II. Complications

III. Epidemiology

  1. Worldwide
    1. Latent TuberculosisPrevalence: 2 Billion people
      1. One third of world population has Latent Tuberculosis
      2. Over half of cases in China, India, and Southeast asia
    2. Active Tuberculosis will develop in 10% of latent cases
      1. Most frequent cause of death for young adults
      2. In 1998, 8 million Active Tb cases, 2 million deaths
      3. In 2015, 10.4 million Active Tb cases, 1.4 million deaths
        1. An additional 0.4 million deaths occurred in HIV patients with Active Tb
      4. In 2019, 10 million Active Tb cases, 1.4 million deaths
  2. United States
    1. Latent TbIncidence: 10-15 Million in U.S.
    2. Active TbIncidence has fallen
      1. 1992 cases: 26,673 (10.5 cases per 100,000)
      2. 2006 cases: 13,779 (4.6 cases per 100,000)
      3. 2014 cases: 9,421 (2.96 per 100,000)
      4. 2019 cases 9,000
    3. Active TbIncidence in U.S. born patients declined since 1992
      1. Incidence rose 74% between 1953 to 1985, before it started falling in 1992
    4. Active TbIncidence in foreign born persons Incidence increasing (4-5x U.S)
      1. Foreign borne patients represent 66% of new Tb cases in U.S.
      2. Foreign borne patient Active TbIncidence: 15.4 cases per 100,000
      3. U.S. borne patient Active TbIncidence: 1.2 cases per 100,000
      4. Latent Tb infection in 30-50% of Minnesota Refugees
      5. Drug-resistant TB is twice as likely in Refugees
    5. Active TbIncidence by ethnic groups in the United States (in 2014)
      1. Asians: 17.8 cases per 100,000
      2. Native hawaiians and others from the pacific islands: 16.9 per 100,000
      3. American indians or alaskan natives: 5.0 per 100,000
      4. Blacks: 5.1 per 100,000
      5. Hispanics: 5.0 per 100,000
      6. Whites: 0.6 per 100,000
    6. Other factors related to resurgence of Tuberculosis in the United States
      1. HIV epidemic
      2. Multidrug-Resistant Tuberculosis
    7. References
      1. (2014) CDC - Trends in Tuberculosis, accessed online 11/2/2016
        1. http://www.cdc.gov/tb/publications/factsheets/statistics/tbtrends.htm

IV. History

  1. George Orwell died of Tuberculosis in 1950
    1. Shortly after Nineteen Eighty four was published

V. Pathophysiology

  1. Mycobacterium tuberculosis is a Acid Fast Bacillus
  2. Transmission
    1. Mycobacterium tuberculosis is carried in airborne droplets
    2. Transmitted from an infected patient with respiratory Tb (laryngeal, lung) via sneeze, cough, speak, or sing
  3. Infection
    1. Latent Tuberculosis occurs when the Immune System walls off Tuberculosis infection, forming Granulomas
    2. Active Tuberculosis occurs when the Immune System can no longer contain Tb in Granulomas and the bacilli multiply
      1. See Tuberculosis Risk Factors for progression from Latent to Active Disease
      2. Latent Tuberculosis progresses to Active Tuberculosis in up to 5 to 10% of cases
      3. Risks for progression include Immunosuppression, Diabetes Mellitus, IV Drug Abuse, low body weight and age <5 years old
  4. Dissemination
    1. Active M. Tb may spread from lung alveoli to brain, Larynx, Lymph Nodes, spine, bone and Kidneys

VII. Symptoms: Active Tuberculosis

  1. Latent Tuberculosis is asymptomatic, noninfectious and without Chest XRay findings of Tuberculosis
  2. Active Tuberculosis mimics other conditions
    1. May mimic cancer presentation (Night Sweats, weight loss)
    2. May mimic Community Acquired Pneumonia (cough, fever, mild Chest XRay infiltrate)
    3. Exercise a low index of suspicion for testing
  3. Non-specific presentation (most common)
    1. Fatigue
    2. Weight loss
    3. Cachexia
    4. Night Sweats
  4. Pulmonary Tuberculosis symptoms
    1. Productive Chronic Cough (>3 weeks)
    2. Hemoptysis (uncommon)
    3. Pleuritic Chest Pain
    4. Dyspnea

VIII. Signs: Active Tuberculosis

  1. Sites of Involvement
    1. Primary infection: lung involvement
  2. Disseminated Disease
    1. See Extrapulmonary Tuberculosis
  3. Findings to consider Tuberculosis Testing (e.g. undifferentiated cough in the emergency department)
    1. Mild Sinus Tachycardia
    2. Mild Hypoxia
    3. Tachypnea
    4. Low grade fever

