When is treatment not recommended for Latent Tuberculosis Infection (LTBI)?

When Not to Treat for Latent Tuberculosis Infection (LTBI)

Systematic testing and treatment of LTBI is NOT recommended in people with diabetes, harmful alcohol use, tobacco smokers, and underweight individuals, provided they do not fall into high-risk categories requiring treatment. 1

Populations Where LTBI Treatment Should NOT Be Pursued

Low-Risk Groups (No Systematic Testing or Treatment)

• Diabetic patients without other high-risk factors 1
• Persons with harmful alcohol use who are not in priority treatment groups 1
• Tobacco smokers without additional risk factors 1
• Underweight persons who do not meet other high-risk criteria 1

These recommendations are based on the principle that the risks of treatment (particularly hepatotoxicity) may outweigh benefits in populations with lower risk of progression to active TB disease 1.

Clinical Situations Where Treatment Must Be Withheld or Deferred

Active TB Disease Not Yet Excluded

Treatment of LTBI should not be started until a diagnosis of TB disease has been excluded by history, medical examination, chest radiography, and when indicated, mycobacteriologic studies 1. If TB disease presence is uncertain due to equivocal chest radiograph, standard multidrug anti-TB therapy should be initiated instead 1.

Absolute Contraindications to LTBI Treatment

• Active hepatitis - relative contraindication to isoniazid or pyrazinamide use 1
• End-stage liver disease - relative contraindication to isoniazid or pyrazinamide use 1
• Previous history of severe liver injury from anti-TB medications 1
• Serum bilirubin concentration above normal range - absolute indication to discontinue rifampin-pyrazinamide combination 2

Previously Completed Treatment

Persons with previously positive TST results who have previously completed treatment for LTBI (≥6 months of isoniazid, 4 months of rifampin, or another regimen) do not need to be treated again unless concern exists that reinfection has occurred 1, 3.

Risk-Benefit Assessment for Borderline Cases

Age Considerations

For persons over age 35 without additional risk factors, the risk of hepatotoxicity from isoniazid must be weighed against the risk of tuberculosis progression 4. Treatment is recommended only when additional risk factors are present (HIV infection, recent contact, immunosuppression, fibrotic lesions, silicosis, diabetes, chronic renal failure, malignancy, or substantial weight loss) 4.

Likelihood of Treatment Completion

Decisions regarding initiation of LTBI treatment should include consideration of whether the patient can continue and complete LTBI treatment under supervision, particularly in correctional settings where release before completion is anticipated 1.

Special Populations Requiring Alternative Management

Contacts of Multidrug-Resistant TB

For contacts of MDR-TB patients, close clinical observation for at least 2 years is preferred over preventive treatment due to limited evidence for efficacy and safety of alternative regimens 3, 5.

Patients with Chronic Alcohol Consumption

History of excessive alcohol consumption makes patients poor candidates for LTBI treatment due to increased hepatotoxicity risk 1. If treatment is deemed necessary, baseline and follow-up monitoring of serum aminotransferases are required 1.

Critical Screening Before Treatment Initiation

Symptom Assessment

Individuals should be asked about symptoms of TB before being tested for LTBI 1. Those with TB symptoms (cough >2-3 weeks, hemoptysis, fever, night sweats, weight loss, chest pain, shortness of breath, fatigue) or any radiological abnormality should be investigated further for active TB before any LTBI treatment consideration 1.

Radiographic Screening

Chest radiography should be performed when efforts are intended for active TB case finding 1. Any abnormality on chest X-ray requires full evaluation for active disease before LTBI treatment 1.

Common Pitfalls to Avoid

• Never initiate LTBI treatment without excluding active TB disease first - this requires symptom screening, chest radiography, and potentially sputum cultures 1
• Do not retreat patients who completed adequate LTBI therapy unless documented new exposure with high likelihood of reinfection occurs 3
• Avoid treating low-risk populations (diabetes alone, smoking alone, underweight alone) where treatment risks exceed benefits 1
• Do not use rifampin-pyrazinamide combination for LTBI due to unacceptably high rates of severe liver injury and death 1, 6, 7