Exogenous Reinfection of Tuberculosis in Taiwan

Study Overview
=================
Brief Summary
-----------------
we hypothesize that exogenous reinfection is very important in the Taiwan endemic. Therefore, we design a series of studies to evaluate the individual contribution of exogenous reinfection and endogenous reactivation in the Taiwan endemic, and to realize the impact of exogenous reinfection. First, we will identify the patients with TB relapse after complete treatment. The M. tuberculosis isolates responsible for their initial and recurrent episodes will then be genotyped to clarify the percentage of exogenous reinfection and endogenous reinfection.

Detailed Description
-----------------
Tuberculosis (TB) remains the most important infectious disease in the world. In Taiwan, the incidence of TB increased in recent years. The failure of control implies the necessity to reevaluate the epidemiology of Mycobacterium tuberculosis. It is widely thought that most cases of TB are caused by reactivation of a latent infection. Treatment programs have therefore focused on cure rates rather than tracking of additional cases. But recent studies showed that exogenous reinfection plays an important role in the development of TB. In addition, it seems that the higher the local incidence, the more important exogenous reinfection is. The question of exogenous reinfection versus endogenous reactivation has an impact on the distribution of resources for the prevention and treatment of TB. Based on these evidences, we hypothesize that exogenous reinfection is very important in the Taiwan endemic. Therefore, we design a series of studies to evaluate the individual contribution of exogenous reinfection and endogenous reactivation in the Taiwan endemic, and to realize the impact of exogenous reinfection. First, we will identify the patients with TB relapse after complete treatment. The M. tuberculosis isolates responsible for their initial and recurrent episodes will then be genotyped to clarify the percentage of exogenous reinfection and endogenous reinfection.

Official Title
-----------------
The Importance of Exogenous Reinfection in the Tuberculosis Endemic of Taiwan

Conditions
-----------------
Tuberculosis

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: culture-proven tuberculosis with recurrence
Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Culture-confirmed relapse of TB<br>Patients who have a recurrent episode of culture-confirmed TB after completion of treatment for the first episode of culture-confirmed TB | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| relapse due to reinfection | proportion of patients with exogenous reinfection in those with relapse of TB | 6 years | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
tuberculosis, relapse, reinfection, reactivation, dormancy, tuberculin skin test