Respiratory Infection Flashcards
What is the primary TB infection?
Host macrophages engulf organisms in the lungs and carry them to hilar lymph nodes. These can disseminate to leave tubercules (granulomas) around the body.
How can a primary TB infection result?
Active TB symptomatic infection
Miliary TB (bloodstream spread)
LTBI
Risk factors for TB?
Social deprivation factors - homelessness, IVDU, alcohol Close contact incl healthcare workers Ethnic minority groups Immunocompromised incl HIV Elderly and very young
Are most symptomatic cases of TB from primary infection or secondary re activation of LTBI?
Re activation of LTBI
How does symptomatic TB most often present?
Pulmonary TB - cough - productive +/- blood
Lobar collapse, Bronchiectasis, pleural effusion, pneumonia
Second most common TB presentation?
GU ‘sterile pyuria’
Kidney lesions, salpingitis, abscesses, infertility, epididymitis
MSK TB presentations?
Bone - Potts vertebra (collapse -> gibbus)
Pain, osteomyelitis, arthritis
CNS TB presentations?
TB meningitis
Tuberculomas
GI TB presentations?
Ileocoecal lesions - pain, bloating, obstruction
Lymphadenopathy in TB?
Hilar, para tracheal and superficial Alan’s
Skin presentations of TB?
Erythema multiforme, nodosum, induratum
What is the typical CXR finding for a primary TB infection?
Central apical portion with left lower lobe infiltrate +/- pleural effusion
CXR findings for reactivated TB?
Apical lesions
NO pleural effusion
Microbiological investigation of TB?
Sputum samples - 3, at least 1 early morning sample
Bronchoscopy +/- lavage
Biopsy LNs
How long does TB sputum culture take? How long for sensitivities?
Culture 4-8 weeks
Sensitivities further 3-4 weeks
Which drug resistance in TB can be detected quicker than the usual culture and sensitivity?
Rifampicin
What does BCG stand for?
Bacillus Calmette-Guerin
Screening for TB?
Mantoux test for close contacts unless known to be immune or vaccinated, in which case interferon gamma testing
Drug management of TB?
Pyrazinamide and ethambutol for first 2 months
Rifampicin and isoniazid for first 2 months then a further 4 months
How long should Rifampicin and isoniazid be given in acute meningeal TB? What else should be given?
12m, alongside steroids (prednisolone)
What is DOT and what is it for?
Direct observed therapy - to ensure good compliance for TB treatment
What side effects do all TB drugs generally have in common?
Liver derangement
Rifampicin side effects?
Orange tears and pee
Liver enzyme derangement and drug interactions - lower active availability of e.g. Warfarin, steroids, oestrogen, phenytoin
Flu like Sx
Liver derangement in Rifampicin use - what is okay and what isn’t?
Mild rise in AST fine.
Stop if bilirubin rises or major transaminase derangement
What alternatives to Rifampicin are second line for TB?
Macrolides and quinolones
Side effects of ethambutol?
Visual disturbance
Renal impairment
Side effects of isoniazid?
Peripheral neuropathies - comorbid RFs
What drug is given to prevent peripheral neuropathy in isoniazid use?
Pyridoxine
What is TB and how is it spread?
A chronic granulomatous disease caused by mycobacterium tuberculosis bacteria
Spread by infected droplets
What is the specific pathogen often implicated in pneumonia associated with exposure to sick birds?
Chlamydophila Psittaci
What does coxiella burnettii cause?
Q fever
3 most important causes of atypical pneumonia?
Mycoplasma pneumoniae
Chlamydophila pneumoniae
Legionella pneumophila
Which common causative agent of a typical pneumonia is often difficult to treat with antibiotics?
Haemophilus influenzae
What atypical pneumonia pathogen is implicated in disease with history of water risk-factors incl foreign travel and faulty air con?
Legionella pneumophila
