Tuberculosis
Background
- >1/3 of world's population is infected
- Infection Types
- Primary Infection
- Usually contained by body via formation of tubercles
- Hematogenous spread limited to areas w/ high O2 or blood flow (apical lung, vertebrae)
- PPD positive
- Reactivation Infection
- More common in immunocompromised pts (AIDS, malignancy, DM, CRF)
- Check HIV in pts suspected of TB
- Primary Infection
- Special Populations
- AIDS
- TB is 200-500x more common in AIDS population than general population
- CD4 count
- Increased risk when <500
- Determines the clinical and radiographic presentations of TB
- Peds
- More likely to progress early to active disease
- Presentation more commonly that of primary TB
- >5yr - classic symptoms
- <5yr - miliary TB, meningitis, cervical lymphadenitis, PNA that doesn't respond to abx
- Children are usually not infectious due to their weak cough
- More likely to progress early to active disease
- AIDS
Diagnosis
Clinical Features
Primary Tuberculosis
- Usually asymptomatic (only identified by positive PPD)
- May be rapidly progressive and fatal in immunocompromised pts
- Fever, malaise, wt loss, chest pain
- Tuberculous pleural effusion may occur if subpleural node ruptures into the pleura
- Pleuritic chest pain
- Exudative fluid
- Organisms may not be visible on acid-fast staining (need pleural biopsy)
Reactivation Tuberculosis
- Pulmonary: Productive cough, hemoptysis, dyspnea, pleuritic chest pain
- Systemic: Fever, night sweats, malaise, fatigue, wt loss
- Extrapulmonary
- Lymphadenopathy (painless)
- Pericarditis
- Meningitis
- Adrenal insufficiency
- Arthritis
- Osteomyelitis
CXR
- Primary infection
- Infiltrates in any area of the lung
- Isolated hilar or mediastinal adenopathy may be only finding
- Reactivation infection
- cavitary/noncavitary lesions in upper lobe or superior segment of lower lobe
- Latent infection
- Upper lobe or hilar nodules and fibrotic lesions
- Ghon foci, areas of scarring, calcification
- HIV pts less likely to have classic lesions and may have normal CXR
Treatment
Active TB
- Isoniazid + rifampin + pyrazinamide + ethambutol x8wk followed by INH/RIF x18wk
- 2 drug continuation tx x 18-31wk
Latent TB
- Consider treatment for:
- Recent conversion to PPD-positive
- Persons in close contact w/ individual w/ active TB
- Isoniazid x9mo
Disposition
- Discharge
- Otherwise healthy
- Contact public health services before discharge
- Instructions for home isolation and f/u at appropriate clinic to receive meds
- Do not start TB meds in ED unless specifically instructed by public health
- Contact public health services before discharge
- Otherwise healthy
- Admit
- Ill-appearing
- Diagnosis is uncertain
- Pt is noncompliant