold

What is screening?

involves testing apparently healthy individuals

What is critical goal of surveillance?

control and/or prevent diseases

What is early detection?

objective is to identify disease rapidly before significant spread to facilitate disease control

What are case findings?

identification of infected animals, flocks, or herds during a control program

What is measuring disease?

detect changes in the level of disease in the population

What is the objective of demonstrate freedom?

provide proof that a disease is not present in a population

this is crucial for international trade and for ending existing control measures

What are human health agencies that conduct surveillance?

State/regional public health

Centers for Disease Control and Prevention (CDC)

Food and Drug Administration (FDA)

What are animal health agencies that conduct surviellance?

State Department of Agriculture 

USDA Animal and Plant Health Inspection Service (APHIS)

NAHLN

How is passive surveillance data collected?

utilizes samples collected primarily for another purpose

How is active surveillance collected?

utilizes samples collected specifically for use by surveillance program, involves an ongoing search for cases

How efficient and costly is passive surveillance?

high efficiency, simple and requires relatively few resources

How efficient and costly is active surveillance?

much more expensive to maintain, but may have high levels of completeness

How complete is passive surveillance?

possibility of incomplete data due to underreporting

Who uses passive surveillance?

majority of government systems

Who uses active surveillance?

needed for rare or hard-to-detect diseases

What is an example of passive surveillance?

Antibiograms

What is an example of active surveillance?

Monthly environmental sampling 

What do antibiograms provide? 

information about local antimicrobial resistance

What did the unexpected finding of west nile virus in the US lead to?

major mosquito control program implemented

How did testing for Bovine Tuberculosis shift in the US?

Slaughter Surveillance became the primary method for identifying infected herds

What did the surveillance system that eradicated brucellosis rely on?

Dairy Cattle Surveillance, which used the milk ring test to screen pooled milk samples 2-3 times per year

How do veterinary hospitals conduct surveillance for Hospital Acquired Infections (HAI)?

active environmental surveillance