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Tuberculosis
Aka: Tuberculosis, Mycobacterium tuberculosis, Tb
- See Also
- Tuberculosis Screening in Children
- Tuberculosis Risk Factors (Tuberculosis Screening Indications)
- Tuberculosis Risk Factors for progression from Latent to Active Disease (Latent Tb treatment indications)
- Tuberculosis Related Chest XRay Changes
- Extrapulmonary Tuberculosis
- Tuberculin Skin Test (TST, Purified Protein Derivative, PPD)
- Mycobacterium Tuberculosis Antigen-Specific Interferon-Gamma Release Assay (IGRA)
- Latent Tuberculosis Treatment
- Active Tuberculosis Treatment
- Susceptible Tuberculosis Treatment
- Possibly Resistant Tuberculosis Treatment
- Multiple Drug Resistant Tuberculosis Treatment
- Tuberculosis Resources
- Complications
- See Extrapulmonary Tuberculosis
- Epidemiology
- Worldwide
- Latent TuberculosisPrevalence: 2 Billion people
- One third of world population has Latent Tuberculosis
- Over half of cases in China, India, and Southeast asia
- Active Tuberculosis will develop in 10% of latent cases
- Most frequent cause of death for young adults
- In 1998, 8 million Active Tb cases, 2 million deaths
- In 2015, 10.4 million Active Tb cases, 1.4 million deaths
- An additional 0.4 million deaths occurred in HIV patients with Active Tb
- United States
- Latent TbIncidence: 10-15 Million in U.S.
- Active TbIncidence has fallen
- 2014 cases: 9,421 (2.96 per 100,000)
- 2006 cases: 13,779 (4.6 cases per 100,000)
- 1992 cases: 26,673 (10.5 cases per 100,000)
- Active TbIncidence in U.S. born patients declined since 1992
- Incidence rose 74% between 1953 to 1985, before it started falling in 1992
- Active TbIncidence in foreign born persons Incidence increasing (4-5x U.S)
- Foreign borne patients represent 66% of new Tb cases in U.S.
- Foreign borne patient Active TbIncidence: 15.4 cases per 100,000
- U.S. borne patient Active TbIncidence: 1.2 cases per 100,000
- Latent Tb infection in 30-50% of Minnesota Refugees
- Drug-resistant TB is twice as likely in Refugees
- Active TbIncidence by ethnic groups in the United States (in 2014)
- Asians: 17.8 cases per 100,000
- Native hawaiians and others from the pacific islands: 16.9 per 100,000
- American indians or alaskan natives: 5.0 per 100,000
- Blacks: 5.1 per 100,000
- Hispanics: 5.0 per 100,000
- Whites: 0.6 per 100,000
- Other factors related to resurgence of Tuberculosis in the United States
- HIV epidemic
- Multidrug-Resistant Tuberculosis
- References
- (2014) CDC - Trends in Tuberculosis, accessed online 11/2/2016
- http://www.cdc.gov/tb/publications/factsheets/statistics/tbtrends.htm
- History
- George Orwell died of Tuberculosis in 1950
- Shortly after Nineteen Eighty four was published
- Transmission
- Mycobacterium tuberculosis carried in airborne droplets
- Active Pulmonary or Laryngeal Tuberculosis transmitted
- Sneeze, cough, speak, or sing
- Risk Factors
- Latent Tuberculosis
- See Tuberculosis Risk Factors (Tuberculosis Screening Indications)
- Reactivation to active Tuberculosis Risk Factors
- See Tuberculosis Risk Factors for progression from Latent to Active Disease (Latent Tb treatment indications)
- Course
- Tuberculin Skin Test conversion within 2-10 weeks of exposure
- Latent Tuberculosis initially
- Tuberculin Skin Test positive without signs, symptoms
- Tubercle bacilli remain dormant and viable for years
- Lifetime risk of developing Active Tb: 10%
- Highest risk is greatest within 2 years of exposure (5-10% of latent cases become active)
- See Tuberculosis Risk Factors for progression from Latent to Active Disease (Latent Tb treatment indications)
- Symptoms
- Latent Tuberculosis is asymptomatic
- Active Tuberculosis mimics other conditions
- May mimic cancer presentation (Night Sweats, weight loss)
- May mimic Community Acquired Pneumonia (cough, fever, mild Chest XRay infiltrate)
