Serology & Heartworm QUIZ & LAB

Question 1

Answer 1

A+

Question 2

a. Test is more specific, than sensitive
b. Test is more sensitive than specific
c. Test is equally sensitive and specific
d. It can’t be determined from this data

Answer 2

a. Test is more specific, than sensitive

Sensitivity - 520/ 520 + 83 = 86.2%
Specificity = 600 / 600+ 30 = 95%

Question 3

a. 1:1,000
b. 1:10
c. 1:10,000
d. It can’t be determined with this information

Answer 3

a. 1:1,000

Question 4

Measuring levels of antibodies against Disease X in the serum of a patient is
1. Indirect serology
2. Direct serology

Answer 4

1. Indirect serology

Question 5

Wash steps are very important in antigen-antibody complex testing to prevent…
1. False positives
2. False negatives

Answer 5

1. False positives

Question 6

When evaluating an animal for active infection of a specific disease, the minimum serology requirements are…
1. The convalescent titer is 4x higher than the acute titer
2. The convalescent titer is 2x higher than the acute titer
3. The acute titer is 4x higher than the convalescent titer
4. The acute titer is 2x higher than the convalescent titer

Answer 6

1. The convalescent titer is 4x higher than the acute titer

Question 7

1. undetermined, the test failed its controls
2. patient is positive for both FeLV and FIV
3. patient is positive for FeLV
4. patient is positive for FIV

Answer 7

4. patient is positive for FIV

Question 8

a. 1:160
b. 1:320
c. 160
d. it can not be determined from this diagram

Answer 8

a. 1:160

Question 9

What test is the test of choice for diagnosing Heartworm Disease in cats?

Answer 9

Antibody test
(like an ELISA test)

Question 10

If you are asked to dilute a cleaning solution 1:10 and the final volume will be 1 liter, how much concentrate (C) and how much water (W) will you mix together?
a. 900 ml C and 100 ml W
b. 100 ml C and 1000 ml W
c. it can’t be determined from this information
d. 100ml C and 900 ml W

Answer 10

d. 100ml C and 900 ml W

Question 11

An example of a false negative is:
1. a diseased animal incorrectly identified as healthy
2. a healthy animal is correctly identified as healthy
3. a diseased animal correctly diagnosed as diseased
4. a healthy animal incorrectly identified as diseased

Answer 11

1. a diseased animal incorrectly identified as healthy

Question 12

An example of a microfilarial test for Heartworm diagnosis is:
1. Modified Knott’s Test
2. Filter Technique
3. Direct Smear
4. all choices are correct

Answer 12

4. all choices are correct

Question 13

List two limitations of antigen testing (dog or cat) for diagnosis of Heartworm. (i.e. when the test won’t be accurate)

Answer 13

1. Low female heartworm (or none) count in the blood
2. If the patient is on heartworm preventatives it may interfere with results

Question 14

Describe what is happening during an ELISA test. (e.g. describe the technology of how it works, not how the tech adds drops to a cartridge)

Answer 14

• Enzymes bound to the antibodies imbedded in the test cause a color reaction.
• Sample is absorbed into the matrix where it is introduced to the capture reagents for the first time. Once the test is snapped, amplifying and wash solution are released. This helps improve the specificity of the test by clearing debris. The sample hits the absorbent block which makes the flow go back the other direction, so the sample will pass through the reagents for a second time.

Question 15

What is the advantage of Modified Knott’s test compared to Direct Heartworm test? (2)

Answer 15

• Concentration
• Higher chance of diagnosing

Question 16

List three drawbacks to Modified Knott’s Testing compared to any other testing method

Answer 16

1. Low sensitivity on cats
2. Time consuming
3. Multiple steps & lots of supplies compared to other tests (may increase cost!)

Question 17

What does ELISA heartworm test actually detect?

Answer 17

Detects antigens of the Female heartworm

Question 18

Is a positive heartworm dog contagious to others?

Answer 18

Not directly.

• They would be a source to a mosquito which can transmit the disease.

Question 19

IDEXX SNAP test utilizes which Direct Serology Methodology?
a. Latex Agglutination
b. Enzyme-linked Immunoassay
c. Direct Immunofluoresence
d. Polymerase Chain Reaction

Answer 19

b. Enzyme-linked Immunoassay

Question 20

An example of a false negative is:
a. a healthy animal correctly identified as healthy
b. a diseased animal correctly diagnosed as diseased
c. a diseased animal incorrectly identified as healthy
d. a healthy animal incorrectly identified as diseased

Answer 20

c. a diseased animal incorrectly identified as healthy

Question 21

Specificity is equal to
a. true positive/ (true positive + false negative)
b. true negative/ (true negative +false positive)
c. true negative/(true negative +true positive)
d. true positive/(true positive + false positive)

Answer 21

b. true negative/ (true negative +false positive)

Question 22

If a test has a sensitivity of 100%,
1. it should not be used as a screening test because it may have some false positives.
2. it means that the test identifies every animal with the disease, but it may mistakenly flag some healthy
animals as having the disease.
3. it means that the test identifies every animal with the disease, and it never flags any healthy animals as
having the disease.
4. it sometimes yields false negatives

Answer 22

2. it means that the test identifies every animal with the disease, but it may mistakenly flag some healthy animals as having the disease.

Question 23

___ canine blood can be given to any dog that has ___ received a transfusion.
___ canine blood can only be given to a patient with a matching type. If it is not, life-threatening ___ can occur within ___minutes.

Answer 23

1. A-
2. Never
3. A+
4. Anaphylaxis
5. 45min

Question 24

Feline blood typing has no ____ donors. ___ cats are extremely rare but can receive either ___ or ___ blood.

Answer 24

1. Universal
2. AB
3. A or B