Snapshot A 37-year-old man presents to a community hospital severely diaphoretic and short of breath. When confronted by the triage staff, he speaks no English and begins coughing. The nurse on duty notices a tinge of blood on his sleeve and shirt collar. Appropriately, she immediately quarantines the patient. An Xray is ordered. Introduction Infection due to Mycobacterium tuberculosis Majority of symptomatic cases due to reactivation of old disease versus new primary infection Risk factors include immunosuppression alcoholism pre-existing lung disease diabetes advanced age malnourishment living in crowded conditions prison homelessness recent immigration status from developing nations into the US health care workers sick contacts of known TB patients (i.e. family, friends, coworkers) Common cause of fever of unknown origin (FUO) Miliary tuberculosis most severe, often fatal form indicates hematologic or lymphatic dissemination Extrapulmonary tunerculosis presentations include CNS infection vertebral body Involvement (Potts Disease) renal (most common extrapulmonary site) GI Presentation Symptoms classically present for prolonged period of time (>3 weeks) and include cough hemoptysis dyspnea weight loss fatigue fever night sweats cachexia hypoxia Physical exam tachycardia lymphadenopathy cervical is most common crackles/rales wheezes dullness to percussion Evaluation Sputum acid-fast stain leads to presumptive diagnosis because cultures take a few weeks Positive PPD (purified protein derivative) indicates previous exposure only, not necessarily active infection type IV delayed hypersensitivity reaction may not be present in immunocompromised patients (anergy) CXR apical fibrocaseous cavitary lesions indicative of reactivation TB with or without cavitation Ghon Complex hilar nodes and lower lobe nodes characteristic of primary disease multiple, fine, nodular densities indicative of miliary tuberculosis PPD placement and reading PPD placement .5 ml injected intradermally on the volar surface of the arm The transverse induration is measured at 48-72 hours BCG vaccinations render a patient's PPD positive for a least one year Reaction > 5 mm Considered positive in HIV, close TB contacts, CXR evidence Reaction > 10 mm Considered positive if homeless, immigrant from or living in developing nation, IVDU, chronic disease, resident of health or correctional institution Reaction > 15 mm Considered positive in everyone else Negative reaction with negative controls Implies anergy from immunosuppression, old age, malnutriton, and does not rule out TB Differential Pneumonia, HIV, UTI, lung abscess, lung cancer, Aspergillus fungal ball, spinal tumor Active Tuberculosis Treatment Medical Management hospital respiratory isolation / directly-observed multi-drug therapy (DOT) for six months acute treatment phase includes four-drug regimen for X months isoniazid (INH) must co-administer vitamin B6 (pyradoxine) to prevent peripheral neuritis can also cause hepatitis pyrazinamide rifampin turns body fluids orange ethambutol can cause retrobulbar/optic neuritis until drug-susceptibility studies are complete chronic treatment phase rifampin and INH for 6 months Atypical of multi-drug resistant TB Treatment Medical managment supplemental pharmacologic treatment (beyond DOT) indications atypical or multi-drug resistent TB (MDR-TB) Asymptomatic Positive PPD Treatment Medical management prophylactic INH for 9 months indications patients with positive PPD without active symptoms who have CXR suggestive of old infection are recent new conversions (<2 years) have multiple other high-risk factors complications liver toxicity may forgo in patients > 35 because of risk of INH-induced liver toxicity pregnancy is not a contraindication to multi-drug therapy Prognosis, Prevention, and Complications Prognosis good to excellent if identified and treated early miliary TB is most severe, and often fatal form given systemic dissemination Prevention all cases of suspected or diagnosed TB must be reported to local and state health authorities for public safety and prevention sick contacts must be notified and administered prophylactic treatment to prevent further spread of disease Complications untreated TB can spread throughout the lungs and to other major organ systems leading to more advanced presentations (i.e. Potts disease, miliary TB infection) common cause of constrictive pericarditis elevated liver enzymes secondary to RIPE therapy