Clinical Trial: Immune Response After Leptospirosis Infection

Study Status: Not yet recruiting
Recruit Status: Not yet recruiting
Study Type: Observational

Official Title: Serological Response in Patients Infected by Leptospirosis 1 to 7 Years Earlier

Brief Summary:

Leptospirosis is a zoonotic infection induced by pathogen bacteria (genus: Leptospira) growing in water polluted by animal fluids. Due to its 10 fold occurence in French overseas aera, and especially in Reunion Island, as compared to metropoly, it is considered as a major public health issue.

An important inter-individual variability in humoral immune response suggests that vaccination should be recommended in exposed subjects.

This cohort study aimed to determine if subjects that have been infected by leptospirosis for 1 to 7 years still remain immunized, and then do not need vaccination.


Detailed Summary:

Every year more than 500 000 severe forms of leptospirosis are diagnosed in Reunion Island. The risk of mucocutaneous contact with contaminated media remains important due to highly aqueous environment.

Cured subjects that have been infected for 1, 2, 3, 4, 5, 6 or 7 years will be enrolled. The qualitative and quantitative humoral immune response to leptospirosis infection will also be evaluated to determine whether they still get protective immunization. Leptospirosis immunization will be evaluated using micro-agglutination test.

Graded immune responses related to the severity and the length of the infection will also be investigated.

Finally, 3 methods used for leptospirosis diagnosis will be compared. It is expected from this study to evaluate the appropriate conditions in which new vaccination could be required to prevent further leptospirosis infection in cured subjects.


Sponsor: Centre Hospitalier Universitaire de la Réunion

Current Primary Outcome: Leptospirosis immunization assessed by serum immunoglobulin [ Time Frame: 1-7 years after leptospirosis infection ]

Humoral immune response will be measured in serum cured-subjects using micro-agglutination test


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • rate of still-immunized patients [ Time Frame: 1-7 years after leptospirosis infection ]
    Seropositive subjects will be measured using the ELISA serion method and the ELISA recombinant protein method
  • comparison of 3 diagnosis method for leptospirosis [ Time Frame: 1-7 years after leptospirosis infection ]
    Matched results of the 3 methods: micro-agglutination test, ELISA serion method and ELISA recombinant protein method will be compared


Original Secondary Outcome: Same as current

Information By: Centre Hospitalier Universitaire de la Réunion

Dates:
Date Received: September 8, 2016
Date Started: October 2016
Date Completion: September 2018
Last Updated: September 8, 2016
Last Verified: September 2016