SEROEPIDEMIOLOGIC SURVEY OF BORRELIA-BURGDORFERI EXPOSURE OF DAIRY-CATTLE IN WISCONSIN

An ELISA, using purified flagellin of Borrelia burgdorferi as the soli d-phase antigen, was used to measure antibody concentrations to B burg dorferi in dairy cattle in Wisconsin, Serum obtained from 5,060 cows i n 160 randomly selected herds in the state were tested. Serum from an additional 2,600 cattle in Barron County, Wis, a county with a high an nual incidence of B burgdorferi infections in human beings, was also t ested. Only 7% of the cows that were tested, but 66% of the herds that were tested, were seropositive for B burgdorferi. Sixteen percent of the herds had a prevalence of greater than or equal to 15% seropositiv e cows, whereas 50% of the herds had a prevalence of 1 to 14% seroposi tive cows. Seropositive herds were concentrated in the west-central pa rt of Wisconsin. An association existed between the geographic locatio n of seropositive herds and counties in which B burgdorferi infection of human beings was acquired (P < 0.05) as well as the geographic loca tion of seropositive herds and the geographic distribution of Ixodes s capularis (P < 0.05). Barren County, in which B burgdorferi infection is endemic, had a significantly (P < 0.05) higher percentage of seropo sitive cows (17%) than did the state of Wisconsin (7%).