Tuberculosis Flashcards
infected by aerosolized and inhaled particles (few needed) that enter the alveoli and are eaten by macrophages
Mycoplasma tuberculosis
Reactivation of TB usually occurs within what time frame of the primary infection?
2 or more years
What type of organism is TB
acid fast bacilli
Where will TB be most obvious on a CXR?
Apex of the lungs under the clavical(s)
What is the most common finding in active TB
Cavitated lesions
What induration diameter represents a positive TB skin test in a patient with no exposure HX and low risk?
> 15mm
What TB skin test induration is POSITIVE in a PT who is either HIV+, has recent TB contact, fibrotic CXR findings, is immunocompromised, or on prednisone
> 5mm
An TB skin test induration of what size is positive in a patient with IV drug use, resident in crowded setting, hospital worker, or immigrated from high TB prevalence country in last 5 years?
> 10mm
In the 2-step TST procedure, if a person comes back with an initial positive skin test, the next step is ?
Evaluate for latent TB and treat accordingly
In the 2-step TST procedure, if a person comes back with an initial Negative skin test, what are the next steps?
Do a second TB skin test 1-3 weeks later
-If 2nd test negative repeat test at regular intervals if suspected but they probably don’t have TB
-If 2nd test is positive, the person has latent TB and you should treat if needed
What is the main adverse reaction for pyrazinamide?
Increased uric acid - be cautious in gout patients
Peripheral neuropathy is an adverse effect of what TB medication, and what do you need to ensure the patient is taking to avoid this?
Isoniazid; Give B-6 or Pyridoxine at 25mg/day
Hepatitis is an adverse reaction of what three TB drugs?
Isoniazid, pyrazinamide, and rifampin
Which TB drug can cause orange urine and sweat?
Rifampin
The Intensive Phase of TB treatment lasts how long and includes what drugs for treatment?
2 months; RIPE - all four drugs
Continuation Phase of TB treatment lasts how long and includes how many drugs to treat?
4-7 months; Rifampin and Isoniazid (only 2 drugs)
What are the goals for treatment of latent TB?
-Controlling, eliminating TB
-Reducing the risk that latent TB will progress to active TB (contagious form)
Patients with this type of TB don’t have active disease and cannot transmit to others
Latent TB
If a patient has latent TB and is not given preventive drug therapy, they can develop what type of TB?
Active (spreadable)
HIV infection, use of corticosteroids, and use of immunosuppressive drugs can cause ______ in patients with latent TB
Reactivated TB (where it is spreadable) (Reactive TB - this is more of a verb to describe TB going from latent to Active)
HIV infection, use of corticosteroids, and use of immunosuppressive drugs can cause ______ in patients with latent TB
Reactivated TB (where it is spreadable) (Reactive TB - this is more of a verb to describe TB going from latent to Active)
In 5% of patients, the immune response is inadequate to contain the primary infection and they get?
Progressive primary TB; The clinical presentation can look similar to reactivated TB
Slowly progressive SX of malaise, weight loss, fever, night sweats, chronic cough
Presentation of active TB
For latent TB, what drug(s) are used for treatment and what is the normal duration of treatment?
-isoniazid and rifapentine taken once weekly for 12 weeks
-Can give Rifampin alone, once once a day for 4 months
-Can give Isoniazid alone twice daily for 9 months
What are the indications for treating an active TB patient for the full 7 months (as opposed to only 4) in the continuation, or 2nd phase?
Cavitary lesions on CXR & positive sputum culture at the end of the initial phase (2 months)
-You were unable to use pyrazinamide in the first phase
What are the different stages of TB and their characteristics?
- Primary TB: asymptomatic and CXR normal
- Latent TB: been infected but immune response has captured and held infection inside granulomas so it cannot spread
- Active (or reactivated) TB: Signs on CXR; will present with physical SX; can spread TB to others
- Primary progressive TB: when immunocompromised patients get TB; have signs and SX; can spread TB to others
