Tuberculosis
Definition an infection caused by Dx: Ziehl-Neelson stain = waxy membrane
Mycobacterium tuberculosis that most prevent binding w/ normal stains
commonly affects the lungs Under a microscope
Acid-fast bacteria = RED
Pathogenesis Non-acid fast bacteria = BLUE
Primary tuberculosis
Non-immune host exposed to M. Screening
tuberculosis primary infection of the Mantoux test 0.1 ml of 1:1000 purified
lungs protein derivative intradermally result read
Small lung lesion Ghon focus (phagosome 2-3 days later
contains bacteria which multiplies
Diameter
caseous necrosis + hilar lymph node = of Positivity Interpretation
Ghon complex induration
Immunocompetent pts heals fibrosis Previously
Immunocompromised disseminated < 6mm Negative unvaccinated
disease (military TB) Give BCG
Secondary tuberculosis Don’t give
Host becomes Immunocompromised (e.g. BCG/could be
6-15mm +
HIV. Malnutrition, immunosuppressive due to previous
drugs) reactivation of latent TB TB/BCG
Commonly infiltrates the apices of the lungs TB infection
>15mm ++
Extra-pulmonary sites confirmed
CNS meningitis
Vertebral bodies Pott’s disease Alternative Interferon-γ release assay
Renal, GI (IGRA)
Signs + symptoms Bloods- previous exposure to TB proteins
Cough More specific
Haemoptysis Not affected by BCG vaccine
Weight loss
Night sweats CXR Infiltrates/cavitation/millet seeds in
Fever military TB
Sputum/bronchoalveolar lavage
Mx TB drug pharmacology
Active TB Rifampicin liver enzyme inducer
1. Initial 2 months SE: Hepatitis, orange secretions, flu
Rifampicin + Isoniazid + Pyrazinamide Isoniazid liver enzyme inhibitor
+ Ethambutol SE: Hepatitis, agranulocytosis, peripheral
2. Continuation for 4 months neuropathy
Rifampicin + Isoniazid Pyrazinamide
SE: hypercalcaemia gout
Latent TB Arthralgia, myalgia, hepatitis
1. 3 months Isoniazid + Pyridoxine Ethambutol
(Vitamin B6) + Rifampicin SE: Optic neuritis
OR 6 months Isoniazid + B6 Simplified: Liver + Nerve + Joint problems
Directly Observed Therapy (DOT)
A three times a week dosing regimen may be provided for:
Homeless people w/ active TB
Pts w/ poor concordance
All prisoners w/ active/latent TB
Definition an infection caused by Dx: Ziehl-Neelson stain = waxy membrane
Mycobacterium tuberculosis that most prevent binding w/ normal stains
commonly affects the lungs Under a microscope
Acid-fast bacteria = RED
Pathogenesis Non-acid fast bacteria = BLUE
Primary tuberculosis
Non-immune host exposed to M. Screening
tuberculosis primary infection of the Mantoux test 0.1 ml of 1:1000 purified
lungs protein derivative intradermally result read
Small lung lesion Ghon focus (phagosome 2-3 days later
contains bacteria which multiplies
Diameter
caseous necrosis + hilar lymph node = of Positivity Interpretation
Ghon complex induration
Immunocompetent pts heals fibrosis Previously
Immunocompromised disseminated < 6mm Negative unvaccinated
disease (military TB) Give BCG
Secondary tuberculosis Don’t give
Host becomes Immunocompromised (e.g. BCG/could be
6-15mm +
HIV. Malnutrition, immunosuppressive due to previous
drugs) reactivation of latent TB TB/BCG
Commonly infiltrates the apices of the lungs TB infection
>15mm ++
Extra-pulmonary sites confirmed
CNS meningitis
Vertebral bodies Pott’s disease Alternative Interferon-γ release assay
Renal, GI (IGRA)
Signs + symptoms Bloods- previous exposure to TB proteins
Cough More specific
Haemoptysis Not affected by BCG vaccine
Weight loss
Night sweats CXR Infiltrates/cavitation/millet seeds in
Fever military TB
Sputum/bronchoalveolar lavage
Mx TB drug pharmacology
Active TB Rifampicin liver enzyme inducer
1. Initial 2 months SE: Hepatitis, orange secretions, flu
Rifampicin + Isoniazid + Pyrazinamide Isoniazid liver enzyme inhibitor
+ Ethambutol SE: Hepatitis, agranulocytosis, peripheral
2. Continuation for 4 months neuropathy
Rifampicin + Isoniazid Pyrazinamide
SE: hypercalcaemia gout
Latent TB Arthralgia, myalgia, hepatitis
1. 3 months Isoniazid + Pyridoxine Ethambutol
(Vitamin B6) + Rifampicin SE: Optic neuritis
OR 6 months Isoniazid + B6 Simplified: Liver + Nerve + Joint problems
Directly Observed Therapy (DOT)
A three times a week dosing regimen may be provided for:
Homeless people w/ active TB
Pts w/ poor concordance
All prisoners w/ active/latent TB
