TB Flashcards
TB Characteristic
a) The leading killer of people with?
b) Transmission rate
a) HIV
b) Rate slowing
>50% cause found CA, TX, NY, FL and IL
Infection caused by?
Mycobacterium tuberculosis (MTB)
-thick, waxy cell wall
-very slow growing
-generation time >15hr
Risk factors
-Foreign travel/residence
incidence 15X higher than US-born
-Close contact
homeless
prison
Immune weakness
-DM
-HIV
-Excess alcohol use
IV drug use(sharing needles)
Transmission
Airborne via droplet coughing, sneezing
Can stay airborne for several hours
Types of TB 3
Latent TB
Active pulmonary TB
Extra-pulmonary TB
Latent TB
a) characteristic
a) Infected but not contagious
Become active TB anytime
b) Risk of reactivation
Non-HIV coinfection 重複感染
5%
HIV coinfection 5-10%
Will test positive for TB( skin test IGRA)
Reactivation of latent TB
Greatest risk of reactivation
HIV coinfection
Contact with an infected person
Because suppress the immune system
Use of corticosteroids
Chronic kidney disease
DM
irritates lungs
Smokers
Active pulmonary TB
Tubercle bacilli reach the alveoli of the lungs
Ingested by alveolar macrophages
-Most destroyed
-Deposit in the terminal airspaces
-Spread thru blood
Symptoms of active disease
Fever
Weight loss
Night sweats
Productive cough
Hemoptysis Fatigue
Pt presenting with these symptoms should be put in ISOLATION
Extra-pulmonary TB
Lymph node
Pleural
Bone and joint
Central Nervous System
TB skin test
0.0001mg of purified protein derivative (PPD)
Induration read 48-72hr
Positive in pt receiving BCG vaccine
TB skin test result
≥5 mm
HIV
Recent TB contacts
Classic X-ray changes
Organ transplant
TB skin test result
≥10 mm
Immigration from endemic
area within 5 years
IVDU
Residents of high risk
congregate settings
Microbiology lab workers
CKD/DM/cancer
TB skin test result
≤15 mm
All others
Diagnostic Tests
Blood
Interferon-Gamma Release Assays (IGRA)
Blood test used to measure immune response to TB
Only one visit needed for the test
Not affected by BCG vaccine
Diagnostic Tests
Bacterial Culture
Often done from sputum
collection (not 唾を吐く)
Poor samples common
–Takes up to 12 weeks for final
reading
–Only finds pulmonary TB
Anti-Tuberculosis Agents
First Line Agents 3
Rifampin
Rifabutin
Rifapentine
Rifampin
Most commonly used in the US
Cheap
Rifabutin
Fewer drug interactions
- Commonly used in HIV+ patients
Rifapentine
Longer duration of action
- Used in weekly regimens
-Less dose
a) Drug Interactions
b) Administration
a) Potent inducer of CYP-450
Oral contraceptives
-inc the chance of pregnancy
Anti-retroviral
-dec effective HIV
Anticonvulsants
-Inc seizure
b) Take 1 hour before or 2 hours after meals
Food decreases absorption
Adverse Drug Reactions
Rash(very common)
Mild GI discomfort
Hepatotoxicity
*Monitor for anorexia, fatigue, jaundice
*Avoid alcohol consumption
Discoloration of Body Fluids
*Reddish-orange
*Urine, saliva, sweat, tears
Pseudomembranous colitis
*Monitor for fever, diarrhea, and blood in stools
Isoniazid
Used with?
Used with rifampin in most regimens
Isoniazid
ADRs
Peripheral neuropathy
-Tingling, burning, pins-and-needles pain チクチク感
-Results from pyridoxine (B6) deficiency
Hepatotoxicity
-Monitor for anorexia, fatigue, and jaundice
Hyperglycemia
-See in diabetic patients
-Need to monitor blood glucose closely and adjust regimens
