[Serologic diagnosis of human leptospirosis with 3 variants of the passive hemagglutination technique].

A serological study was conducted to evaluate 3 variants of the positive hemagglutination technique (HA) with the use of formalized erythrocytes of fresh lamb (HC) and of formalized Type O, Rh-negative human red blood cells (HH). No significant statistical difference were found between the results of HA and HC and between HC and HH. Unspecific reaction was only observed in 2 of the 200 sera studied by HH and HC. Heterophil antibodies were just observed in 2.5% of the sera studied by HH, and in 100% of the sera studied by HC. The qualitative parameters were determined for the variants used, and this way the repetition and reproducibility of the most useful variant was evaluated.