Tuberculosis Flashcards
Mycobacterium tuberculosis primarily spread by
small particle droplet 1. coughing 2. sneezing 3. laughing 4. singing ** particles can stay in the air for hours; grows slowly in culture
risk factors for tuberculosis (5)
- low socioeconomic status
- poor nutrition
- lack of health care
- overcrowded living conditions
- ethnic minorities
Tuberculosis cohorts(3)
- children
- elderly
- pregnant or postpartum women
Why are children’s ability to transmit TB low
because of low tidal volume
Who is at highest risk of developing active disease in first 2 years after infection
small children
incubation period for tuberculosis
2-12 weeks
Types of tuberculosis infection(4)
- latent TB {most common type seen in US}
- active or primary TB
- miliary TB
- extrapulmonary TB
Skin tests for Tuberculosis and false negatives
false negatives will occur in 10-15% of those with active TB:
- skin tests require good cell-mediated immunity
- active TB decreases CD4 count and cell-mediated immunity
False negatives can occur in who for tuberculosis (9)
- very old TB infection
- infants under 6 months
- recent live-virus vaccine
- overwhelming TB disease
- cutaneous anergy (inability of skin to react because of weak immune system;
- recent TB infection (within 8-10 weeks);
- some viral illnesses (measles, chickenpox);
- incorrect TST admin;
- incorrect interpretation
Clinical manifestations of pulmonary tuberculosis (10)
** many can be asymptomatic
1. low-grade fever
2. malaise
3. poor appetite
4. weight loss
5. night sweats
6. chills
7. erythema nodosum
8. Keratoconjunctivitis
9 mediastinal lymph nodes causing difficulty swallowing or obstruction
10. cough starting at age 10: child under 10 can have full-flown TB without cough
classic presentation of pulmonary tuberculosis (5)
- pneumonia
- pulmonary fibrosis
- coughing or wheezing
- blood-tinged sputum
- chest pain
primary tuberculosis infection response in immunocompetent child or adult (4)
- encapsulation of lesion
- calcification
- cavitation
- upper lobe infiltrates
who is more likely to develop full-blown pneumonia with TB
immunocompromised patients
Once primary TB infection has resolved when can recurrence happen
at any time
Miliary Tuberculosis incidence
- rare in US
2. occurs most often in those < 3 years, elderly, or those with HIV
How does miliary tuberculosis occur
it travels from primary site through blood or lymph and seeds multiple organs.
miliary tuberculosis leads to
necrosis and cassation of organs
miliary tuberculosis looks like what on imaging
miliary seeds
presentation of miliary tuberculosis (7)
- *deadly unless treated
1. high fever
2. malaise
3. poor appetite
4. weight loss
5. fatigue
6. lymphadenopathy
7. hepatosplenomegaly - pulmonary symptom may or may not be present
Types of extrapulmonary tuberculosis (12)
- lymph node disease {starts unilateral}
- meningitis TB
- skin infection TB
- ocular TB
- endocrine gland TB
- GU TB
- cardiac TB
- musculoskeletal TB
- abdominal TB
- middle ear TB
- mastoid TB
12 larynx TB
screening for tuberculosis: primary prevention
screen everyone at risk
Patients should be screened for TB if they (7)
- have spent time with person known or suspected to have active TB
- have HIV or are immunocompromised
- have TB symptoms
- from country where TB is common
- live somewhere in US where TB is common {homeless shelters, jail, imgrant camp}
- use drugs IV
- experience change in risk factors
Types of tuberculosis tests
- skin test
2. blood test
What is positive for use of Skin tests for TB
- cheap, easy, accurate in child and adult
2. requires follow up regarding 48-72 hours or must be redone
Blood tests for TB (4)
- interferon-gamma release assay {IGRA}
- is expensive
- does not require follow-up reading
- preferred if pt received BCG
Skin tests for TB (6)
- plant with 0.1 mm
- administer intradermally
- read within 48-72 hours
- read across arm
- mark area of induration not erythema
- record in mm not just positive or negative
when not to use TB skin test (2)
- if pt has hx of previous positive
a. can cause huge, blistering reaction
b. perform blood test or x-ray instead - if pt had live vaccine or immunoglobulin within last month because can cause false negative
TB skin test > or = to 15 mm
consider positive in everyone
TB skin test if > or = to 10 mm
considered positive in children under 4, people with other medical conditions, immigrants, IV drug users, healthcare providers, and anyone who has been exposed
TB skin test if > or = 5 mm
considered positive in patients with organ transplants, clinical findings suggestive of TB, HIV, immunosuppression, and those who have had contact with known or suspected TB Case
In what population is TB blood tests highly inaccurate
children under 5 so administer skin test
Treatment of Tuberculosis is usually administered by
TB clinic or infectious disease specialist
monotherapy for treatment of TB
unless treating latent TB it is contraindicated
treatment of active TB
never treat with a single dose because mycobacterium can quickly become drug resistant
In TB, what is used to decrease inflammation, mortality, and neurologic disability if pleural or pericardial effusion present
corticosteroids
Tuberculosis medications (5)
- isoniazid {INH} most commonly used for latent TB
- Rifampin
- Pyrazinamide
- streptomycin
- ethambutol
What is the NP role in TB treatment
- stay up-to-date because treatment changes as pattern of drug resistance change
- PCP can treat latent TB, most cases will be handled by local health department
At risk for false positive TB (BCG) rxn (5)
- other non-TB mycobacteria;
- previous BCG vaccine;
- incorrect TST administration;
- incorrect interpretation;
- incorrect bottle of antigen
