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Use of a Gamma-IFN Assay in Contact Tracing for Tuberculosis in a Low-Incidence, High Immigration Area

This study has been completed.
Ligue Pulmonaire Genevoise
Information provided by:
University Hospital, Geneva Identifier:
First received: November 13, 2007
Last updated: NA
Last verified: November 2007
History: No changes posted
After exposure to an active case of tuberculosis (TB), close contacts may be infected. They are then considered as having latent tuberculosis infection (LTBI). Detecting LTBI is the main goal of contact tracing procedures after exposure to TB. Until recently, the only test available for detecting LTBI was the tuberculin skin test (TST). More recent tests are now available (Interferon-gamma release assays: IGRA), which are more specific and sensitive than the TST. This study compares the TST and an IGRA in the routine activity of contact tracing in our area.

Tuberculosis Latent Tuberculosis Infection

Study Type: Observational
Study Design: Observational Model: Case-Only
Time Perspective: Prospective
Official Title: Production of Gamma-Interferon by Circulating Lymphocytes Exposed to Antigens Specific of Mycobacterium Tuberculosis: Contribution to the Identification of Latent Tuberculosis Infection in Contact Tracing

Resource links provided by NLM:

Further study details as provided by University Hospital, Geneva:

Primary Outcome Measures:
  • Correlation between results of TST and IGRA tests and exposure scores [ Time Frame: 2 months after exposure ]

Enrollment: 295
Study Start Date: October 2004
Study Completion Date: January 2006
Detailed Description:

Setting: A TB clinic in Geneva, Switzerland, a low incidence area for TB with a high immigrant population.

Aim of study: to compare results of an IGRA test (T-SPOT.TB, Oxford Immunotec, UK) and the TST, and their correlation with exposure scores in subjects exposed to cases of contagious TB.

Methods: Prospective study of all contacts screened in our area, and accepting to be included. Simultaneous recording of age, gender, origin, history of recent travels or exposure, BCG vaccination status, infectiousness of index case, 5 different exposure scores, TST, and result of the T-SPOT.TB blood test. Univariate and multivariate analysis.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
All subjects screened after exposure to a case of active and contagious tuberculosis in the Geneva area

Inclusion Criteria:

  • Exposure to a case of contagious TB
  • Willingness to participate in study

Exclusion Criteria:

  • Known HIV infection
  • Known previous TB or treatment for LTBI
  Contacts and Locations
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Please refer to this study by its identifier: NCT00557765

Centre antituberculeux; Geneva University Hospital
Geneva, Switzerland, 1211
Sponsors and Collaborators
University Hospital, Geneva
Ligue Pulmonaire Genevoise
Principal Investigator: Jean-Paul Janssens, M.D. Centre antituberculeux
  More Information Identifier: NCT00557765     History of Changes
Other Study ID Numbers: 04-184
Study First Received: November 13, 2007
Last Updated: November 13, 2007

Keywords provided by University Hospital, Geneva:
Latent tuberculosis infection
Interferon gamma release assay
Contact tracing

Additional relevant MeSH terms:
Latent Tuberculosis
Mycobacterium Infections
Actinomycetales Infections
Gram-Positive Bacterial Infections
Bacterial Infections
Antineoplastic Agents
Antiviral Agents
Anti-Infective Agents processed this record on July 21, 2017