IX. Diagnosis

  1. Tuberculosis Screening
    1. Indications
      1. Asymptomatic with Tuberculosis Risk Factors
        1. See Tuberculosis Risk Factors (Tuberculosis Screening Indications)
        2. Avoid Tb screening in low risk populations (low Positive Predictive Value)
      2. Symptoms (see above)
        1. Chronic Cough >3 weeks
        2. Hemoptysis
        3. Chest Pain
        4. Fever
        5. Night Sweats
        6. Anorexia
        7. Fatigue
        8. Unexplained Weight Loss
    2. Screening Tests
      1. See Tuberculosis Screening for lab selection
      2. Tuberculin Skin Test (TST, Purified Protein Derivative, PPD)
      3. Mycobacterium Tuberculosis Antigen-Specific Interferon-Gamma Release Assay (IGRA)
        1. Cost of IGRA is approaching that of Tuberculin Skin Test
        2. IGRA tests will likely replace the Tuberculin Skin Test in longterm
          1. Some caveats (e.g. age under 5 years old)
  2. In suspected pulmonary Tuberculosis
    1. Induced Sputum samples on 3 consecutive days or
    2. Gastric aspirate may be used in young children or
    3. Bronchoscopy with bronchoalveolar lavage and biopsy
  3. In suspected Disseminated tuberculosis (Extrapulmonary Tuberculosis)
    1. Obtain specimens from infection site (e.g. urine, Lymph Nodes, Pleural Fluid, cerebrospinal fluid, Bone Marrow)
  4. Detection of organisms and drug susceptibility
    1. Acid fast stain (Sputum, body fluid, biopsy)
      1. Sensitive to >5000 bacilli per ml
    2. Fluorescent stains and DNA probes for rapid diagnosis
    3. DNA whole genome sequencing
      1. Performed at many labs (identifies strains, mutations and predicts drug resistance)
      2. Has replaced culture in many regions of the world
    4. Mycobacterial cultures
      1. Sensitive to 10 bacilli per ml
      2. Replaced by

X. Labs

  1. Diagnostic testing as above
  2. HIV Test
    1. Test every person with Tuberculosis

XI. Imaging: Chest XRay

  1. Obtain in all positive PPD (TST) or IGRA patients
  2. See Tuberculosis Related Chest XRay Changes

XII. Course

  1. Tuberculin Skin Test conversion within 2-10 weeks of exposure
  2. Latent Tuberculosis initially
    1. Tuberculin Skin Test positive without signs, symptoms
    2. Tubercle bacilli remain dormant and viable for years
  3. Lifetime risk of developing Active Tb: 10%
  4. Highest risk is greatest within 2 years of exposure (5-10% of latent cases become active)
    1. See Tuberculosis Risk Factors for progression from Latent to Active Disease (Latent Tb treatment indications)

XIII. Management

  1. Report all cases of Latent and Active Tuberculosis to local or state health departments
  2. Latent Tuberculosis
    1. See Latent Tuberculosis Treatment
    2. Positive PPD or IGRA without signs of Active Tb
      1. Confirm no Active Tb (cough, Night Sweats) before starting single drug Latent Tb management
      2. Chest XRay is performed at time of Latent Tb diagnosis
    3. Treatment indicated if risk of Tb Progression from latent to active disease
      1. See Tuberculosis Risk Factors for progression from Latent to Active Disease
  3. Active Tuberculosis
    1. See Active Tuberculosis Treatment
    2. Symptomatic patient (e.g. fever, weight loss, Hemoptysis)
      1. Patient isolated in negative pressure room and wears mask
      2. Healthcare workers wear N-95 Mask
      3. Obtain diagnostic testing
        1. Chest XRay
        2. Sputum acid-fast bacilli smear and culture
      4. Consult with pulmonology or infectious disease
      5. Consult public health
    3. Protocols for Active Tuberculosis management
      1. Susceptible Tuberculosis Treatment
      2. Possibly Resistant Tuberculosis Treatment
      3. Multiple Drug Resistant Tuberculosis Treatment
  4. Post-exposure Prophylaxis
    1. Indications
      1. Exposure to untreated active pulmonary or laryngeal Tuberculosis
      2. Regardless of prior BCG vaccine or prior Tuberculosis treatment
    2. Protocol: Asymptomatic contact
      1. Treatment indications based on Tuberculosis Testing at baseline AND 8-12 weeks after exposure
        1. Tuberculin Skin Test (PPD) of 5mm or greater OR
        2. Mycobacterium Tuberculosis Antigen-Specific Interferon-Gamma Release Assay positive
      2. Start treatment if positive testing
        1. Isoniazid (INH) with Vitamin B6 supplementation for 9 months
    3. Protocol: Symptomatic contact
      1. Follow Active Tuberculosis protocol as above

