I. Q Fever in Milwaukee Area Cattle

A series of evaluations on 781 herds of cattle in the Milwaukee milk shed showed that the incidence of Q fever in these herds increased from 32% in 1957 to 61% in 1959 and 73% in 1962. Comparative studies showed that 226 herds in 1959 and 161 herds in 1962 represented new infections; also, that 120 herds positive in 1957 or 1959 were negative in 1962. A study of individual cows in 20 herds confirmed the results of the pooled herd studies. In a random sample of 50 capillary agglutination test (CAT)-positive herds, 84% were found to be shedding Coxiella burnetii in their milk. These results clearly demonstrate that Q fever has spread progressively throughout the herds in the Milwaukee milk shed and has become endemic to the cattle of our area.