Tuberculosis Flashcards
(40 cards)
What is pulmonary TB
life threatening infection of the lungs that can disseminate
Why is Tb spreading globally
HIVAIDS
Poverty
Lack of health services
New, resistant strains
Who is affected by TB more
racial and ethnic minorities
1 death every 15 seconds
how is Mycobacterium Tuberculosis spread
through respiratory droplets by people with ACTIVE TB (bacilli in the respiratory droplets)
**Exposure must be prolonged
What 2 things can happen if someone is exposed to TB
Don’t develop TB
Immune system responds 2-8 weeks after exposure
What is the immune response to TB exposure
Macrophages wall of the bacteria and it remains dormant for years (Latent TB Infx)
Is latent TB infective?
No, and its not even symptomatic. but it CAN be reactivated
will have + skin test
What if the immune system fails?
Macrophages form granulomas inside which TB multiply
What is in the middle of a granuloma
Necrosis (caseating)
over time, it will liquefy, break through the wall, and bacteria will spill out
What happens after a granuloma breaks open
Cavitations (large air spaces) form, prefect breading ground for bacteria
Hundreds of bacteria spill out and can disseminate to the rest of the body
What are the stages of TB
Primary: 5% become Active (PPTB), 95% become Latent (LTBI)
Secondary: Reactivated TB( LTBI–>Active)
When is secondary TB more common
if patient has not received prophylaxis
What is the first indication of HIV
Sudden onset TB infection
What constitutes “immunosuppressed” individuals
HIV Substance Abuse Immunosuppressive therapy Kids <5 Malnourished
What are RF for TB
Immunosuppressed
Crowded living conditions
Exposure to TB through work/travel
Nationality (African, Asian, or Latin American)
It is crucial to preform a TB test prior to starting someone on
Immunosuppressive therapy, like Humira
make sure they don’t have LTBI
When is the risk for LTBI–>Active the greatest
in the first two years
What are symptoms of active TB
*Cough >3 weeks, +/- sputum or hemoptysis
CP, fever, chills, fatigue, anorexia, weight loss
–Sx can be absent in mild disease
What is a classic TB physical exam finding
*Post-tussive rales (just like PNA)
What are CXR findings in PPTB
*Hilar adenopathy
PE
Hilar or middle lobe infiltrates
What are CXR findings in Reactivation TB
Apical/upper lobe infiltrate/cavitation
What are CXR findings in healed primary TB
Ghon/Ranke complex- calcified primary focus with hilar lymph node
(minority of patients)
How can you test for TB
*Sputum culture (1-8 weeks)
NAT
Sputum smear (supports, doesn’t diagnose)
Biopsy (Necrotizing granulomas)
What is proper technique for sputum culture
3 morning sputum specimens
