Specificity of an immunochromatographic test for anthrax.
OBJECTIVE
To evaluate the specificity of an immunochromatographic test (ICT) for anthrax in cattle.


METHODS
A comparison of an ICT with blood smear and culture in uninfected cattle.


METHODS
Two hundred and forty blood samples were collected from dead cattle at two knackeries within Victoria and tested on-site with an ICT for the detection of protective antigen (PA) of Bacillus anthracis. Blood smears were prepared on-site and blood samples transported to the laboratory for aerobic and anaerobic culture. The results of the ICT were compared with blood smear and culture. Animals were regarded as not infected with B anthracis if the organism was not detected in a stained blood smear or on culture. Ten healthy yearling cattle were vaccinated with live spore anthrax vaccine and blood samples collected on days 0 to 7 and day 15 were tested in the ICT for the presence of PA.


RESULTS
All blood samples from the 240 knackery cattle were ICT, smear and culture negative. All blood samples from the 10 vaccinated cattle were ICT negative.


CONCLUSIONS
The ICT is a test with high specificity in cattle (98.5 to 100%; 95% CI) and recent vaccination of cattle does not give rise to positive reactions.
Muller
J D
JD
Victorian Institute of Animal Science, Department of Primary Industries, 475 Mickleham Road, Attwood, Victoria 3049.
Wilks
C R
CR
O'Riley
K J
KJ
Condron
R J
RJ
Bull
R
R
Mateczun
A
A
D000818:Animals; D000881:Anthrax / Q000175:diagnosis / Q000662:veterinary*; D000907:Antibodies, Bacterial / Q000276:immunology*; D000942:Antigens, Bacterial / Q000097:blood*; D001408:Bacillus anthracis / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis*; D002845:Chromatography / Q000379:methods / Q000662:veterinary; D011237:Predictive Value of Tests; D011933:Reagent Kits, Diagnostic / Q000662:veterinary; D012680:Sensitivity and Specificity
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D011933:Reagent Kits, Diagnostic