immuno-diagnostics prac

Question 1

TB testing pass or fail: Animals showing a negative bovine reaction and a positive or negative avian reaction.
i.e. no swelling at B + either no swelling or swelling at A

Answer 1

non reactor (pass)

Question 2

TB testing pass or fail: Animals showing a positive bovine reaction equal to or less than a positive avian reaction.
i.e. swelling at both but swelling at B but this is equal to or less than the swelling at A

Answer 2

non reactor (pass)

Question 3

TB testing pass/fail: Animals showing a positive bovine reaction not more than 4mm greater (or 2mm using a severe interpretation) than a positive avian reaction.
i.e. swelling at both but swelling at B is 1-4mm larger than swelling at A

Answer 3

inconclusive (retest)

Question 4

tb testing pass/fail: Animals showing a positive bovine reaction and a negative avian reaction where the difference is 4mm or less (between 1-2mm difference using a severe interpretation).
i.e. no swelling at A + 1-4mm swelling at B which is 1-4mm

Answer 4

inconclusive (retest)

Question 5

TB testing pass/fail: Animals showing a positive bovine reaction more than 4mm greater (or 2mm using a severe interpretation) than a negative or positive avian reaction.
i.e. swelling at both but swelling at B is more than 4mm larger than at A

Answer 5

reactor (fail)

Question 6

when do you read TB test

Answer 6

72 hours +/- 4 hours after injection of tuberculin

Question 7

how do you perform a nasopharyngeal swab in the horse

Answer 7

• Put gloves on
• Open the swab in an aseptic manner
• Measure the distance between the nasal opening and the medial canthus of the eye, using the swab.
• Pass the swab, in accordance with your measurements, via the ventral meatus
• Be sure to avoid the dorsal meatus and nasal diverticulum
• Rotate the swab once in place, for at least 10 seconds (ideally 30-60 seconds)
• Correctly insert the swab back into the container/transport medium and ensure it is secure
• Label the swab container with patient name, date, swab site and own initials

Question 8

how do you perform an oropharyngeal swab in the horse

Answer 8

• Put gloves on
• Aseptically open your swab in preparation
• Place your thumb and middle finger on one hand on the zygomatic arches, to gently tilt the head back
• Hold the swab with the other hand, between your forefinger and middle finger, and gently open the mouth by putting your little finger on the incisors of the lower jaw
• Insert the swab and gently roll/rotate it across the pharyngeal area, for around 5-10 seconds
• Correctly insert the swab back into the container/transport medium and ensure it is secure
• Label the swab container with patient name, date, swab site and own initials