XIV. Complications

XV. Prevention

  1. Bacille Calmette-Guerin Vaccine (BCG vaccine)
    1. May be indicated in high risk young children in endemic areas
    2. Routinely performed in Mexico, South America, Africa, Asia and Western Europe
  2. M72/ASO1E Vaccine
    1. Reduced progression to pulmonary Tuberculosis by 50% in HIV negative after Tb exposure and positive PPD
    2. Tait (2019) N Engl J Med 381(25):2429-39 [PubMed]

XVI. Resources

Images: Related links to external sites (from Bing)

Related Studies

Ontology: Mycobacterium tuberculosis (C0026926)

Definition (NCI) An obligate anaerobic, weakly Gram-positive species of mycobacterium that is the cause of most cases of tuberculosis.
Definition (NCI_CDISC) Any bacterial organism that can be assigned to the species Mycobacterium tuberculosis.
Definition (MSH) A species of gram-positive, aerobic bacteria that produces TUBERCULOSIS in humans, other primates, CATTLE; DOGS; and some other animals which have contact with humans. Growth tends to be in serpentine, cordlike masses in which the bacilli show a parallel orientation.
Definition (CSP) species of gram positive, aerobic bacteria that produces tuberculosis in man, other primates, dogs, and some animals which have contact with man; growth tends to be in serpentine, cordlike masses in which the bacilli show a parallel orientation.
Concepts Bacterium (T007)
MSH D009169
SnomedCT 36354002, 113861009
LNC LP16659-2, LA20996-7
English Mycobacterium tuberculosis, M TUBERC, MTB - Mycobact tuberculosis, M. tuberculosis, Mycobacterium tuberculosis NOS, Mycobacterium tuberculosis (Zopf 1883) Lehmann and Neumann 1896, m tuberculosis, mtb, m. tuberculosis, mycobacterium tuberculosis, tb bacillus, tuberculosis mycobacterium, bacterium tuberculosis, tuberculosis bacillus, Bacillus tuberculosis, Bacterium tuberculosis, Mycobacterium tuberculosis typus humanus, Mycobacterium tuberculosis var. hominis, MYCOBACTERIUM TUBERCULOSIS, Koch's bacillus, Human tubercle bacillus, Mycobacterium tuberculosis hominis, TB bacillus, MTB - Mycobacterium tuberculosis, Mycobacterium tuberculosis (organism), Mycobacterium tuberculosis hominis (organism)
Dutch Mycobacterium-tuberculose NAO, Mycobacterium tuberculosis, Tuberkelbacterie
French Tuberculose à Mycobacterium SAI, Bacille de Koch, M. tuberculosis, Mycobacterium tuberculosis
German Mycobacterium tuberculosis NNB, Mycobacterium tuberculosis
Italian Mycobacterium tuberculosis NAS, Mycobacterium tuberculosis
Portuguese Mycobacterium tuberculosis NE, Mycobacterium tuberculosis
Spanish Mycobacterium tuberculosis NEOM, Mycobacterium tuberculosis (organismo), Mycobacterium tuberculosis hominis (organismo), bacilo de Koch, bacilo de la tuberculosis humana, Mycobacterium tuberculosis, Mycobacterium tuberculosis hominis
Japanese 結核菌NOS, ケッカクキンNOS, マイコバクテリウム・ツベルクローシス, 結核菌, ヒト型結核菌
Swedish Mycobacterium tuberculosis
Czech Mycobacterium tuberculosis, Infekce způsobená Mycobacterium tuberculosis NOS
Finnish Mycobacterium tuberculosis
Polish Prątki gruźlicze, Mycobacterium tuberculosis
Hungarian Mycobacterium tuberculosis k.m.n.
Norwegian Mycobacterium tuberculosis

Ontology: Tuberculosis (C0041296)

Definition (MSHCZE) Jedno z infekčních onemocnění lidí a dalších živočichů způsobené druhem MYCOBAKTERIUM.
Definition (MEDLINEPLUS)

Tuberculosis (TB) is a disease caused by bacteria called Mycobacterium tuberculosis. The bacteria usually attack the lungs, but they can also damage other parts of the body.

TB spreads through the air when a person with TB of the lungs or throat coughs, sneezes, or talks. If you have been exposed, you should go to your doctor for tests. You are more likely to get TB if you have a weak immune system.

Symptoms of TB in the lungs may include

  • A bad cough that lasts 3 weeks or longer
  • Weight loss
  • Loss of appetite
  • Coughing up blood or mucus
  • Weakness or fatigue
  • Fever
  • Night sweats

Skin tests, blood tests, x-rays, and other tests can tell if you have TB. If not treated properly, TB can be deadly. You can usually cure active TB by taking several medicines for a long period of time.

