Tuberculosis Lecture Powerpoint Flashcards
Tb is a ____ disease due to ______
multi-organ, disseminating miliary Tb which spreads hematologically to diff tissues throughout the body
Gold standard for diagnosis of Tb***
Quantiferon gold, highly specific and sensitive for Tb
Hepatotoxicity in patients receiving pharmacologic treatment for Tb
- routine LFT before beginning 4 drug regimen
- if normal no more tests unless symptoms develop
- if abnormal, monthly LFT’s required
- If these results are less than 2x the upper limit with no side effects repeat in one month
- if they are greater than 2x the upper limit, consult physician
- if they are 3x the upper limit at any time, consider stopping therapy
- drug induced hepatotoxicity is defined as AST/ALT
-Isoniazid is the most hepatotoxic of these drugs
Historically Tb was often labeled as….
….consumption
___% of the population is infected with Tb
25%
Tuberculosis risk factors (4)
- Those in close contact with Tb patients thru facilities or family
- Healthcare workers
- Individuals born in countries with high prevalence of Tb
- Medically underserved populations
Populations at risk for progressing to active Tb infection once exposed (4)
- People with recent Tb infection
- Immunosuppressed patients (HIV, cancer, DM, long term corticosteroids)
- IV drug or substance users
- Children
Tb causative agent and infectious process
Mycobacterium tuberculosis (acid fast bacilli that transmits thru inhalation of aerosols to any high area of o2 flow in the body - lungs most popularly but any system)
Name the 3 stages of Tb infection
- Primary
- Latent (asymptomatic, CXR is normal or shows ghon complex, 90% never develop active infection unless reactivated due to immunosuppression)
- Reactivated (in immunocompromised will often present in different organ systems)
Ghon complex
Ranke complex
Fibrotic calcified lesion from local inflammatory response of the lungs from inhaled Tb bacteria indicating latent Tb infection seen on CXR
Further calcified lesion from Tb bacteria exposure that is an evolution of the ghon complex and indicates a latent Tb infection seen on CXR
Immunocompetent hosts have a __% lifetime risk of reactivation of Tb infection, but HIV patients its ___% per year
10, 10
Granuloma formation mech of action
- Macrophages, lymphocytes and antigenic material forms caseous necrosis lesions
- Calcification of these areas occurs creating ghon complexes
- Cavitations (holes) form most often seen at the apices of the lungs (that’s why we auscultate and palpate em!)
Scofula
Lymph node infection by Tb
Pott’s disease
Skeletal infection by Tb
Sinus tracts
Hole in skin manifestation often with purulent material from deep granuloma from Tb in deep tissue
Active Tb symptoms (4)
- Intermittent fevers
- Night sweats
- Wasting
- Chronic cough
Rasmussen’s syndrome
Massive hemoptysis when a cavity from progressed Tb infection erodes into the pulmonary artery
Tb lab studies (4)
- PPD
- Acid fast smear/culture
- CXR
- Quantiferon gold
PPD screening*** and what causes false negatives?
- Screens for exposure not active disease
- Read 48-72 hrs after otherwise invalid
- measure diameter of induration, not redness and record in mm with 0 mm representing negative
- Test only at risk populations
- 2 step testing required, might see first test neg and 2nd test positive so that’s why we do it (booster phenomenon)
- **false negatives are due to anergy, steroids, or HIV
CXR signs of primary, latent, or reactivated Tb infection
Primary: calcified peripheral nodule with or without calcified hilar lymph nodes
Latent: rarely shows findings may reveal fibrotic area
Reactivated: granuloma (multiple), cavitation (usually apical), hilar lymphadenopathy, pleural effusions
***Having a BCG vaccination will lead to what result on PPD and what result on Quantiferon gold test?
Will result in false pos on PPD, does not affect accuracy of quantiferon gold test
CDC guidelines for positive PPD skin tests*** (Induration of 5, 10, or 15 mm)
Induration of 5 or more mm is positive in…
-HIV patients
-Recent contact of Tb disease
-person with fibrotic changes on chest radiograph
-patients with organ transplants
-patients taking immunosuppressants for other reasons
Induration of 10 or more mm is positive in…
-Recent immigrants
-IV drug users
-High risk location residents
-Mycobacteriology lab personnel
-Children
Induration of 15 more more mm is positive in…
-Any person including those with no known risk factors for Tb
Tb reporting
Must report to PA department of health within 5 days
Steps following active Tb diagnosis (5)
- Get baseline LFT, CBC, and platelets
- Isolate patient if coughing until at least 2 weeks after treatment or 3 sequential sputum specimens for AFB return negative
- 3 drug initial therapy minimum
- If fail add 2-3 drugs to regimen (not just one)
- Involve local health department
Active Tb treatment options (5) and how long are they taken?
- Isoniazid
- Rifampin
- Ethambutol
- Pyrazinamide
- Modifications made in drug resistance, pregnant patients, or children
-Drugs taken for 6-9 months
***Isoniazid patients can develop peripheral neuropathy as a side effect. What is given as supplement to prevent this?
-Vit B6 20-50mg/day
Drug found beneficial to treatment of multi drug resistant TB
Bedaquiline fumarate
Latent Tb treatment options (3) and ADR of each
- Isoniazid (can cause itching or rash, increased LFT’s)
- Rifampin (can stain body fluids)
- Rifapentine (can stain body fluids)
Children <5 year old post Tb exposure protocol
Need treatment ASAP despite PPD results, retest in 3 months
