2023.Iss1.Rum diagnostics & interpretations

Question 1

Serology in bovine infectious disease diagnosis

Which antibody class is highest in bovine serum?

Answer 1

IgG (IgG1>IgG2)

Question 2

Serology in bovine infectious disease diagnosis

What is serology used for?

Answer 2

used to measure the amount of antigen-specific antibody in serum, to determine whether cattle have been infected with or vaccinated against a specific agent

Question 3

Serology in bovine infectious disease diagnosis

What is seroconversion?

Answer 3

2-fold or greater increase in antibody titer between a sample collected during infection (acute), and a second sample collected 2-4 weeks later (convalescent), indicating recent infection or vaccination

Question 4

Serology in bovine infectious disease diagnosis

Can seroconversion be measured in calves?

Answer 4

Calves with circulating maternal antibodies may not seroconvert when they are vaccinated or infected
**thus a lack of seroconversion does not indicate that a calf has not been infected or immunized

Question 5

Interpretation and Analysis of individual diagnostic tests & performance

What type of test helps rule out disease when a negative test result is obtained?

Answer 5

Sensitive test
SNout

Question 6

Interpretation and Analysis of individual diagnostic tests & performance

What type of test helps rule in disease when a positive test result is obtained?

Answer 6

Specific test
SPin

Question 7

Interpretation and Analysis of individual diagnostic tests & performance

Continuous vs categorical diagnostic tests: type of test, source of errors, reliability indicators

Answer 7

Question 8

Diagnostic strategies for ruminant populations

How does test diagnostic sensitivity influenced by sample size?

Answer 8

as sensitivity decreases, the required sample size increases

Question 9

Current and emerging diagnostic approaches to bacterial diseases of ruminants

What is the gold standard diagnostic for johne’s disease?

Answer 9

fecal culture