Lower Tract Infections Flashcards
how is TB spread
through respiratory droplets in the air
what is pulmonary TB
where the infection only effects the lungs
where else may be infected in extra pulmonary TB
bone, kidneys, lymph nodes, brain and larynx
what is the treatment for TB
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
why are 4 drugs given in the treatment of TB
to prevent resistance developing
what are the symptoms of TB
fever, night sweats, weight loss, sputum, coughing up blood, pleuritic chest pain, breathlessness
what is miliary TB
where the bacteria is spread to all parts of the body through the blood
what increases the risk of miliary TB
severe malnourishment or immunosuppression
what will be seen on a chest x-ray in TB
consolidation in the apex of the lung
why does TB affect the lung apex
as this most oxygenated area of the lung so the aerobic organism moves there
what staining is used in TB and why
Ziehl-Neelson staining as gram staining can’t go through the fatty cell wall of the bacteria
what organism causes TB
Mycobacterium tuberculosis
what is the Tuberculosis sensitivity test
where some TB antigens are injected under the skin - if your T cells are already sensitised then you will get a red circle appear at the site of injection
how do you get false positives with the TST
from the BCG vaccination
how do you get false negatives from the TST
being immunosuppressed as you can’t amount a T cell response
what is the INF Gamma assay
where a sample of blood is taken and TB antigens are added - sensitised T cells will then produce INF gamma
what is bronchitis
inflammation of the airways
what are the symptoms of bronchitis
cough, fever, breathlessness, sputum (not purulent)
what mostly causes bronchitis
smoking
what are the natural preventions to respiratory tract infections
normal flora in upper respiratory tract, cilia, mucus, sneezing/coughing and lymph tissue
what are the the symptoms of pneumonia
fever, cough, purulent sputum, shortness of breath, nausea, vomiting, rigor
what is pneumonia
inflammation of the parenchyma of the lungs
what is lobar pneumonia
where a whole lobe of a lung is affected
what is the most common organism causing community acquired pneumonia
streptococcus pneumoniae
what is the treatment for community acquired pneumonia
amoxicillin (or doxycycline if allergic)
what is the treatment for severe community acquired pneumonia
co-amaxiclav and clarithromycin (works for atypical organisms)
what are the outcomes of pneumonia
resolution
organisation (healed with fibrous scarring)
complications
what are the complications of pneumonia
lung abscess, bronchiectasis, empyema
what is hospital acquired pneumonia
contraction of the infection 48hours after being in hospital
what is the most common causative organism of hospital acquired pneumonia
staphylococcus aureus
what is the treatment for community acquired pneumonia
co-amoxiclav
what is aspired pneumonia
where you breath in exogenous material
how does the histology of TB appear
caseating granulomas with langerhan giant cells
describe the pathogenesis of TB
- engulfed by alveolar macrophages
- inflammatory response causing the formation of a primary complex
- either progression to active disease or latent stage
- the latent infection then either self resolves or becomes reactivated to cause post-primary infection
what is Ghon’s focus
the primary complex formed in TB - where inflammation of the lung parenchyma occurs due to the immune system reacting against the bacteria
what cells are most important in the immune response in TB
T cells
what increases the risk of reactivation of TB
immunosuppression (HIV, chemotherapy, transplant, steroids)
diabetes
kidney disease
