[Serologic diagnosis of human leptospirosis with 3 variants of the passive hemagglutination technique]. / Diagnóstico serológico de la leptospirosis humana mediante 3 variantes de la técnica de hemaglutinación pasiva.

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.

[The reactogenicity and immunogenicity of the first Cuban vaccine against human leptospirosis]. / Reactogenicidad e inmunogenicidad de la primera vacuna cubana contra la leptospirosis humana.

A controlled double-blind trial was conducted with the participation of 80 adult volunteers of both sexes, who were randomly divided into groups of 40 individuals each one. The case-base study received the vaccine and the control group was administered placebo to know the safety, the behaviour of reactogenicity, and to star the immunogenicity studies of the first Cuban vaccine against human leptospirosis. The vaccine used in the case-base study was an inactivated and trivalent vaccine containing strains of Leptospira canicola, icterohaemorrhagiae and pomona, since they have the highest circulation in the country. The results obtained showed the inocuity of the vaccine as no adverse severe reactions were detected. The general symptomatology observed was low, where as febricula was the most common general symptom. It appeared during the first 3 days of observation and there were no significant differences between the 2 group. Only a mild pain at the site of the injection was reported as a local symptom, which was more frequent in the vaccinated group than in the control group (7.8 against 1.5%, respectively). The seroconversion obtained was of 29% by microagglutination, and of 34.2% by ELISA. The final results allowed to conclude that this vaccine is safe for human adults at the ages under study, and give the possibility to continue other studies in more advanced stages to complete the requirements for obtaining its license.

[Evaluation of the counterimmunoelectrophoresis technique for the serologic diagnosis of leptospirosis]. / Evaluación de la técnica de contrainmunoelectroforesis para el diagnóstico serológico de la leptospirosis.

The counterimmunoelectrophoresis (CIE) technic was assessed for leptospirosis serological diagnosis by using an antigenic preparation from Leptospira biflexa Patoc I strain. It was showed that the CIE technic had 82% sensitivity and 100% specificity. The antigen used showed a gender-specific reactivity on detecting antibodies in patients infected by different leptospirosis serogroups by microagglutination test. Antigen stability for CIE technic was 6 months without loss of titre.

[Comparative study of serologic techniques for the diagnosis of human leptospirosis]. / Estudio comparativo de técnicas serológicas para el diagnóstico de la leptospirosis humana.

A comparative study was carried out in order to assess 3 serological techniques employed at the Provincial Centers of Hygiene and Epidemiology for diagnosing leptospirosis. The study included 49 sera from patients with leptospirosis confirmed by the techniques of passive hemoagglutination (HA), plate macroscopic agglutination with thermoresistant antigen (TR) and indirect immunofluorescence (IIF). Sensitivity was 90% for HA, 96% for TR and 84% for IIF. IIF was performed with the use of 5 different antigens and the highest serological reactivity was obtained with the strain belonging to Canicola serogroup.

[Serotyping of strains of non-tuberculous mycobacteria]. / Serotipaje de cepas de micobacterias no tuberculosas.

Forty strains of mycobacteria, belonging to Mycobacterium-avium-intracellulare-scrofulaceum complex, isolated from symptomatic respiratory patients, were studied. For such study, agglutination-adsorption technique was applied, using specific antisera elaborated at the "Pedro Kouri" Institute of Tropical Medicine, National Reference Institute, with titers ranging close to 1:320. The results obtained demonstrated that the prevailing types were those of the species Mycobacterium intracellulare (31 strains), prevailing serotypes 9 (Darden), 8 (Davis), 12 (Haweel) and serotype 26 followed by the species M. avium (3 strains) and M. scrofulaceum (2 strains).