Active Screening of Latent Tuberculosis Infection in School Contacts of Active Tuberculosis Patients

Study Overview
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Brief Summary
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The goal of this observational study is to investigate the proportion of Mycobacterium tuberculosis (MTB) infection in school contacts of active tuberculosis (ATB) patients. The main questions it aims to answer are: the proportion of MTB infection among school contacts of ATB patients risk factors related to tuberculosis (TB) infection health economic evaluation of screening strategy

Official Title
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Active Screening of Latent Tuberculosis Infection in School Contacts of Active Tuberculosis Patients

Conditions
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Tuberculosis, Latent Tuberculosis Infection

Intervention / Treatment
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* Diagnostic Test: QuantiFERON-TB Gold (QFT) test


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 13 years old or above; Students in junior middle school, high school and university; Close contact of school active tuberculosis case (e.g. in the same classroom, in the same dormitory); Himself/herself (together with his/her guardian for age under 18 years old) willing to participate in trial and sign informed consent. Exclusion Criteria: Current clinical or sputum culture confirmed active tuberculosis Have completed a full course of treatment for ATB or LTBI

Ages Eligible for Study
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Minimum Age: 13 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Contacts<br>School contacts of ATB patients | Diagnostic Test: QuantiFERON-TB Gold (QFT) test<br>* Participants will be tested by QuantiFERON-TB Gold (QFT) test to see if they have ever infected by MTB. Those with positive results will proceed to sputum Xpert MTB/RIF, physical examination and chest CT scan, as well as sputum culture if necessary to distinguish latent TB infection (LTBI) from ATB. X-ray scan is conditional on age above 15 years with a positive QuantiFERON-TB Gold (QFT) test result.<br>* Other names: Sputum Xpert MTB/RIF;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The prevalence of tuberculosis (TB) infection in school contacts | The prevalence of TB infection is defined as the number of participants with positive results in QuantiFERON-TB Gold (QFT) test in study population. Positive result in QFT test indicates higher response than the cut-off value of 0.35 IU / ml of INF-γ detected in at least one test tube (TB1 or TB2). | baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Age | Age as possible risk factor of tuberculosis infection | baseline | 
| Sex | Sex as possible risk factor of tuberculosis infection. | baseline | 
| Vaccination history checklist | Bacillus Calmette-Guérin (BCG) vaccination history as possible risk factor of tuberculosis infection. | baseline | 
| Patterns of contacting checklist | Duration, size of space of exposure to active tuberculosis-infected patient; as possible risk factor of tuberculosis infection. | baseline | 
| Co-morbidities / medical history checklist | Co-morbidities / medical history [cardiovascular disease, bronchial asthma, digestive ulcer, nephritic syndrome, glomerulonephritis, diabetes, hyperthyroidism, systemic lupus erythematosus, ankylosing spondylitis, epilepsy, schizophrenia, depression, HIV infection, glucocorticoid use, biologic agent use, immunosuppressive agent use, or other relevant co-morbidities / medical history]; as possible risk factor of tuberculosis infection. | baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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latent tuberculosis, active screening