Flashcards in Tuberculosis Deck (35):
What is the mortality associated with TB.
TB kills 2 million people/year.
What group of people are particularly vulnerable to TB infection.
TB is the leading cause of death in patients with HIV.
What are the risk factors associated with contracting TB infection if you are HIV+. (5)
Low CD4 count.
What is the UK incidence of TB.
What is the mortality due to TB in the UK.
Approximately 350 deaths/year.
How is latent TB diagnosed. (2)
Interferon-gamma testing (if mantoux positive or non-reliable).
What stain is used for TB.
What CXR finding suggest TB. (4)
What is the histological hallmark of TB infection.
What is PCR used for in diagnosis of TB.
Rapid identification of rifampicin resistance.
How do you diagnose active TB infection. (3)
If CXR suggests TB, take sputum samples. (>3 with one early morning sample, before treatment if possible).
Send samples for MCandS for acid fast bacilli testing.
If spontaneously produced sputum cannot be obtained, bronchoscopy and lavage may be needed.
What samples could be taken if active non-respiratory TB is suspected. (8)
Pleura and pleural fluid.
In the samples taken from a patient with non-respiratory TB, how long should the samples be cultured for.
Incubate the samples for up to 12weeks on Lowenstein-Jenson medium.
What investigation should be carried out in all patients with non-respiratory TB (apart from cultures).
CXR to look for active respiratory TB.
How might pulmonary TB present. (12)
It may be silent.
Pyrexia of unknown origin.
Haemoptysis (may be massive).
Pleural effusion (exudate).
Superimposed pulmonary infection.
What may be present in the cavities of pulmonary TB.
Aspergilloma/mycetoma may form in the cavities formed by TB.
What are the features of miliary TB. (4)
Occurs following haematogenous dissemination.
Signs may be non-specific or overwhelming.
Look for retinal TB.
Biopsy of ling, liver, lymph nodes or marrow may yield AFB or granulomata.
What are the features of GU TB. (5)
Where might renal TB spread to. (4)
What should you look for in bone TB. (2)
What should you look for in skin TB.
Look for jelly-like nodules.
What are the features of peritoneal TB. (3)
Look for AFB in ascites.
What is acute TB pericarditis.
A primary exudative allergic lesion.
What is the mortality rate for TB meningitis.
What are the features of TB meningitis. (11)
Often worsening over 1-3weeks:
Seizures (may be the only first sign).
Cranial nerve palsies.
What are the risk factors for TB infection. (6)
Contact with TB.
Immunosuppression (HIV, DM, malignancy, extremes of age).
What is the causative organism in TB.
What is the route of transmission for TB.
What is a Ghon focus.
A pale yellow, caseous nodule, usually a few mm to 1-2cm in diameter.
It is the classical tuberculous granuloma (the primary lesion).
It is usually located in the periphery of the lung.
What are the symptoms of miliary TB. (12)
2-3weeks of fever, weight loss, night sweats, anorexia and a dry cough.
Hepatosplenomegaly may develop.
The presence of a headache may indicate coexistent TB meningitis.
Widespread crackles in advanced disease.
Choroidal tubercles may be present on fundoscopy.
CXR may show 'millet seed' lesions.
Anaemia and leucopenia reflect bone marrow involvement.
What is the differential for consolidation/collapse on a CXR. (3)
What is the differential for cavitation on a CXR. (5)
Granulomatosis with polyangiitis (Wegener's granulomatosis).
Progressive massive fibrosis.
What is the differential for 'miliary' diffuse shadowing on a CXR. (4)
What is the differential for pleural effusion/empyema on CXR. (4)
Connective tissue disorder.