Counterimmunoelectrophoresis in the diagnosis of human leptospirosis.

Counterimmunoelectrophoresis (CIE) was applied on sera from patients with leptospirosis caused by leptospires from different serogroups and on sera from a control group. The CIE using an antigen prepared from a single leptospira strain agreed with the microscopic agglutination test using a battery of different antigens in 91% of the leptospirosis sera. CIE was sensitive and specific, comparatively easy to perform, used little amounts of serum and antigen, gave rapid results and allowed the examination of large numbers of specimens at a time.