A Novel Therapy With a 1-Month Ultrashort Regimen to Halt Progression From Latent Infection to Active Tuberculosis Among Close Contacts (The TB-YOUTH Study)

Inclusion Criteria: 1. Aged ≥13 years and body weight ≥ 30 kg; 2. School-registered individuals including: * Currently attending junior / senior high school or university students; * School staff members; 3. Close contacts of active pulmonary TB index cases (confirmed or clinically diagnosed) within the school, defined by meeting both of the following: * Teachers/students sharing the same classroom or dormitory with the index case; * Exposure history: Prolonged sharing of enclosed space (\>4 hours total within 1 week) with the index case; 4. Confirmed LTBI status through screening; 5. Voluntary participation with signed informed consent form (for adults ≥18 years); 6. Parental / guardian consent and co-signed informed consent form (for minors aged 13-17 years). Exclusion Criteria: 1. Current active TB disease (clinically or bacteriologically confirmed); 2. Documented isoniazid/rifampicin resistance in the corresponding M. tuberculosis strain from the index case; 3. Self-reported use of rifamycins (e.g., rifampicin, rifapentine) or isoniazid for \>14 consecutive days within the past 2 years; 4. Prior completion of full-course of treatment for ATB or LTBI; 5. Hypersensitivity or intolerance to rifamycins (rifapentine / rifampicin) or isoniazid; 6. HIV positive serostatus or AIDS patients; 7. History of viral hepatitis (e.g., chronic hepatitis B, chronic hepatitis C) or liver cirrhosis; 8. Liver dysfunction (TBil\>2.5mg/dL \[43umol/L\] or ALT / AST\>2ULN) or renal dysfunction. 9. Current receiving immunosuppressive therapy or biological agents. 10. Hematologic disorders with either PLT\<50×109/L or WBC\<3.0×109/L. 11. Other conditions deemed unsuitable for TPT by investigators.