Aspects of human brucellosis.

Human brucellosis still presents difficulties in diagnosis and prevention. Townspeople may be infected by drinking raw milk while on holiday. Laboratory tests are still unsatisfactory as indicators of clinically active disease. High titre antibodies may be found without overt symptoms, particularly in persons occupationally exposed to repeated infection. In contrast, cases have been recorded in which no antibody appeared despite a positive blood culture. A preliminary study of leukocyte migration inhibition suggests that this may prove useful in detecting disease associated with low or absent antibodies, but is not likely to provide an infallible guide to clinical activity.