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

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.

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Key information

Conditions

Tuberculosis Actinomycetales Infections Bacterial Infections Bacterial Infections and Mycoses Gram-Positive Bacterial Infections Infections Latent Infection Latent Tuberculosis Latent Tuberculosis Infection Mycobacterium Infections

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Centre antituberculeux; Geneva University Hospital

Geneva, Canton of Geneva, 1211, Switzerland

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Primary outcomes

Correlation between results of TST and IGRA tests and exposure scores

Time frame: 2 months after exposure

Sponsors and collaborators

Lead sponsor

University Hospital, Geneva

Other

Collaborators

Ligue Pulmonaire Genevoise

Registry information

Official study 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

Important dates

Study start: 2004
Study completion: 2006
First posted: Nov 14, 2007
Registry last updated: Nov 14, 2007

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Published trials that share one or more normalized conditions with this study.

Completed