Indirect hemolysis test in the serodiagnosis of bovine brucellosis.

An indirect hemolysis (IHL) test was compared with 4 other serologic procedures in sensitivity and specificity, using bacteriologic findings from cattle in Brucella-infected herds. The test was more sensitive than the complement-fixation and tube agglutination tests, was similar to the Rivanol test, and was slightly inferior to the card test. It was more specific than the Rivanol, card, and tube agglutination tests, but had less specificity than the complement-fixation test. Results of all procedures were affected in varying degrees by the method of vaccination and time period of sample collections after vaccination. Twenty vaccinated Brucella-free adult cattle were also studied, using the IHL and other tests. Only a few cattle that were previously vaccinated had reactions to the IHL test.