Immune Response After Leptospirosis Infection

NCT02898519 — Unknown, 175 participants, Centre Hospitalier Universitaire de la Réunion

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

Registry	NCT02898519, acronym SERO7LEPTO
Status	Unknown
Study type	Observational
Enrollment	175 (Estimated)
Sponsor	Centre Hospitalier Universitaire de la Réunion (Other); collaborators: Institut Pasteur
Conditions	Leptospirosis
Interventions	cohort (Other)
Dates	start 2016-10-01, primary completion 2017-12-01 (estimated), completion 2018-09-01 (estimated), first posted 2016-09-13, last updated 2016-09-13

-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.

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+Detailed description

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.

+Arms and interventions

cohort (Other): Blood sampling

+Outcome measures

Primary outcomes

Leptospirosis immunization assessed by serum immunoglobulin [1-7 years after leptospirosis infection]: Humoral immune response will be measured in serum cured-subjects using micro-agglutination test

Secondary outcomes

rate of still-immunized patients [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 [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

+Eligibility

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Subjects diagnosed for leptospirosis by polymerase chain reaction measured in Reunion Island Hospital between 209-2015
* with social security issue

Exclusion Criteria:

* Leptospirosis diagnosis not confirmed by polymerase chain reaction
* subject exhibiting immunodepressive status (cancers, transplantation, immune deficit, blood disorders)
* under medication: corticoids, immunosuppressor, chemiotherapy

+Investigators

NICOLAS TRAVERSIER, MD, Principal investigator, CHU DE LA REUNION