QuantiFERON®-TB Gold In-Tube for the Diagnosis of Tuberculosis Infection in Contact Tracing Study.

Study Overview
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Brief Summary
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Hypothesis: a combined strategy of tuberculin skin test (TST) followed by QuantiFERON-TB Gold In-Tube (QFT-IT) to confirm positivity (tuberculosis infection,in contact-tracing study will allow avoiding unnecessary preventive treatment without increasing rates of tuberculosis cases among contacts screened. Aim of the study: to compare a combined strategy of the TST and the QFT-IT with TST alone for the diagnosis of tuberculosis infection and for therapeutic decision in contact tracing study. Design and setting: Prospective, multicentre, comparative study in 12 hospitals in Spain. Study population: 870 subjects, household contacts of patients with culture positive pulmonary and/or laryngeal tuberculosis will be randomized to one of two strategies: Arm A (standard practice), in which treatment decisions will be based on the TST result, and Arm B (experimental), in which treatment decisions will be based on the QFT result. Interventions: participants in arm A will undergo TST; participants in arm B will undergo TST, and, in case of a positive result, QFT-IT as well. Participants with positive TST (arm A) and positive QFT-IT (arm B) will be diagnosed with tuberculosis infection and will be treated with isoniazid for 6 months. All participants will be followed for two years. End-points of evaluation: development of tuberculosis and proportion of subjects for whom treatment is prescribed in each arm.

Official Title
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Comparison of Two Strategies for Therapeutic Decision-making in Tuberculosis Contact Tracing: a Standard Strategy Based on Tuberculin Skin Test (TST) Alone vs TST Combined With QuantiFERON®-TB Gold In-Tube (QFT-IT)

Conditions
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Latent Tuberculosis Infection

Intervention / Treatment
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* Drug: Preventive treatment with Isoniazid.
* Drug: Preventive treatment with Isoniazid


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥18 years. Close contact of a pulmonary and/or laryngeal tuberculosis case. Written informed consent. Exclusion Criteria: HIV infection. Immunosuppression other than HIV, such as decompensated liver disease, chronic renal failure, corticosteroids treatment, malignancy under chemotherapy therapy. Prior tuberculosis or positive TST. Strain resistant to Isoniazid (index case).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Arm A, Standard practice, TST<br>Participants allocated to screening as stablished by current practice (TST) | Drug: Preventive treatment with Isoniazid.<br>* If TST positive: participant will be treated with Isoniazid 300 mg/d, for 6 months.<br>|
| Experimental: Arm B, Experimental, TST plus QFT-IT<br>Participants allocated to screening with TST, and if positive, followed by QFT-IT to confirm tuberculosis infection. | Drug: Preventive treatment with Isoniazid<br>* If QFT-IT positive, Isoniazid 300 mg/d, for 6 months.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Development of tuberculosis. |  | Assessment of primary end-point: 24 months after randomization. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prescription of treatment. |  | The day 0 (visit 2) after randomization. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Tuberculosis, Latent tuberculosis infection, Tuberculin skin test, Interferon-gamma release assays, Contact-tracing study