Enzyme immunoassay for surveillance of Q fever.
An enzyme-linked immunosorbent assay (ELISA) was developed to monitor antibodies against Coxiella burnetii among animal populations used in research and teaching facilities. Various antigenic components of C burnetii prepared from phase I and phase II whole cells and commercially available antigens were evaluated. A trichloroacetic acid extract was selected for routine use. There was a linear relationship between the transformed absorbance readings of the ELISA results and microagglutination (MA) titers. Comparison between positive or negative results of the MA test and ELISA gave 98.6% concordance. Using the MA test as the standard, ELISA results were 97.8% sensitive and 100% specific. The efficacy of ELISA was evaluated by testing ruminants with known histories of C burnetii infection. Antibody prevalence was 0 in 117 sheep with no history of C burnetii infection, 22% in 145 naturally infected sheep used for research, and 53% in 115 sheep used for vaccine field trials. Forty-eight percent of 120 dairy cows and 52% of 79 goats from endemically infected herds were seropositive. These results indicate that ELISA should be the test of choice for mass screening and surveillance of animals when Q fever is a suspected biohazard.
D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis*; D002417:Cattle / Q000276:immunology; D003201:Computers; D003381:Coxiella / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006041:Goats / Q000276:immunology; D011778:Q Fever / Q000276:immunology*; D012756:Sheep / Q000276:immunology
D000907:Antibodies, Bacterial