NIH: National Institute of Allergy and Infectious Diseases

Definition (NCI) A chronic, recurrent infection caused by the bacterium Mycobacterium tuberculosis. Tuberculosis (TB) may affect almost any tissue or organ of the body with the lungs being the most common site of infection. The clinical stages of TB are primary or initial infection, latent or dormant infection, and recrudescent or adult-type TB. Ninety to 95% of primary TB infections may go unrecognized. Histopathologically, tissue lesions consist of granulomas which usually undergo central caseation necrosis. Local symptoms of TB vary according to the part affected; acute symptoms include hectic fever, sweats, and emaciation; serious complications include granulomatous erosion of pulmonary bronchi associated with hemoptysis. If untreated, progressive TB may be associated with a high degree of mortality. This infection is frequently observed in immunocompromised individuals with AIDS or a history of illicit IV drug use. --2004
Definition (MSH) Any of the infectious diseases of man and other animals caused by species of MYCOBACTERIUM.
Definition (CSP) infectious diseases of man and animals caused by Mycobacterium species and characterized by formation of tubercles and caseous necrosis in the tissues; any organ may be affected but in man the lung is the major seat of the disease and the usual portal through which the infection reaches other organs.
Concepts Disease or Syndrome (T047)
MSH D014376
ICD9 010-018.99
ICD10 A15-A19.9 , A15-A19
SnomedCT 56717001, 186282009, 263912007, 154292008, 187285000, 154281007, 373576009, 371569005
LNC LP28599-6, MTHU020835, LA10513-2
English Tuberculoses, Tuberculosis, INFECTION TBC, MTB - Mycobacter tuberculosis, MTB - Mycobacterium tuberculosis infection, Mycobacter tuberculosis, Mycobacterium tuberculosis infection, Tuberculosis NOS, TB, tuberculosis (diagnosis), tuberculosis, TB (tuberculosis), Infection TBC, Infection tuberculosis, Tuberculosis [Disease/Finding], Kochs Disease, Disease, Koch's, Koch's Disease, Koch Disease, Disease, Kochs, infection tuberculosis, tuberculous, tuberculosis (TB), TBC, tuberculosis infection, Tuberculosis (A15-A19), Tuberculous infections, Tuberculosis NOS (disorder), Tuberculous (disorder), Infection due to Mycobacterium tuberculosis, TB - Tuberculosis, Tuberculous, Infection due to Mycobacterium tuberculosis (disorder), Tuberculosis (disorder), Tuberculous (qualifier value), Koch; infection, infection; Koch, infection; tuberculous, tuberculosis; general, tuberculosis; infection, Tuberculosis, NOS, TUBERCULOSIS
Italian Infezioni tubercolari, Tubercolosi NAS, TB, Infezione tubercolare, Tubercolosi
Dutch TBC, infectie tuberculose, infectie TBC, tuberculose NAO, Koch; infectie, infectie; Koch, infectie; tuberculeus, tuberculose; algemeen, tuberculose; infectie, tuberculose-infecties, tuberculose, Tuberculose
French Tuberculose SAI, TB, Infection à la tuberculose, Infection à TBC, INFECTION TUBERCULEUSE, Infections tuberculeuses, Tuberculose
German Infektion TBC, Infektion mit Tuberkulose, TB, Tuberkulose NNB, TUBERKULOSE INFEKTION, Tuberkuloese Infektionen, Tuberkulose
Portuguese Infecção TBC, Infecção tuberculosa, Tuberculose NE, INFECCAO TUBERCULOSA, TB, Infecções tuberculosas, Tuberculose
Spanish Tuberculosis NEOM, Infección TBC, Infección tuberculosa, INFECCION TUBERCULOSA, tuberculosis, SAI, tuberculosis, SAI (trastorno), Tuberculosis NOS, TB, infección por Mycobacterium tuberculosis (trastorno), infección por Mycobacterium tuberculosis, tuberculosis (trastorno), tuberculosis, tubérculo (calificador), tubérculo, Infecciones por Mycobacterium tuberculosis, Tuberculosis
Japanese 結核感染, 結核, 結核NOS, ケッカク, ケッカクカンセン, ケッカクNOS
Swedish Tuberkulos
Czech tuberkulóza, TBC infekce, Tuberkulóza NOS, Infekce tuberkulózní, Tuberkulóza, Tuberkulózní infekce, TBC
Finnish Tuberkuloosi
Polish Gruźlica, Ftyzjatria
Hungarian tuberculosis k.m.n., tuberculosis, Fertőzés, tuberculotikus, Fertőzés, TBC-s, Tuberculotikus fertőzések, TBC
Norwegian Tuberkulose