click below
click below
Normal Size Small Size show me how
Lung Infections & TB
Opportunistic Lung Infections and Tuberculosis
Question | Answer |
---|---|
Epidemiology of TB ? | * 1/3 of the world is infected... *highest rates in blacks and Native Americans bc low Vit D.... * Almost all are foreign-persons.... * prevalent in warm and cold limates |
Top countries that have TB ? | * Mexico, Philippines, India |
Top races that are infected in the US ? | * Hispanics, African-Americans, and Asians |
Some contributing Factors for acquiring TB ? | * having HIV..... *contact with TB in a foreign person .... * HLA-Bev15 gene on chromosome 17 mutations..... * anyone working closely with someone with TB |
TB survivability ? | * Highly resistant to drying out and can live in spit for a very long time.... * need UV light (sun) to kill it |
TB growth ? | *slow growth bc nutrients are hard to transport across waxy membrane..... *incubation time is 8 wks |
Gram staining ? | * Acid Fast - resistant to staining due to waxy coat by Mycolic Acid |
How TB is spread ? | * inhalation of droplet nuclei |
Cx Sx ? | * Early - asymptomatic or get flu like Sx and remain carriers .... *Later - Chronic cough with mucopurulent expectorant, often containing blood, chest pain, sob, malaise, fatigue, fever, and lots of weight loss |
Primary TB patho in weeks 0-3 ? | * TB uses its mannose cap to attach to the macrophages mannose receptor and proliferate within the macrophage and spread |
Primary TB patho after week 3 ? | *macros present TB via MHC-II and IL-12 to T cells -----> Th1 cells----> IFN-gamma---> activates the macrophages and activates and TNF to cause caseating granulomas |
Primary TB ? | * get TB that causes lung scars and lymph node caseation and can go to liver and spleen to cause miliary TB |
Secondary TB ? | * after the primary infection lays latent or get reinfected and cause caseating granulomas of the lungs and can get miliary TB again |
Some Laboratory Diagnosis of TB ? | * Sputum in morning or urine ..... * Acid Fast stains such as Ziehl-Neelson or Auramine-rhodamine |
Common board culture used ? | * Lowenstein-Jensen (egg based medium) |
New test used ? | * Interferon Gamma Release Assays --- mixes bd with TB antigen and measure the amount of IFN-gamma after 24-48 hrs.... *if infected with TB, IFN-gamma should be high |
PPD Test = ? | * Positive: 10mm or more erythema and induration after 48 hr ..... * + does not mean active disease |
TB Prevention ? | * BCG Vaccine (PPD test ineffective after) and Vit D |
Mycobacterium avium-intracellulare (MAC or MAI) ? | * MAI found in the environment, associated with birds, with no person to person transmission.... * mimicks TB and smoking/alcohol can predispose |
HIV and TB/Mycobacterium ? | * M. tuberculosis manifest early in the course of AIDS; atypical mycobacteria are seen late in the course of HIV disease..... so can have both at the same time |
Pneumocystis jiroveci ? | * an inhaled fungus that is usu in ppl that are T-Cell Deficient |
Pneumocystis jiroveci presentation ? | *: Alveoli are found filled with organism, desquamated alveolar cells, and foamy proteinaceous material; radiographs show bilateral diffuse infiltrates. |
Pneumocystis jiroveci tmt ? | *Trimethoprim-sulfamethoxazole |
Board Buzz words for TB ? | *Acid Fast -Cord Factor -Droplet nucleii -Caseous necrosis -Lowenstein Jensen media -BCG vaccine -PPD -Ghon focus |