- Exercise a low index of suspicion for testing
- Non-specific presentation (most common)
- Fatigue
- Weight loss
- Cachexia
- Night Sweats
- Pulmonary Tuberculosis symptoms
- Productive cough (typically 2-3 weeks)
- Hemoptysis (uncommon)
- Pleuritic Chest Pain
- Dyspnea
- Signs
- Sites of Involvement
- Primary infection: lung involvement
- Disseminated Disease
- See Extrapulmonary Tuberculosis
- Findings to consider Tuberculosis Testing (e.g. undifferentiated cough in the emergency department)
- Mild Sinus Tachycardia
- Mild Hypoxia
- Tachypnea
- Low grade fever
- Diagnosis
- Tuberculosis Screening
- See Tuberculosis Risk Factors (Tuberculosis Screening Indications)
- See Tuberculosis Screening for lab selection
- Tuberculin Skin Test (TST, Purified Protein Derivative, PPD)
- Mycobacterium Tuberculosis Antigen-Specific Interferon-Gamma Release Assay (IGRA)
- IGRA tests will likely replace the Tuberculin Skin Test in longterm
- Some caveats (e.g. age under 5 years old)
- Cost of IGRA is approaching that of Tuberculin Skin Test
- In suspected pulmonary Tuberculosis
- Induced Sputum samples on 3 consecutive days or
- Gastric aspirate may be used in young children or
- Bronchoscopy with bronchoalveolar lavage and biopsy
- Detection of organisms
- Acid fast stain (Sputum, body fluid, biopsy)
- Sensitive to >5000 bacilli per ml
- Fluorescent stains and DNA probes for rapid diagnosis
- Mycobacterial cultures
- Sensitive to 10 bacilli per ml
- Labs
- Diagnostic testing as above
- HIV Test
- Test every person with Tuberculosis
- Imaging: Chest XRay
- See Tuberculosis Related Chest XRay Changes
- Management
- Latent Tuberculosis
- See Latent Tuberculosis Treatment
- Positive PPD or IGRA without signs of Active Tb
- Confirm no Active Tb (cough, Night Sweats) before starting single drug Latent Tb management
- Chest XRay is performed at time of Latent Tb diagnosis
- Treatment indicated if risk of Tb Progression from latent to active disease
- See Tuberculosis Risk Factors for progression from Latent to Active Disease
- Active Tuberculosis
- See Active Tuberculosis Treatment
- Symptomatic patient (e.g. fever, weight loss, Hemoptysis)
- Patient isolated in negative pressure room and wears mask
- Healthcare workers wear N-95 Mask
- Obtain diagnostic testing
- Chest XRay
- Sputum acid-fast bacilli smear and culture
- Consult with pulmonology or infectious disease
- Consult public health
- Protocols for Active Tuberculosis management
- Susceptible Tuberculosis Treatment
- Possibly Resistant Tuberculosis Treatment
- Multiple Drug Resistant Tuberculosis Treatment
- Post-exposure Prophylaxis
- Indications
- Exposure to untreated active pulmonary or laryngeal Tuberculosis
- Regardless of prior BCG vaccine or prior Tuberculosis treatment
- Protocol: Asymptomatic contact
- Treatment indications based on Tuberculosis Testing at baseline AND 8-12 weeks after exposure
- Tuberculin Skin Test (PPD) of 5mm or greater OR
- Mycobacterium Tuberculosis Antigen-Specific Interferon-Gamma Release Assay positive
- Start treatment if positive testing
- Isoniazid (INH) with Vitamin B6 supplementation for 9 months
- Protocol: Symptomatic contact
- Follow Active Tuberculosis protocol as above
- Complications
- See Extrapulmonary Tuberculosis
- Prevention
- Bacille Calmette-Guerin Vaccine (BCG vaccine)
- May be indicated in high risk young children in endemic areas
- M72/ASO1E Vaccine
- Reduced progression to pulmonary Tuberculosis by 50% in HIV negative after Tb exposure and positive PPD
- Tait (2019) N Engl J Med 381(25):2429-39 [PubMed]
- Resources
- See Tuberculosis Resources
- References
- Orman, Moran and Swaminathan in Herbert (2016) EM:Rap 16(11): 2-3
- Frieden (2003) Lancet 362:887-99 [PubMed]
- Hartman-Adams (2014) Am Fam Physician 89(11): 889-96 [PubMed]
- Potter (2005) Am Fam Physician 72:2225-35 [PubMed]