Evaluation of counterimmunoeletrophoresis with the serovars icterohaemorrhagiae and patoc antigens in the diagnosis of human leptospirosis

Abstract

Counterimmunoelectrophoresis (CIE) was applied on paired sera from 135 pacients with leptospirosis and on 69 sera from a control group. The sera from pacients were subdivided in 4 groups according to the results obtained by the Microscopic Agglutination Test (MAT). The first samples sera from 58 pacientes were non reagent by MAT. Six monthly samples of sera were taken from 7 patients to follow-up and to determine the level of agglutinin and precipitin antibodies present using MAT and CIE. Serovars icterohaemorrhagie and patoc were used as antigens. Three types of antigens were compared, 1) Triton-X-100 extracted; 2) heat extacted and 3) a pool of them. The CIE using icterohaemorrhagiae derivated antigens types agreed with MAT in 92.64, 92.64 and 94.11% of the leptospirosis sera. The patoc antigens types reacted with the control group in 7.24, 86.95 and 84.05% of the samples, and consequently were eliminated from the present study. The icterohaemorrhagiae CIE reaction become positive earlier than MAT negative sera, and reverted to negative earlier in the follow-up samples from the pacients. The CIE was sensitive and specific, gave rapid results and was easy to perform.