Tb
Tuberculosis
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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 Tuberculosis
Prevalence
: 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 Tb
Incidence
: 10-15 Million in U.S.
Active Tb
Incidence
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 Tb
Incidence
in U.S. born patients declined since 1992
Incidence
rose 74% between 1953 to 1985, before it started falling in 1992
Active Tb
Incidence
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 Tb
Incidence
: 15.4 cases per 100,000
U.S. borne patient
Active Tb
Incidence
: 1.2 cases per 100,000
Latent Tb
infection in 30-50% of Minnesota
Refugee
s
Drug-resistant TB is twice as likely in
Refugee
s
Active Tb
Incidence
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
Mycobacteria
l 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]
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