Tuberculosis 1

Question 1

sputum: test for what?

Answer 1

mycobacterium tuberculosis - acid fast bacteria so the entire cell holds on to the dye (resists decolorization)

Question 2

tuberculosis: definition

Answer 2

a broad range of illnesses caused by the pathogen mycobacterium tuberculosis complex. human to human transmission

Question 3

mycobacterium: aerobe or not? spores? shape? cell walls? stain positive for?

Answer 3

aerobic. non spore forming. non motile bacilli. high cell wall lipid content. stain positive for acid fast bacilli

Question 4

mycobacterium: growth compared to common bacteria?

Answer 4

slow: generation time of 15 - 20 hours and mature growth in 3 - 8 weeks

Question 5

public health concern: when do you need isolation?

Answer 5

m. tuberculosis complex spread human to human so isolation required to prevent transmission. members of non tuberulous mycobacteria are environmentally acquired, no spread via human to human so no isolation required

Question 6

2 investigations for TB

Answer 6

Chest X ray: look for granulomas. sputum samples for AFB

Question 7

TB and social determinants of health?

Answer 7

influence the 4 stages of TB pathogenesis: exposure from crowding, poor ventilation, urban residences. infection from contact with source case. disease: age, malnutrition, HIV, smoking, alcohol, ets. access to health care: stigma, homelessness, geographic/economic or cultural barriers

Question 8

8 social risk factors for acquiring TB in canada

Answer 8

foreign born from areas with high TB prevalence. travel to those countries. aboriginal decent. HIV/AIDS. homelessness. current/former residents of correctional facilities. alcohol dependence. injection drug users.

Question 9

how you get TB: infection is transmitted by?

Answer 9

exclusively by airborne route in droplets of moisture termed droplet nuclei: created by coughing, sneezing, singing, etc.

Question 10

TB: droplet nuclei filtered by?

Answer 10

N95 masks, not by surgical masks

Question 11

TB flow chart: exposure to infectious TB –> ? –> 3 options?

Answer 11

primary infection: 5% primary progression disease. 95% latent infection. rarely: hypersensitivity reaction

Question 12

TB flow chart: what happens with latent infections?

Answer 12

no disease in 95%. 5% have post primary TB due to reactivation (60% respiratory, 40% not)

Question 13

3 clinical forms of TB?

Answer 13

latent TB infection. primary progressive TB infection. post primary (reactivation or active TB) that can be pulmonary or extrapulmonary

Question 14

what is latent TB? evidence of active disease?

Answer 14

dormant or inactive infection: no evidence of active disease so asymptomatic,, negative microbio work up, unremarkable radiology and histopathology

Question 15

latent TB: positive markers of latent disease?

Answer 15

TST (skin test). granuloma on chest x ray

Question 16

latent TB: isolation?

Answer 16

non infections so no isolation required

Question 17

primary progressive infection: following exposure, what happens?

Answer 17

following exposure to infectious TB aka primary infection: most often subclinical or asymptomatic

Question 18

primary progressive TB infection: presentation?

Answer 18

in infants/young children, or those with advanced HIV/AIDS: fever cough, chest x ray shows patchy infiltrate and mediastinal lymph node enlargement

Question 19

post primary “reactivation” TB: what? characterized by?

Answer 19

development of active TB following a period of latency. characterized by symptoms, microbio confirming AFB presence, and or abnormal radiographic imaging or histopathology of necrotizing granuloma

Question 20

post primary reactivation TB: pulmonary vs. extrapulmonary features?

Answer 20

pulmonary: infectious, chronic cough, fevers and weight loss, sputum culture positive. extrapulm: non infectious, chronic and indolent, tissue biopsy culture positive