Flashcards in Mycobacterial Infections Deck (24):
What are the rapid growing mycobacteria?
What are the slow growing mycobacteria?
M avium complex
What is a common sourse of Non-TB pulm infections?
inhalation of aerosols from natural water source or from a heating system
MAC, M kansii, M absessus
In what population does progressive lung disease occur
Pts with underlying bronchiectaisis or COPD
What are the 2 clinically seen forms of MAC?
What is the typical imaging finding in Non-TB Myco Infections
Interstitial infiltrates with rare cavitation and involvement of >3 lobes
How is Non-TB Myco Infection confirmed?
Clinical H and P
-2 pos cultures
Lung or tissue biopsy positive AFB smears
Pos culture from pleural fluid or non pulm site
What Abtx are used for Mycobacterium infections
Clarithromycin OR azithromycin
What is the cause of Pott's Disease?
Bone infiltration with Mycobactrium
What part of the world is TB most common?
Sub saharan africa
What are the 3 possible consequences of inhalation of droplet nuclei?
Organism cleared 70%
Primary TB with active disease 5%
Latent infection with possibility of reactivation. 5%
Very small number have late progression as a result of latent TB
What is the finding in initial infection that is not conrolled by local defenses?
Ghon Complex seen on X-ray: Unilateral lymphadenopathy
Hematogenous dissemination if CMI not adequate. Active disease and contageous
What are the S and S of Primary TB?
Fever and pulmonary symptoms
hilar adenopathy, perihilar infiltrates, effusion
How is latent TB diagnosed?
Evidence of a cell mediated immune response.
Positive TB skin test
Interferon Gamma release assay (Quantiferon Gold)
How is the Tuberculin Skin test read?
mm of induration
NOT erythema perpendicular to the long axis of the forearm
Under what circumstance would a TB skin test be negative when they ARE infected?
Anything that would supress the Cell mediated immunity
What diagnostic test for TB would you use if you know someone has recieved the BCG vaccine?
What is the LBTI Treatment for TB?
Isoniazid 300mg daily for 9mon
What are the risk factors for Tuberculosis?
Chronic Renal Failure
Gastrectomy, jejunoileal bypass
Weight Loss >10% ideal body wt
What are the symptoms of TB?
Diurnal Fever becoming more marked as disease progresses
Fever and NS
Grad Cough Prog. with devt of sputum production
What are general principles of TB Tx?
Always use at least 2 drugs
Appropriate drug doses
Take drug regularly
Adequate duration of therapy
What is included in the 4 drug treatment for TB?
INH, ethambutol, rifampin, pyrazinamide
Daily for 8wks OR
Daily 2wks then 2x week
3x week for 6wks
DOT recommended for schedules that dont require daily dosing
What defines Drug resistant TB?
Lab confirmed resistance to INH and RIF