Jam. Muskens et al., SEROLOGICAL RESPONSE OF CATTLE TO BRUCELLA ALLERGEN AFTER REPEATED INTRADERMAL APPLICATIONS OF THIS ALLERGEN, Veterinary microbiology, 48(1-2), 1996, pp. 174-178
A study was conducted to determine whether an allergen that has been p
repared from a mucoid strain of Brucella abortus triggers a serum anti
body response that interferes with the interpretation of serologic tes
ts results. Fifteen cattle seronegative for Brucella antigen were test
ed with the SDTH test several times, Blood samples were collected week
ly and tested with the serum agglutination test and complement fixatio
n test. Results show that some cattle tested seronegative after each o
f the SDTH tests while other cattle tested weakly positive with the se
rum agglutination test or the complement fixation test. All seropositi
ve cattle tested seronegative 4-7 weeks after the last SDTH test indic
ating an antibody response of a transient nature. We conclude that ser
ologic tests results indicating infection are reliable when recorded f
our weeks after a single SDTH test. If cattle are tested with the SDTH
test several times an interval of seven weeks should be observed afte
r the last test to ensure a reliable interpretation of the serologic t
ests results.