Medicine
A 29-year-old nurse is evaluated in the clinic for employment contract renewal.
She is asymptomatic, and her clinical examination is unremarkable. Her laboratory tests are within normal range. Her skin purified protein derivative (PPD) test after 48 hours is 12 mm. Which of the following is the most appropriate management?
Explanation
Core Concept: Latent Tuberculosis Infection (LTBI) occurs when a person is infected with Mycobacterium tuberculosis but does not have active TB disease. Healthcare workers are at higher risk of occupational exposure.
Clinical Presentation: Patients with LTBI are completely asymptomatic and are not contagious. Complications, if reactivation occurs later in life, include active pulmonary or extrapulmonary TB.
Diagnosis: First-line screening tools include the Tuberculin Skin Test (TST/PPD) or Interferon-Gamma Release Assays (IGRAs). A PPD induration ≥ 10 mm is considered positive for healthcare workers. The gold standard to rule out active disease before starting LTBI treatment is a chest radiograph and clinical symptom review.
Management: Acute management involves confirming the absence of active TB (normal CXR, no symptoms). Long-term definitive management of LTBI aims to prevent reactivation. Standard regimens include Isoniazid for 6 or 9 months, Rifampin for 4 months, or weekly Isoniazid + Rifapentine for 3 months.